Tony, im a EE in the industrisl industry. I never really had a professional opportunity to work in the Ee field. On the other hand, I have always love the audio end as a hobby. Recently I have embarked into xar audio. I have watched your videos and it rekindled my love of it. I have applied it to my car design and I have excellect car tunes. Thank You. Keep up the instructional videos.
For all the folks hemmimg and hawing over balanced XLR and RCA not being able to carry a balanced signal... An RCA can carry a balanced signal, if it uses a twisted pair wire. The cable assembly will simply be unshielded. We often wire studio installs with telescoping shields, where the shield (pin 1) is disconnected at the input of each device. this drains static and RF back to the Chassis Ground in only one direction, terminating to a common ground bus. This avoids ground loops. The shield in a balanced audio system carries no signal... At least we hope not!
Take an ohm meter (DMM) and check the resistance from the battery ground connection on amplifier to the RCA outer ring on amplifier (with everything unplugged from amplifier). If you have less than 100 ohms it is a single-ended input.
DAmoreEngineering Wow, thanks for the reply! I know you guys explained the same thing in the video, but for some reason I feel that this explanation is more solid. On an unrelated note, I had always known about your company from Steve Meade's videos, but now once I figure out which type of RCA I need I'll most likely end up buying from you. Keep up the awesome work guys, this type of potential customer relations and not keeping this information hidden and secret like everyone else really shows what kind of a company you are.
lowellaby You have a positive and ground connection on any amplifier that runs on DC. The "battery ground connection" is the big ground connection for which you hook up your main ground wire to.
This probably explains why I had noise I could never find and I was running Stinger 4000 rca from my Audio Control LC2i to my amps. Probably needed regular RCAs and not twisted pairs and I was a victim of just thinking they were better newer technology.
Wouldn't this require a HU with differential outputs? Otherwise, how would would the sine waves become inverted to one another across the twisted pairs to begin with? Seems to me that the wire that goes to the sleeve on a twisted pair rca would not carry a wave at all if the HU has 'single ended' outputs, as it were. From what i see after a google search, HUs with differential outs are a unicorn, only a few boutique models have ever had them.
It is inexplicable why amplifier manufacturers don't advise the type of RCA connector that works better - unless of course it makes no difference. I have both types and have never* heard the slightest difference when connecting all these permutations: (1) Sources: Phono stages, CD and SACD disc spinners, Radio, Computer soundcard, DAC: into (2) various pre-amplifiers and integrated amplifiers; (3) between computer and DAC; (4) between Turntable and (4.1) phono stage (4.2) SUT (4.3) Head Amp (4.4) pre-amp. Another point. The DI can have a shield. It can be floating (ie not connected to either of the 'return' connections on the RCA, it can be connected to both (I think this is best), or it can be connected to one end only - usually the source end. *Unshielded connectors have sounded poor when run in close proximity to a power amp or TV. Another vid including 'balanced' connectors may help.
Is it okay to use a twisted cable on a single-ended input? You said it is bad if you use a coaxial RCA cable on a differential input, but I did not hear (or maybe I missed it) you say if you used twisted cable on a single-ended input.
My crossover is single. Would it matter using the double from my head unit to the crossover before it gets to the amps? Only reason I ask is because I just got my expensive twisted rca in today. Wish I saw this video a week ago.
What's the difference between Differential Input signal system and a Balanced signal system (like an XLR cable) ? I'm guessing DI inversion occurs in the amp (receiving end) and Balanced inversion occurs at the source (transmitting end). Correct me where I'm wrong.
Hey Anthony, another question: would it be the best of both worlds if use a shieded twisted pair, like a CAT6 STP cable and ground the shield? thanks and regards, Dieter
I'm using DI in my Polk audio amp since November and I haven't had a problem but I'm curious what's the side affect because I didn't understand that much in the video
Good and informative video. Could you add some examples of amps with differential RCA inputs? I have seen lots of amps and I must say I only come to think of one that did not have RCA ground connected to ground.
My 2008 model Kicker ZX750.1 has differential inputs. It also has a button to switch between low and high level signal, which eliminates the need to use Hi-Low converters. On the JL Audio there's an article that says it could be part of the same circuit. So my guess is that if they have the Hi-Low input switch they definitely have differential inputs. JL amps also use differential inputs.
Hey Anthony, nice video! I have a question: I use a Marantz AV7005, which offers XLR out (not sure if balanced) and 9 surround channels run on cheap TDA7492 chip, which has differential inputs. No ground to - , signal passes through 2 op amps before being amplified. The 2 main front channels comes from the Marantz and go to a 845 SET power amplifier. This has the input - grounded. Here comes the question: Knowing that I can get balanced and unbalanced outputs, which cable type should I use where? Thanks and regards, Dieter
i just bought an Alpine PDX-v9 5 channel amplifier. I want the best cables for this amp. should i use a twisted wire rca? I want the best conduction of sound. i was thinking about using 12 guage speaker wire for the mids and highs. what do you think?
okay so if i get my meter and check for continuity from the amps ground to the shell of the rca coming out of the amp it should beep that means single coax rca and if no beep its twisted pair? is there a way to tell if you need twisted pair? if i was just looking to see if i need it
Never knew! But what brands go under which category? Specifically looking for Rockford's, as that is what I have. T series. I'm guessing differential since their rcas are twisted.
So if only amp manufacturers had a standard way of saying "this product works best with twisted-pair RCAs" or "this product works best with single-ended RCAs."
They don't tell you cause it doesn't matter. This guy is full of BS. Twisted pair is to lower the capacitance of the wire, nothing more. Single ended doesn't exist, it is called coax after the coax TV cables. Both types have the ground and signal both connected to the ground and signal. Anyone who tells you differently is lying.
Joshua's Recordings Sorry, bud, I'm going to take the electrical engineer's opinion over yours. Does it matter for a non-audiophile? Maybe not. Does it not matter at all? Absolutely not. I have a background in masters-level electronics principles from my time in the USAF. This guy knows his stuff.
Numinous sorry man, not opinion. RCA cables are not balanced, look it up. For the most part I like this channel. Even though their is a difference in the cable types, you can use either type of cable on any amp. Twisted pair is better for longer runs because of reduced capacitance. However both types of cables have ground connected to ground and signal connected to signal. If they didn't you would have noise no matter what kind of equipment you connect coax to. This is because of something called ground reference. It is also what causes that hum when you plug a RCA or mini jack connector halfway in. Believe whatever you want, but this guy is wrong by the laws of electrical engineering. Not to say that everything he says is wrong.
Joshua's Recordings Why should I believe you, especially in light of what I know? Specific, reputable, peer-reviewed citations, please? Additionally, you're straight-up charging him with being publicly dishonest. That's a serious accusation. Where's your proof of his intentional malevolence; what's the motive and its proof?
Numinous Wow, for someone who claims to have a masters in electronics principles you sure don't know much about RCA cables. I'm not trying to say that this guy is being intentionally misleading. A lot of people believe weird things in the audio industry. Things like a $350 power cable makes a difference. The soild, non arguable truth is that an RCA cable is a two conductor cable with signal and ground. You need three conductors to be balanced, hence XLR and TRS cables. I frankly don't care what you believe, if you want to believe a twisted pair RCA cable cannot be used on some amps, well, go ahead.
Can you tell me what type of rca cable I should buy to eliminate 60 Hz hum getting picked up from a power lead running right along side it? I need 35 ft L/R audio from a cable tv box to a pa system with aux inputs.
Joe Mirabile ... An unbalanced 'RCA' will not solve your problem.. There is no unbalanced cable that will solve the problem.. Separate the signal cable from the power cable.. Here, distance is your friend...
Half of what he is saying is impossible and a complete lie. RCA cables cannot use "common mode noise rejection" (or what he calls differential input) at all. You would need a BALANCED audio cable with THREE conductors to use common-mode rejection. RCA cables only have TWO conductors: the tip and the barrel, or what is called an UNbalanced cable. Your audio travels in the center wire of an RCA cable and the outer shield intercepts incoming noise and shorts it to ground on both ends. There is no third wire for ground in an RCA cable, only the positive and the grounded negative, making this again completely impossible. *All* RCA cables are, as he is calling it, single-ended. The only thing you'll accomplish by twisting the two wires together is increasing the wire's Capacitance which rolls off treble and is not a good thing. Look up some of the terms I've used here to see how RCA shielding really works.
+Tony D'Amore CAT5 cable is not a cable used for RCA interconnects or audio at all for that matter. There's next to no dielectric and the capacitance would be off the charts. edit: Have you heard of Shielded CAT5/5e/6 cable? That's what we use when we run network cables by high voltage lines or fluorescent lights to avoid packet loss. Twisted pair doesn't do a thing to reduce EMI (noise) in network cables. www.computercableinc.com/ccinc/images/CAT5E-Shielded-Outdoor-Double-Shielded---.jpg
+Matt A I've used it many times with great results. But my point is that you need 2 wires to transmit a differential signal. I take it you are from the pro audio world where 3 wires are used, the 3rd being a shield that has nothing to do with the audio signal being transmitted.
+Tony D'Amore In that case, I suppose you'd have no problem comparing a coaxial RCA cable and amp beside a "differential input" RCA cable and amp, with each RCA wrapped around a high voltage wire and speakers hooked up to the amp to show us that what you're saying actually works in practice? And I'm not talking about a cheapo coax wire just to intentionally make it sound bad, I mean something with at least a 95% braid and 100% foil shield, or a dual 95%+ braid properly terminated on both ends.
+Matt A One major difference between pro audio vs car and home audio is the output impedance and input impedance of the audio transmitting and receiving devices respectively. The high impedance in the pro audio world allow outside noise to mix with the signal much more easily than with home or car audio setups. So every possible method is used to prevent noise in pro audio interconnects including attempting to shield the conductors with aluminum foil or braid.
An RCA connector only has a Tip and barrel it can not be balanced. Also Balanced cables only work if there if the both the source and receiver and both balanced you need three conductors to have a balanced audio Cable. You can not achieve CMRR with an RCA connector.
Thanks Mr. D'Amore for the quality information. Always good to hear it from a quality engineer rather than from someone who thinks they know what they are talking about. Love all the new product you are developing and can't wait to see more.
I did not experience any difference in quality or performance on my Audison LRX 1.1k with cheap and expensive RCA cables, tried both of these types as well. Marketing crap.
The issue with Differential Input Cable doesn't surprise me. Monster Cable had manufactured these since the 1990's with Interlink 300 & 400 Series. There are White Stickers with Arrows denoting the Signal Flow which plugs into the source.
Very helpful- I bought a new differential preamp and amp but kept coaxial cables and couldn't explain the noise that I created. Eventually went xlr but wish I saw this video prior. In the real end figured that it was caused by halogen sconces emitting noise to the room even on separate electrical drops.
In my experience, it is extremely rare nowadays to use RCA-style for DI signals. Maybe that 's why this info is not common in the industry, These days the industry convention dictates XLR cables for DI. The 3 pins of XLR are signal+, signal- and shield. For example, my CD player has both outputs. All the best, Rob
What???.... So what Im getting is some gear basically has noise reduction apparently built in to but could possibly not be used with coaxials because of some extra shielding for noise reduction? Really? Is it because like noise reduction wires plus noise reduction (whatever you said in the amp) equals just no noise? Or is there more of a difference then just shielding between a coaxial and twisted cable?
I have never heard of this! One thing I don't understand, the majority of RCA cables marketed for automotive amplifiers seem to be twisted pair. ALL of Rockford Fostgagte's cables are twisted pair, so does that mean they are DI?
Mr Damore, are you able to show us how one sounds compared to the other if you use the wrong one? I know you are busy, but I really would appreciate it! Or maybe anyone else has a link to a video like that? Thank you! -iMickey503-PDX
cool video thanks. Personally, I'm not a fan of RCA connectors to begin with, and think its old technology. But sometimes, that's all you get, and why I feel the whole car audio industry is behind the times, with little (no?) innovation in the last 20 years.
Per JL website: "JL Audio’s Differential-Balanced Input circuits" ... "This works equally well with differential-balanced, or unbalanced signal sources, making this input architecture compatible with all standard car and marine audio equipment, using standard, unshielded, twisted-pair RCA cables. No special cables are required, unlike the fully balanced connections used in professional audio" (jlaudio.zendesk.com/hc/en-us/articles/209357588-Differential-Balanced-Inputs). ----So which are you exactly referring to? Any specific amp for example?
Hello i have a weird problem. I have 3 Jvc ks ax6500 and they all work. And after measuring the positive and negative input to ground the value is 10Kohm on all 4 channels But from 1 rca negative to the other 3 rca negative it's 0 ohms, is this a problem?
Thankyou for explaining this,glad I found this, suscribed.... sorry for your haters, everyone is a scientist who seams to not even know what their talking about but they read it Somewhere, I was wondering is it a good idea to twist(spiral loomed/tekflexed together of course + Elton + - to -) my + & negative power cables going to my rear battery bank ,will I gain anything ?
I’m trying to figure out if my amplifiers are differential or single ended. Mosconi as100.4 measured approximately 1100 ohms. The amplifiers are measured that are differential are like in the 10 thousand plus ohms readings.
Wow that's some AWESOME info man!! I know this is old but this is however NEVER mentioned anymore lol. I'm a noob and I am glad I found this for my first SQL build!! 👏🏼👏🏼👌👌💪💪🔥
So, what is Kimber PBJ? It looks like twisted pair (braided, actually). No shield. But it's not called out as specifically single-ended or differential. It sounds the same as my Blue Jeans LC-1. I guess I always assumed that all RCA cable is single-ended.
What kind of equipment uses RCA connectors for differential signals? I notice this video offers no context at all in this regard. Working in pro-audio my whole life, I never encountered RCA connectors being used for differential signals, and doing so would prevent differential with shielding. But maybe this video isn't even about audio signals.....some context would be useful.
A very good, informational video, and thorough lecture on the two main signal cables, DAmoreEngineering. Thumbs up. The 2 methodologies are explained well. Therefore, we are not going to make mistakes based on connectivity to amplifiers for our hi fi audio systems.
If the head unit has SE outputs and the amplifier has SE inputs = coax cable If the head unit has SE outputs and the amplifier has Diff inputs = twisted pair If the head unit has Diff outputs and the amplifier has Diff inputs = twister pair If the head unit has Diff outputs and the amplifier has SE inputs = bad no matter what as you will shorting out half of the head unit's outputs. In this case you would need an amplifier with Diff inputs or a converter to convert the head unit's outputs to SE
DAmoreEngineering, Sorry for the late reply. Just saw this. Most head units with Diff outputs has a current limiting resistor so when it connected to a grounded input, there is no harm done. This is done for compatibility. It is true the level is then down 6db which is the proper level for most unbalanced inputs.
Any chance you know what it would be considered if I'm going from an IPhone Lightening connector to RCA converter back to a BOSS car amplifier (pf1800)?
So, I am looking at a JL Audio VX1000/5i amp for a new car audio build. It has RCA inputs and in the documentation I noticed it says Differential Input on those inputs. So what do you use with a source that is not Differential? Any problems there? Also, which cable?
I have big questions. Please. My HU is a Pioneer DEH-80PRS. From what is available online I have found that this might be a "single ended" RCA preout head unit. If I use twisted/ balanced RCA cables to an amplifier that is ALSO "single ended," what could happen? Is there any loss or risk? Any gain? Any chance of damage?? Also, my DMM says 1166 on the ohm reading when connecting the positive lead to the RCA Input outer ring and the negative lead to the ground on the disconnected/ unpowered amp model amp PX1900.4 Massive. Does this mean the amp is "single ended?" Or "differential?"
I've been looking for a decent explanation on RCAs and how to wire them up for different scenarios for awhile. Although this isn't exactly that Tony's explanation combined with knowledge I already learned just turned the light bulb on in my head! Lol
Hi, recently bought an audiolab 8300cdq and Audiolab 8300XP. Reading through the manual it make no mention of SE or DI RCA connection. I dont have an Ohm meter so is there another way to tell?
There is a question that I've been wanting to get answered. If I measure a balanced car audio signal with a digital multimeter and get 8 volts reading would that become 4 volts going into an unbalanced RCA input at an amplifier? That would seem to be the case because the inverted signal or basically half the voltage is getting grounded at The amp anyways so the voltage will be cut in half right?
Ya, except that in car audio, almost every aftermarket HU does not use balanced or differential pre-amp outs. All of the speaker outputs are balanced/differential. So, if a RF P600X4, for example, with balanced-differential inputs, then I presume you can use either type of RCA, but twisted would be better; however, because the HU pre-amp outs are not balanced-differential, it does nothing. -- I just saw this vid again today. There's twisted pair RCAs that have single and even double shielding. In that case, one could use such cables on an amp that has a grounded outer ring.
This is all car audio correct? You wouldn't be able to use a balanced style connection without the ground connection provided by the vehicle chassis. Amazing, I never knew they had car audio equiptment that used this tech.
Testing both of my amplifiers, a 4 channel Pioneer and a mono Kicker, I got roughly 17k ohms on the Pioneer, and roughly 6-30m ohms on the Kicker. The Kicker amplifier specifies that it's a differential model, while the Pioneer doesn't mention anything about the type of input it uses. So I am going to assume that the Pioneer is a single ended based off of the lower resistance shown vs the known differential resistance shown on the Kicker. I hope I am correct in my assumption!
I have got 2 question. How can i know if cable is balanced or unbalanced if i look at it or any other way to find out.? 2. If my amp has balanced rca input and i have got balanced rca cable do i need also headunit or any other source wirh balanced rca output?
Hmmm. The twisted pair interconnect won't give common-mode rejection if it's used in an UNbalanced system.. I know of no balanced system that uses a phono (RCA) configuration (perhsps there are).. Also, a slight error in presentation (if I heard you correctly). The common noise that comes in off the cable is NOT "out of phase" and thus cancels at the input.. Rather, common mode noise is IN phase and presents the same voltage at the inputs. The amplifier senses the "difference" at the inputs.. Because the amplifier sees the "equal" in phase voltages at the input, the noise is not amplified....
You may have had experience with this but when running RCA cables close to cabling for light clusters induces noise, for example in my case the loom is down the left hand side of an E90 and following the factory loom which are basically the cables going to the light cluster down the left hand side down to where the factory amplifier normally is, when you put your foot on the brake static noise can be heard. I want to keep my RCA run tidy with the factory cabling but have found it to be problematic in that it picks up EMI whenever I put my foot on the brake. I have verified this when disconnecting the plug that runs to the rear light cluster and the noise is no longer there. The cabling is the 6 channel Stinger 4000 series. I have tried other cables but to no avail. Running it down the centre console works better but I have found it to be untidy for cable management. The headunit is an aftermarket 80prs, so it’s a straight RCA run from the headunit to the amp. The amplifier is a class D five channel JBL GTR 7535.
Interesting video. I think I have a differential amp. I have always been told to stay clear of unshielded twisted cables. When playing from a digital source with my shielded cables I have 0 noise when playing from my phono preamp I have lots of interference. So if I do have a diffential amp (cyrus 8) Would the twisted cable eliminate this noise? I get more confused every day😂
Cool. Thank you so much for this. I’m trying to add a phono preamp signal to a b&k avr505 receiver but it has to be a 15’ cable for proper placement of the turntable without drastically altering the setup. I tested the turntable signal with a shorter standard RCA cable (6.6’ Prosolutions Blue Soft analog rca) and it worked great. The new long cable creates low level static/feedback/white noise through the speakers with one end just plugged into the receiver inputs. I believe the new cable is a center lead, shielded coax. This maybe my issue.
To be more understandable, differential input means balanced type cable, more often come in XLR form (Usually Starquad structure). Single ended not necessarily in coaxial, but more often in RCA type. Unbalanced RCA may consist 2 or more cores of wire in TRS cable.
I just add tin foil heavy duty Reynolds and zip ties to the outside and let the body do some shielding along that path no noise with any cables. DIY for ya from a old school MECP installer.
Why is this not mentioned anywhere ever? This 8 year old video has explained why swapping around RCA's has cured noise in some of my systems when the RCA's themselves had no faults... awesome.
Most noise picked up by RCA cable is 60 hz line and high power radio Being an average car is mostly metal on the outside it becomes a Faraday cage and blocks most interference before it can get to your cables Also proper routing of cables keeps the noise generated by the vehicle at a minimum
Thank you. but i am not sure i understand how to tell if the amp is single ended: should it have no resistance between the rca input and the ground ? i think you mentioned it should have 1000 ohm or less ?
Tony, im a EE in the industrisl industry. I never really had a professional opportunity to work in the Ee field. On the other hand, I have always love the audio end as a hobby. Recently I have embarked into xar audio. I have watched your videos and it rekindled my love of it. I have applied it to my car design and I have excellect car tunes. Thank You. Keep up the instructional videos.
Thanks a bunch Robert
For all the folks hemmimg and hawing over balanced XLR and RCA not being able to carry a balanced signal... An RCA can carry a balanced signal, if it uses a twisted pair wire. The cable assembly will simply be unshielded. We often wire studio installs with telescoping shields, where the shield (pin 1) is disconnected at the input of each device. this drains static and RF back to the Chassis Ground in only one direction, terminating to a common ground bus. This avoids ground loops. The shield in a balanced audio system carries no signal... At least we hope not!
Thank you
Very informative. I didn't even know there were two types of RCAs.
Great video on a subject that nobody seems to ever explain, and is actually important to know.
The only problem is that nobody lists what kind of RCA input or output they have on their headunit or amplifier.
Take an ohm meter (DMM) and check the resistance from the battery ground connection on amplifier to the RCA outer ring on amplifier (with everything unplugged from amplifier). If you have less than 100 ohms it is a single-ended input.
DAmoreEngineering Wow, thanks for the reply! I know you guys explained the same thing in the video, but for some reason I feel that this explanation is more solid.
On an unrelated note, I had always known about your company from Steve Meade's videos, but now once I figure out which type of RCA I need I'll most likely end up buying from you. Keep up the awesome work guys, this type of potential customer relations and not keeping this information hidden and secret like everyone else really shows what kind of a company you are.
+DAmoreEngineering What exactly is a battery ground connection on an amplifier? Chassis ground won't work? Thanks for your time.
lowellaby You have a positive and ground connection on any amplifier that runs on DC. The "battery ground connection" is the big ground connection for which you hook up your main ground wire to.
@LD Blake I have disputed this topic in these comments many times. You do not need a ground or shield wire to send a differential signal.
This probably explains why I had noise I could never find and I was running Stinger 4000 rca from my Audio Control LC2i to my amps. Probably needed regular RCAs and not twisted pairs and I was a victim of just thinking they were better newer technology.
I was so waiting for him to write on the wall on accident.
Audio school w/Tony D! Great vid, thanks for sharing your knowledge!
Big D wiz..I'm outta heeeeerrr
How to understand which amlifire what kind of type is ? I checked several manuals during the video and did not get any information.
Mind Blown.... I really thought RCA's only differed in quality of the material and marketing :)
We already have a standard for differential signaling over a balanced line: AES14. AES14 uses XLR or TRS connectors, not RCA.
Car audio has been using differential signals via RCA since the 1980s
Nice refresher course. Thanks!
excellent explanation, thank you very much.
Wouldn't this require a HU with differential outputs? Otherwise, how would would the sine waves become inverted to one another across the twisted pairs to begin with? Seems to me that the wire that goes to the sleeve on a twisted pair rca would not carry a wave at all if the HU has 'single ended' outputs, as it were. From what i see after a google search, HUs with differential outs are a unicorn, only a few boutique models have ever had them.
It is inexplicable why amplifier manufacturers don't advise the type of RCA connector that works better - unless of course it makes no difference. I have both types and have never* heard the slightest difference when connecting all these permutations: (1) Sources: Phono stages, CD and SACD disc spinners, Radio, Computer soundcard, DAC: into (2) various pre-amplifiers and integrated amplifiers; (3) between computer and DAC; (4) between Turntable and (4.1) phono stage (4.2) SUT (4.3) Head Amp (4.4) pre-amp.
Another point. The DI can have a shield. It can be floating (ie not connected to either of the 'return' connections on the RCA, it can be connected to both (I think this is best), or it can be connected to one end only - usually the source end.
*Unshielded connectors have sounded poor when run in close proximity to a power amp or TV.
Another vid including 'balanced' connectors may help.
They do, If it says they support CMRR then your good to go.
So the higher end amplifiers you're referring here are class A and AB?
Is it okay to use a twisted cable on a single-ended input? You said it is bad if you use a coaxial RCA cable on a differential input, but I did not hear (or maybe I missed it) you say if you used twisted cable on a single-ended input.
My crossover is single. Would it matter using the double from my head unit to the crossover before it gets to the amps? Only reason I ask is because I just got my expensive twisted rca in today. Wish I saw this video a week ago.
What's the difference between Differential Input signal system and a Balanced signal system (like an XLR cable) ? I'm guessing DI inversion occurs in the amp (receiving end) and Balanced inversion occurs at the source (transmitting end). Correct me where I'm wrong.
Reminds me of my engineering classes
Hey Anthony,
another question:
would it be the best of both worlds if use a shieded twisted pair, like a CAT6 STP cable and ground the shield?
thanks and regards,
Dieter
I'm using DI in my Polk audio amp since November and I haven't had a problem but I'm curious what's the side affect because I didn't understand that much in the video
Good and informative video. Could you add some examples of amps with differential RCA inputs? I have seen lots of amps and I must say I only come to think of one that did not have RCA ground connected to ground.
My 2008 model Kicker ZX750.1 has differential inputs. It also has a button to switch between low and high level signal, which eliminates the need to use Hi-Low converters. On the JL Audio there's an article that says it could be part of the same circuit. So my guess is that if they have the Hi-Low input switch they definitely have differential inputs. JL amps also use differential inputs.
So in a way coax is passive noise cancellation, and twisted is active cancellation?
Thanks so much. Well explained!
Hey Anthony,
nice video!
I have a question:
I use a Marantz AV7005, which offers XLR out (not sure if balanced) and 9 surround channels run on cheap TDA7492 chip, which has differential inputs. No ground to - , signal passes through 2 op amps before being amplified.
The 2 main front channels comes from the Marantz and go to a 845 SET power amplifier. This has the input - grounded.
Here comes the question:
Knowing that I can get balanced and unbalanced outputs, which cable type should I use where?
Thanks and regards,
Dieter
well there's something i didn't know, now i do thanks! awesome vid & info bro!!!
Realistically, in 2019, how common are single-ended inputs on car amplifiers?
i just bought an Alpine PDX-v9 5 channel amplifier. I want the best cables for this amp. should i use a twisted wire rca? I want the best conduction of sound. i was thinking about using 12 guage speaker wire for the mids and highs. what do you think?
You say that you just came out with these rca cables. So does the information in this video only apply to your brand of rca cables?
Very educational, thanks a lot sir :-) Very useful infos
Anyone know if the DD M series sub amps are twisted pair rca or single ended?
okay so if i get my meter and check for continuity from the amps ground to the shell of the rca coming out of the amp it should beep that means single coax rca and if no beep its twisted pair? is there a way to tell if you need twisted pair? if i was just looking to see if i need it
Never knew! But what brands go under which category? Specifically looking for Rockford's, as that is what I have. T series. I'm guessing differential since their rcas are twisted.
Keep up the good work !
So if only amp manufacturers had a standard way of saying "this product works best with twisted-pair RCAs" or "this product works best with single-ended RCAs."
They don't tell you cause it doesn't matter. This guy is full of BS. Twisted pair is to lower the capacitance of the wire, nothing more. Single ended doesn't exist, it is called coax after the coax TV cables. Both types have the ground and signal both connected to the ground and signal. Anyone who tells you differently is lying.
Joshua's Recordings Sorry, bud, I'm going to take the electrical engineer's opinion over yours. Does it matter for a non-audiophile? Maybe not. Does it not matter at all? Absolutely not. I have a background in masters-level electronics principles from my time in the USAF. This guy knows his stuff.
Numinous sorry man, not opinion. RCA cables are not balanced, look it up. For the most part I like this channel. Even though their is a difference in the cable types, you can use either type of cable on any amp. Twisted pair is better for longer runs because of reduced capacitance. However both types of cables have ground connected to ground and signal connected to signal. If they didn't you would have noise no matter what kind of equipment you connect coax to. This is because of something called ground reference. It is also what causes that hum when you plug a RCA or mini jack connector halfway in.
Believe whatever you want, but this guy is wrong by the laws of electrical engineering. Not to say that everything he says is wrong.
Joshua's Recordings Why should I believe you, especially in light of what I know? Specific, reputable, peer-reviewed citations, please?
Additionally, you're straight-up charging him with being publicly dishonest. That's a serious accusation. Where's your proof of his intentional malevolence; what's the motive and its proof?
Numinous Wow, for someone who claims to have a masters in electronics principles you sure don't know much about RCA cables.
I'm not trying to say that this guy is being intentionally misleading. A lot of people believe weird things in the audio industry. Things like a $350 power cable makes a difference.
The soild, non arguable truth is that an RCA cable is a two conductor cable with signal and ground. You need three conductors to be balanced, hence XLR and TRS cables.
I frankly don't care what you believe, if you want to believe a twisted pair RCA cable cannot be used on some amps, well, go ahead.
Thank you for this
Thanks for the great info highly appreciate it!
I'm listening 🎧
Can you tell me what type of rca cable I should buy to eliminate 60 Hz hum getting picked up from a power lead running right along side it? I need 35 ft L/R audio from a cable tv box to a pa system with aux inputs.
Joe Mirabile ... An unbalanced 'RCA' will not solve your problem.. There is no unbalanced cable that will solve the problem.. Separate the signal cable from the power cable.. Here, distance is your friend...
Half of what he is saying is impossible and a complete lie. RCA cables cannot use "common mode noise rejection" (or what he calls differential input) at all. You would need a BALANCED audio cable with THREE conductors to use common-mode rejection. RCA cables only have TWO conductors: the tip and the barrel, or what is called an UNbalanced cable. Your audio travels in the center wire of an RCA cable and the outer shield intercepts incoming noise and shorts it to ground on both ends.
There is no third wire for ground in an RCA cable, only the positive and the grounded negative, making this again completely impossible. *All* RCA cables are, as he is calling it, single-ended. The only thing you'll accomplish by twisting the two wires together is increasing the wire's Capacitance which rolls off treble and is not a good thing. Look up some of the terms I've used here to see how RCA shielding really works.
Ah no. Have you heard of Cat 5 cable?
+Tony D'Amore CAT5 cable is not a cable used for RCA interconnects or audio at all for that matter. There's next to no dielectric and the capacitance would be off the charts.
edit: Have you heard of Shielded CAT5/5e/6 cable? That's what we use when we run network cables by high voltage lines or fluorescent lights to avoid packet loss. Twisted pair doesn't do a thing to reduce EMI (noise) in network cables. www.computercableinc.com/ccinc/images/CAT5E-Shielded-Outdoor-Double-Shielded---.jpg
+Matt A I've used it many times with great results. But my point is that you need 2 wires to transmit a differential signal. I take it you are from the pro audio world where 3 wires are used, the 3rd being a shield that has nothing to do with the audio signal being transmitted.
+Tony D'Amore In that case, I suppose you'd have no problem comparing a coaxial RCA cable and amp beside a "differential input" RCA cable and amp, with each RCA wrapped around a high voltage wire and speakers hooked up to the amp to show us that what you're saying actually works in practice? And I'm not talking about a cheapo coax wire just to intentionally make it sound bad, I mean something with at least a 95% braid and 100% foil shield, or a dual 95%+ braid properly terminated on both ends.
+Matt A One major difference between pro audio vs car and home audio is the output impedance and input impedance of the audio transmitting and receiving devices respectively. The high impedance in the pro audio world allow outside noise to mix with the signal much more easily than with home or car audio setups. So every possible method is used to prevent noise in pro audio interconnects including attempting to shield the conductors with aluminum foil or braid.
At last a tutorial without the thumping bass and background noise thats how I like it
Promoagent : but it's 100% Wrong.
i have americam bass amp 1100.1 what rca cable is good
An RCA connector only has a Tip and barrel it can not be balanced. Also Balanced cables only work if there if the both the source and receiver and both balanced you need three conductors to have a balanced audio Cable. You can not achieve CMRR with an RCA connector.
wrong
Quite nearly balanced. Why? The center connection is nearly the same connection point on the barrel side.
Twisted type.
that analog is better than digital
Thanks Mr. D'Amore for the quality information. Always good to hear it from a quality engineer rather than from someone who thinks they know what they are talking about. Love all the new product you are developing and can't wait to see more.
I did not experience any difference in quality or performance on my Audison LRX 1.1k with cheap and expensive RCA cables, tried both of these types as well. Marketing crap.
The issue with Differential Input Cable doesn't surprise me. Monster Cable had manufactured these since the 1990's with Interlink 300 & 400 Series. There are White Stickers with Arrows denoting the Signal Flow which plugs into the source.
I doubt that amps with differential inputs are made with RCA jacks instead of XLRs. That would be kind of dumb.
Very helpful- I bought a new differential preamp and amp but kept coaxial cables and couldn't explain the noise that I created. Eventually went xlr but wish I saw this video prior. In the real end figured that it was caused by halogen sconces emitting noise to the room even on separate electrical drops.
In my experience, it is extremely rare nowadays to use RCA-style for DI signals. Maybe that 's why this info is not common in the industry,
These days the industry convention dictates XLR cables for DI. The 3 pins of XLR are signal+, signal- and shield. For example, my CD player has both outputs. All the best, Rob
Yes, some car audio companies would use balanced signal with two RCA's. But that's not what Tony Bologna is describing here.
@@RobotUndergroundalways making me hungry man 😂😋
Can you post a video on How to determine if a amp is a single ended or differential?
+Nikko Civic Open the manual and read it.
What???.... So what Im getting is some gear basically has noise reduction apparently built in to but could possibly not be used with coaxials because of some extra shielding for noise reduction? Really? Is it because like noise reduction wires plus noise reduction (whatever you said in the amp) equals just no noise? Or is there more of a difference then just shielding between a coaxial and twisted cable?
I have never heard of this! One thing I don't understand, the majority of RCA cables marketed for automotive amplifiers seem to be twisted pair. ALL of Rockford Fostgagte's cables are twisted pair, so does that mean they are DI?
So the Signal is coming from a what high end CD player, going into a. high end Amplifier? What Audio Equipment has a DIFFERENTIAL OUTPUT? Examples?
Mr Damore, are you able to show us how one sounds compared to the other if you use the wrong one? I know you are busy, but I really would appreciate it! Or maybe anyone else has a link to a video like that? Thank you! -iMickey503-PDX
cool video thanks. Personally, I'm not a fan of RCA connectors to begin with, and think its old technology. But sometimes, that's all you get, and why I feel the whole car audio industry is behind the times, with little (no?) innovation in the last 20 years.
I hope I am understanding but what if head unit is differential and amp is single ended?
Per JL website: "JL Audio’s Differential-Balanced Input circuits" ... "This works equally well with differential-balanced, or unbalanced signal sources, making this input architecture compatible with all standard car and marine audio equipment, using standard, unshielded, twisted-pair RCA cables. No special cables are required, unlike the fully balanced connections used in professional audio" (jlaudio.zendesk.com/hc/en-us/articles/209357588-Differential-Balanced-Inputs).
----So which are you exactly referring to? Any specific amp for example?
Hello i have a weird problem. I have 3 Jvc ks ax6500 and they all work.
And after measuring the positive and negative input to ground the value is 10Kohm on all 4 channels
But from 1 rca negative to the other 3 rca negative it's 0 ohms, is this a problem?
Thank you for explaining this, very helpful as I'm starting to make my own RCA connections.
Excellent presentation. Simple, but effective. You might consider a discussion on UTP vs. STP and if STP how to properly connect the shield.
All these TH-cam experts in the comments. Lmao!
Thankyou for explaining this,glad I found this, suscribed....
sorry for your haters,
everyone is a scientist who seams to not even know what their talking about but they read it Somewhere,
I was wondering is it a good idea to twist(spiral loomed/tekflexed together of course + Elton + - to -) my + & negative power cables going to my rear battery bank ,will I gain anything ?
Elton*= to
I’m trying to figure out if my amplifiers are differential or single ended. Mosconi as100.4 measured approximately 1100 ohms. The amplifiers are measured that are differential are like in the 10 thousand plus ohms readings.
Wow that's some AWESOME info man!! I know this is old but this is however NEVER mentioned anymore lol. I'm a noob and I am glad I found this for my first SQL build!! 👏🏼👏🏼👌👌💪💪🔥
Didn't get how the noise is subtracted from the twisted-pair line...
I believe it works on the principle of phase cancellation. Same concept as extracting acapellas from music
So, what is Kimber PBJ? It looks like twisted pair (braided, actually). No shield. But it's not called out as specifically single-ended or differential. It sounds the same as my Blue Jeans LC-1. I guess I always assumed that all RCA cable is single-ended.
Twisted or braided will be differential, shielded will be single or coaxial.
ahhh.....No.....RCA Phono connectors aren't an Engineering approved Legit "Balanced" cable Direct termination plug type despite some Unscrupulous manufacturers selling "Pseudo-Balanced" RCA phono terminated Balanced conductor interconnect Cables.....We live in almost totally Unregulated "Audiophile" snake Oil marketing Sales schemes .......
The connector type has no effect on whether or not the circuit is a true balanced circuit. USB are balanced for instance.
What kind of equipment uses RCA connectors for differential signals? I notice this video offers no context at all in this regard. Working in pro-audio my whole life, I never encountered RCA connectors being used for differential signals, and doing so would prevent differential with shielding. But maybe this video isn't even about audio signals.....some context would be useful.
A very good, informational video, and thorough lecture on the two main signal cables, DAmoreEngineering. Thumbs up. The 2 methodologies are explained well. Therefore, we are not going to make mistakes based on connectivity to amplifiers for our hi fi audio systems.
Thank you George
Your welcomed, @@TonyInvents
Which rca to use if the amps need twisted pair (Taramps) and the head unit and eq needs coaxial (Sony head unit, Rockford 360)
Interested as well in what to do in such cases where there's a mismatch...
If the head unit has SE outputs and the amplifier has SE inputs = coax cable
If the head unit has SE outputs and the amplifier has Diff inputs = twisted pair
If the head unit has Diff outputs and the amplifier has Diff inputs = twister pair
If the head unit has Diff outputs and the amplifier has SE inputs = bad no matter what as you will shorting out half of the head unit's outputs. In this case you would need an amplifier with Diff inputs or a converter to convert the head unit's outputs to SE
DAmoreEngineering, Sorry for the late reply. Just saw this. Most head units with Diff outputs has a current limiting resistor so when it connected to a grounded input, there is no harm done. This is done for compatibility. It is true the level is then down 6db which is the proper level for most unbalanced inputs.
Any chance you know what it would be considered if I'm going from an IPhone Lightening connector to RCA converter back to a BOSS car amplifier (pf1800)?
What about if the amplifier has a feedback loop from the negative input to the output?
So, I am looking at a JL Audio VX1000/5i amp for a new car audio build. It has RCA inputs and in the documentation I noticed it says Differential Input on those inputs. So what do you use with a source that is not Differential? Any problems there? Also, which cable?
Just happen to stumble on this working on a system build 2018
Why does car audio use rca and home audio uses better sounding cables like hdmi?
I have big questions. Please. My HU is a Pioneer DEH-80PRS. From what is available online I have found that this might be a "single ended" RCA preout head unit. If I use twisted/ balanced RCA cables to an amplifier that is ALSO "single ended," what could happen? Is there any loss or risk? Any gain? Any chance of damage?? Also, my DMM says 1166 on the ohm reading when connecting the positive lead to the RCA Input outer ring and the negative lead to the ground on the disconnected/ unpowered amp model amp PX1900.4 Massive. Does this mean the amp is "single ended?" Or "differential?"
I've been looking for a decent explanation on RCAs and how to wire them up for different scenarios for awhile. Although this isn't exactly that Tony's explanation combined with knowledge I already learned just turned the light bulb on in my head! Lol
Does your source unit have any effect on what cables will work best?
Hi, recently bought an audiolab 8300cdq and Audiolab 8300XP. Reading through the manual it make no mention of SE or DI RCA connection. I dont have an Ohm meter so is there another way to tell?
There is a question that I've been wanting to get answered. If I measure a balanced car audio signal with a digital multimeter and get 8 volts reading would that become 4 volts going into an unbalanced RCA input at an amplifier? That would seem to be the case because the inverted signal or basically half the voltage is getting grounded at The amp anyways so the voltage will be cut in half right?
Ya, except that in car audio, almost every aftermarket HU does not use balanced or differential pre-amp outs. All of the speaker outputs are balanced/differential. So, if a RF P600X4, for example, with balanced-differential inputs, then I presume you can use either type of RCA, but twisted would be better; however, because the HU pre-amp outs are not balanced-differential, it does nothing.
-- I just saw this vid again today. There's twisted pair RCAs that have single and even double shielding. In that case, one could use such cables on an amp that has a grounded outer ring.
This is all car audio correct? You wouldn't be able to use a balanced style connection without the ground connection provided by the vehicle chassis. Amazing, I never knew they had car audio equiptment that used this tech.
But it's have a signal loss from eddy current.
im actually mad that i dont know this.......thank you for this vid!!.....wtf
Testing both of my amplifiers, a 4 channel Pioneer and a mono Kicker, I got roughly 17k ohms on the Pioneer, and roughly 6-30m ohms on the Kicker. The Kicker amplifier specifies that it's a differential model, while the Pioneer doesn't mention anything about the type of input it uses. So I am going to assume that the Pioneer is a single ended based off of the lower resistance shown vs the known differential resistance shown on the Kicker. I hope I am correct in my assumption!
I have got 2 question. How can i know if cable is balanced or unbalanced if i look at it or any other way to find out.? 2. If my amp has balanced rca input and i have got balanced rca cable do i need also headunit or any other source wirh balanced rca output?
Hmmm. The twisted pair interconnect won't give common-mode rejection if it's used in an UNbalanced system.. I know of no balanced system that uses a phono (RCA) configuration (perhsps there are).. Also, a slight error in presentation (if I heard you correctly). The common noise that comes in off the cable is NOT "out of phase" and thus cancels at the input.. Rather, common mode noise is IN phase and presents the same voltage at the inputs. The amplifier senses the "difference" at the inputs.. Because the amplifier sees the "equal" in phase voltages at the input, the noise is not amplified....
You may have had experience with this but when running RCA cables close to cabling for light clusters induces noise, for example in my case the loom is down the left hand side of an E90 and following the factory loom which are basically the cables going to the light cluster down the left hand side down to where the factory amplifier normally is, when you put your foot on the brake static noise can be heard. I want to keep my RCA run tidy with the factory cabling but have found it to be problematic in that it picks up EMI whenever I put my foot on the brake. I have verified this when disconnecting the plug that runs to the rear light cluster and the noise is no longer there. The cabling is the 6 channel Stinger 4000 series. I have tried other cables but to no avail. Running it down the centre console works better but I have found it to be untidy for cable management. The headunit is an aftermarket 80prs, so it’s a straight RCA run from the headunit to the amp. The amplifier is a class D five channel JBL GTR 7535.
Interesting video.
I think I have a differential amp.
I have always been told to stay clear of unshielded twisted cables.
When playing from a digital source with my shielded cables I have 0 noise when playing from my phono preamp I have lots of interference.
So if I do have a diffential amp (cyrus 8)
Would the twisted cable eliminate this noise?
I get more confused every day😂
Cool. Thank you so much for this. I’m trying to add a phono preamp signal to a b&k avr505 receiver but it has to be a 15’ cable for proper placement of the turntable without drastically altering the setup. I tested the turntable signal with a shorter standard RCA cable (6.6’ Prosolutions Blue Soft analog rca) and it worked great. The new long cable creates low level static/feedback/white noise through the speakers with one end just plugged into the receiver inputs. I believe the new cable is a center lead, shielded coax. This maybe my issue.
To be more understandable, differential input means balanced type cable, more often come in XLR form (Usually Starquad structure). Single ended not necessarily in coaxial, but more often in RCA type. Unbalanced RCA may consist 2 or more cores of wire in TRS cable.
Your a smart Guy Well Explained ! Can U Explain How to Wire 2 12" Dual Voice Subwoofers To 1 Ohm ...?
I just add tin foil heavy duty Reynolds and zip ties to the outside and let the body do some shielding along that path no noise with any cables. DIY for ya from a old school MECP installer.
Why is this not mentioned anywhere ever? This 8 year old video has explained why swapping around RCA's has cured noise in some of my systems when the RCA's themselves had no faults... awesome.
Can be used the component video cable as a RCA audio cable?If not why?
Thanks. Spent all day trying to figure out why this Monster cable I just cut open had red/white wires instead of a single signal wire. Now I get it.
Most noise picked up by RCA cable is 60 hz line and high power radio
Being an average car is mostly metal on the outside it becomes a Faraday cage and blocks most interference before it can get to your cables
Also proper routing of cables keeps the noise generated by the vehicle at a minimum
Thank you. but i am not sure i understand how to tell if the amp is single ended: should it have no resistance between the rca input and the ground ? i think you mentioned it should have 1000 ohm or less ?