Do subwoofers affect speaker impedance?
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- เผยแพร่เมื่อ 10 ก.ย. 2024
- If a subwoofer input is being fed properly, it's from the output of the main power amplifier. But, does connecting a subwoofer's input to the speaker terminals change the impedance of the speaker? Have a question you want to ask Paul? www.psaudio.com...
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Love the vides Paul. The fact that you digress to calculating the g-focrce on subs is exactly what makes your videos so interesting.
I recently purchased 2 subs, not very expensive ones and having dual subs was a game changer in my system. They really filled in the bottom bass of my monitor audio platinum 200 towers. Absolutely love the sound, much more life like.
This question has been on my mind as well, so I'm glad Paul addressed it. I discovered the truth of better sub integration using the speaker-level inputs years ago when I was using a little Def Tech sub. It always sounded a little flabby when I used the LFE on my NAD amp, but when I hooked it to my vintage Pioneer integrated amp using the speaker level inputs, it suddenly sounded like a different sub, tighter, more controlled, and more like an extension of the main speakers. I've used subs that way ever since. It's nice to hear Paul validate my experience.
mind if I ask how you exactly hooked the speaker L/R red/black outputs of your amp to the L/R red/black high-level inputs of your sub?
@@rurouni762 thanks for your question. First, it is necessary that the sub have the speaker-level inputs. Not all do, but strangely the cheaper ones often do. Then it is just like hooking up any other speaker: red to red and black to black for the left and the right channels. Because the sub draws so little wattage, you can run wires right off the same amp terminals you use for the main speakers. This will drop the impedance that the amp sees by a tiny amount, but not enough to affect anything. If your amp has second set of speaker outputs, you can use those.
Thank you PAUL for explaining why subwoofers are needed and giving a explanation on how to connect the subwoofer the right way, so the sound can be as true to the source as possible, what you explain is just what i have experienced in my home made rig of audiophile amplifiers and speaker setup.. 👍👍
I still have a couple of ancient REL Q50's, with new speaker cones using hi level connection. They are now 20 years old +++. Still producing the goods. 2 subs are good, always.
REL is the best subwoofers using hi level connection... I love mine...
Thanks Paul, your channel is awesome , all the questions I find I'm asking myself, I then find you are providing the answers.
When are you going to film a new outro in front of the new building?
Hopefully next week. Thanks for the reminder.
3:34 Paul knows his audience.
Exactly the answer I was searching for
Thanks!
Just make sure you're not running a full balanced output (bridged) power amp into a grounded or common return subwoofer input. You will have a bad day if you do.
A number of the Class D amps actually run bridged. I would suggest asking your amp manufacturer if it is OK to do the connection if it’s Class D.
@Douglas Blake ground posts?
Hi Sir, I am using a Onkyo TX NR 686 receiver which states 7.2 with 2 preout for subwoofers. However there is no option to select 7.2 in speaker configuration and able to select only 7.1 configuration, which means 2 subwoofer output is not independent and it is simply parallel is what I assume. I have dual onkyo SL105 active subwoofer and if i connect those dual subwoofers does it affect the impedance rating of the powered subwoofer? When i check the specification for SL105, it states 12kohms for low level input jacks but my speaker rating is only 6ohms which is not clear to me. Does impedance rating is so important for a powered subwoofer? Your reply will be more useful to me and thanks in advance.
is there any difference between "connecting 2 separate sets of speaker cables from the amp out to the speakers and the sub" and "amp-to-speaker-to-sub" in practice? which would you prefer? thanks.
what about passive subwoofer with built in crossover with two voice coils for satellites?
That was a popular scheme for home theater setups before powered subs became the norm -- the L+R channels of the receiver would be connected to the sub, in which the two woofer voice coils would be driven through low-pass inductors and the satellites would be connected to a second set of terminals in the subwoofer that were tied to the input terminals either directly or via a high-pass capacitor.
Here are photos of the crossover from a Cerwin-Vega subwoofer that uses that sort of passive scheme:
i.ebayimg.com/images/g/th8AAOSwuhFaQ8Hn/s-l1600.jpg
i.ebayimg.com/images/g/owQAAOSwVtZaQ8Hw/s-l1600.jpg
@@editorjuno yep, that's it! how does that affect impedance?
@@MatijaVabec -- Below the crossover frequency, the amp would see the impedance of the woofer voice coils plus a fraction of an ohm from the series inductors and the speaker cable and above it, the capacitors will add a fraction of an ohm. This is essentially a simple first-order crossover setup, nothing fancy and a very gradual slope.
I use the LFE put on my reciver. And the sub integrates perfectly👌 And I also get more bass in movies that way.
I don't like to use the speaker highlevel input on a sub.
There are a lot of ways to do it. I have a QSC amp (GX5) that splits the full-range input entering Ch 1, sending 20 Hz -100 Hz to (CH1) the subwoofer(s) and 100 Hz - 20 kHz to (CH2) the full range speaker. So you would use two of the amps for stereo. one amp for the right channel and one amp for the left channel.
@@LincolnRon Jupp.. I know there are many ways to do it.
I just use the LFE and I can choose the frequenzy range going out to the sub in the recivers menu if I want.
My sub has 0, 90, 180 and 270 degree phase adjust but I had to finetune it on my reciver to get it really perfect. If I did not use the LFE output I could not do that last bit of finetuning and it would not sound that great.
But I don't cut off the front speakers. They are full range 5way JBL TL260 so that would mess up my sound really bad😝 But offcourse that depends on the speakers. But I find that in most cases it's best to let the speakers play full range without adjusting the x-over. Unless it's really small bookshelf speakers.
@Douglas Blake Not even an issue. My phase is perfect. When I use the LFE output but not if I use the pre-out 8r rhe speaker connections.. I can even sit down on the floor just 20-30cm away from the sub and speaker and it sounds like 1 single speaker. Just like it's supposed to do👌 Mostly bass is delivered the same to both left and right channel anyway so.
@Douglas Blake Jupp🙂 That's why it's the best alternative for my setup. And it's a combined home cinema and stereo setup so😎
My integrated amp only has two set of binding posts. One set for L and one for R. Can i also connect my sub to those same binding posts that the speakers are using?
@Douglas Blake yes is has high level speaker level inputs so thats good news. Cheers.
While connecting at speaker level, should i be concerned about my bookshelfs still producing its lower frequencies? My speakers are rated down to 40hz but I reckon it would be better go have the sub do 80hz and lower and speakers above 80. How would i cut off the lower frequences of the main speakers? It is a worthy presuite?
@Douglas Blake Thanks for the insinght. I've read positives of releiving the main speakers of the lower frequencies and other good points why one shouldn't worrie about. I guess I'll need to try for myself. The sub i plan on getting is an Amphion Impact 400. Speakers are Amphiom Argon 2, integrated amp is a Primare A30.1 and DAC is a Hegel HD20. Thankfully the sub has lots of wiring posibilities. If I wanted to try releiving the speakers of the low end, can I accomplish this with my current setup, or do I need a seperate high pass filter?
Fyi...Amazon says the ebook format is not correct. At this time it cannot be downloaded.
I know. Dammit. The table of contents wasn't right and they pulled it. I am working on getting it resubmitted. Sigh.
It doesn’t change the impedance of the speakers. It changes the impedance on the amplifier which will have to work harder. If you add a 8 Ohm Subwoofer to a 8 Ohm speaker the amplifier will see an impedance of 4 Ohms.
I think we are talking about active sub woofers here which are no problem. But yes, connecting a passive sub across a full range speaker would not be a good idea. Not only because the impedance drop but I would also expect the passive crossover in a passive sub woofer to have some negative interaction with the full range speaker crossover. And note that passive sub woofers typically do not have any crossover. They are meant to be run directly from a dedicated amp with some form of line level bass management.
Andy Delle , He is referring to connection coming from the speaker output of the amplifier. It has to bypass the subwoofer amplifier. Check second 19 of the video.
@@FungedeBagre Yes, if connecting an ACTIVE sub woofer with built in amp to the speaker terminals of the main, it poses no negative issues. The "speaker input" terminals on an active sub woofer amp or in fact high impedance. They just use speaker wire terminals as it's easier to connect a speaker wire. Inside the sub amp, the speaker terminals go though voltage divider, then a mono sum, and that most likely ties directly to the RCA jack which is often available for a receiver LFE output.
For the ones who believe speaker cable makes a difference in sound does this mean you need two sets of the same speaker cable? One to the sub and one to the speaker from the sub?
No. The speaker cables to your main system are critical on a highly resolving system, but those that feed the high level input on a subwoofer don't carry current and thus aren't as important.
So you can run subwoofers with valve amplifiers?
Tube amps are for mids/highs. They actually reduce bass frequencies, unless you get super expensive ones.
Sure, and many people do. Valves typically have pretty poor current delivery because they are primarily a voltage amplification device. They don't handle the low impedances of speakers too well and, because they are single ended devices that can't easily be direct coupled to a speaker, are typically are interfaced by an output transformer. These transformers aren't the best for delivering low frequencies and thus, a subwoofer really helps fill in the gaps.
At last I get this answer…
You don't have to learn much anymore you just need to Google it...? The most important thing I learned at college was all that I didn't know.
... the Johari Window, and self awareness.
Upon reading your submission, I immediately thought of both the Johari Window, and Donald Rumsfeld's memorable quotes re: intelligence gathering;
"because as we know, there are known knowns; there are things we know we know.
We also know there are known unknowns; that is to say we know there are some things we do not know.
But there are also unknown unknowns-the ones we don't know we don't know."
Lucky to be alive? Do you think it was luck or was there a higher power/energy that decided it wasn’t your time? If the later, then should you and we be thankful that you are still around?
Thanks for the video, I’m considering buying another SVS SB-1000 to go stereo via the high pass through
I think Paul meant to say "Non-Parasitic"!!!😉
Why is everyone so rapped up with numbers is a bit weired
Douglas Blake sometimes they do most of the time they don’t. Your ears and what you hear is what matters the most . But the people obsessed with numbers always miss the mark and hardly ever enjoy the music because they’re to wrapped up in the numbers .
@@Audiofreak71 Do you have any statistical evidence of that? (just kidding!!)
@@Audiofreak71 Spot on mate
Douglas Blake like I said those that only look at numbers always miss the mark and all the joys of listening to music goes over your head . It’s to bad because listening to music without wondering if this number lines up with that number is so much less stressful. Anyway have fun with them numbers 👍
Rick Morales haha ikr sounds about right
This whole theory doesn't pass the smell test, because it assumes that the subwoofer's built-in power amp is somehow completely neutral and transparent to the so-called "sonic quality" or "sonic signature" of the main L+R power amp when in fact the power amps in subwoofers are just as likely to have their own "sonic quality" or "sonic signature" as any other power amp. IOW, whether Paul's subwoofer connection preference is better than some other scheme is a crapshoot with too many variables to generalize.
@Douglas Blake -- I'm not referring to the impedance issue, about which Paul is clearly correct, but rather to the supposition that driving the subwoofer(s) from the L+R power amp's speaker terminals is superior to other schemes because of imparting the L+R power amp's "sonic quality" or "sonic signature" to the subwoofer sound. Moreover, how much "sonic quality" or "sonic signature" is audible @ 50 Hz and below? Not a helluva a lot, I'd venture -- timbre differences between (e.g.) a contrabassoon and a Fender bass would be in their differing harmonic spectrums, which would show up in the L+R speakers rather than the subwoofer(s).
yeah. the idea doesn't even make any sense. maintaining a signature by passing it through another signature. i mean, hellooooo? did you forget something? can't believe he still holds this belief.
@Douglas Blake of course it won't, it does something more complicated than that... it complicates the system's phase response. every amplifier introduces phase shift. while the main amps already do that once, feeding that amplified signal into the sub's amplifier effectively doubles the phase complication on the sub. the mains are shifted once but the sub is shifted twice, see the problem? in a designer's perspective, this practice is an unnecessary complication that doesn't actually yield anything and should be avoided. and it's a dead end, meaning the problem can't be solved. in a usual set up, if the phases between 2 paths are different, you can shift the phase of one path so they line up. but with this practice, you can't do that. you shift the mains? the sub is also shifted further away as it takes the output of the mains as an input, effectively collapses the 2 paths into one. and honestly, i don't think this practice will get any sub anywhere near seamless integration regardless of other factors.
@Douglas Blake let me explain it this way. the input signal is 0 degree shifted >> to the main amps >> the main amps shift the phase by, let's say 5 degrees >> the 5 degree shifted signal is fed to the sub amp >> the sub amp shifts the phase by another 5 degrees. now the phases between the mains and the sub are 5 degrees off at ALL FREQUENCIES. now the phase control on the sub amp, what does it say? 0 degree - 180 degree, right? there's no -n degree. yes, you can only shift phase forward, not backward. no matter how you adjust the phase control on the sub amp, the mains and the sub will always be off by at least 5 degree, no less. as i said, it's a dead end.
@Douglas Blake 1) the 5 degree is just an example. in reality it can be anything. 5, 180, 360 degree or even more. seriously, dude. are you even listening?
2) uhhhh... do you know what crossover frequency is?
Like this one Paul not a lot, What's the sequel? 99% BS the true facts