How to tune an amp with just a multi-meter in 5 easy steps!
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- เผยแพร่เมื่อ 19 มิ.ย. 2024
- If you don't have fancy equipment then this is an easy way to tune for both bass and mids and highs with just a simple multi-meter. You can pick up an inexpensive multi-meter to do this with on Amazon or Harbor Freight for under $10. Follow these 5 easy steps and you'll be in a better position to preserve your speakers vs just an ear tune. Of course, using a scope or a SMD DD1 is much better but this is a cheap easy way to tune.
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Thanks for the clear explanation.
now this is what you call an alternative....thanks for the effort and the info itll be a tech saver.....thanks again
Thanks!!
Thank you that really helped. 👍
Glad we could help
Also if you’re amp has a clipping indicator should you still use this method to ensure power is set correctly?
Can you turn the bass boost via remote knob up and down after this method?
I’ve seen people use .707 with the volts after sq root does it work ?
Would you set the ohm for what the speaker is rated or the ohms that you would wire them?
If u have a dual voice coil or multiple subs. Use the final OHMs(impedance) that goes to the amp after you wired the subs
For the AC do I set it at 200 or 250 ?
You should compare the dd1 vs the multimeter to see how close they can get
Do you set the crossover first before setting the gains?
Also, what if you run a DSP before the amplify? Will you set up a DSP and you set up all the crossover points and sum signals.
But I set up the DSP set my summing signals set my channel paths and set all my crossovers then adjust the gain sensitivity on the amplifiers? It’s simple to do with my JL audio or D 900/5 because it has a clipping indicator.
But if I run my DSP set all the crossover points do I have to turn the subwoofer crossover point off and the set the inputs sensitivity on my subwoofer amp? Or can I keep the crossover setting done in the DSP and still set the gain sensitivity on the for amp ?
It's best to adjust all of your settings to how you like them and then adjust the gain on your amp(s). But keep in mind that you're locked into those settings because that's what you set your amp gain/voltage point to.
Sorry if I sound dumb but how about if I’m using 2 dual 4ohm subs wired in series parallel at a 4ohm load each sub is 250w rms , would I be doing 500x4 or 250x4
If you have two 250w subs that are 4ohms each, then wiring them in parallel would give you a 2ohm load... ...so you would use 500x2... ...which equals 31.623V (i.e., AC VOLTAGE).
If you have two DUAL-VOICE-COIL 250w subs that are 4ohms each voice coil, then wiring them in series to give you 8ohms for each sub and then wiring both 8ohm subs in parallel (on the amp) would give you a 4ohm load... ...so you would use 500x4... ...which equals 44.721V (i.e., AC VOLTAGE).
Ok, I have a Sony XAV 5500 head unit. Set my subwoofer level to max and then adjust my gains? Or setting the subwoofer level is only for the Alpine Head Units? I'm am basically a noob that is just trying not to cook my subs.
Yeah I think on the Sony it’s attenuation so set to 10
My sub is super under rated at 1500rms but most people put 2000 to 3000rms to it for daily. So do I still use 1500?
I'm a little late to this so you may have figured out by now, but if I were you I'd still use the 1500, they say that for a reason so unless you don't care to blow a sub or two, I'd stick to what they say, most people may have gotten a "golden" pick but others may not
I have the skar dual evl 12s, and the amplifier rp 2000. Do i do the square root of the amp watts rms which is 44.72 or the subwoofer rms which is 2500, and the square root of that is 50 so when i have my meter on the speaker terminals do i use 44.72 or 50, i see people say its the rms of the amp
Evl is 1250 rms 2500 max
@@kmcmuscle9973he has 2
Since your amp cannot put out 2500 tune to amp to avoid distortion
after setting gain if you would like a 80hz lpf how would you know when its set to 80hz? or any crossover without a cc1:) thanks!
To answer your question if have a crossover on the headunit use that because you can get the accurate setting, if you’re using the crossover on the amplifier, normally it gives you a range and you kind of have to gauge it based on the numbers. So you can come close to 80hz but not accurate. But if you don’t have it on the head unit, don’t worry it doesn’t make a huge difference if let’s say you end up at 85 Hz versus 80hz.
1. turn off crossover
2. play your 80 hz test tone at normal level (just enough to get reliable voltage measurement at next step)
3. measure output AC voltage, lets say get X
4. turn on crossover and dial knob until voltage decreases to X * 0.501 (if your amp crossover is 12dB/octave slope)
example: you measure 8.4V at 3rd step, so you turn knob until you see 4.2V
constants for other slopes:
6 dB/octave -> 0.708
12 dB/octave -> 0.501
18 dB/octave -> 0.355
24 dB/octave -> 0.251
so for dual 2 ohm with 1 ohm at box terminal should just rms of sub times 1?
Correct
You set for one mid.
If you have 2 on a 2 channel amp
I'm guessing you need to double the voltage figure ?
No. The gain knob is adjusting each channel the same amount. Each channel has nothing to do with the other otherwise. Think of a multi-channel amp (2/3/4/5/etc, doesn't matter) as if it's a bunch of monoblock (1-channel) amps stuffed in a single box with one linked gain knob that controls them all equally. The math is the same regardless of channels, and the resulting voltage will thus be the same. The voltage you see at one output will be the same across all other outputs.
Do as the video says on one channel, then move the multimeter to the other channel to verify. The reading should be identical (or very very close to it, accounting for any slight production variations between the same electronic components used in each channel, such as the transistors. There's always a small tolerance in these parts). If you want to be anal about it, do the adjustment again for the channel that reads the highest so you know that all others are safely below the max allowable setting. This will allow you to dial out those slight tolerances so they can't negatively affect your gear over time.
Hope that's helpful :)
Mp3/flac/ wav file format for car audio?
My subwoofer has a 4+4 ohm 500w rms value. Should I set the multimeter to 31 volts or 44 volts?
Wire your subwoofer in parallel.
Then it will become 2ohms
500x2= 1000
√1000= 31.62 volts
To set my gain for my Subs. I have 2, each at 150 watts. Do I still value my amps output for 150 or 300 watts? Sure could use some help.
You add up all watts that you want your amp to produce (in total). In your case that would be 300w.
Do the speakers need to be unhooked from the amp when tuning the mids & highs with the multimeter ?
yes
you want to run your engine, so alternator is feeding the highest power to the amps. disconnect the speaker wires!!
@mikestivers8302 how come I cannot get a stable reading for my amp[subs]...but I can for my highs[amp]....the reading for my subwoofer amp is all over....yet when I get the reading for highs amp it's stable 1.1...1.3..1.5...2.0...etc??
are you in the A/C Voltage setting? those look like fluctuations from listening to music..? use a test tone at 50 hz. i just did 2 amps, run engine, do the math, and get the gain turned until you hit target voltage. keep in mind, if your SUB say's it will handle 500 watts but your AMP only puts out 250, test the math for 250.@@luisparamo9402
My speaker+tweeter in parallel has a final impedance of 2.66. My amp is 40w@4 and 60w@2. Would my equation be v=2.66•40 squared? How do i know how many watts to multiply 2.66 by?
it is 2.66 ohm resistance to DC. Tweeter has very high impedance to lower frequencies. Calculate with speaker impedance (i guess 4ohm) only. Tweeter also must at least have series blocking capacitor
Are we suppose to use these same steps to set bass boost ?
Never use any loudness or boosts of any kind on headunits or amps.. all it does is muddy the signal and clip
What if it doesn’t and it sounds good. Still say no to using bass boost??
Why don’t you use a -5db test tone for the mids and highs and a -10db test tone for the bass. If the amp is bigger than the subs using a -7.5db test tone would be best. Using the 0db test tone won’t get the full potential of the amp. Most of the songs aren’t even recorded at 0db anyways.
What if you have 2 350 rms 4 ohm wired in parallel so 1 ohm is it 350x4 or 350x4 and then doubled ?
No it would be 700 x 1 I believe so 700 rms total.
First off, your impedance math is incorrect. 2 x 4ohms paralleled isn't 1ohm, it's 2ohms...
i have jbl stage a9004 running 3.5inch in dash with hpf on and midbass in doors with lpf on in doors. i have high level inputs from DSP to amplifier.
the issue i am facing is that if i try to adjust the gain from DSP then the AC voltage on speaker outputs does not change on the amplifier. The strange thing is that left channels from amp shows 14.4 volts and right channels shows 33 volts.
wondering what could be the reason?
Ok sounds like either the amp or the dsp is bad. I’m guessing DSP since there is no output change when you try to adjust the dsp.
1. Try to bypass the dsp and test the left and right channels against each other to see if they are different. You can bypass the dsp by just hooking up your phones output with a cable that converts into an rca. Or any other source you can plug into the amp. If you still have the problem it’s the amp if you don’t it’s the dsp. Hope that helps
@@BreakersStereo yes, actually DSP is fine, the problem here is the high level inputs in the AMP are acting weird. i tried the RCA input in amp and L-R channels are fine.
while using the fader in the HU, Left and Right are ok.
so, now running from DSP to LOC to Amp.
Thanks for your advice.
My subwoofer is 600 rms dvc4 ohnm. Does that mean 600x4 then square root of the total?
Yes
@@karjalakat6139 what if you have 2 350 rms 4 ohm in parallel is it is it still just 350x4 or 350x4 then x2?
watever your going to wire it down to your amp is your final impudence.. if you go wire your 4 ohm dual down to 2 ohm at your amp then itlle be 600x2 if your not then x4 . again watever your last ohm is going in to your amp
How do you tune a 4 channel amp that runs a sub as well as 4 speakers- thanks
Not a good idea to run a sub on a 4 ch amp unless you have a 5ch amp to do so. All car subs do not need NO VOCALS coming out of a car sub
Ya don’t run subs off a 4 channel just buy a separate mono amp or get a 5 channel
On the subwoofer voltage you said 31. Then you set it to 3.1, I assume the decemal is in the wrong location on your math. I needed 34, but my amp maxed at 14. So i set it to 3.4
31 is the right Number, you may need another more powerful amp to reach the voltage of your subwoofer, subs need a lot more power than a speaker
@@descargasism ok.
you set yours to 3.1, so kind of confusing lol
Do I disconnect door speakers to do this there running off aftermarket double din
You don’t have to just set the crossover to the highest settings on the front and rear channels on the headunit so you don’t damage them
Are you doing peak watts or rms watts
ALL RMS WATTAGE ONLY. Remember there is no such thing as PEAK WATTS
@@________GHOST________ Thank you. been looking for this answer for awhile!!!
My speakers say 100 rms on box. So times that by 2 and get square root?
What is the impedance ?
How do you turn the crossover off on an amplifier?
Lowest number if its the hpf only and highest number if its lpf only... most amps have an option of hpf/lpf/through on the crossover selection, in this case, set it to "through"...
Most mono amps do not have an option for off. So what most people think is off is really setting it to Maximum. That's not really off its more like full open. To be honest, I'd do the gain setting with it full open and then again with it set to around 80hz and see if you get same results (same spot where the gain ends up being)
And what happens when you tune your amp but your parking sensor goes incredibly loud? Can't find a solution
See if there is a setting in the vehicle control center that adjust the sensor volume.. what kind of vehicle do you have?
@@BreakersStereo I have a Peugeot 308 allure 2016, I've been checking in the menu but there is nothing about it, may I can get a scanner or something?
Why not set it to hpf?
The radio? Yeah if it has it yes set the hpf
He forgot to mention to use the power output number you want. If you amp does 200 watts rms but you only want 75 watts. Use 75 watts in the equation.
I think he was referring to how much the speaker can handle not the amp
Why turn the bass all the way up on the head unit
Idk
So that you set the absolute maximum output signal that the system will ever see, and set your gain based upon that. If you set your gain with a lower input signal than what the headunit can be set to output, then at some point in the future you or someone else happens to turn that bass setting up, you'd be overdriving the sub because the output gain of the amplifier will have been exceeded with a higher input signal than it was originally set for.
It's a safety measure, as well as guaranteeing that you are setting the system up for it's maximum potential. Once the gain is set up with the bass at max, you can turn it down to where you typically want it, and still have the ability to turn it up if the need arises without overdriving your gear.
Is it 500 peak or rms should be a little more specific my guy smh
I think RMS
This went a little too fast. Couldn’t follow along lol
I add these videos to a playlist for DIY then I go to speed settings and slow it down. This was real informative but I feel you on the speed.
so i need to turn up the sub level all the way up on my alpine cde 143bt and then turn the gain up? i set it up with the sub level at zero, did i do that wrong or is it ok?
Set volume on your alpine radio to 31. Then turn your subwoofer level on the radio to all the way up to 15. Then set the gain.