DON'T SET AMP GAIN with a DIGITAL MULTI-METER!!!!

[@meade916]

Love your video's! very easy to listen to and understand. I do think i need to get you DD-1+ for Christmas. It's a lot more to that than i think you realize :). FYI: If you want to know how much power your amp is actually presenting to a sub, we have the AMM-1. Not trying to push my stuff on your channel my brother, sorry. I'm just sayin' we have something for everything. Also, i would like to point out that there is a lot more to setting gains than just watching for a light or watching for the wave form to start clipping. Whether it is a DD-1 or an O-scope, the proper procedure when using them should be talked about (because there is important things like gain overlap to consider). I almost ALWAYS tell people to buy and learn how to properly use the scope first and then there is no way they won't like the "upgrade" the (i won't say it because i ain't trying to spam your page with my product haha!) Thanks for the mentions! Watch for an email!

[@DIYAudioGuy]

Hey man, been watching your stuff for years. I've got a few videos coming up in the next few weeks that you might be interested in. 😉 Edit: I'm definitely not trying to discount the importance of the proper procedure. But the real value of the DD1 is that you know for sure what you're looking at. When the light is on you're distorted. End of story.

[@meade916]

@@DIYAudioGuy well i think i want to send you a Plus (DD-1+) that is...because it is a lot more than just a light. The standard issue DD-1 is a step up from a scope for sure. But the plus does so MUCH more. email sent. Thanks again!

[@scottbe1]

Your a legend Steve!!! One of your videos came up when I was watching youtube probably around 5 to 6 years ago. Between you and my father, yall got me hooked into car audio and I will never turn back.

[@catalin94doru]

Oooo man , wish i could buy all your gear , curently i have the combo (dd1 +cc1) , but very hard to find them in europe/romania , and not reallly cheap for us either 😅. Next i wanna have the amm1 ❤️

[@passionatelyloud130]

Wow.. amazing find you here.now.I know from where is coming all the abilities...🙏

[@codyharrelson89]

I can't remember the last time I bought an amp that didn't have a clip indicator on it. Also up sizing the amp a little from the rms actually needed is a good way to stay away from clipping. As far as the "75% rule", you use the oscilloscope to see where the head unit clips.

[@Jpilgrim30]

True and that’s why I like amp brands that are underrated. Buy what you need and get extra overhead built in 😂

[@vimlamanohar5494]

Qa9

[@HifiVega]

My buddy Justin just showed me how to set my gains with a multimeter a few years ago!

[@DIYAudioGuy]

I'm a sneaky bastard. 😂🤣😂🤣

[@mitas3484]

The 75% rule is good if you dont know the output voltage for the head unit, but if you know the preout voltage from the datasheet, you can measure that on the RCA cables in AC on the center pin and the shield. Turn it down just a smidge when its at the target voltage. Then you hook up the head unit to the amplifier, and match the input voltage with the output voltage of the head unit. You can do this by reading the datasheet from the amp manufacturer, and it should have a place it says Input voltage, usually something like 0-4/5v. Then adjust the gain knob for gain, until its in the area of the output voltage for the preout. The simplest way for this is to divide the gain into percentage, so for 5 its easy, each volt is a 20% increment. Again, adjust it down just a smidge to be safe. This allows the amp to run at full juice at max volume without clipping. If you want to match the RMS of the speaker, to the output of the amplifier, complete step 1 to find the unclipped voltage of the head unit, then use the math method of sqrt(Watt*Ohm) of the speaker, to get a rough estimate of the voltage you need to set. Play a 40hz/1k test tone, and set the voltage to around that, and then turn it back just a smidge. After this you should be golden, no distortion, no speaker blown and happy days! If you have no multi-meter, reset the amp gain, turn up the head unit to max, listen for distortion and turn it down until its gone. Then turn up the amp gain to max excursion for the speaker, or until it distorts, then bring it back down until it doesn't and you're golden (Less accurate method though, even compared to multi-meter)

[@DIYAudioGuy]

Yep.

[@Spidamann10]

So if you have 5v preouts on headunit, can you help me with how to set my amp gain or how to test the rca cable. Would I turn my amp gain to 5v? Also I have 500watts x 4ohms= 2000. The square root of 2000 is 44.12v, I should get that when testing the speaker terminals in ac mode. Seems high & especially when he said the same thing in the video. That was about a whole different amp & etc. Appreciate the help

[@mitas3484]

@@Spidamann10 Remember that the watts is not linear, and at high volume you need a lot of voltage for not a lot of extra volume. You should turn the headunit volume at 40hz until you get 5v between the ground and center pin. Then hook up the RCA to the amplifier, with the amp gain turned all the way down. Now turn the AMP gain, still with the headunit set to its max clean voltage, and slowly turn up the AMP gain until you measure roughly 45v AC on the outputs. You can do this with the speakers plugged in, should be fine. If the amp is MORE powerful than the speakers, you will hear them reach over excursion, and dial it down 1.5-2 hours on the clock to leave headroom. If the amp is LESS powerful than the speaker, it will clip before you reach 45v, and in this case you should watch for the clip light and turn it down 2 hours, or when you hear it start to affect the sound then turn it down 2 hours.

[@kewlbug]

Stopped by local shop here just to find out where my deck maxes out, The guys told me they were backed up for a month and it'd be like $100 to do it. crazy. So now I've got the O scope

[@DIYAudioGuy]

A lot of shops don't want to work on your car unless they're selling you equipment.

[@TRONMAGNUM2099]

I think the nicer portable Oscilloscopes on the market are better than the DD-1. I recently upgraded to the Hantek portable Oscilloscope. It has a built in signal generator. The screen is really nice too. I'm now able to input a signal in the amp and watch how the crossover performs at different frequencies. With a scope you can get into repairing amps and other electronics if you want. Way more versatility with a scope.

[@DIYAudioGuy]

Oh cool! I did not know that. That's so much nicer than plugging in a cell phone into the RCAs.

[@jayinmi3706]

On the setup in my car I tried 3 different ways. I used JL Audio's gain procedure with a meter, I used a SMD DD-1, and I used an Oscope. The differences were negligible. Same amps, same everything. I just wanted to see what worked better, and I was surprised how close they all were.

[@DIYAudioGuy]

Exactly! If you avoid brands that inflate their power numbers and stay away from bottom of the barrel distorted junk all three methods are going to get you very close to each other. You got to remember, back in the day, shops would set by ear or use a multimeter. Nobody had a DD1 in 1996, and only the high-end shops would have RTA's and oscilloscopes. Even then they would not use those tools on every install. They would only dig those out if they were up charging a customer on a sound quality installation.

[@jayinmi3706]

@@DIYAudioGuy I've been installing professionally since 1994. I remember. lol

[@natskar]

I actually bought this oscilloscope multimeter of your recommendation last week. Been using it on multiple systems since, works great! I love how I can SEE when it starts to distort, track the voltage, and use my ears to tune amps. Like I might have a good ear and the target voltage might look fine, but the graph shows otherwise, and now I feel more confident off properly tuning it every time

[@DIYAudioGuy]

I'm glad to hear it's working for you!

[@fosterhilton2042]

Been doing it for 25 years. Works good. And damn sure works better than any of the over priced so called amp tuning devices Like SMD AND OTHER NAME BRANDS.

[@DIYAudioGuy]

Good to know.

[@n5yiz]

yep

[@DJDOUBLE077]

For the price difference...no justification

[@preston_the_hoonigan]

For anyone wondering about the “75 percent” idea… you can tune the Pioneer DEH-80PRS at full tilt (100 percent). It doesn’t clip at full tilt.

[@DIYAudioGuy]

That's a great piece of gear!

[@dyslectische]

@@DIYAudioGuy same here. I use a Pioneer 100% no problems . And if the radio clip IT set the radio amp off. I had one time and the reason the radio do this on a music nummer that is over power in the bass. For the rest IT always set Amps on hearing and a coin. Well the old days in the 90's lol

[@martinbubenheimer6289]

I use a below $50 oszilloscope and it works fine. A more expensive one would hopefully have some more auto-adjustment to see automatically a wave or two of the actual voltage and frequency, but it works manually as well.

[@25hztolife14]

A cheap multimeter is a tool only when one knows how to use it. Under or over powered ratings, RMS, formulas, and pen/pencil are useful additional tools. I set my system that way. Something else useful is testing many individual frequencies, see what voltage is good that would not distort, writing it down then setting the gain that way. I did that with RCA Voltage set at it's highest and Bass boost up to 9db at 62Hz, 100Hz, and 180Hz; and the volume at 32. I know I don't distort at all. I don't really use the Bass boost to 9db but I know I can without distortion if I wanted to.

[@DIYAudioGuy]

You are not wrong, it's all about knowing how to use the tool.

[@buitenb]

Cheap multimeters with “ true rms” are not that good . That’s a problem with the higher frequencies.

[@wiradharma7030]

Another cheap option is to use small speaker with non polar capacitor(2.2uf-3.3uf will do) attached to one of the pin. Set gain to minimum then increase until distortion heard(easily notice as it was quite loud) on the small speaker. Edit: then decrese gain until no distortion heard.

[@s1wheel4]

Never thought. Interesting. Nice info bro.

[@LionWithTheLamb]

Yea, that clipping is pretty loud on a tweeter and you can hear it easily.

[@s.o.s.exploration2412]

I did my do diligence when coming back to car audio since my daughter is now into her teenage years. So, I decided to check out as many amp dyno videos as I could to see what companies are valid as well as efficient. Currently use a Maxspeedingrods Android Head unit, Orion XTR750.4 to run my front and rear 6.5"/1" components, and CT-SOUNDS 1000.1D into a dvc 2 ohm ct sounds tropo 10 in a sealed box with 3/4" mdf and proper internal space required by sub wired down to 1ohm for max wattage. All of course powered with a rear Yellowtop Optima battery and battery isolator. It sounds fantastic! Be upgrading to two 12s eventually once I upgrade my components as I'm a SQL guy. 😉

[@DIYAudioGuy]

Awesome!

[@Blue_3is]

I appreciate you making this update vid, but I’ve been using your metod every since I watched that video and I haven’t had any problems! Although I have noticed that with amps that have a clip light, after setting gains with multi-meter it will clip and I’ll have to turn it down just a little bit. Anyways, thank you, I’ll look into an O-Scope! 💪🏽

[@DIYAudioGuy]

Those clip lights are awesome.

[@flaman78]

I love how you circled back on this topic. Great info.

[@DIYAudioGuy]

So many people had questions that I felt I needed to. I think it's important to point out that there are better ways to do it and that sometimes these better tools are worth the money.

[@JohnDoe-mx1sq]

It doesn't really matter if your amp does below, above or right at the rated numbers. The impedance of the driver changes with frequency so you need to set it up for your specific setup and there's nothing on the gain knob that is going to indicate that to you. Also the input level determines how much gain you need to hit a certain power level. Portable O-Scope is a must have.

[@DIYAudioGuy]

For me it's not about trying to make a certain amount of power, It's about not clipping.

[@JohnDoe-mx1sq]

@@DIYAudioGuy well you don't want to smoke your drivers, unless you like the smell 😅

[@DTW-bx2vy]

I just use my handy DIY Distortion Detector to set my amplifier gains. All I used was a small 3" Visaton - FRS 7, 2 1/2" 8-Ohm Speaker, an Audyn Cap - Plus Series 2-Layer Metallized Polypropylene Foil Capacitor, small 5-way binding post, & a project box to put it in. I plug in my Multimeter Probe Wires into the 5-Way Binding Post & connect the probes into my speaker terminals & use a -5dB 40Hz Test Tone Track & get a distorted sound threw the speaker only when distortion/clipping is present. It is extremely accurate & only cost about $20.00 to make.

[@DIYAudioGuy]

👍

[@angryace4017]

The screen resolution on a handheld is not accurate enough to see distortion. The DD-1 and DD-1+ do not measure to clipping, they measure to 1% THD so the systems set with these are very clean. In addition, the DD1+ can be used to gain match as it has a DMM built in. They are expensive for sure but as you pointed out, you can't rely on what MFG power ratings are. My personal system is JL Audio XD v2 series amps. These are rated for 75w @4 ohms and 300w @2 ohms (sub) but in actuality, they put out 100w @4 ohms and 450 @2 ohms. The extra power, particularly on the sub, took the system to the next level. On the flip side, I had customers with cheap BOSS amps come in for diagnostics and they are nowhere near rated power. The good news is, it usually results in an AMP sale and installation labor :D. If you are going to get a DD-1 then get the DD-1+ for the built in DMM function.

[@DIYAudioGuy]

👍

[@SPLaholic]

I have the LM2001 and love it. I tuned my taramp 8k with it, because I didn't really trust the clip LED on the amp. Well, with the o-scope, I found out that the clip LED is pretty much spot on. I now know I can trust it, but, I'll still use the o-scope as a little bit more of a safety measure.

[@DIYAudioGuy]

Awesome!

[@chicken133221]

Thank you. Just bought an Abestop Oscilloscope. New to checking anything electrical. Normally read manuals buy what seems right, connect, power on and go.

[@_BAD_MERC_]

I installed for over 20 years and into my later years of setting amps I used inspectors lacquer that would leave evidence if "somebody that knew better" put a pipe wrench on their gains. Far too many times we'd have launched subs and smoked amps and nobody knew nuthin'! If you've never used it - it's a great way to tell if the adjustments have been tampered with.

[@DIYAudioGuy]

People see a knob they can't help it, they just have to turn it up.

[@tonydize3944]

I spoke before you ended the video I'm so glad you mentioned that dd-1 is not always the best as most of us like the big amp lol

[@DIYAudioGuy]

If you are a pro working in a shop it is a great tool. But not a good investment if you just plan to install one amp every few years.

[@dliriumtrigger]

sound clips didn't give me a jumpscare on this video. i believe one day we can add limiters on old youtube videos. i have an old hamburger phone video that has audio that makes me cringe really bad whenever i watch it. thanks DIY Audio Guy. your videos are most effective in helping me learn about audio amplifiers.

[@ruebarb1]

Thank you, I was able to use the multimeter to verify gain against the built in light on Key 500.1, worked perfectly

[@kingdon5383]

To check for the headunit distortion, you can connect your lil o scope to the pins of the speakers it’s connected/powering to, ONLY if your speakers are not powered by your external amplifier. And turn the your volume knob up until you see it distort on the oscope with its kinked line. One of the BIGGEST problems people tend to do is use the EQ after setting your gains/volume knob distortion-free. Don’t listen to the “make sure to flat out eq, signal, etc”. BEFORE you set your gains on the amplifier or set the volume knob distortion-free, set up how you like your EQ however you like it. For example for me I like lots of treble and lil bit of mids, so I set to +5db on treble and +3db on my mids, it just comes out clearer and cleaner for me it might be different for you. THEN I go to set up the oscope on the speaker wire or amplifier channels, and turn the gains till clipping. Keep in mind though this is only if your power rating between the amplifier+speaker/amplifier+subwoofer combo are matched RMS like said in video. HOPE THIS HELPS!

[@DIYAudioGuy]

The problem is they are using the EQ wrong. You're supposed to use the EQ to cut, not boost.

[@chiefgeek2020]

When you set gains with a o-scope you need to put it in FFT mode so that you can see the harmonics, if you try and lool at the sine wave to set the gain you will surely be leaving some power on the table.

[@DIYAudioGuy]

I don't think the cheap scopes will do that.

[@kewlbug]

Would be interesting to see a video, or your opinions on the DD-1 Manual and using the 0, -5 and -10 tracks. I set everything to 0db and the system just has no power compared to when I just tuned it by ear (the "yup, thats loud enough" method). Also, through research (testing oscope on my headphone amp) finding out Spotify drops -14db if using "normalize volume" and tons of songs out there are rarely at 0db.. Gonna try the -5db track for highs and -10db on my bass tonight. It sounds to me like this is a CRITICAL element to consider regardless of using voltmeter, O-scope, DD-1 etc. Enjoying the audio journey with you. My next rabbit hole is crossovers, as the back of the manual indicates I maybe should be using closer to 100hz instead of the golden 80hz number. Along with further REW tuning after making any changes.

[@DIYAudioGuy]

There's a lot of confusion about 0 vs -5 vs -10. I think I do need to make a video on that.

[@sophiarodriguez1861]

I admire your honesty and transparency!! You're my new hero!

[@DIYAudioGuy]

That is what I shoot for.

[@Drgluee]

I like the Multi-Meter for under voltage. I have 2 Sundown SA 10's rated at 750w a piece, running parallel to get 1 ohm at 1,500w. I have a 2,500 RMS Orion XTR, so I have to adjust the gain to about 38 volts so I don't over power the SA's.

[@DIYAudioGuy]

Yea. I think the DD 1+ displays voltage. So you can use it to make sure that you're not distorted and then turn the amp down to match the subs.

[@Seriosha]

It cannot be emphasized enough that you have to check the specs of your DMM for the Frequencies at which the AC RMS Measurement is rated. If you use a 1kHz Tone on a DMM the result will be utter useless on a lot of Devices. Even a 100Hz Signal can already get you far off from an accurate reading depending on the DMM! Also: make sure that all FILTERS (like highpass/lowpass and Bass Boosts etc) are OFF when you do this - both at the Head-Unit aswell at the Amp. Your Readings WILL be different depending on the Frequencies otherwise, which can absolutely be harmful! And then use a proper 0dB Sine Wave (Tone) at a frequency the DMM is rated for. This is important since a lot of Videos or Tracks have non-nominal Volumes. Note that a later added Bass-Boost WILL NOT be covered by your measurement and could easily push your Amp into Clipping in the frequency-regions the Bass-Boost is affecting! Also: i assume your x10 rule is your way of incorporating losses? Which seems quite high to me. Modern Amps have pretty high efficiency, and since we know that Amps x Volts gives us Watts, i would put that Volt number definately higher, even up to 13,7 which is around a normal cars electric system voltage when running. If you account for a loss of 10%, this would still put you in a pretty safe place when calculating with, let's say: 12. But you're of course absolutely right when you say: Just us an oscilloscope. Because even the crappiest one can easily handle the frequencies which are relevant to audio-applications. Thanks for keeping up the good work for us Audio Guys out there

[@DIYAudioGuy]

Great points!

[@hifi31029]

What if I want to use my eq or bass boost then what? And what settings do I set the lumy to like time and range?

[@kingdon5383]

@@hifi31029 you don’t set your eq flat. If you have stock speakers like me, I like to boost certain frequencies to get the sound I want (I have a JVC KD-X482BT headunit with a 13 eq band). You set your EQ first before dialing your gain because if you EQ after tuning your gain correctly, you’ll be sending a clipped signal to your speakers due to the boost in Db. For example if I boost mid on the headunit to +2db, I’ll be boosting 1khz and few other frequencies too. Since 1Khz test tone is used for tuning speakers, when you go to turn your volume up to the supposedly max unclipped signal before setting eq, you’ll be sending +2Db increase in 1Khz tone or in this case if I were to play music it’ll be +2Db however each song has different Eq frequencies bouncing up n down. So always set your eq if you are going to use it. It’s best to keep it neutral however some stock speakers are not that good at reproducing certain frequencies like mine 👍🏾

[@bigchungus-oj8zz]

You are a “professional” right? I’m surprised you don’t have a DD1. TY very much for mentioning the 3/4’s volume setting when setting gain. I wish that you could feature this dilemma in a video. I’m a big fan, SUB’d awhile back, keep it coming. Peace out..:)

[@DIYAudioGuy]

Nope, not a professional. I've never worked in a shop, I've never worked in the industry. I am a DIY'er.

[@charliefrancis6438]

Never smoked an amp when i used a multi meter to set gains If you’re an idiot you might not hear distortion when your gain is to high , but I appreciate your diligence

[@DIYAudioGuy]

👍

[@MisterEE100]

I think you did a bang on job explaining the differences. I know you like that hand held all in one, but personally I don't think the screen has enough resolution. The $40 hand help oscilloscope is so much nicer to look at and use imo.

[@DIYAudioGuy]

You are not wrong. The resolution could be a lot better.

[@josegiraldez6230]

Yes the $40 or $50 one is a lot easier to see , it has alot cleaner resolution than the Luimy ..But there again the luimy does a lot more stuff.. Steve Meade is right when it comes to the DD1+ and understanding overlap but it is very good to understand the oscilloscope first and learn it well before stepping up to the dd1+

[@jamesr3364]

Easiest method is buy a decent amplifier with a clip indicator! Problem solved. But I did use the equation on a kicker CXA 1800 amp in a friends vehicle worked great and I of course rounded down to be safe! Thanks

[@DIYAudioGuy]

That is a solid strategy.

[@JacesOwnWorld]

Good video. I have three things I want to mention: 1. I disagree with you on manufactures providing the exact rms power ratings. Not every same amp will put out the same exact wattage as one another. One NVX VAD800.4, for example, might put out 800rms x 4 at it rated ohm’s, while another NVX VAD800.4 might put out 900rms watts at the same rated ohm. Just like vehicles, the manufacturer puts out its hp and torque, knowing not all manufactured same year Camaro SS’s, for example, are going to put out the exact same hp and tq. Same thing applies to amps. 2. I disagree with matching an amp rms power to a subs rms power, at their given ohm. I don’t know how many amps I’ve had in my lifetime. It’s a lot. But this I do know, that every single amp I’ve matched to my sub on rms power and ohm’s, has had to be replaced at one point in time. Whether that point of time was one month, or two years, they had to be replaced due to the amp overheating. Why were these amps overheating? Because they were being pushed to their limits too often! And when it’s giving its max energy for long periods of time, just like a gym rat, if he does his max all the time, they will burn out FAST! And an amp does just that. Now, not everyone listens to their music blasted high for long periods of time. So having that matched rms for its ohm’s might work out just fine. But for those of us who do have our music blasting loud frequently, I have found it best to find an amp that puts out more rms power than the subs rms, at their given ohm. For example, I have a Sundown SA-10 D4 Classic, wired to a 2ohm load, and it’s rated at 750W rms (even though everyone knows this sub can easily handle 1200-1400W rms). The amp I push it with is a NVX VAD17001, which pushes 1350W rms @2ohm (it has been test benched to do over 1600W rms @2ohm stable). This amp slaps my Sundown sun hard. I’m only pushing about 1000W rms to my Sundown sun too, and the amp never get hot. Why? Because it’s not pushing even close to what it can. So using a higher rms rated amp isn’t bad imo. But you do have to be careful on not overpowering your sub, and know that your sub can handle the power. 3. I use a NVX VAD800.4 for my F&R Audison Voce components, and have been doing so for 4 years now. I don’t know how many db’s my car reads, but it gets LOUD to say the least. This NVX amp is amazing, and is why I have been sold on NVX amps in general. It also has been tested to push far more than it’s 800rms as advertised, which shows how good the quality of this amp is, especially for the price. I’m an NVX amp and Sundown sub enthusiast for life now. Both are amazing brands! Highly recommend them!

[@DIYAudioGuy]

I have the old version of that amp. Rock solid.

[@russellcrabtree5314]

The DD1 plus ➕️ has 2 great options. You also can see the exact voltage the RCAs are sending. If your head unit specifications say 4v and the DD1 plus reads 3.5v at clipping then adjusting to 4v you are clipping at 4v. If the head unit voltage is actually 4.5v then there is some overhead voltage that needs to be corrected. Big Dummy Math is from from a big dummy and the spade fuses are for internal short protection and not to regulate power consumption. Google it!

[@DIYAudioGuy]

That is one reason why I like to use the DD1 to check the RCA's, that additional info is useful stuff.

[@casey360360]

I have and have had for several years more than 1 DSO shell that I use for work. It’s fairly accurate and has a fast response.

[@DIYAudioGuy]

👍

[@JoeJ-8282]

I would definitely use an o-scope if you know how to use one properly, because then you can see the waveform and see in real time as soon as it starts to change shape from a sine wave to a more square one, (with flat top and bottom peaks, which is then clipping, which is very bad, and so if you see that start to happen then you want to turn the levels back down again until you don't see ANY of that flattening happening on the o-scope screen, but rather ONLY a totally smooth curve), however, if you still don't have an o-scope at all, then there IS still one way to utilize a regular digital multimeter to determine the clipping point of an amp, and that is to put the meter in DC Volts mode and watch for the point where that voltage starts to rapidly go up, because a totally clean (i.e. UNdistorted) sine wave won't show hardly ANY DC volts, BUT at the point where the waveform starts to go into clipping distortion and it begins to get the flat top and bottom crests on it, then those flat tops and bottoms, (the clipping), will immediately begin showing up on your meter as DC Voltage, and you DON'T want ANY of that for a totally clean and undistorted signal!

[@DIYAudioGuy]

That's a neat trick! I'm going to have to try that out. Other cool thing about the O scope, If you've got some kind of problem with the signal you can see it in the waveform. Say you've got some kind of extraneous noise you will see the wave get wonky.

[@Jacobkilowatt]

I bought one of the $30 diy solder together oscilloscope kits off of Amazon and it works extremely well for setting the gains of amplifiers

[@DIYAudioGuy]

Cool.

[@williambiddle4507]

I bought one the same model but it was already put together but I cannot figure out how to work this thing there's no instructions or anything with it just one little manual that shows how to build it any idea if there's any information on how to run this thing

[@jeffhaddow5994]

There is a fuse rating for the JP8 in the manual on the first page, for single use 120A, or strapped together rated at 240A

[@DIYAudioGuy]

I can't believe I missed that!

[@jeffhaddow5994]

@@DIYAudioGuy happens to the best of us! 😁

[@kewlbug]

crazy, Just got mine today! gonna solder up some RCA to 4mm leads and other types of leads

[@DIYAudioGuy]

Nice!!

[@damon323]

Ok, but another video you made taught me precisely to use a multimeter..? Lol! Which I thought is genius because I can set the exact wattage to specific speakers. Not just my subs, but my door speakers as well.

[@DIYAudioGuy]

Toward the end of the video I'll give you some extra tips for using a multimeter. I made this video because I wanted to make a video talking about some of the drawbacks of the multimeter method. The biggest drawback is that people can't seem to do math. If you can do the math then the multimeter will work just fine.

[@damon323]

@@DIYAudioGuy Ok, I can absolutely see that. Whatever tool makes it easiest. But to me, your video showing the multimeter was my favorite. Wish I had know this going back to my 20’s. I was that guy back then that thought the gain was basically a volume knob. Haha!

[@DIYAudioGuy]

@@damon323 Back then I used the "set it about half way" method.

[@decibellx2194]

A VOM works perfectly well as long as you back down about 1.0 to 1.5% on your amp. Ive found that using the pre-out voltage and the AMP specs works well but it ALWAYS (for me anyway) needs to be backed down a percent or so or it still clips.

[@hvcool]

Me getting my credit card ready to buy all the SMDs plus other tools just to work on my system once LOL

[@fuidiehockn4599]

option #4 play a say 100hz test tone. Turn the gain up until the tone shifts... yeeees you can hear that really good. turn back a little bit!

[@DIYAudioGuy]

Setting by ear.

[@jimmyjam5588]

I love the honesty. But you should go more in depth of how much you can do with the o scope, such as resistance, dc volt, ac volts, the capacity, hz that your playing, how to measure the volts on a rca or when it clipping, that o scope is a #1 tool for a diy guy I be glad to help you out if needed

[@DIYAudioGuy]

For sure, these tools can do a whole lot more!

[@xsmatt81]

for a long time i usually just tuned by ear/dmm..its pretty easy on smaller speakers to hear distortion compared to a large woofer. A DMM like you said is helpful say you have a amp rated at 760rmsx1chan (mono) and a sub rated for 600wRMS in my case a RF P3 '12..ahhh yes the DD1!..a friend had one and sold it to me for $50 bucks..he had laying around he was selling all his car audio stuff in this case a DMM is helpful once you find amps THD/distortion that DD1 does. Probe amp output and lower gain to match ball park voltage to the sub. (35.4v * 35.4v)=1,253.16/2ohm = about 620w RMS with a 40hz tone...TLDR this NVS amp i have on my car was putting out about 42volts which is more than rated on rms box

[@DIYAudioGuy]

Now that I've done this a few times I'm starting to recognize what distortion sounds like.

[@bobbybyrkett7751]

Justin it's also important to use an o-scope to gain match say using multiple amps. Great Great video Justin keep up the good work !!!

[@DIYAudioGuy]

👍

[@SpeedOfLight2K]

You can use a tweeter with a capacitor to set your amps with as well if you don't have the money to buy a SMD DD-1 or a oscilloskop, might not be so fancy but it works. (I have both the DD-1+ and a oscilloskop)

[@DIYAudioGuy]

Sam over at barevids has a video on that.

[@cyanidebill]

Good video Voltage X fuse rating Divide by efficiency I use both, get into the ball park then you the scope to find my max…Then you have to use a RTA.

[@DIYAudioGuy]

Thanks!

[@cyanidebill]

@@DIYAudioGuy it’s voltage of the car not watt…brain fart. The efficiency of the amp was the 3rd parameter.

[@DIYAudioGuy]

@@cyanidebill I knew what you meant.

[@sarahthompson6240]

I’m curious to know what the community thinks about using dummy loads to set gains. When you place a load across the amp you will see voltage go down as current is drawn as they are inversely proportional. If one wants to truly dial in their system, wouldn’t this be the most accurate method? I know they are purely resistive loads and will not have the same effect on the amp as speaker which is inductive (constantly changing). The problem with using a speaker to load down the amp is, you run the risk of blowing it by putting a sinewave through it and cooking the coil. Not to mention the neighbors will hate you. Anyways, I’ve just been playing around testing with dummy loads and am interested if anyone has experience with this.

[@DIYAudioGuy]

You definitely get a different result when there's a load on the amp. But, how many people have dummy loads laying around?

[@sarahthompson6240]

Haha. Only the hardcore nerds. Just putting it out in the ether I guess.

[@commonsenseisdeadin2024]

@@sarahthompson6240 i set gains without the load so then I'm close and then i plug the sub in and i check it again and won't have to go far to set it on the load. I have a cigarette lighter volt meter i plug into the car to see how bad voltage drop is. If significant i will turn the gain down until the drop isn't so bad, clipping or not. I only do this on sub amps, i haven't had a 4 channel that drug my voltage down 😂 4 channels i set on music and am usually never near clipping, way to bright to go that high imo.

[@mescko]

@@sarahthompson6240 I wonder if I'm the only other one here who understands the ether reference?

[@Bassotronics]

Thanks. Very important to know. Love all the vids!

[@DIYAudioGuy]

Glad you liked them!

[@Mr.NpK143]

I couldn't wait to watch your video on my new Samsung Fold 3 😁! Great video sir as always 👍 👏. Always simple, informative, precise, and direct. No gimmick in music or fancy captions. I love it! Thanks, and by the way if you'll sell DYI shirts I'd definitely buy a few. Anyways great job.

[@DIYAudioGuy]

I've got a few shirts up on teespring, they should be showing up in the merch shelf below all of the videos.

[@stanmondzelewski9253]

I just got the aukuyee on black friday sale for 38 bucks. Theres several videos about it. Next level car audio compares it to a bench top o scope and a clip light on his amp.

[@DIYAudioGuy]

Cool

[@christiandshatto7765]

Great explanation ( I still use my liumy2001, and it's falling apart, but gets the job done with proper test tones. Real quick, the d4s, jp8 suggests a 120amp fuse

[@DIYAudioGuy]

👍

[@christiandshatto7765]

@@DIYAudioGuy after the holidays I'll probably order the newer liumy, but they appear low on stock( maybe cargo ship issue? Idk). In the future, I'm also considering the dd1+. I like the idea of 'gain overlap' setting 👍🏼

[@DIYAudioGuy]

@@christiandshatto7765 Nothing wrong with upgrading when you can!

[@mrdanomac7937]

A few years ago I got a DD1, mostly cause oscilloscopes are silly expensive where I am. A decent oscilloscope was more than the DD1 even factoring in the exchange. I tested all the head units I had (Pioneer, JVC, Kenwood, Alpine) and only the Kenwood did not clip at full volume with a 40hz track. The Pioneers did, but their max was 62 (from memory) and it didn't clip at 60/62. I bought the DD1 and justified it as it takes out the guesswork and I can crank it all the way up and not blow anything up! I also set gain overlaps, 2.5db for the full range amps, and 7.5db for the subwoofer/monoblock amps.

[@DIYAudioGuy]

Awesome!

[@mrdanomac7937]

@@DIYAudioGuy Maybe if you could get a DD-1 you could do a video about gain overlaps: what they are, how they are used, why they are used and what is typically used to set amps, even if just a starting point. I know others set higher overlaps than I do, I thought I'd err on the safe side. 🤔😁

[@cruzmorales2237]

I also use the DD-1 but adjust the voltage to match the speakers in every channel as per manufacturer, the only thing I had problem when starting this hobby is what signal use to adjust levels. That was 4 years ago until I got the DD-1 and a lot of videos from JL AUDIO, MOSCONI, AUDISON, AUDIOCONTROL, AUDIOFROG, AND LATELY HELIX. THANKS, I thing I got the idea

[@DIYAudioGuy]

From what I gather the DD1 + added a lot of functionality, much more than just a light.

[@DjR3aper]

4:39 for me that would actually be more of a reason to use a multimeter instead of o scope. For example, i take 2 american bass xmaxx 6krms total and i hook them up to a salt 6k on good electrical, i might cook them not know that i'm sending 9,500rms (after rise) watts to them. However if i use the multimeter and set it to a target voltage, i won't be over powering them.

[@DIYAudioGuy]

That's a lot of power.

[@richardwallace5625]

The Rockford amps show clipping from the deck and from the amp, was kind of bad timing to say you need to have an oscilloscope right as you flashed Rockford Amps on the screen 😂🤣 Hahaha no biggy but gave me a chuckle

[@DIYAudioGuy]

Yea, the new prime series all have that feature.

[@davidschreckengost7959]

I have found the easiest way to test! Find the actual voltage with the muti meter, no speaker connected. And run a amp clamp to see what the actual amps are. Then you can figure out what the actual watts are. You have full actual numbers to figure out what is going on

[@DIYAudioGuy]

Power Factor and Impedance Rise kzbin.info/www/bejne/faauYXmCns-Meqc

[@atmosphericpressure3560]

DMM method works. If you are running outside of freq resp or right on the edge then there is a problem. I only have amps the Dereck has ran on the AD-1 so I have ample headroom. Just make sure that your sub(s) are disconnected. Good video DIY

[@DIYAudioGuy]

Thanks!

[@bobadingo]

Set all Equalization flat. turn volume on head unit to maximum and adjust amplifier gain for no distortion and you're through.. .

[@outlawGFXaus]

All that boss talk got to ya huh , lol great vid again dude

[@DIYAudioGuy]

Like a Boss.

[@2knives]

When setting gains, it's important to have the car running. With the car not running, it measures 12.2 volts at amp. With the car running, I was measuring 14.3 volts at amp. When I was setting up my old school Alpine v12 4 channel amp, that 2-volt difference, according to alpine's specifications in the manual, equated to 35 Watts RMS per channel into four ohms at 12volts versus 50 Watts RMS per channel at 4 ohms at 14.4v. When using a multimeter to calculate output voltage it's pretty important to know what your amp is capable at RMS wise in respect to the voltage at the amplifiers terminal.

[@kewlbug]

I could be wrong but I think input voltage might only effect the amps and efficiency of real world watts able to produce, not so much the signal levels. I can't be sure without testing both ways and comparing.

[@olmosbananas]

well yeah, you dont want to run your system without your car on as it will deplete your battery. also 99% of the time you will be listening to music with the car running. and while the alternator charges your battery, your voltage will go up.

[@jasonneal]

On the Fluke O-scope I have and can enter the ohm load when setting the gains. I use a multimeter to set my crossovers.

[@DIYAudioGuy]

Awesome!

[@michaelbloom5342]

You can also use a $5 Piezo tweeter to set gains. Play a 40Hz tone, and when you hear buzzing, back off until the buzzing goes away. Done and done.

[@DIYAudioGuy]

👍

[@henrycaldwell238]

Thanks for all the Videos. I do the same thing and have for years. Was pretty shocked well not really but was surprised to see the AMP fuse ratting on every Taramps amp at half rated power. They do have full fuse rating but only if you play a set tone LMAO!!!

[@DIYAudioGuy]

Not sure what to make of that.

[@wb5mgr]

BTW …if a manufacturer tells you that their amp makes 1500w peak power it is easy to convert that to RMS power. Just multiply it times .707 and that will give you the theoretical RMS number. So in that case 1500x.707=1060.5w which is probably close to what you might see from an amp that claimed 1500w peak.

[@DIYAudioGuy]

kzbin.info/www/bejne/hKayapVnm76cqbs

[@califmike2003]

Need your help please. I have a JBL Stadium 4 amp, 4channel, 4ohm, so 100x4= 400, sq root is 20v. Now when i set my multimeter to AC voltage and stick the probes into the positve and neg speaker terminal on one channel, and play a 1000hz test track at 75% volume, and turn up gain i only get like 2.8 v, nowhere near 20v, whats wrong ?

[@BappaOnyumbe]

your multimeter is not accurate with a 1000hz tone, same here

[@chickenpimp5190]

I prefer to use an o-scope myself. They're cheap enough now there's really no reason to not have one. When I bought my Skar amps I used a multimeter but wasn't sure if I should use the numbers from Big D Wizs tests or Skars ratings. Ultimately I used Skars ratings since my subs aren't resistive loads. Once I got an o-scope I figured out I had a little headroom and readjusted.

[@DIYAudioGuy]

Yeah, they're so cheap now.

[@JWard2]

For the laymen the clip light on the amp is just as accurate & will be just as good as any of these tools.

[@DIYAudioGuy]

One of many reasons why I recommend the JP series of amplifiers. Affordable amp with a clip light? Hell yeah.

[@ElevatedVehicles]

@@DIYAudioGuy so true. Down 4 sound makes great amps. I tested the response time of my JP amp with my Steve Mead DD1 and it was spot on

[@cory7598]

I have a DD1+, a multimeter & a DM-RTA which has an oscilloscope. I still typically use my ears to set the gains. I use a 40hz tone, it's so much quicker and I end up with a similar setting regardless. I'm not bragging about being lazy, I have a DD1, I should use it.

[@DIYAudioGuy]

If your ears work just as good as your other tools then why not use your ears? How is that lazy?

[@cartruck1070]

Lots of good info in this vid. Thank you. 😎👍👍

[@DIYAudioGuy]

Thanks!

[@JoshM7]

After adding DSP I've set up my head unit to use 40/40 volume. I had to stop using the RCA out because of unfixable hum and used the high level inputs on the DSP-408 and 40/40 on the head unit requires setting the volume in the head unit to -16dB to prevent overloading the DSP's high level inputs. So I feel like after doing that any chance of distortion from using max volume on the head unit is eliminated. I have zero noise after doing this and it's nice knowing I can max it out instead of trying to stay at 34/40 like I used to. I feel I do everything car audio related differently than anyone else lol.

[@DIYAudioGuy]

That's what makes it fun!

[@JoshM7]

@@DIYAudioGuy Indeed! I'm going to try out some crossovers I built the other day. I ordered new speakers and I have everything but the woofers. Bought a $7 soldering iron kit and assembled the crossover for them. The woofers are Back-ordered so it'll be 2 weeks before I can install but I'm so excited to try it out in the car. Then I can say my system is really custom. Crossover and everything. (I used Xsim to plan the crossover. In car response will be different but hopefully DSP EQ-able) I tested the crossover with some Polk T15s and posted it as a video on my channel. Next time I might get a bread board or something and make it smaller but it was very fun to learn how to solder and all that. Soldering is easy as long as you're patient.

[@phillipwarner5504]

Used volt meter setup n found I can pretty much crank mine all the way up because I'm only running a 1500d amp on a on a 1200 rms sub set my gain a little over half n it sounds good no need for more

[@DIYAudioGuy]

Ears are the ultimate test equipment. If you like the sound then it is good.

[@johnstarks5323]

An old hack I used to use, On your sub amp, place an 50 - 200uF 100V Electrolytic Non-Polarized Crossover Capacitor in series with your sub. You can actually hear it clipping your subs with out damage. then just set your gains accordingly, for less than $10 bucks.

[@DIYAudioGuy]

So the cap will start to hum, or what?

[@johnstarks5323]

@@DIYAudioGuy No, it takes away most of the current from the signal subtracting the bass. leaving you to hear the voltage from the bass signal and you can clearly hear the clipping if you are clipping. In most cases, the bass can hide the clipping within a signal. This is a cheep hack while your setting your gains. after your gains are set, remove the cap.

[@DIYAudioGuy]

@@johnstarks5323 OK, I get it! You are using a high-pas filter so that you only hear the high frequency harmonic distortion.

[@johnstarks5323]

@@DIYAudioGuy Yep. I still use the active (electronic) sub woofer cross over. but use a passive high pass capacitor in series with the sub-woofer. so i can hear the clipping with in the voice coil. with out all that bass energy masking audible detection. it's just a crude hack that I discovered in the 1990's

[@ganeshnarayan5505]

Hey Justin thanks for sharing this video.

[@DIYAudioGuy]

Thanks for watching.

[@vinsonwalton28]

Accurate numbers are very important.

[@cromagnon305]

I feel that using a dmm is possible but you should probably use a 60hz tone as the dmm a/c is probably optimized to sense 60hz ac but I could be wrong But an oscope is definitely preferable

[@DIYAudioGuy]

I like to think of the multimeter as a 75% tool. For 25% of the money you can get a tool that will do 75% of the job. If 75% is good enough there's no need to spend the extra money.

[@commonsenseisdeadin2024]

A DMM is not limited to 60hz for mains power. Usually its bandwidth is up to 300khz or around there.

[@xtv007]

$200 for a one trick pony is a tough nut to crack but the DD-1 is fast and very accurate. If it will save that $201 amplifier, then it was worth it. I have at least one amp in each of my vehicles so I'm protecting my investment and consider it money well spent. I also use the dummy math for my amps and amps ratings. 10x the fuse rating is close enough to the efficiency loss of class D amps to be safe.

[@DIYAudioGuy]

Yes, worth it if you need to set up multiple amplifiers.

[@mikestivers8302]

@3:35 perhaps, but there are so many vids of people testing amps on their dyno, just look up your amp to see what the actual 'certified' output is. *also i have a new CT amp and there is NO gain control for the rca input voltage, so in this case, the a/c voltage test at 75% volume works just FINE. **my humble components and 1 little 8" sub are loud enough that i can't justify endangering my ear drums - it will play louder and cleaner than i'm willing to turn that dial..

[@commonsenseisdeadin2024]

With the black probe on the shield of the rca and the red probe on the prong, oscope will show you your sine wave all the same. If you have a bnc connector found on oscilloscopes then buy a "RCA female plug to BNC male jack adapter" and easy as plugging it in. For the price of a dd1 or even a little more than the lummy i suggest a Hantek 2d42($150) or 2d72($199). Its a multimeter, 2 channel oscilloscope and a waveform frequency generator. Very quick and much nicer than the lummy. I don't see the dd1 being any easier than my oscope not to mention on bigger systems or when your system is tuned lower than 40Hz, the dd1 isn't a good tool to use as if tuned to 40, you might be clipping at 32 where box tuning is. Oscilloscope don't care what frequency you play, it will tell you frequency, voltage + and -(which half bridge amps run negative voltage down running a plain of 0v. IE 0v down to -100v up to 0v up to +100v down to 0v. Full bridge runs all positive IE 200v rail then it will run a plain of 100v, drop to 0, back up to 100v and up to 200v back down to 100v.... Fyi)

[@DIYAudioGuy]

I've got a pair of RCA speaker adapters that I use anytime I need to probe an RCA. Very handy thing to have on hand.

[@user-sh5dy5tr9d]

I have a friend that I think can help with this. 👍 I've seen reviews and tests on my amp (Pioneer D9705) that shows the specs are accurate.

[@roadlife9312]

Used a meter and o scope in the past .brought a dd1 makes it a hole lot simpler. Upgraded to a dd1÷ like it even more ...got dd1 for sell if interested

[@DIYAudioGuy]

I almost talked myself into a DD1+

[@roadlife9312]

@@DIYAudioGuy you wouldn't be disappointed. It does so much more..I do some installs and a lot of troubleshooting. It was worth the investment

[@kewlbug]

So this is odd, Did my Alpine HD149BT. I still had a channel plugged into the dsp but turned down. With a 1khz 0db You could clearly HEAR the distortion start exactly from 27 to 28 on the volume But the wave looks great all the way to 35 (max) scale adjusted to fill the screen and everything. When I ran it through the DSP too (dsp not even turned up high) you clearly see the wave form develop a weird "dent" at the 27-28 mark. Validating what I heard. really weird.

[@DIYAudioGuy]

I have a pair of Kenwoods for my mids and highs, they emit a high frequency hum when clipping.

[@Bennybenyt123]

Hey man, keep going!!! I love presentation and video dimensration , if that's spelled right.. as a new guy I need help too . I watched the enclosure then freaking bought crap now I'm putting it 😤 it back rt .so with out going any further can show you what I have 3 15s Memphis mono Amp for 1 kicker driver

[@DIYAudioGuy]

If you're anything like me then projects are never actually finished.

[@rrod0589]

@DiyAudioGuy I'm a subscriber on your channel I really enjoy your content thank you for all the information,tips and reviews. I'm having trouble adjusting my sound system. I kept the stock factory radio, tapped into the rear subwoofer to get the signal for the Loc NVX XLCA2, Leige Audio LG-500.1D hooked up to a 10 Kicker solobarick L5 wired at 2-ohm. My question is did you have to adjust the loc like the amplifier !😂

[@DIYAudioGuy]

Yes, that loc has a gain control. If you check the manual it will tell you what voltage it can output. You can use remote to read the voltage coming out of the RCA's.

[@srtfourtom]

Hey man, please correct me if I'm wrong. If you took a multimeter and set it to dc millivolts and put the leads on the amplifier output and testing with a sine wave. I would think that the reading would be zero until it started clipping and then would read dc volts as soon as it started clipping?🤔

[@schaefertribe76]

It seems like you could use the same multimeter method and formula to first find your clip volume on the head unit? …if 75 or 85% is kind of an arbitrary number… or am I reading too far into this? Would this be beneficial prior to setting amp gains in order to get a more accurate voltage reading and gain adjustment on the amp?

[@chichidouglas5078]

I use a piezo buzzer. They won't work for mids or highs though but for that I made a distortion detector that cost $20 to make. It does the same thing as the clipping light on some bass knobs.

[@DIYAudioGuy]

Cool!

[@chrisbennett8538]

I used one just like your video said sounds great set with a multi meter

[@DIYAudioGuy]

Yep, it works fine.

[@sermac3246]

Love this channel👍

[@DIYAudioGuy]

Thanks!

[@miketucker5997]

Great video. Keeps things simple. However, two observations. While RMS power is certainly more honest than “Peak” or “Dynamic “ power ratings, it really needs to be stated with a specified total harmonic distortion value. 400W at 2 Ohms at 10% THD is already in clipping. Look for 0.5% or less. Second, you already had an oscilloscope based on a prior video, and a pretty decent one at that. There is a built in oscilloscope function on the DATS.

[@DIYAudioGuy]

A lot of home audio gear, especially cheaper stuff will list their power at 10% THD.

[@miketucker5997]

@@DIYAudioGuy As I mentioned, at 10% THD the amp is already in hard clipping. My Dynaco ST-416 is rated 200W per channel, both channels driven, at 0.25% THD. But then it is a BIG amp, 19” X 14” X 7” tall and weighs 53 pounds. I always wondered about power ratings of car amps, didn’t seem possible to get the rated power out of such a little chassis.

[@natskar]

@@miketucker5997 different class probably, class d amps are much more efficient and can be smaller

[@mescko]

@@DIYAudioGuy They didn't used to get away with that. Back during what I call the golden age of home audio (when my Sansui 9090 was made) power ratings were much more stringent. Minimum continuous power ratings, and amps had to run for extended periods, and power supplies had to be up to the task, the main reason receivers like my 9090 are so bloody heavy. It's half transformer! And they were not cheap, you plug the purchase prices then into an inflation calc--Shite! I used to have a Kenwood KR-9050, the biggest receiver they ever made--200w/channel @ 8 ohms continuous, with only .02 % THD. it weighs 52 lb. The original owner thoughtfully wrote in the owner's manual how much he paid for it in 1981. $1150. Today, over $3500.

[@kewlbug]

People should know, setting the gain coming from your deck isn't always so straightforward. We try to use a 0db track to see where the deck clips, but most all music out there doesn't hit 0db. Most mixing shoot for -6db I believe. If you are using volume or audio normalization on Spotify, you might even be at -14db! Theoretically, you could set to a -14db track and always leave Normalization on (Spotify), or use a 0db on Spotify. But I do believe you're losing some dynamic range (If you care about that). Myself, I think I'm gonna try a -5db track on my Head unit, -5db on my 4ch and -10db on the sub amp. I don't wanna leave some juice on the table. Let me know if you think I'm wrong about all this. EDIT: I see now mastering might actually be -1db target.. Still things to keep in mind when setting everything. I found the max 0db level on my head unit, but some music tracks definitely can go beyond that. I am guilty of going a few clicks up here and there.

[@DIYAudioGuy]

Definitely a lot of debate about this. As you say the difference is in source material can be highly variable. I always try to point out the pros and cons and talk about the methods and the background, then leave it to each individual to decide which test tone to use when setting gain. One thing that you'll also notice is that older music is quieter. Over time the sound engineers that mix the music have gradually been bumping up the volume. You will definitely see this in both pop and country music.

[@maniacalmonster2293]

Yeah you can use a multimeter to find the clipping point of a head unit also. No expensive tools needed. Just find a specs for your head unit and find voltage output which is usually around 2v for good amount of them. And what you do is you probe your RCA themselves to get the voltage coming out of them you would want to turn your stereo deck at full volume or low volume and probe one of the RCA cables with the black probe from the multimeter on the outer metal part shell and the red probe on the inner inlet connection. And just turn down or turn up your head unit until your multimeter his reading that voltage output for your head unit. So say that comes out to volume level of 25 when your multimeter is reading at 2v that would always go down one notch volume less than that just to be safe if you don't have an oscilloscope 😁

[@DIYAudioGuy]

Yep

[@mikeriverajr4447]

you defintiley can use a multimeter, it is especially safe when the amp is much more powerfull than the speaker because then you know its always clean, also, distortion is almost always audible so if you hear it back of it

[@DIYAudioGuy]

For sure.

[@bigchungus-oj8zz]

I hate to say this, but I have to. I think that the gain setting methods are all flawed next to using a DD1. Most of the parameters are best guess’s and until you take the gain to clip, you can’t know how close to maximum you are. Even with a DD1, the test tone is actually a guess along a spectrum and is the test tone “lossless”quality? Is this a fair representation of the music that will be played? Another gray area to me is when string gain, why would we flatten the equalizer? If we set gain with a flat eq then apply the smiley face curve, haven’t we in essence just turned up the gain. Drives me crazy.

[@rz9708]

Definitely recommend the dd1+ it's worth every penny.

[@DIYAudioGuy]

It is definitely on my wish list.

[@olbluetundra881]

I have used my fluke for years to get close then use my oscope to fine tune. Compared it to the clip indicator on my taramps and skar amps. It's pretty close. For the average person. The cheaper multimeter will get the job done. Let's face it. Most people don't spend thousands on a little bump. None of my systems are below 8k rms so I use the scope.

[@DIYAudioGuy]

Exactly, the $ spent on tools should be proportional to the $ spent on gear.