How reliable is setting gain with a multimeter?

[Weigel21]

I'm not saying one's ears are a "better" way, but that it can be as effective. The DD-1 has had much success among users, but has had it's fair share of issues as well. My biggest gripe with it however is it's price. I can't see it costing more than $10-15 to make each one of them (given they are supposedly built by hand and not mass produced in an assembly line). I'm betting my estimate is high if anything, and even with the R&D put into the building of it, I can see why it'd ever be worth more than $100.

An O-Scope is nice, but they can be confusing to use, to my understanding. Again, never used one and no shops in my area have anything to effectively set gains. Their installers play music to set the gain, I've asked. Test tones are more effective, at least they have proven so with my ears. I've played with using music ran through Audicity (spelling?) and found the recording level and used test tones of the same peak recording level. It was quite difficult to hear distortion with the music and it wasn't until the signal was fully clipped that I could hear any real change. The test tone was much easier to hear a change in.

Did a quick Google search and while this guy says it allows you to detect when clipping begins, not distortion, it shows that such a method is quite accurate as he uses a DD-1 and an O-scope to confirm.

[_paralyzed_]

One of the main reasons for setting gains is so we don't damage equipment.

This guy (Weigel21) uses test tones, which by his own admission, might damage equipment.

Isn't that like giving a suicidal man a loaded gun to distract him from being suicidal?

[CleanSierra]

Weigel, I could find tons of videos of people doing all kinds of shit the wrong way on Youtube. From putting up a, Christmas tree, to ghost riding a car, to how to properly curl your hair with a curling iron.

Setting gains WITHOUT KNOWING WHERE THE SOURCE(head unit) distorts, makes the DMM method invalid for setting gains and wrong. I know it's worked for you and that's great news. It's not at all the RIGHT way to do things and if you don't understand that, I'm sorry.

As far as the cost of the DD-1. I'm rocking 2 amps that are roughly $1000 each new. A $140 tool that allows me to set the gains properly is a worthwhile investment. If you think the device only costs $10-15 in parts, I'd challenge you to create a similar product that does the same job and only charge half what the SMD tool costs.

[MrSkippyJ]

Whatever. I've used test tones for setting gains for a few years now without ever having any issues. Seems to work out just fine for me and everyone's install I do. Some day I may finally get my hands on a DD-1 or O-scope and check such for myself, but thus far, I seem to be good. If you guys wish to suck Meade's cock and bloat about the DD-1 so much, go for it. There are much cheaper ways to effectively detect distortion.

So you have no actual data or testing to back up what you are saying. Gotcha.

I too have never blown up any equipment and have only recently started using any tool at all to set my gains. The thing is, I did set it to where I thought it started sounding bad. I was safe, never blew up anything. Then I discovered via the DD-1 that my source was way too low, I turned that up, reset my gains accordingly and actually gained on the term lab and ear-o meters. I never knew I had so much more I could get out of my system safely until I had a tool to help me.

[Weigel21]

Yes, new speakers and subs being exposed to full rated power or worse yet, clipped power, for any extended period of time could damage them. Setting gains with a DD-1 and O-Scope, I doubt many leave a driver wired to the amplifier, but even still, if they took 10 minutes to set the gain using either, jumping from just under clipping to clipping trying to find that sweet spot, damage could potentially occur to the driver wired up.

Hell, even setting the gain with either of those and then just going flat out with the system at full unclipped power with new drives runs a high risk of damage occuring, so how could I ever claim that setting the gain with the drivers attached runs no risk whatsoever.

[MrSkippyJ]

there is no reason to set gains with the drivers connected.

[Weigel21]

That video doesn't show the way I've done things, but it was the first one that popped up showing anything close with any sort of backing via other tools.

I have used test tones to find where it seems the HU's internal amplifier clips, which is going to be lower than the Preamp outputs, but I don't do system for comp to where an extra .5dB in clean output is dire. I then set the gains for the sub amp and full-range drivers (if applicable) using test tones as well. Do I get the most clean output possible with such, no, I doubt I do. However, I have faith that the output produced is clean and unclipped.

[Weigel21]

That video doesn't show the way I've done things, but it was the first one that popped up showing anything close with any sort of backing via other tools.

I have used test tones to find where it seems the HU's internal amplifier clips, which is going to be lower than the Preamp outputs, but I don't do system for comp to where an extra .5dB in clean output is dire. I then set the gains for the sub amp and full-range drivers (if applicable) using test tones as well. Do I get the most clean output possible with such, no, I doubt I do. However, I have faith that the output produced is clean and unclipped.

Not one I've installed a system for, not even myself, has used the volume levels I use when setting the gains as all find a comfortable output level before such. Well, I have gone up to my gain setting level before to show off for a few people as to how loud my system can get in my personal car, but don't get anywhere near such daily.

Again, this is a community full of people into competition, so i should have learned by now that many in here have spent thousands to run ungodly amounts of power all in seeking the highest SPL they can with what they've got.

For a daily commuter with a humble system looking to just satisfy themselves and are not looking to have the neighborhood hear their shit, the method I've been using has worked and I'd be more than willing to test any install I've done with a DD-1 or O-scope to see if it is in fact clean output. I have no doubt they would be, but being set for the maximum clean output, that I won't dare claim.

[Weigel21]

there is no reason to set gains with the drivers connected.

With a DD-1 or O-scope, no, I see no reason for such, but I'm not going to say that someone out there hasn't done such.

With the method I use, one has to have the drivers wired up though.

Some day, I could see even the DD1 and O-scope being said to be inaccurate, but for now, they are claimed to be the most accurate way, so long as the one using them knows what they are doing and the equipment isn't faulty.

[MrSkippyJ]

i have competed, in my almost 20 years of having systems in my vehicles a total of 3 times. I don't use it to gain extra dbs, i used it to get the max out of the equipment I bought. Why would I spend money on a 1500 watt amp if I didn't plan on using it to it's potential? To your point, sure anyone can set stuff low enough that they are sure there isn't any clipping but why?

Also, why would their accuracy change?