Sub distortion

Did all that. Adjusted to 24 v and now I barely have any volume from my sub... even with the gain on sub turned up to +12 db

 

That sounds correct. The sensitivity on the sub you chose is only like 86dB @ 1Watt, and I'm sure the tiny enclosure design isn't helping.
Now to properly correct, you would adjust all the other speakers' gain down to match. Use the pink noise generator we were talking about.

The volume knob will probably be turned up relatively high compared to what you're used to afterwards.

Put the gain back to 0dB, that's just going to complicate things... unless it was +12 when you did the measurements.

 

So all eq adjustments on head unit/ bass boost etc is just going to mess with output voltage on the amp again? This POS Sony head unit I bought has very little in the way of speaker adjustments. I don't know if adjusting the speakers gain all the way down is even an option. This is a good exercise is setting up though, I'll dig in again

 

Well yeah, setting sensitivity on your amplifier input is setting the max threshold without distortion. If you boost or turn the volume past where it was set when you calibrate the input, you are increasing the voltage and introducing distortion.

I’ve kind of skimmed through this thread and it looks like everyone is just getting around to the realization that the equipment you are using will not meet your expectations. Likely what you will need to consider is adding another sub driver and more power, or replacing the one you have with something that can handle a lot more power, then add a lot more power.

You are going to want a sub/amp combo that can reach 10-12dB higher SPL than all of your other speakers combined. That’s what the typical house curve looks like on a tuned system.

 

Excellent point @dolbytone . I’ve experimented with a lot of car stereos over the almost 30 years I’ve been doing this. Two things. I know enough to be dangerous, and one sub sealed is not enough for me. Correct me if I’m wroung, but adding a second sub increases db by 2 or 3 db. I’ve also found “power”. I have 2 4ohm DVC subs and I’m putting 1200W to both of them, 600 each. Correct my statements if I’m wrong @dolbytone and @treyus30 .

*edit*. @Yzx'er , you might want to consider a vented box as well. They are bigger, but increase the volume of your current sub. Trade off is you lose a little sound quality for the gain of volume output.

 

There are factors but basically yeah.

As an example for sealed vs. ported, I’ve got sealed 2 10” in my Tacoma and my buddy has a ported 12”, we are running the same JL HD900/5 amplifier which does 100W/Ch and 500W sub. It’s barely enough power on my setup and he has as much sub as I do. Running ported is just more efficient in most cases.

Knowing this, when I was deciding on what subs to install in my 4Runner, I still ended up sealed but went with 1200W on sub over about 550W for all of the door/dash speakers. It was a good decision, there is plenty of bass.

You have to keep in mind how much power is required to reproduce each part of the spectrum at equal apparent loudness. Bass takes multiple the amount of power that midrange does and you can run tweeters loud as shit on 20W.

It’s all about getting the design right on paper and then going out and finding the equipment that satisfies the system requirements. Be honest about what you are expecting and don’t focus nearly as much on budget, because this is where most people run into problems with expectations.

 

Vented (properly tuned), and much more sensitive driver rather than a 2nd driver. You're correct that there'd only be a +3dB increase with a 2nd... hence just get a driver that's +3 or +6dB @ 1W to begin with.

The problem is going to be trying to fit a proper vent in that tiny enclosure of his. It'll probably need to snake to some degree.

 

Yes, ultimately any volume adjustment is a voltage adjustment, whether it's low-level from your RCA out (<6V RMS) or high level out of your amp. Use what's available to achieve the flatness you desire.

But this is why I have each speaker on an amp.