Added second sub and amp, no louder

[Jessica]

Check to make sure that they are wired the same and you don't accidentaly have one out of phase.

Check and make sure that if your amps have a "phase" knob, they are the same. Make sure you LPF and Subsonic or infrasonic are the same.

Other than that, i don't know.

[SteadyMobbin]

Wicks-

Engine off Battery Voltage 12.64

Engine on bat voltage 13.93

Amp 1 at rest 14.0

Amp 2 at rest 14.0

Amp 1 full volume test tone 12.2

Amp 2 full volume test tone 12.1

GoldenEye- gains are set with SMD handset, AC voltage from each amp 69v

BigMan- power is through d block

Thanks so far everybody

[TeamHT]

Doubling power AND cone area should net you +6dB theoretically.

That should definitely be perceivable.

How's your voltage drop at the input to the amps?

But this is why paper does not always translate to the real world. I've doubled power and cone area and sometimes gained and sometimes lost. It is very rare that I've seen an actual 3db jump and car acoustics, enclosure, and proper wave will definitely affect the overall score. I would assume that there should at least be an audible difference with double everything.

I would really look to the wiring of everything. It also sounds like two separate single enclosures, build a single enclosure for both subs

[bbeljefe]

If your electrical was up to par and all other things being equal, your additional amp and sub only increased the sound pressure by ~3db.

Go here and check to see if you can tell the difference between 3db up, 3db down or flat in a 440hz tone. ← Fun test to take, share your score if you like... I scored 10 of 10.

After you get electrical squared away, get some boxes with holes in em if you want to be loud. :-)

[BoomZoom808]

Adding a second sub should be louder sounds like cancellation or out of phase as others have stated IMO...

[Wicks]

Doubling power AND cone area should net you +6dB theoretically.

That should definitely be perceivable.

How's your voltage drop at the input to the amps?

But this is why paper does not always translate to the real world. I've doubled power and cone area and sometimes gained and sometimes lost. It is very rare that I've seen an actual 3db jump and car acoustics, enclosure, and proper wave will definitely affect the overall score. I would assume that there should at least be an audible difference with double everything.

I would really look to the wiring of everything. It also sounds like two separate single enclosures, build a single enclosure for both subs

Totally agree, that's why I always include that "theoretically" statement.

It won't ever be that perfect +6dB but that's what you could aim for.

Regardless, yeah OP you should be able to tell some difference.

Your voltage drop doesn't look that bad so your amps shouldn't be severely drooping.

Triple-check your phase between the subs. I've been sure of my wiring before and sure enough it turned out to be out of phase.

Since you have two separate boxes, I would look into a cancellation issue.

Move each box around as much as you can, reorient them in different positions and see if you notice differences.

Do you always get that 69Vac at the sub outputs?

Try disconnecting the remote and signal wires to one amp and measure the output of the other.

Then switch and test the remaining amp.

I'm wondering if a single amp will produce a higher output voltage then two amps together due to something pulling the signal down?

[Tim Osburn]

How are your rca run did you use a splitter on them? When you split you get signal loss. You may need a better head unit with higher voltage outputs or a line driver.

[goldeneye4564]

then like others have already filled in, check for phasing issues, set the sub sonic to 0 and play a 10 htz tone on LOW volume and see if they are moving the same.

if you still have issues, build a ported box for both of them already!

[SteadyMobbin]

Thanks for all the replies everybody. I guess I have some work to do once the weekend arrives.

[Go-N-Def]

Could it be polarity, if there's 2 subs 2 amps 1 firing opposite.