I have 2 12's running off a 1500 watt amp, the subs are rated at 550 RMS.

When first installing the system, one of the subs wasn't working, so i had the amp just hooked up to the one working sub.

I now have a replacement sub and the amp powering both subs.

My question is, is there any reason that the amp powering one sub would be louder than the amp powering both subs? Or is that just crazy talk??

Thanks in advance for all the answers!

 

How are your subs wired?

Is one of the subs out of phase from the other?

 

what does out of phase mean and how do you tell?

the amp is mono channel, so i have two wires coming out from the postive and two coming from negative, then those wires running to the subs.

Thanks.

 

The positive lead from your amp is going positive terminals on both subs? Same for the ground?

 

yes, it's all wired correctly.

When i was runnign just one sub, i just plugged both + into + and both - into the -.

 

It probably has a lot to do with the box too, but I wanted to know if it could be anything else.

Thanks.

 

plus now you're splitting the power to two subwoofers instead of one. now they're both recieving half of the power your one subwoofer was getting.

edit* also depends on the OHM load. are they DVC subs?

 

what about the wiring inside the box to your speakers?

something you can do to try to see if they are in phase together is take one side of the speaker terminal, reverse the polarity and see if it gets louder. if so, something is out of phase.

usually when you have 1 sub or 2 subs, your final impedence will change.

from what i read, you have mono amplifier. lets say sub 1 is dual 4 wired in parallel for final impedence of 2 ohms, then you have sub 2 which is exactly the same, when you wire those 2 together into the amplifier, you are wiring the 2 subs into a parallel configuration once again so your final impedence is 1 ohm into the amplifier. if you take 1 sub out of the equation, your final impedence to the amplifier is 2 ohms. 2 ohm load at the amplifier will produce half as much power as 1 ohm.

so lets say with 1 woofer which is 2 ohm, your amp will produce 500 watts.

with 2 woofers which is a 1 ohm load, your amp will double power output to 1000watts, split that up with 2 woofer and both of them are getting 500 watts.

so your end result is doubled power outout and doubled the cone area. theoretically you should gain 6db.

 

Hmm - what subs and amp are you running?

From your post it looks like your subs are dual voice coil. If you are running one DVC (assuming 4 ohm coils) in parallel you would be presenting a 2 ohm load to the amp.

If you are running one 4 ohm DVC in series you would be presenting an 8 ohm load to the amp - net effect would be your amp delivering about ~1/4 the power you had in parallel.

Now with two 4 ohm DVC subs you could have the following loads and power effects:

A. SUB1 in Parallel, wired in Parallel with SUB2 wired Parallel = net load would be 1 ohm (amp may not handle it).

B. SUB1 wired Parallel, wired in series with SUB2 wired Parallel = net load would be 2 ohms.

C. SUB1 wired series, wired in parallel with SUB2 wired series = net load would be 4 ohms.

D. SUB1 wired series, wired in sereis with SUB2 wired series = net load would be 16 ohms.

If your amp is 2 ohm stable you would want to use option B, otherwise option C would be the safe approach.


Of course this is all for not if your subs are not DVC - need model numbers for the amp and subs.