Ive got a two channel amp which has right speaker, left speaker outs.
Well ive currently got one sub running off the amp which my friend
installed so i have no idea how its set up right now. What im
wondering though is how i set up 2 subs on it, should i put one on the
right speaker one on the left? Or do i need to bridge them somehow?

Jim,
We really need to know more about the specific amp and subwoofer
involved. I'm going to make some assumptions to get you started, but
if you could fill in the gaps, it would be helpful.

If you have a stereo amplifier driving a single sub, then the amp is
probably bridged mono, and the sub is probably configured as a
four-ohm load. This is the most common configuration.

If this is the case, you're going to have a hard time adding a second
sub and keeping the load at 4 ohms. You could add a second 4-ohm sub
in series with the first, but you'd have no real change in volume.
Your cone area would double, which is usually good for about a 3 dB
increase, but you'd also be increasing the overall impedance of your
load from 4 ohms to 8 ohms, which causes about a 3 dB decrease, so
you'd be back where you started.

The only way you're likely to get more bass out of your current setup
just by adding a speaker would be to add the second speaker in
parallel to your existing one. This gets you the 3 dB increase from
doubling the cone area, PLUS another 3 dB because you'd be dropping
your impedance in half, causing your amplifier to put out almost
double the power.

The only caution with the is you have to make sure your amp can handle
the decreased load impedance. If your existing sub is a 4-ohm load,
and you hook up another one in parallel to it, that gives you a 2-ohm
overall impedance, which is a pretty varsity load for an amp that's
bridged mono. Compared to the number of different amps on the market,
there are relatively few that will handle a 2-ohm mono load.

Hope this helps, and get back to us with specifics about your system
when you can.

Scott Gardner



On 10 Dec 2003 01:07:58 -0800, (Netstorm)
wrote:

Ive got a two channel amp which has right speaker, left speaker outs.
Well ive currently got one sub running off the amp which my friend
installed so i have no idea how its set up right now. What im
wondering though is how i set up 2 subs on it, should i put one on the
right speaker one on the left? Or do i need to bridge them somehow?

(Scott Gardner) wrote in message ...
Jim,
We really need to know more about the specific amp and subwoofer
involved. I'm going to make some assumptions to get you started, but
if you could fill in the gaps, it would be helpful.

If you have a stereo amplifier driving a single sub, then the amp is
probably bridged mono, and the sub is probably configured as a
four-ohm load. This is the most common configuration.

If this is the case, you're going to have a hard time adding a second
sub and keeping the load at 4 ohms. You could add a second 4-ohm sub
in series with the first, but you'd have no real change in volume.
Your cone area would double, which is usually good for about a 3 dB
increase, but you'd also be increasing the overall impedance of your
load from 4 ohms to 8 ohms, which causes about a 3 dB decrease, so
you'd be back where you started.

The only way you're likely to get more bass out of your current setup
just by adding a speaker would be to add the second speaker in
parallel to your existing one. This gets you the 3 dB increase from
doubling the cone area, PLUS another 3 dB because you'd be dropping
your impedance in half, causing your amplifier to put out almost
double the power.

The only caution with the is you have to make sure your amp can handle
the decreased load impedance. If your existing sub is a 4-ohm load,
and you hook up another one in parallel to it, that gives you a 2-ohm
overall impedance, which is a pretty varsity load for an amp that's
bridged mono. Compared to the number of different amps on the market,
there are relatively few that will handle a 2-ohm mono load.

Hope this helps, and get back to us with specifics about your system
when you can.

Scott Gardner



On 10 Dec 2003 01:07:58 -0800, (Netstorm)
wrote:

Ive got a two channel amp which has right speaker, left speaker outs.
Well ive currently got one sub running off the amp which my friend
installed so i have no idea how its set up right now. What im
wondering though is how i set up 2 subs on it, should i put one on the
right speaker one on the left? Or do i need to bridge them somehow?


Hey thanks for the reply, i did some wiring of it and it didnt work to
well.

My system is this

2 dhd 1200watt subwoofers
1 boss 800 watt 2 channel amp
The box is a bandpass box with 4 port holes.

My setup before was in a single badnpass box with 2 portholes and the
one sub and was really loud. I went ahead and tried wiring up my new
sub and in the new box and ive run into some major problems. First i
tried running both subs on the 2 channels at 2 ohms each. This was not
good, the bass was around 1/6th of what the single one in the other
box sounded like, and I had no air movement coming from the ports. So
then i went ahead and rewired it both to 8 ohms and went ahead and
bridged it so it was running bridged at 4 ohms. This too had no bass
in it barely it sounds like ive got a 6 inch sub running at 50 watts
in there. Ive got a few possible reasons for this but I dont know.
When I got the box I had to dremel the holes for the subs because mine
wouldnt fit snug in there so now they fit just not snug because i was
too lazy, basicly they each have 2 screws in and have some gaps behind
them a bit. Then it could also be the wiring, I thought ive wired
everything correctly I followed the subwoofer wiring designs just like
it shows and am using 16 gauge speaker wire. Another thing it could be
is maybe my gain needs to be messed with? One last thing could be the
amp, its 800 watts but its a boss so you know its way over rated, but
then again I would of thought 2 subs on it would sound better than
one, maybe it doesnt produce enough power and I need a bigger amp for
those subs in that box? I dont really know a lot about this stuff I
have only just started in car audio so it would be great if someone
could help.