Need help bridging a 2ch amp

[stillmatic]

I got two 12" subs and a 2ch amp that's only 2ohm stable in stereo mode. Apparently, I can't bridge the subs using a parallel connection because they start to sound jerky. So I tried running a series connection but my amp wouldn't power up the subs at all.

Is there any way I can bridge my subs using the amp I have right now or do I need to get one that's 2ohm stable in bridge mode? Also, how do I take advantage of my amp's 2ohm stable stereo mode? Is there a certain connection for this?

Here's how I wired my subs just to give you guys an idea:

Series Connection - Bridge & Stereo mode = no sound from subsL Sub + >>> Amp L +L Sub - >>> Sub R +R Sub - >>> Amp R -

Parallel Connection - Bridge only = Jerky soundL Sub & R Sub + >>> Amp L +L Sub & R Sub - >>> Amp R -

This is how my amp's speaker inputs look like

+ -------- - (Bridge)L + - - + R (Stereo)

[IvoryJ30t]

here, ill get it running for you.

ok, what kind of subs are they, and what kind of coil [single voice coil, dual voice coil] and what is the impedance per coil?

and what is the amp's output in stereo [watts RMS, not peak] peak watts is what is on the amp. if you dont know the rms rating, just tell me what kind of amp it is...

[stillmatic]

They're Sony Xplods Model #XS-L121P5, 350watt RMS, 4ohms single voice coil

Amp = Legacy PB449X, 125w x 2

[IvoryJ30t]

pyramid amp? thats what that part number looks like...sure its a legacy?

[stillmatic]

My bad, it's a pyramid.

[IvoryJ30t]

oh, woops. just noticed its single voice coil. sorry. it will work, but not the way i said, and at a much lower power

[IvoryJ30t]

wire both subs straight to the amp. dont bridge the amp, or run it [the subs]in parallel with it bridged, it will mess the amp up. the best thing to do is run the amp bridged and feeding one sub, or each sub on each channel.

that amp wont work the way you want it to.im getting the amps info so i can tell you the best thing to do.

[IvoryJ30t]

ok, that amp will overpower one sub, but underpower both. if the subs were dual voice coil, i could have made it work. best bet is to run each sub to its own channel.

[stillmatic]

ok, yeah dude, that amp will have no problem feeding those subs. its simple. usually there is no switch for bridged mode. what you want to do if there is no switch is connect {amp[left +]} connect that positive to both positive sides of the subs [producing 2 ohms] and connect both negative sides of the subs to {amp[right -]} and bridge amp left - and amp right + with a small loop of speaker wire.

I lost you after this post so I'm just gonna quote this one.

Basically, what you're saying is connect the subs in parallel and run a loop wire to where? Left - and Right +? I assume you're referring to Left - and Right + in stereo output mode.. If so, then both Left & Right subs + and the loop wire will be connected to one point, and the negative point in the Left Amp output will be by itself. Did I get that right?

Also, can I do this method even though my amp has a bridge switch?

[stillmatic]

ok, that amp will overpower one sub, but underpower both. if the subs were dual voice coil, i could have made it work. best bet is to run each sub to its own channel.

You're exactly right about the overpower/underpower part. I guess I have no choice but to go underpowered for a while then.

BTW, which component is causing the problem.. the amp, subs, or both?

Thanks for all your help dood!

Edit: You think I'll be better off bridging one of my subs than use both of em in stereo mode? What do you think?

Edit2: Nevermind, you already covered it in one of your posts. Hehe

[IvoryJ30t]

what happened was, i looked up the specs of the amp, started typing, realized the specs were peak, not rms, and corrected myself. your gonna have to run them underpowered, or try to trade them for dvc 4ohm coil subs.

[IvoryJ30t]

yeah, sorry i was kinda confusing. i posted and realized i was wrong and fixed it.

se the problem is this- the amp can do125x2 @4 ohms [decent for individual]250x2 @2 ohms [both subs parallel on one channel=each on own channel]500x1 @4ohms [overpowers one sub, but cant handle two in parallel]

also, bridging the amp, and running the subs in series is no good either because even though its 500x1 @ 4ohms, the speakers in series would be a 8 ohm load and drop the amps output to 250 watts, which is then split by the speakers for 125 watts each [same as each sub on its own channel]

[stillmatic]

I see :thinker... Thanks for explaining everything, man :ylsuper!