Bridging two12" subs and one 15" sub to my Rockford fosgate T 1500bd amp

if setup 4 channel amp with low pass filter for the sub channel and other 2 channels for speakers with no filter, some amp you can use amp as 3 way if one or two subs, bridging output will give you more power for the sub. be aware that bridging 2x4ohm subs will give you 2 ohms and potentially damage the amp.

You can not bridge a 1 channel amp. Bridging is when you combine the output of a bridgeable two channel amp into one channel, typically to power a sub woofer.

Hey i have looked over many rockford manuals,(i own a 300.1 my buddy owns a 325.1) and for there mono(.1) amps there hooked together on the inside so channel A+ and B + are cencted on the inside the amp. So you ither hook one 2ohm sub to channel A or you can hook 1 4ohm subs to channel A and 1 4ohm sub to channel B. There 2ohm stable so any lower will eventualy burn the amp out.

run them in sereis hooking them all up together and bridging the amp

amp is way too small to power a 15 inch sub. But you should get some sound out of it, not silence. You can use a 9 volt battery to test your sub, if the sub pops when the 9 volt is placed across it's terminals then it's ok. If it does not pop then your sub may be bad, or the coil may be frozen. (It can still read 4 ohms if frozen). If your amp powers smaller speakers fine, you know it's not the amp. If the sub tests ok, then verify your connecting it properly to the amp's correct bridging terminals.

Hello jtkpay,

Rockford-Fosgate claims their latest V-power 1500bd is stable to 1 ohm, and I would think that your Oldschool would also be. The 2 wiring options for 3 subs with 2 ohm dvc would give you a 1.34 ohm load and a 3 ohm load. The 1.34 ohm option would mean more watts to the subs, but the amp will run hotter. The diagrams look like this:




Using just 2 of the Kickers, you can wire 3 different ways, with final impedances of 0.5 ohms, 2 ohms, or 8 ohms. You do not want the 0.5 ohm load. It's bad for the amp. You don't want the 8 ohm load. It doesn't allow the amp to produce as much power. So that leaves only the 2 ohm, with coils in series and subs in parallel. It looks like this:


Hope this helps. If it does, please rate as "FixYa".

if your sub will handle it, bridging it will give you more power. The best thing to do is to find out how much power the amp puts out ( RMS ) and if it is in your power handling range bridge it. It sounds better and gives you a harder punch because of more power.

The amp has failed and will need to be repaired.

Let me know if you have any other questions.

There's a lot more factors involved than that.

• Power capability of the subs
• Type/size of the sub box
• Allotted space in the vehicle for the sub box
• Voice coil impedance of the subs versus the capability of the amp
• Etc.

no thats not it you are lucky you havent burned it up like that. wire each speaker to its own source positive and negative, you loose power when you bridge an amp and use two speakers, its best to hook up without bridging you will get more volume that way.