Looking for opinions on the best way to wire what i have. 2 12 JBL power series. They are 5 ohm, 280W continuous, 350W max in a ported box built to specs from jbl. I have a RF Punch X360.2 amp. 90x2 into 4 Ohms or 180x2 into 2 ohms. Should i bridge or run stereo with the amp. Should i run stereo w/the speakers; or parallel or bridged? I was going to run stereo, each channel seperate to each sub at 90W, but thought there may be a better way. Thanks for any help.

 

thats prolly the best way, unless your amp is one ohm stable

 

run them at the 2 ohms and watch the freq. settings in that ported box. remember that a ported box is ineffiecnt and they wont sound as good as if they had thier recommened power. a sealed box would be better because u can "manipulate" a power output by using a smaller or larger box.

 

Actually, a ported box, if built correctly to proper specifications of the sub, is much more efficient than a sealed box. However, it is much larger than a sealed box for the same sub and sound quality is lower. I say run the amp bridged. And if they are 5 ohm, single voice coil subs wiring them in series should give a load that is more friendly to your amp, but will be a bit lacking in power. And im guessing that your amp isnt 2 ohm stable bridged so wiring the subs in parallel might not be the best option. You could try it but the amp will most likely overheat and shut off quicker than youd want. Of course you can always hook up a sub to each of the channels, but the bass line is intended to be played mono, not stereo. So in effect, you might get a different bass line from each sub due to the fact that they are running off of two different channels (think of a surround sound system) and are out of sync and out of phase with each other resulting in a bass line that is technically "safe" but weaker than what you could have.
my 2 cents.....

 

That Punch amp should be stable to 2 ohms, at least, just make sure, if you do run it at 2 ohms, to use the biggest power wire you can, effective power consumption almost doubles when you're running into 2 ohm (Plus, big wire can't hurt anyway!)

 

The amp is stable to 2 ohms, but if i run parallel that would put me at 2.5 ohms. Then if i bridge the amp doesn't that halve the ohms? So it would be at 1.25 ohms. I thought i saw that running in parallel OR bridging 2 channels would each double the load. I understand the speaker in series or parallel ohm calculations, but i'm not clear on the amp side. Thanks for your help so far.

 

Well, yeah, forgot about the 5 ohm thing... I'd just run it in parallel and eat the last 1/2 ohm. Not much else you can do in a situation like that...

 

Bridging and ohms seems confusing, but it really isn't. Sometimes people say the load is halved when you bridge your amp. THAT IS NOT TRUE. It's a physical impossibility. The ohm load is presented to the amp by the speaker or speakers. If you have a 4 ohm set-up, bridging the amp will NOT change this fact. What happens is the amp is "working" differently. You are using part of each of your 2 channels. The current and voltage demands of your amp are the same as when you use a 2 ohm, 2 channel configuration. Also, the same amount of heat is generated, and heat kills. That's why most 2 channel amps that are "safe" to use into 2 ohms in 2 channel mode, can only be safely used with a 4 ohm set-up when bridged. Any amp has limitations and running this amp bridged into a 2 ohm set-up makes the amp try to exceed those limitations. These are merely electronic devices that must be used as designed. If not, they will fail eventually, or go into a protection mode when overtaxed. Your amp is safe to use into 4 ohms when bridged. If you parallel your subs to 2.5 ohms then that is what the amp will see, not half that. Whether you choose to use that set-up is your choice. If you don't overdo it, you may get years of service from that set-up, maybe not. But if you "crank it up", that may be another story.

 

Yep 4 ohm stable in bridged mode.....

try bridging the amp and running a single JBL.....

If not then you will need to rethink your choice of woofers...and consider others that are more user friendly.....

You could get two dual voice coil subs...wire the voice coils in series and parallel the two subs to get a presentable load.
This is done for SPL with what they call "cheater amplifiers that are 1/2 ohm stable...

Just a possibiliy

 

the dude, JL Audio recommends NOT running speakers in series. You can read the info on their site.

I would have to second what LinearPower said and then Capone.

If you have to keep those two subs and that amp, then just run it in stereo. It won't be quite 90 watts to each, but that is the best you can do with what you have. If you ever decide to go with a different set of subs or amp, I would go with subs, because no matter what amp you ever get, you will always have an odd-ball ohm-load. You might want to look into one high quality 4-ohm subwoofer, whether it be a single voice coil 4-ohm or a dual 2-ohm voice coil (wired in series to present a 4-ohm load).

Hope this helps.

 

Who makes an amp that is 1/2 ohm stable, never seen one??

 

Boss Overdrive, Audiobahn, Logic Soundlab. Not exactly a who's who of car audio. There are others.

1/2 ohm stable DOES NOT mean quality. Just remember that fact. An amp that will produce 100 watts RMS into 1/2 ohm is more than likely NOT any higher in build quality than an amp that will produce 100 watts RMS into 4 ohms. It's my opinion, but the whole business of using ridiculously low impedances is way overrated. Inexperienced people are led to believe that there is some magic involved in using a very low impedance. No magic, just a different design. Not necessarily better, just different. JL makes a series of amps that will produce it's rated output at any impedance between 1.5 and 4 ohms. It is all about the quality. Also, Linear Power TO3 series is not dependent on low impedance. It will produce the same output into 2 or 4 ohms. Great amps. There are others. Most times you get what you pay for.

 

Yeah, I know 1/2 ohm doesn't mean its a good amp, but the highest I have seen is 1 ohm, didn't know they had a half ohm!

 

Autotek (these are some of the whose who of sub amps), USamps,
GS redline series, Orion are 1/2 ohm stable

Kenwood, Hifonics, etc make 1 ohm stable amps....

You'd need one hell of a power supply to drive these.....stiffening caps included....

I would agree that magic doesn't make these amplifiers work....physics does..
I would also agree that most often than not....you will get what you payed for....if you shop around and do research.

I would also agree that the OHM rating are not the only factor to take into consideration when buying an amp....

there is signal to noise ratio, frequency response, THD, power supply chips,
crossover options, class of amplifier etc etc.....

 

Autotek (these are some of the whose who of sub amps), USamps,
GS redline series, Orion are 1/2 ohm stable

Kenwood, Hifonics, etc make 1 ohm stable amps....

You'd need one hell of a power supply to drive these.....stiffening caps included....