My installer bridgede my MTX 282 amp into the JL 8 inch dual voice - the dual voice comes in 2 or 4 or 6 ohm dual voice - mine is 4 ohm

The installer suggested that we could get more power to the JL if we instead order/install a dual 2 ohm

I was happy with the sounds from the dual 4 ohm (until all of a sudden it lacks its former punch after two days) and they said good because my amp has to work less with the dual 4 ohm - so you (I) and the amp are happy.

The MTX manual says do not bridge 2 4 ohm speakers but does not mention bridging a dual 4 ohm speaker

1) Why does the amp have to work less to power a dual 4 ohm - is not 4 ohm a measure of resistance - doesn't the dual 4 ohm need more power to do the same thing

2) Has he violated MTX manual stating do not bridge 2 4 ohms and what would get damaged - the speaker or the amp

3) does a dual 4ohm speaker either work or not or can one coil be damaged such that the speaker still works a little.

Please help me so I can calm down knowing all is right.

 

Here is what he means. The amp you have can be bridged to supply 280 W RMS (real power) into 4 ohms. If the amp is bridged right now it is either supplying both voice coils in series (8 Ohm), which usually yields half of tha available power of the at 4 ohms. So effectively your getting something around 140 W to your speaker. THe other possibility is that the amp is bridged and is only feeding one voice coil. I don't know that this will harm anything, you would have to see what each voice coil can handle. My experience is a sub can usually handle as much as you provide. If you were to get the 2 ohm voice coil speaker you would be able to take advantage of both voice coils by connecting them in series giving the amp a 4 ohm load. It may seem confusing by my explination PM me and I'll give you my number if you want a very clear simple explination.

 

Don't understand the amp warning.

Generally you run dual voicecoil speakers in parallel -- thus a dual 4 OHM speaker would drop to 2 ohms of impedence when run in parallel.

 

Here is what he means. The amp you have can be bridged to supply 280 W RMS (real power) into 4 ohms. If the amp is bridged right now it is either supplying both voice coils in series (8 Ohm)(yes I just got back from the installer and this is the case), which usually yields half of tha available power of the at 4 ohms. So effectively your getting something around 140 W to your speaker. THe other possibility is that the amp is bridged and is only feeding one voice coil[No he wired coils in series I don't know that this will harm anything, you would have to see what each voice coil can handle. My experience is a sub can usually handle as much as you provide. If you were to get the 2 ohm voice coil speaker you would be able to take advantage of both voice coils by connecting them in series giving the amp a 4 ohm load. I was happy after the install before the bass started to fade yesterday - the sub is in the cabin - we had ordered a 2ohm dual which we are going to install friday as the possible fix assuming the current sub somehow is defective It may seem confusing by my explination PM me and I'll give you my number if you want a very clear simple explination.

I just find it hard to believe the sub went bad brand new, decent brand, I did not abuse it as all I was ever looking for was a nice subtle hint of bass

 

I don't believe a speaker should go bad that quickly either. I have two subs that I've used for about 5 yrs or more with no issue. It sounds to me that you should be able to get something under warranty. Is the installer the same person you bought the equipment through, or just someone you know? I believe in always buying from a reputable company, especially because of cases like this.
So the power has just weakened since the first day...battery ok?, just seems strange for that to happen. I hope the new speaker will fix the problem. Good luck!

 

I don't believe a speaker should go bad that quickly.....No problem with warranty its covered (sound advice - they custom made the footwell sub box, etc just the hassle i like driving the car but not to go get it fixed.
So the power has just weakened since the first day...battery ok I never played without the engine going no - all seems well RCA getting signal, etc just that the sub is losing strength - maybe it is freezing up for whatever reason - we shall see Friday when they are going to start with the speaker replace with the more appropriate dual 2 ohm

 

Glad to hear it will be covered under warranty. How much did they charge for the box? Did they custom make it from their own design or did you give them modifry's design? Any pics?

 

So right now you have an 8 ohm total load. If you get the 2 ohm dual voice coil sub and run the voice coils in series, you will have a total of a 4 ohm load. The amp is ratted for this and should give twice the power to your sub as you currently have.

JeffA

 

They charged a good bit. They custom made it from scratch but had done so before. i was fed up with doing things myself

 

So right now you have an 8 ohm total load. If you get the 2 ohm dual voice coil sub and run the voice coils in series, you will have a total of a 4 ohm load. The amp is ratted for this and should give twice the power to your sub as you currently have.

Thanks - This is what everyone is agreeing with so I am comfortable that I have a handle on the fact the amp has not been wired incorretely - ruling out that the installer may have hurt the amp (if he in fact wired in series not paralle.

I am almost understanding something. Just help here - Ohms are a measure of resistance. I assume (perhaps incorrectly) that the more ohms, the more resistance. Doesn't an amp have to work harder to pump through higher resistance. And so this is why 4 ohms allows the amp to power more freely? I just do not understand why people have said that the AMP will be working less hard and running cooler with the 8 ohm verses the 4 ohm. - albiet it will be offering 1/2 the power to the speakers