I just bought some audio gear and I think the sales rep has stuffed up, need some guidance as I know very little bout this sorta stuff. Here go's, 400wrms sub @ 4ohm and mono block amp 250wrms @ 4ohm or 400wrms @ 2ohm. The rep told me that the sub was 2ohm (I should have checked myself) and the amp @ 2ohm would fully power the sub.

If I run the amp at 2ohm into the 4ohm sub, will it work properly, what will happen.

Regards Paul...

I just bought some audio gear and I think the sales rep has stuffed up, need some guidance as I know very little bout this sorta stuff. Here go's, 400wrms sub @ 4ohm and mono block amp 250wrms @ 4ohm or 400wrms @ 2ohm. The rep told me that the sub was 2ohm (I should have checked myself) and the amp @ 2ohm would fully power the sub.

If I run the amp at 2ohm into the 4ohm sub, will it work properly, what will happen.

Regards Paul...


Mate the only way you can run a 4 ohm sub on 2 ohms is if you wire it with another 4 ohm sub. There is no switch to change the resistance of a speaker... You cant just say run the amp at 2ohm into the 4ohm sub either, the amp will produce various amounts of power dependant on the load resistance(the ohm value of the speaker).

Do you understand?

if its a dual 4ohm sub
then all you have to do is wire the sub at 2ohms

Funny this thread should be made, i stumbled apon this website explaining wiring speakers in series and parallel.

http://www.termpro.com/articles/spkrz.html

An amp 'sees' a load of 2 ohms. It doesnt actually run at 2 ohms per se. When it sees a load of 2 ohms it will generally produce more power than if it saw a 4 ohm load. etc..

An amp 'sees' a load of 2 ohms. It doesnt actually run at 2 ohms per se. When it sees a load of 2 ohms it will generally produce more power than if it saw a 4 ohm load. etc..

So if an amp produces 250wrms @ 4ohm load and is connected to a sub of 400wrms @ 4 ohm, then the sub is under powered by 150wrms ??

So if an amp produces 250wrms @ 4ohm load and is connected to a sub of 400wrms @ 4 ohm, then the sub is under powered by 150wrms ??

Bingo. This is not necessarily a problem when you consider the way power and loudness are related. The difference between how loud you can get when you compare 250W and 400W is precisely 2.04dB, which isn't a big deal.

But.. as has been covered before by people much clueier than me, if you drive the amp so loud that it starts to clip it'll be sending a square wave to the speaker which is going to break it.

The moral of the story is that you'll be just fine with the setup you bought, so long as you keep an ear out for distortion and back off the volume.

Bingo. This is not necessarily a problem when you consider the way power and loudness are related. The difference between how loud you can get when you compare 250W and 400W is precisely 2.04dB, which isn't a big deal.

But.. as has been covered before by people much clueier than me, if you drive the amp so loud that it starts to clip it'll be sending a square wave to the speaker which is going to break it.

The moral of the story is that you'll be just fine with the setup you bought, so long as you keep an ear out for distortion and back off the volume.

Thanks for the advice, I'm not that bright when it comes to amps and subs and wire gauges and RMS and Ohms and watts. I can install and wire all the components correctly, it's just the technical mumbo jumbo that throws me. Thanks for again

Regards Paul...

take it back and slap the salesman in the face with it. he told you something you didnt get, simple as that.

u bought it from strathies didnt u? :bowrofl:

have look at this website can be a big help when you are wiring them up
http://www.the12volt.com/caraudio/boxcalcs.asp

No, why did you asume I did, just curious.

personal experience i've had (few times i've gone) = lousy sales ppl, lousy installers...lost my business for good (well, unless something is super on special lol)

Talk about un-helpful sales people, Alberts in midland. Went their for some prices earlier this week, the guy I spoke to was good for ph u ck all. He asked what i was looking for and when I told him he said " yeh look over on that wall" then he went and sat back down to his magazine, and I'm pretty sure it was'nt his lunch break cos it was 3pm. Rude pr!ck

ooh ur a perth-ian...missed that :P lol go alberts morley (i've done good business with them) or alberts cannington (come recommended by Woob)

should hook u up :)

sealed a deal with JB's