My buddy just bought a wet sound amp. Now the amp says 75 watts per channel with 4 ohm speakers 150 watts with 2 ohm speakers. Which speaker type should he get and why? We don't really understand the whole ohm stuff. Thanks!

 

They here is this amplifier can support both a 2 and 4 ohm speaker. So you get more power with the 2 ohm speaker. So it is a no brainer.

Now if you have another amplifier that is rated for a 4 ohm speaker when you put a 2 ohm speaker its current output goes down and you do not get the benefit of going to a lower resistance and thus more power. But in your buddy's case the amp can handle a 2 ohm speaker so i would use the 2 ohm speaker for more power output.

 

If you want more information on impedance (which is what the ohm rating is), check out this website:

http://www.bcae1.com/

There is a directory of topics on the right side of the home page that you can scroll down for the topics of interest to you.

Your buddy will want to tune the amp and will find useful information on that topic as well at that site.

The Wetsound amp is very similar to the Arc 125.2 mini which I had for a couple of years. Your buddy can use either 2 ohm or 4 ohm speakers; the latter will be plenty loud with the Wetsound amp. The difference will be that the volume setting on the head unit will be a couple of bars higher than if he was using 2 ohm speakers for the same sound volume.

4 ohm impedance speakers are more common than 2 ohm; so he'll have a broader selection to choose from.

Carl

 

Not correct. When you put a 2 ohm versus 4 ohm speaker on an amp the current goes up. In fact it doubles. If the amp isn't rated for two ohms it will fry.

In the OP's case, I would use either a 4 ohm or 2 ohm speaker since the amp is rated for either. The determining factor for me would be the speakers sensitivity if listed (I'd get the more sensitive speaker), or the better sounding of the two if you have a chance to listen to both.

 

a 4 ohm speaker will (usually) make more sound for a given amount of electricity than a 2 ohm speaker (4 ohm speakers are [usually] more efficient) ....but will usually get hotter and are more likely to burn out if you like to listen at high volumes for a long period....Notice the usually(s) in the statements above, there is some variability in speaker manufacturing...often times 2 ohm speakers will sound better over a greater volume range (both loud and quiet) whereas 4 ohm speakers usually sound better at mid range loudness....personally I would go with 4 ohm speakers, as they are more efficient and sound more than good enough for a motorcycle system..

 

Folks,

I am an electical engineer with a masters degree from Cornell university, have designed electronics for the military and space vehicles. What I said at the top is absolutely correct. Of course, the current will go up, that is why I said that if the amplifier can handle the current , which it can in this case, go to the lower impedance (resistance)
for louder audio.

This is defined by a very simple equation P= (VxV)/R where P is power , V is battery voltage and R is imedance. The smaller the resistance the more power out, but you need an amp that can handle the current at lower impedances.

The only negative with two ohms is that you have less choices of speakers, not as common as 4 ohms

 

right

 

Good info, thanks!

 

Well,......I stayed at a Holiday Inn Express last night !!! Does that count ?? LOL!!

 

well...your not going to find 2 ohm speakers.....the issue concerns if you are going to use 4 speakers....you can use four 8 ohm speakers (two per channel) which will result in 4 ohms....OR....four 4 ohm speakers (two per channel) which will result in 2 ohms per channel.