I know this isn't an audio forum, but I would think someone knows the difference.

This is what I have....


Everyone talks about how adding an ARC or the like amp greatly improves their sound. Well, I beg to differ. I don't know if it's because I never had a factory system since my bike is an '09 EGS, so I never heard what it could have been like before the amp. I went straight with what you see in the pic. I just can't understand why I have to turn my head unit up to 3/4 to get loud. I'm thinking it may have to do with my speakers so I've been contemplating upgrading to the J&M 7.25's, but I don't want to purchase them if it's going to sound the same. Apparently these Alpines are 4 ohm.

What are the differences? Are they wired differently for 2 ohm?

This is what Crutchfield had to say.......

English terms would be nice since I'm not an audiophile.


Don't get me wrong, it sounds great at 3/4 volume. I'm just wondering if I need to look a little deeper into this system to get full potential.

 

This link will have more information in it than you asked for. If you read through it, you'll understand the relevance of matching head unit/amp output impedance and speaker impedance:

http://www.bcae1.com/spkrmlti.htm

If your head unit is 4 ohm impedance, and your speakers are 4 ohm impedance, they match and unless there's a problem with the head unit or speaker wiring, the unit is performing as intended.

If you're running more than two speakers, then the link's explanation of seried and parallel wiring may be relevant depending on how the head unit is wired.

Carl

PS: Couldn't tell from the pic what the ARC audio product is.

 

The most important factor in matching speaker impedance is the output impedance of the source. Power transfer depends on how well the output impedance (the radio in this case) matches the load impedance (the speakers in this case). Unless the output impedance is the same as the load impedance, maximum power transfer will not occur and the sound can become distorted at high volume levels.

 

If you have the Arc KS125.2 mini amp, that can run either 4ohm or 2ohm. With 4ohm speakers it's a 70W amp, with 2 ohm speakers it's a 125W amp.

 

OK, so I've looked at the Alpine, CNET, and Crutchfield sites and neither have the info on the ohms for the head unit unless I'm missing something.


http://www.crutchfield.com/p_500IDAX...ures_and_specs


http://reviews.cnet.com/in-dash-car-...=mncolBtm;rnav


http://www.alpine-usa.com/product/view/ida-x100m

Any help?

 

The amp should have ratings on it for what it's able to handle. Most commonly, amps are typically rated as "stable" at 4 ohms stereo or 2 ohms mono. Mono would typically be for hooking up a sub or two and "bridging" the amp. If you take 4 ohm speakers and wire them in series, you will have a 2 ohm load on the amp and it may not be able to handle that. Basically it will overdrive the amp and can cause it to overheat and shut down.

Having said that, you might be able to run 2 ohm speakers on an amp rated for 4 ohm stereo and be ok at moderate volume levels. Problem is we have to turn it up to overpower the wind and exhaust. You should get more volume (all things being equal), but "clean" power is the key to being able to crank it up and not damage the amp and speakers, and not getting distortion. Bottom line, better off not exceeding the load rating of the amp.

 

OK, so how do I know if it's running at 4ohm or 2 ohm?

 

Head unit isn't really the issue since you are running through the ARC amp. The ohm rating on the amp is what you should focus on. Wonder how many volts your RCA outputs are sending to the amp? IIRC, it should put out about 5 volts or so.

Just checked the ARC website and they say the 125.2 mini amp is stable to 2 ohms stereo. Is that the one you have?

http://www.arcaudio.com/productdescr...125.2-mini.asp

 

I can already see that I'm going to learn a lot from this thread!

 

That's dependent on the speakers. For your setup, you would want a 2 ohm speaker hooked to the left and right output on the amp. Otherwise, it would take 2 4ohm speakers wired in series to each output to get a 2 ohm load.