Hi I am new here! And right off the bat I need your help. Any idea/feedback is appreciated! [img]smile.gif[/img]

OK here's the situation. I just recently got a pair of front components (Focal K2 Power 130KP) and an amp (Audison LRx 2.150) powering those speakers. My deck is Alpine 9833. I just had the Focal and Audison installed a week ago and those are where the problems are.

Right after the installation, I noticed that there was alternator whine. After several days I brought the car back to the audio shop and they fixed it for me. According to the installer, the RCA cable that came with the amp kit (which is Phenix Gold) was too long and he had to loop it, and the looping probably picked up noise more easily. So he replaced that with the same but shorter cable for me. He also turned the gain on the amp down a bit so that the noise isn't so much amplified.

Now the alternator whine is gone. However, I can notice that the music doesn't sound as nice. The highs aren't as lively and the mid and voice aren't as clear. I am pretty sure it's not just in my head. My friend (who's quite knowledgable car audio) said the install guy might be using a cheaper cable which has better sheilding (foil instead of breaded) but worse sound quality. I checked the cable myself and it seems to be the breaded kind.

Now, assuming the installer didn't lie to me, then the cable is actually better ('cause it's shorter). And I am having such a dramatic difference (no noise, but less sound quality) just because of the less gain on the amp. Is it possible? Before the gain adjustment, I was playing at volume 10 to 13 on my deck. Now I am playing at around 15 to 20. Max is 35 by the way. In theory using the mid rather than the lower volume range on the deck is better. I don't understand... the installer did these two things (ie. shorter cable, and lower gain on amp which results to playing at more closer to mid range on deck) which are supposed to lower the noise and supposedly increase sound quality, but why am I getting worse sound, despite the fact that noise is gone?

In the remotely possible case that the installer lied to me and installed a noise suppressor or a ground loop isolator as a cheap band-aid solution, where would I spot them and what do they look like?

Sorry for the long post and I tried to keep the thoughts and ideas as organized as possible. I am just quite frustrated right now 'cause needless to say I spent big bucks on those stuff and I expect GOOD quality sound! And now I am getting crap! sigh... please help me!

In the mean time I will try to turn up the gain on the amp and see if that will make any difference.

Thanks in advance!

Argh all the "breaded" are supposed to be "braided". I can't spell! lol

It sounds like a ground-loop isolator fix to me, but you aren't going to want to accuse them of that without doing some research first. Check behind the head unit.

The proper fix is usually related to improving the ground connections on, and between the head unit and amplifier.

I agree with Dave, check behind the head unit and near the amp, it has to be in one of those two spots. Going to a shorter cable of even inferior quality would not make that much of a pronounced difference. Also I would get it tuned so that max volume occurs closer to 33-34 on the volume dial.

what does a ground-loop isolator look like? Anybody have a pic of that? Does that just connect between the RCA cable and the head unit or the amp?


>Also I would get it tuned so that max volume occurs closer to 33-34 on the volume dial.

Why is that? Regarding the amp gain vs. deck volume, right now the amp gain level is being set to around the mid level, and my normal playing volume on the deck is 15 to 20 out of 35 which is around mid level too. Isn't mid level on both deck and amp a good thing?


I am very noob when it comes to car audio and install so please educate me [img]smile.gif[/img] (if I wasn't so noob I wouldn't spend money to let somebody install for me.... now I learned that if you want anything to be doen right you gotta do it yourself)

Personally I like asmuch control as possible, if you are on a scale of say 0-50, some people say they like it when their stereo's are loud at 15, some at 25 etc. I like it when you have more control over the volume by allowing the use of the numbers from 26-50 [img]graemlins/thumb.gif[/img]

Oh and a ground loop isolator is generayy a little black box with RCA input and output oigtails at each end. some are larger and I have seen green translucent ones. And you don't have to do it yourself to get it done right, you just have to find a good honest installer. I would recomend Tim Baillie if you are anywhere near Langley.

First, I'd like to know what year, make and model car the system is in. Also, please list the equipment , including the speakers being used. I assume you are trying to achieve sound quality, not SPL?
Steve

Regarding deck volume and/or amp gain, I guess DWVW you are coming from the perspective of "control". How about sound quality? If my normal listening volume is at the deck's mid volume and the amp's mid gain, is that in theory optimal?

I went to Speaker City and that store has been around for a long time as far as I understand. And when I brought the car back to fix the noise, I SPECIFICALLY told the installer I do not want to have noise suppresor or ground loop isolator, because I do not want to lose sound quality. If I find one in my car I would be REAL mad. This is kinda ironic... I paid so much money for the install job, and now I have to take things apart to check stuff. I might as well do it myself in the first place. Sigh.

Regarding my car and my equipment, I listed my equipment on top but I guess they are hart to spot in the midst of my long-ass essay [img]smile.gif[/img] So here it is again:

Car: 1999 Honda Prelude TypeSH
Headunit: Alpine 9833
Amp: Audison LRx 2.150
Front Speakers: Focal K2 Power 130KP
Rear Speakers: stock


And yes, I am trying to achieve SQ [img]smile.gif[/img]

Then disconnect those shiz rear speakers.