# New setup has distortion after a few mintues.



## goffmj (Feb 4, 2011)

So after a year of trying to figure out what the deal is with an Alpine I had, I finally decided to just get another deck. I ended up with a Kenwood BT945U. It's a pretty sweet piece of head unit, but I've noticed now an issue with my setup. I'll be able to play music just fine for about 3-4 minutes, and then out of the blue the music's instrument's sound gets real low and distorted, followed by the vocals getting raspy and the volume lowering a bit. Does anyone know what sort of issue this sounds like? When dealing with my Alpine, I replaced most everything. New wiring in car to the front and rear speakers, a new set of speakers for both front and rear, etc. I know it didn't do this with the OEM stereo, and I just can't figure it out. I don't have the model numbers in front of me, but my current setup is the Kenwood and 2 plate Infinity 4x6 2ohm speakers and 2 coaxial 6x9 Infinity 2ohm speakers. Could the 2ohms on both speakers just be too much for the deck to constantly run?

Really at a loss here.. Any insight would be appreciated!


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## Damger (May 10, 2011)

did you run your rca's and power wire down the same length of the car?


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## mrflamboynt (Apr 23, 2011)

i have found a lot of head units that make noise have ground issues.... try giving it a custom (good) ground if you have not done that already..... you may also want to pull the head unit out of the car and bench test it.... are you using amps for your mids? start troubleshooting those.... you just have to start testing individual parts of the system until you find the cause.... it could be any one of them causing the problem....

sorry i dont have the answer you were looking for, but its probably the correct one....

- Wes


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## Chaos (Oct 27, 2005)

Running 2 ohms on each channel of the deck is almost certainly the problem. Kenwood specs their power ratings at 4-8 ohms, and does not recommend nominal impedance lower than that.

What you need is a four channel amplifier for the highs that can drive two ohms per output, which is the vast majority of them.


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## sqshoestring (Jun 19, 2007)

Chaos said:


> Running 2 ohms on each channel of the deck is almost certainly the problem. Kenwood specs their power ratings at 4-8 ohms, and does not recommend nominal impedance lower than that.
> 
> What you need is a four channel amplifier for the highs that can drive two ohms per output, which is the vast majority of them.


Yes.

A lot of amps/HU reduce output now instead of protecting/shutting down. A HU amp is something you use for talk radio or desperation or a temp thing, they don't work that well.


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## ChrisB (Jul 3, 2008)

I've been through this before regarding Infinity Kappas:



























If for some reason you think my crapsman meter is inaccurate, I can repeat the reading with a 5 month old Fluke 117.


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## goffmj (Feb 4, 2011)

Thanks for all the replies, guys. Sorry for the lack thereof on my part; took a much needed vacation over my birthday week.

Anyway, now I'm thinking it has been my speaker setup this entire time, with my previous Alpine and my current Kenwood. That's a frustrating thought, but one I probably should have considered first. Though I may rerun my ground just to be sure.

You're right, all I have currently is the HU amp. I had thought with my front speakers being smaller 4x6 plates that them being 2ohms would be less of an issue. So, do you guys recommend investing in amps for the front and back? Or getting some 4ohm speakers for the front and back instead? I really only plan on keeping this car another year or so, but if I can find some cheap amps, I may invest the time of installing them. Would love something bigger than 4x6 in the door, but as I said, I only plan to keep the car another year or so, I don't know if I want to do too many modifications.


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## goffmj (Feb 4, 2011)

Ok, new question. As it sounds right now, my front sound very under powered. These are my Infinity Kappa 462.9cfp's. I love 'em, but they're so small.. Anyway, would it be worth powering them with a 2 channel amp? And then maybe leaving the rears on the HU amp until I get my new car and go more in-depth later.


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## sqshoestring (Jun 19, 2007)

I think you would be far happier with an amp, and you can use it in any car. A 4x50 would work wonders and they are fairly cheap you can get a RF prime for ~$100 and a kenwood for little more, those are very well known names. Or go used I am sure you can get many good amps for under $40-50 shipped if you know what brands are not junk. An 8ga kit will run one of those they are cheap, just have to wire it to your HU wires, tap into them so you can 'cut and run' when you bail on the car and just plug a HU back in. You can get a roll of deadener at home depot/etc look for gutter repair tape in a small roll. Pull your panels and put a couple layers around the speaker to deaden it and over any holes near it, that will help bass/midbass from them. Last time I bought some it was $7 or so. Get some lamp cord in bulk unless you find some HT wire on sale for better price. 8ga kits are cheap on amazon and epay, check at walmart too. Cheap enough and you can leave that stuff in the car.

I should add, if you really want to cheat put a power booster in your car that is exactly what they are for. Don't expect high volume like an amp, but the EQ can help a lot and some of them do get louder than any HU. Or find an amp with an EQ built in if your HU does not have EQ.


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## Vancomycin (Mar 21, 2011)

sqshoestring said:


> I think you would be far happier with an amp, and you can use it in any car. A 4x50 would work wonders and they are fairly cheap you can get a RF prime for ~$100 and a kenwood for little more, those are very well known names. Or go used I am sure you can get many good amps for under $40-50 shipped if you know what brands are not junk. An 8ga kit will run one of those they are cheap, just have to wire it to your HU wires, tap into them so you can 'cut and run' when you bail on the car and just plug a HU back in. You can get a roll of deadener at home depot/etc look for gutter repair tape in a small roll. Pull your panels and put a couple layers around the speaker to deaden it and over any holes near it, that will help bass/midbass from them. Last time I bought some it was $7 or so. Get some lamp cord in bulk unless you find some HT wire on sale for better price. 8ga kits are cheap on amazon and epay, check at walmart too. Cheap enough and you can leave that stuff in the car.


Great advice from sqshoestring (as always)!


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## sqshoestring (Jun 19, 2007)

I been running this 4x50 dragster I bought on epay for $36 iirc shipped a few years ago, it looks 8 to 9/10 pretty nice condition with the cable cover, fan cooled, supposed to be a good amp in the EU but not known much here. It works great IMO its not much quieter than the Kicker 4x70 I had in there or the alpine 345 4x75, just a little less and the clipping is fairly mellow if I go there and has better breakup than the kicker actually. That is important to me because I tend to run smaller amps hard as they go, and I can still hear lol, but I never play them clipped I hate that. Its been in there since last summer it works that well. Have to drop a 4x125 class D in now that I just got. I have at least half a dozen 4ch or pairs of 2ch I could have in there instead.

Just trying to help, and trying to understand why everyone into audio does not have a few amps in the closet in case of emergencies....lol.


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## goffmj (Feb 4, 2011)

sqshoestring said:


> I think you would be far happier with an amp, and you can use it in any car. A 4x50 would work wonders and they are fairly cheap you can get a RF prime for ~$100 and a kenwood for little more, those are very well known names. Or go used I am sure you can get many good amps for under $40-50 shipped if you know what brands are not junk. An 8ga kit will run one of those they are cheap, just have to wire it to your HU wires, tap into them so you can 'cut and run' when you bail on the car and just plug a HU back in. You can get a roll of deadener at home depot/etc look for gutter repair tape in a small roll. Pull your panels and put a couple layers around the speaker to deaden it and over any holes near it, that will help bass/midbass from them. Last time I bought some it was $7 or so. Get some lamp cord in bulk unless you find some HT wire on sale for better price. 8ga kits are cheap on amazon and epay, check at walmart too. Cheap enough and you can leave that stuff in the car.
> 
> I should add, if you really want to cheat put a power booster in your car that is exactly what they are for. Don't expect high volume like an amp, but the EQ can help a lot and some of them do get louder than any HU. Or find an amp with an EQ built in if your HU does not have EQ.



Really appreciate the advice! As my setup sounds now, I'm not sure I could make it a whole year, lol. So I think I'm going to return the Kenwood deck (hopefully they'll take it) and invest in an amp. A local place has a Kenwood KAC-8405 available for $150. Seems like a nice compact 4-channel amp. My thoughts were to run 2 channels to the fronts and 2 channels to the rear for now, and then later if I go the component route in my next car, I could ditch my rear speakers and bridge those 2 channels for a sub, correct? Really trying to adopt mobile electronics as a hobby, just wish I had the car I knew I would be keeping for a while, then I wouldn't be trying to cut so many corners in my setup here. And of course, I'd like to install the amp myself. The only way one learns.  But perhaps I should make a new thread for that.. Thanks again for the help!


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