Hey guys, I'm getting more distortion than expected as I turn up my volume. Here are the components under investigation:

Source: Pioneer FH-8000BT Head-unit
Amp: Pioneer GM-4300F (100Wx2 @ 4ohms)
Speakers: Infinity 6020cs Reference Series (90W rms handling)

Today I set the gain on my amp to set out 90W when my head-unit volume is turned to 60 (max is 62, and I never go above 45 or so). However, I start to get a LOT distortion around 40, or 2/3 of the maximum power, about 60W.

Now, I know the speakers should be solid way above this, and it's a great SQ head-unit. So my thoughts are this, but I'm looking for system experts thoughts here:

1. Amp is producing a lot of distortion above 60W? That's only 60% of the capacity, and although Pioneer amps aren't top notch, it should be cleaner than it is.

2. I used a 10ga. wiring kit for power. Possible this is insufficient for my current draw?

3. I ran the speaker out from the amp to the speaker hook-ups at the back of the head-unit, then used the existing wiring to the doors. Maybe the stock wiring can't handle above 50W or so?

To avoid other questions, my RCAs and power are ran down opposite sides, I have a good ground (essentially 0 ohm resistance along the ground path), and I used KnuKonceptz RCA cables.

 

Let me preface this with "I'm only trying to help"

I had similar issues with a similar setup. I changed a lot at once to address the issue. New speaker wiring from front to back, didn't use the OEM wiring at all. I also re-grounded what happened to be a poor ground. These two solved 98% of my issues.

Pushing wires through the door grommets is actually easier on the tC than any other car I've done it on... That is as soon as you realize that you can pull up on the wires/tubing in the door to make it a straight shot from the door into the cabin.

Also, are you using the "loudness" feature on your deck? I've found that enabling this on my setup (Premier DEH-P980BT) causes all sorts of distortion- no matter the gains. It's been disabled since I ditched the stock speakers.

 

Thanks for the tips. I'm pretty sure I have the "loudness" disabled, but I'll double check that. I'm thinking the most likely culprit is the wiring, but I'll see if there are other ideas before I tear that out. Thanks again.

 

Well some things I see wrong are using the stock wireing at any point from an amp setup......never good,it is cheap and always leads to issues.

Sounds like you tuned the amp but if it goes to 62,tune it witha tone disk at 45 and set max wattage to the speakers to that level and never go past of course.

Did you solder the wires to the speakers,that can lead to poor sound as well.....

10guage should be fine for that amount of wattage,but may want to goto 8 or 4 wven so you can upgrade at some point in the future.

make sure the speakers are not wires backwards,even factories wire them backwards once in a while,9volvt battery on the wires to see if it goes out or in.

turn off all loudness setings,and make sure EQ is set to flat,try to use amp to crossover from comps to sub,if you need help on where to get disks or how to set crossover points let me know.I got it down very well now.

those are pretty good speakers so they should handle what you are giving them and be very clean.

 

Some more notes from my head/bookmarks

You want to set your gains with your head unit at ~75%, volume (47ish on our decks) This will help with the varying volumes of different sources/media. If possible grab a test tone CD and use that with your DMM. (my preferred method) Make sure you're cars running when you're setting the gains. (voltage increases while the cars running)


Great site for test tones:
http://www.ronelmm.com/tones/

 

Thanks for all the pointers guys. I did use a test tone CD to set it, but at a higher volume, so I'll try with it lower like you both suggest. No, I didn't solder the wires to the speakers.

From the looks of it, I will need to replace the wiring. Any suggestions on inexpensive qualitiy wiring? And what gauge should I use, 18ga?

 

i used 12n for mine but running like 120w to each and wanted room to upgrade to active and more power down the road........14 is a good size,and cheep to purchase.

 

Is the amp running "full-range", such that the speakers are getting the full bass frequencies too? If so, that's your likely cause of distortion, as opposed to any of the other possibilities that have been discussed thus far.

If not, and you're using a crossover, what is your high-pass filter frequency & slope?

 

I'm not running a cross-over, but I can adjust the cross-over controls in the headunit and on the amp. I'll play with them, thanks for the idea.

 

Watching I plan on upgrading my stock headunit so this would help me out a lot

 

yeah too much bass level in the comps will add to distortion,start crossing them at 80hz and see how much lower you can take them,mine are set at 55hz now and that is about all I can go with out them starting to buzz at high volume.

 

I'm still running the '08+ stock sub which runs off the front speaker lines. With my current configuration, if I set the front line at a high-pass filter, won't that also effect the sub? This is undesirable.

I guess the solution is to break down and finally order my sub set-up :D

 

yeah it will lead to some distortion in the sub probably and very littel midbass in the comps.leaving them tinny sounding.

 

i'd check the amp ground wire.