How to set C400.4 dials

JBHorne

Hello. I am new to the forums but not to Polk! I have been installing Polk products in home theaters for a few years, but this is my first attempt at car audio. I installed everything myself in a 2006 Ford Explorer Eddie Bauer.

My setup:

Pioneer AVIC-Z1
Front Doors - Polk Audio MMC5250 (passive crossover / single input)
Rear Doors - Polk Audio MMC570
Subwoofer - Polk Audio SR124DVC
All new wiring running directly to amplifiers
C400.4 for all 4 door speakers
C500.1 for subwoofer
Plus capacitor, distributed fuses, etc.

Anyways, I am running into a problem. The door speakers all sound funny. They are sharp in the upper range but lack midrange "punch". I have the equalizer set to flat, HPF off, and no other "enhancements". I guess I must have a problem with my settings on the amp. I am testing this with the sub turned off, and I just don't seem to hear any midrange. I honestly have not spent any time tweaking anything yet, but how should I set the switches and gains on the C400.4? It is frustrating me because I am simply not getting any good midrange out of any of the four speakers! I don't mean that it is just "not there"...it is...just "muted".

Any suggestions to start with? What about the "Crossover x1 or x10" settings and such?

Thank you very much!
Justin

vawakemonster

I think your speakers could be out of phase check your wiring.

MacLeod

Welcome to the Club brother.

A few things:

First off, Polk speakers are notorious for being kinda thin in the midbass when theyre first fired up. However, after a few hours of playing they start to break in and loosen up and really start to come alive. Within a month you wont recognize them!!

Second, make sure you turn the tweeter's attenuator on the MMC5250's crossover to -6 db. That should help a ton.

As for the gain settings, I would disconnect the sub and rear speakers then turn the front gain all the way down. Now stick in a CD that best represents the type of music you listen to and is superbly recorded. Now turn the HU's volume up to no more than 3/4's. Now turn the gain up on the front channels until the speakers start to distort slightly. Once they do, back it down a smidge until the distortion goes away.

Now set the rear gain all the way down, reconnect the rear speakers and start bumping that gain up til it blends in best with the front speakers. Itll probably be a little lower than the front. After that, reconnect the sub and adjust the sub amp's gain til it blends in best.

None of the gains should be above the "noon" position.

JBHorne

So yeah. I'm an idiot. Who knew that white was positive??? LOL. So I just reversed the wiring at the amplifier for all 4 speakers and damn they rock now. So all I have to do now is adjust the gains a bit. You discuss the "break in period." How long should I wait before turning of the volume loud?

Thank you guys a million.

Justin

MacLeod

I would wait at least a week before getting too loud with them. Theyll take about a month to fully break in but if you set your gains properly, you wont be overdriving them so after a week they should be ready for some spirited listening.

JBHorne

So how do you set the bass boost knob and the one next to it (not sure what it does....boost at certain frequencies???) on the C500.1? what about the crossover point? Can I not just let my headunit control the LPF and HPF @80HZ?

Also, should i set the gains by listening to them, or by the voltage calculation method? if i do the calculator/volt meter method, how do you connect the volt meter and what settings to use.

Thanks guys,
I'll post pictures soon.

vawakemonster

I would let your HU do the HPF and LPF and expirement around with that on the HU alot. MY mm2104 SVC doesnt sound right unless its LPF is at 63 or even 50 80 souns meh and anything above makes it sound thin and crappy. and then set the amp to all ranges.

I think the 3/4 volume and turn it till destortion and then back off method works fine but I wouldnt let my gear get that loud for about 8 or so hours of listening. so about a week. unitl you set the gains.