Polk Audio MM6501 components with Polk Audio PA D5000.5

PhiDeltBeers

Ok, I just bought a brand new Lexus IS-F (good-bye Nissan GT-R ) with the Mark Levinson stereo. I've already torn the car apart and have purchased the following items:

Audiocontrol LC6i
Polk Audio MM6501 component speakers
Polk Audio PA D5000.5 Amplifier

Already own:

JL Audio 12" W3 (2Ohm) Subwoofer

This is the biggest car audio project I've ever attempted. I have alreay figured out all of my signals coming from the stock Mark Levinson amp, so they are ready to be wired into the Audiocontol LC6i when it arrives.

So, I've been reading on here a lot and have learned that "bi-amping" the MM6501's might be better than just running, both, the midwoofer and tweeter through the supplied crossover. I'm toying with running the midwoofers off the front channels of the D5000.5 and the tweeters off the rear channels. I would also use the supplied crossover on the tweeters only.

Here's where I get confused.... It seems the D5000.1 has a band pass filter (BPF) on the front channels only and range from 40Hz to 4000Hz. I'm just trying to figure out if I should run the midwoofers through the band-pass or simply run the high-pass from aroung 60Hz? Or should I just set them up they way they were supposed to be and use the supplied crossover for both, the midwoofers and the tweeters.





FWIW, this sight has really helped me to this point! I'm getting there...just need a bit more advice. Thanks!

PhiDeltBeers

Anyone?

SHould I set the midwoofers to 4000Hz low pass and around 60Hz high pass and let the supplied cross over do its thing with the tweeters? Or just set the midwoofer at 60Hz high pass? At this point, I've only run 1 set of speaker wires to the doors to just run the crossover on both the midwoofers AND the tweeters. I'm trying to figure out if it's worth it to run another set of speaker wires to bi amp the components. Then, if I do it, how to set them up.

Arun, Macleod, dskip...any advice?

arun1963

Ok, lets start at the top.

Bi-amping normally refers to running each driver on a separate channel but via your passive xover i.e. fixed cut off point for mid and tweeter. The MM xover does not do that. However with that amp, you can ditch the passive, run each driver off a separate channel and have variable xover points. That's called an active network.

Run the mid bass off the 'Fronts' after you have selected BPF. This option will let you run your mid in a band pass i.e. cut off at the low end, beyond which the sub takes over and at the top, beyond which the tweets take over. Set the LPF to 4000 (all the way right) this gives you the cutoff at the top. Set the HPF to 80 (all the way left) this sets the cut off for the lower end.

Hook your tweets to the rear, select HPF and set it to 4000. With your sub, start with the lpf all the way down at 40. Now start raising it slowly to the point you feel the sub blend well with the mid bass. You don't want the sub to overpower the MB and make the sound boomy. If 40hz is 7 o'clock, you probably don't need to go much beyond 9.

MacLeod

Not much left to add as that about sums it up.

I gotta say though that's its pretty damn cool those new amps have that extensive a crossover network in them.

arun1963

Mac,

Have you tried the new pa 4000.4? or was it just the 2ch version?

PhiDeltBeers

Thanks Arun! This is the exact info I was looking for! So just sit the passive crossover to the side and this setup should prove to be much better? Also, the EQ on the stock Mark Levinson HU is crap. It only has a treble, mid, and bass. I guess, without buying an aftermarket EQ, I'll just have to play with it a bit? I'm also assuming I'll just have to "toy" with the gains on the sub, mids and tweeters to get a good blend.

I'm never going to compete in stereo competitions as I was just looking to get a bit of better sound out of my car. The Harmon Kardon stereos in my previous BMW's blow away the Mark Levinson. Just hoping to get some decent sound, but from what I've researched, I believe I've purchased some pretty good equipment. Just have to learn to tune it now.

MacLeod

By bi-amping and with that flexible crossover, you'll be able to dial in a pretty good sound even with just a 3 band EQ and playing with different levels between the mid and tweet. Generally you'll have the tweeters gain set a little lower than the mids or you could keep them the same and use the faded control on the head unit to change their levels.

Arun- I haven't tried any of the D series amps. The 2 channel I bougt was the PA330.

PhiDeltBeers

Thanks guys...hopefully when I recieve all the hardware, I can get it set up as discussed here. Also one more question..., The Audiocontrol LC6i has 6 input channels. The stock Mark Levinson stereo only has 1 sub woofer, therefore, only a positive and negative. When connecting the ML sub speaker wires to the LC6i (let's say channel 3 input), do I just use either a left or a right channel on the input?

PhiDeltBeers

Amp came in today and it's been frustrating. I was running the new speakers off the stock amp and it sounded very good. I'm working on it tonight and have hooked up the amp and the LC6i. There is a LOT of static on the bass notes and a loud buzz. I have the gain turned all the way down on the amp. I've double checked polarity on all speakers. I'm just completely stumped. Anyone have a clue as to what I might check next? I'm going back to reading the manuals at this point, specifically the LC6i.

PhiDeltBeers

Ok, so I figured out the gain levels on the LC6i had to be "calibrated", then set the amp gains. It sounds good at volume, but I have a "hiss" sound now at no volume or even if I turn the audio off. It's mainly noticable through the tweeters. Any of you guys have some recommendations on what might be causing this or how to get rid of it?

PhiDeltBeers

The higher I set the gains on the LC6i, the more hiss I get. Conversly, if I set the gains lower on the LC6i the hiss goes down, but I have to compensate with the gains on the amp (by turning them up) and the hiss comes back.

MacLeod

This is what's gonna happen when you use speaker level inputs. The only thing you can really do about it is either get a head unit with RCA outputs or get big enough amps where you can turn the gains on the LC6i down to the floor but still have enough power to have good volume.

PhiDeltBeers

I was afraid of that. I was hoping the the Polk Audio PA D5000.5 would have enough power, but it might not. Looks like I might have to just find a "happy medium" and see if I can live with it. Ugh!

MacLeod

No dude, you're going to need monster amounts. A friend of mine in MECA competed for years with a stock head unit and laid waste to the field but had to run literally 300 watts PER DRIVER to have enough juice to get over the noise floor.

You won't need that much for daily driving but you'll need more than 50-75. I'd think 150 per channel would be a good place to start.

Vital

Or get an external good quality line driver in between your LC6 and PAD5000.5.
Tru SSLD6 comes to mind. Probably one of the best line driver/conditioner there are but will cost you about $200 used.

PhiDeltBeers

Might look into that as well, but I'm still tinkering and it's getting better. However, I just noticed something interesting on my lunch break. When connecting my factory sub wires (brown and lime green) to the LC6i, it's outputting a high frequency. I even took the sum jumper of to test it. I'm curious to know if the LC6i is able to take 1 set of speaker inputs into just a left or right now and work like that? So, essentially, I'm not getting the low sub frequencies. Noticed this when setting the low pass filter to around 60hz and hardly anything was coming out of the sub even at maximum gain settings. Maybe I should just hook the sub into a cheap scosche LOC and run that to the amp and just do the compenants off the LC6i. Oh the joy!

PhiDeltBeers

Been researching the line drivers a bit. Any reason to go for the $200 ones as opposed to say $50 - $80? Only need a 2 channel with my setup. And anyone else agree with Vital, that this could be what I need instead of going with a more expensive amp. Heck, at the end of the day, I could just sell the LC6i and go with an MS8 for the same money I'd be spending on the LC6i and a high dollar line driver. Opinions?