[jkdas]

1) Polk looked yummy!
2) GZ isnt my type But it get fed up a very juice mono. *jealous* . The sub;s too boomy for my taste. Plays tad wide too,no depth too. Big box?
3) I was wondering why such a setup sounds funny... I want a sub to be hidden. In his setup, music was disjoint. Sub played from rear, highs from windscreen (liked it when I kept my head on the steering wheel). Well,it was coz he has the tweeter pointing towards the windscreen. Changed it to point as its now in the pix,as myself and redFire it played better and in tandom with the sub.
4) Vocal is not not what momo does well or its about tuning? It wasnt alive enough for me.
5) Maybe the 40x4 needs to be changed to something more powerful. Maybe momo needs more power.
6) More damping too I presume.

[greenhorn]

overall, i think it needs some tuning, and tuning the 9887 is not a task for mere mortals. I was stumped by the HU to be honest, and its settings are a mess.

the highs were more , but still very rough and bright, thats why the tweeter was moveded fwd and put on a seperate channel ( and toned down).

similarly the sub was subdued earlier - it was a polk sub, but the poor JBL amp had no control.


bottom line - initially the front comps were playing very loud and very clean, but they sounded rough and bright, even at higher volumes. the alpine amp has taken care of that, and the sub wasnt up to the task earlier.

now we have a brawny amp driving a brawny sub, and some toned down front speakers. probably why it sounds like this. There were also some phase problems. I think the sub's phase has been corrected, but wonder about the comps

iPlay, what frequency is the LF crossover for the sub set to ? i hope to 80 Hz or less. dont remember what it was before

[iPlay]

Originally Posted by greenhorn

iPlay, what frequency is the LF crossover for the sub set to ? i hope to 80 Hz or less. dont remember what it was before

It was 80Hz. You changed it 63Hz. But my untrained ears couldn't pick up any noticeable difference.

[Bass&Trouble]

Originally Posted by iPlay

It was 80Hz. You changed it 63Hz. But my untrained ears couldn't pick up any noticeable difference.

This could also be because the crossover from the mono is set to 63 Hz or under. If this is true, the crossover from the head unit will be redundant for anything above the crossover frequency set from the amp.

Just try with the commonly used 80Hz/ 12dB for fronts and subwoofer both at the head unit. After saving this to a preset, go to the Setup menu and while a song is playing keep reversing phase of the subwoofer and keep whichever makes the bass sound better.

Of course, before doing the above setting, please make sure -

1. there is no equalization happening at the amp

2. crossover frequency is set to 80Hz or higher

3. Gain level is matched to the pre-out voltage of the head unit. This can be increased or decreased later if required.

[DocG]

I believe the Polk MOMOs require a ton of power...Have a friend in the states who uses the MMC6500 (125W rms), and he says that they sound like crap if you feed them less than 100W rms.

His car has a competition level ICE...So why not try pushing them to the max before tossing them...

[cyclops]

Originally Posted by Bass&Trouble

Of course, before doing the above setting, please make sure -

1. there is no equalization happening at the amp

2. crossover frequency is set to 80Hz or higher

3. Gain level is matched to the pre-out voltage of the head unit. This can be increased or decreased later if required.

hi! a bit OT, but i had a small query on the point#3 stated here. in an ideal tuning setup, is the gain set to match the pre-out voltage?

e.g. I have a pio 5050 HU which is having 4v pre-out and the amp (GT5 A604) is having gain range of 6v-200mv. should the gain on the amp be set at 4v for optimum performance?

i am also enclosing the side profile pic of my amp (illustrative). which position should the gain be set in order to make it at 4v (in terms of clock hands).

[Technocrat]

Wow thats some unique setup in a Swift, COngrats iPlay.

Btw could someone elaborate on bi-amping the comps? I didnt understand what it meant.

[Bass&Trouble]

Originally Posted by cyclops

in an ideal tuning setup, is the gain set to match the pre-out voltage?

In an ideal world - yes. In an ideally tuned setup - not necessarily.

But if you are worried that there is something terribly wrong with your setup and don't know where to start, setting the gains close to the theoretically correct point would be a good start.

Post that, you could listen and see if you find the speaker levels too feeble or the bass to be lacking and then fine tune.

Originally Posted by cyclops

e.g. I have a pio 5050 HU which is having 4v pre-out and the amp (GT5 A604) is having gain range of 6v-200mv. should the gain on the amp be set at 4v for optimum performance?

In the case of the pictured amplifier, it is difficult to judge where the 4 volt point would be without using any measuring instruments.

Starting at the 6V position, you could keep the head unit at about 80% of the volume with an original CD of your favorite music playing, and then slowly turn the gain knob clockwise till the point where distortion is audible from the speakers connected to the concerned channels. Then turn it down a tiny bit and leave it at that.

This will not be the 4V position . But it should serve well with music.

[greenhorn]

Originally Posted by Technocrat

Btw could someone elaborate on bi-amping the comps? I didnt understand what it meant.

usually there are 2 pairs of pre outs used for the front and rear comps.

In this case , the first pre out is connected to the tweeters via one amp channel, and the other pre out is connected to the woofers via another amp channel, and there is seperate wiring, and the crossover frequencies are set electronically within the HU.

iplay, are the stock crossovers still hooked up ?

[Technocrat]

In this case , the first pre out is connected to the tweeters via one amp channel, and the other pre out is connected to the woofers via another amp channel, and there is seperate wiring, and the crossover frequencies are set electronically within the HU.

Hmm so since the cut off frequencies are not from amp this is not an active setup?

This is genuine query, will help me in better understanding of active systems.

Also in this case the comps XO are not being used right?

[Bass&Trouble]

Originally Posted by greenhorn

usually there are 2 pairs of pre outs used for the front and rear comps.

In this case , the first pre out is connected to the tweeters via one amp channel, and the other pre out is connected to the woofers via another amp channel, and there is seperate wiring, and the crossover frequencies are set electronically within the HU.

iplay, are the stock crossovers still hooked up ?

Way to further confuse poor "T 4R TECHNO".

Little earlier it has been clarified that he is merely using two different channels of amplifications for the tweeter and midrange while doing the crossover scene with the stock Polk passive network itself. So in all, 4 channels of amplification i.e. a 4-ch amplifier is being used to drive a single 2-way component set.

On a different note, I hope the front channel pre-outs are being used to feed the tweeter channel amp inputs and the rear channel for the midwoofers or vice versa. This way, the TA on the HU can be used to the full extent to correct arrival differences between the midwoofer and the tweeter.

[Technocrat]

Way to further confuse poor "T 4R TECHNO".

You bet I am confused now

How can you give 4 channels to a pair of XOs which takes only 2 channels?

I can understand if the front channels are directly driving the Tweeters & rear channels driving the Mid-woofers(This is what I knew as active setup)

[greenhorn]

How can you give 4 channels to a pair of XOs which takes only 2 channels?

That , even I'm not sure

what you know as the active setup is what he's running.

But i think it would be better of the stock crossover is used for the tweeter , since most are fragile , and need to be protected from any accidental LF content

how the crossovers have been set, I' m not sure , since he said the frequencies were set using the amps, and that the crossovers in the HU had been set to the respective max position.

One thing i was wondering was, in the 9887, if the active 3 way setup is enabled, the fader is disabled(according to the manual), but in his HU, both the 3 way active crossover as well as the fader settings were active !

[hydrashok]

The Polk Momo comps shown have a "Dual Input" (or similarly named feature). They have a switch on each XO where you can choose a "single input" or a "dual input". If you choose "single", a single channel of the amp can power the midbass & tweeter.

If you choose "dual", there will be two wires going into the XO as input -- one for the midbass (one channel of the amp) and one one for the tweeter (another channel of the amp). This way, two channels of the amp will feed one XO. And (from the output are of the XO) each tweeter will be fed by a channel of the amp, and each midbass will be fed by a channel of the amp.

From the pics, I understand that the front pre-outs & rear pre-outs of the HU go into the 4-channel amp (hopefully in the way B&T mentioned).

Two speaker outputs of the amp will feed the left channel XO (one for tweeter & one for Midbass) and the other two speaker outputs of the amp will feed the right channel XO (again, one for tweeter & one for Midbass). The tweeter outputs of each XO are connected to the tweeters and the midbass outputs of the XO are connected to the midbasses. This way, the comps are "bi-amped" through the passive XOs.

The Frequency cutoffs for the fronts & rears are probably set at the HU itself, making the setup "quasi-active".

I guess this is how it is setup.

[Bass&Trouble]

Originally Posted by hydrashok

The Frequency cutoffs for the fronts & rears are probably set at the HU itself, making the setup "quasi-active".

No need for setting any cutoff from the HU for the channels feeding the tweets. The passive crossover is adequate. And he isn't running the head unit in pro mode. So he can't cut the tweets even close to the desired frequency from the HU. HPF of 200Hz must be tops.