[tdgesq]

The grey clips work fine. I've used both. Just installed my door boards as well.

[snaimpally]

Originally Posted by kaigoss69

Dynamat not only reduces/eliminates rattles, it also makes your drivers sound better as it adds mass to the baffle and absorbs vibrations, that would otherwise lead to cancellations.

Dynamat provides mass loading so that surfaces do not transmit vibrations as easily. For sound absorption, use something like Dynaliner, Ensolite, Volara, etc. For example, http://www.thefoamfactory.com/closed...foam-roll.html.

For best results, two layers of Dynamat and a layer of closed cell foam (the thickest you can fit) do a great job.

[snaimpally]

Can you please post pics of the underseat woofer? I'm curious as to how they make it fit and what the grill looks like etc.

[Wongway]

Originally Posted by snaimpally

Can you please post pics of the underseat woofer? I'm curious as to how they make it fit and what the grill looks like etc.

I don't know why I never thought to take pictures of it beforehand, but thankfully, my installer/friend did.

[Wongway]

minor update for myself:

Again, total novice when it comes to tuning sound. So I've had to do a lot of asking and guessing. Don (6spdcoupe) has been more than helpful with suggestions and things to try.

So, with 6spdcoupe's advice, I flipped the phase 180degrees on the passenger side 4"mid. Figured, if the theory was sound, I'd also flip the driver side tweeter 180degrees as well.
Soundstage instantly sounded like it just extended beyond the confines of the car. As if I wasn't impressed with the door boards already, my mind was pretty well blown by what I got out of this.

[kaigoss69]

Lost you on why you reversed polarity on drivers side tweeter.

[Wongway]

I honestly could be wrong on why I did this. But for the moment, I'm still pretty blown by the effect.

The theory I could garner sort of works like this:
(I used a Butterworth crossover for the tweeters and the high side of the 4"mids, don't have a good explanation why, I just liked that sound from them with that crossover)
In the crossover range there is some sound duplication; the tweeter and the woofer are both emitting the same sound signal, but out of phase. With two signals 180 out of phase, they cancel each other.

Not sure if I applied the theory correctly, but making that assumption, I figured, might as well try it.

I also figured that the reason for flipping the passenger side mid was to compensate for the phase impression with the driver side mid being so close and the passenger so far.
Going farther with that thinking, was why I tried flipping the driver side tweeter.
If my assumption was correct;
It would keep the driver side tweeter and woofer from cancelling each other out, as well as tweaking my ear's impression of phase from the left and right sides.

[kaigoss69]

Originally Posted by Wongway

I honestly could be wrong on why I did this. But for the moment, I'm still pretty blown by the effect.

The theory I could garner sort of works like this:
(I used a Butterworth crossover for the tweeters and the high side of the 4"mids, don't have a good explanation why, I just liked that sound from them with that crossover)
In the crossover range there is some sound duplication; the tweeter and the woofer are both emitting the same sound signal, but out of phase. With two signals 180 out of phase, they cancel each other.

Not sure if I applied the theory correctly, but making that assumption, I figured, might as well try it.

I also figured that the reason for flipping the passenger side mid was to compensate for the phase impression with the driver side mid being so close and the passenger so far.
Going farther with that thinking, was why I tried flipping the driver side tweeter.
If my assumption was correct;
It would keep the driver side tweeter and woofer from cancelling each other out, as well as tweaking my ear's impression of phase from the left and right sides.

I understand your reasoning, but I believe the passive crossover designs already compensate for the phase shift (tweeters are connected in reverse polarity inside the crossover network). I believe this is only true for 2nd order (12dB/oct) filters though.

Cars are strange listening environments for many different reasons, and it certainly never hurts to experiment around like you did to see if the change has a positive or negative effect.

I would like to hear from Don if the reason for his suggestion is based on the design of the Jehnert crossover, or the specific acoustic phase response of our cars. I've never tried flipping that mid, but perhaps I should give it a go!

While we are on the topic, I also remember hearing that Ken at MusicarNW once may have recommended flipping the polarities of both underseat midbass drivers. It would be great if one of the vendors could comment on this topic. While phase relationships between the different drivers in the system is a very complicated thing, the common denominator is the fact that the driver positions in relation to the driver (the human one ) remain fairly constant in every case (e9x platform), so if the professionals out there have already tested this and confirmed which polarity arrangement works best, we could all benefit from that.

I have actually never attempted to play with phase in this car because the MS-8 manual recommends for everything to be connected in the correct polarity, and the processor ends up making the necessary corrections through EQ. Might be an interesting exercise though nonetheless...

[6spdcoupe]

Originally Posted by kaigoss69

I understand your reasoning, but I believe the passive crossover designs already compensate for the phase shift (tweeters are connected in reverse polarity inside the crossover network). I believe this is only true for 2nd order (12dB/oct) filters though.

Cars are strange listening environments for many different reasons, and it certainly never hurts to experiment around like you did to see if the change has a positive or negative effect.

I would like to hear from Don if the reason for his suggestion is based on the design of the Jehnert crossover, or the specific acoustic phase response of our cars. I've never tried flipping that mid, but perhaps I should give it a go!

While we are on the topic, I also remember hearing that Ken at MusicarNW once may have recommended flipping the polarities of both underseat midbass drivers. It would be great if one of the vendors could comment on this topic. While phase relationships between the different drivers in the system is a very complicated thing, the common denominator is the fact that the driver positions in relation to the driver (the human one ) remain fairly constant in every case (e9x platform), so if the professionals out there have already tested this and confirmed which polarity arrangement works best, we could all benefit from that.

I have actually never attempted to play with phase in this car because the MS-8 manual recommends for everything to be connected in the correct polarity, and the processor ends up making the necessary corrections through EQ. Might be an interesting exercise though nonetheless...

That's easy for me to answer .. he doesn't have passives and Is fully active.

[Bicax]

I was wondering if these would be a good replacement for underseat woofers for those who already have a trunk subwoofer?

[kaigoss69]

Originally Posted by Bicax

I was wondering if these would be a good replacement for underseat woofers for those who already have a trunk subwoofer?

Of course!

[Bicax]

Damn... When the hell does this "upgraditis" stop?...

[6spdcoupe]

Originally Posted by Bicax

Damn... When the hell does this "upgraditis" stop?...

Unfortunately, never !

[kaigoss69]

Originally Posted by Bicax

Damn... When the hell does this "upgraditis" stop?...

You didn't get your upgradeitis shot this year?

[Bicax]

You're right, I got one hell of a shot. But then I read things like these and...

I just have to stop coming here

[taibanl]

Originally Posted by 6spdcoupe

Unfortunately, never !

Shouldn't it be 'fortunately' for a guy in your position?

[Bicax]

Originally Posted by taibanl

Shouldn't it be 'fortunately' for a guy in your position?

Not if he's spending all the money he's making on getting door boards for his car

[6spdcoupe]

Originally Posted by taibanl

Shouldn't it be 'fortunately' for a guy in your position?

I wish it was, but it is also not a 'click and buy' type of thing either. I also spend countless hours with emails and the phone. The OP can certainly attest to this !

Besides, what makes you think I don't have my own bites from upgrades too ?

[6spdcoupe]

Originally Posted by Bicax

Not if he's spending all the money he's making on getting door boards for his car

Sadly .. not as much margin as one would think And they don't offer them for my car.

[emoon3]

Originally Posted by 6spdcoupe

I wish it was, but it is also not a 'click and buy' type of thing either. I also spend countless hours with emails and the phone. The OP can certainly attest to this !

Besides, what makes you think I don't have my own bites from upgrades too ?

Don has certainly gotten a couple, "I was thinking last night and I think I want to change everything we just discussed..." emails from me in the last week or so.

He calmly talked me back down to Earth - even though it would have meant more money in the sale for him.

Don, I promise no more of those emails from me. Not that I don't stay up redoing the system in my head most nights mind you...

[Wongway]

Really, if I could think of more ways to send money and business his way, I would. I don't think I've ever run across anyone that's been as helpful before and after the sale as Don ever has been, in any business!

[6spdcoupe]

Originally Posted by emoon3

Don has certainly gotten a couple, "I was thinking last night and I think I want to change everything we just discussed..." emails from me in the last week or so.

He calmly talked me back down to Earth - even though it would have meant more money in the sale for him.

Don, I promise no more of those emails from me. Not that I don't stay up redoing the system in my head most nights mind you...

I try my best ! Definitely some interesting conversations !