I am going to upgrade the stock speakers to 5.25 front and 6.5 rear.

Should I use the stock door enclosures?

Should I cut out the back of the enclosures?

Should I use MDF and make a baffle?

I have heard that enclosures are too small and hurt midbass.

I have a GS4.

Late.

Ryan

 

I kinda have the same question. I have Focal Utopias (6 1/2's)
in modified factory front door enclosures in my SC 400 and it doesn't seem like I'm getting the midbass I should. They are in phase, so that isn't the problem. Maybe somebody can give us an answer.

Shane

 

The pods in my Mk I GS are around 2 litres volume in the front and about 4 litres in the back. I know some people on the list have done it, but I would be wary about using anything larger than a 5 inch speaker in these. The enclosure volume is much too small.

The stock woofer crosses over to the door speakers somewhere around 100 Hz. If you fit a 6.5 inch speaker, the midbass will roll off too early and there will be a gap in the response between 100 and 200 Hz.

I'd suggest you fit five inch speakers front and back. A 130 mm driver fits nicely without too much cutting of the pod - any bigger than this and you're into serious cutting. It's a good ideal to fix a wooden sub-baffle to the front of the pod, as this will move the driver closer to the door panel cutout hole and also stiffen the baffle. I'm sure Percy has got a much better handle on this than I have - but that's what I did.

If you use 6.5 inch drivers mounted on a baffle to take advantage of the door's larger interior volume, they will probably extend lower than 100 Hz, which will give you a response bump around 100 Hz = boomy bass. You cannot adjust the woofer crossover frequency on the stock amp.

Stevie

 

Stevie is right Ryan. Just got off the phone with a buddy of mine who is an installer at Custom Car Stereo right there in Houston.
Told him about the midbass problems with my Utopias. He told me they needed a minimum of .5 cubic feet. OOps!! Guess I'll be pulling the pods and just doing a baffle board. Time for some Dynamat Extreme in the doors. Should be pretty easy. The pods were a pain in the ***. Glad I spent all that time on those

Shane

 

Thanks...hopefully this will be useful for some other folks...

I spent hours cutting the crap out of the pod to fit that damn 6.5". I'll probably leave as is since it is the rear. I was already planning on doing some matting...I am leaning toward raamat.

What about the fronts? How much too small are the enclosures for 5.25 inchers?

I thought those little boxes would help!!!

More feedback....maybe some first hand experience!

Late.

Ryan

 

The door enclosures are very small and do not allow much lower output from the speakers, What we have done with the LS is beef up the stock mount, cut the back out and then matted the door the way I mentioned. We got alot more midbass, very important for realistic sounding music. If you do not want to do that then just sealing up the door and matting around the factory enclosure, the back especially with at least two layers, will still help it sound better.

 

You have to work around what Lexus has already done - or go for a completely new system. An average five inch driver will mate with the stock woofer quite nicely. I measured my Vifas and they had the identical rolloff to the stock Pioneer drivers in the pods. They were about 3dB down at 100 Hz (from memory).

If you try to go lower by opening up the pod and using the whole of the door as an enclosure, the response will not necessarily match the subwoofer rolloff. You could end up with boomy bass.

If you let me have the Thiel-Small parameters of the Focal, I'll model it for you.

Stevie

 

I have MB Quart 5.25s in the stock front door enclosures. The mid-bass is incredible. I have gotten 10 out of 10 for midbass at three of the four USACi SQ competitions I have attended (one 9 out of 10) and two near perfect scores on mid-bass at SLAP competitions.

IMO use a 5 1/4 in the door and be happy.

Todd

 

Ryan,

If your Focals are model Utopia 165 W, you should be OK. The theory says that they will be around 3 dB down at 100 Hz in a 10 litre sealed enclosure. I think that's about .4 cubic feet which is my guesstimate of the door volume.

You could experiment with the port if you like. As it stands it will give you an extra 3dB centered on 150 Hz, which will probably be too much. Try packing it lightly with speaker damping material like dacron or foam to bring it down a little. Or just seal it completely to get your sealed enclosure.

Stevie

 

Definitely do the Raammat over Dynamat Extreme, Raammat is so much cheaper and works great.