Rick

Tech-Law,

Please keep me posted - I am interested if this moves forward.

Thanks.

graham_mitchell

DC, interesting point! Thanks. Car audio is so full of compromises... You could use a digital processor to delay the driver side channel enough to achieve near perfect synchronisation of the two channels. DSP can solve so many car audio problems - I think it will become de rigeur before long

Ahem... back to the group buy

Greg H.

This may be a stupid question in a thread with Phase Angels and Alignment Coherence, but would this subwoofer thing work with just one instead of two? I'm sure more is better, but by how much? I'd like to be in the group buy at about 50% of what Tech-Law is talking.

I called Speaker Works, who did an install like this and they said they could make a sealed enclosure for around $500 each in quantity. They suggested the single sub. Do they know what they're talking about?

Greg H.

Tech-Law

I apologize to all who've sat through our babble - this thread got way OT.

Back to the point - I'm just trying to offer a somewhat elegant solution to a difficult problem - reproducing low frequencies in a Porsche without giving up the backseat or hacking into the sheet metal.

Single Sub is fine - it just won't move as much air as a pair. I'm sure they'd be willing to accommodate if there's enough interest from the group. All those who are interested please chime in or PM me.

DrZ

DC is correct about pathlength equalization. It is the acoustic basis for kick panel mounting of both the mid-range and tweeter that creates such awesome imaging. additionally, reversing one of the driver's polarity in my case placed the female vocalist directly in the center of the dash. Using sound processing to achieve similiar effects is less desirable IMO because it introduces more opportunity for noise and distortion and further deviates from the warmer analog sound that I prefer (another reason why I chose Dynaudio over Focal or MB Quarts).

Regarding on or off axis, I agree that the former is generally more desirable, but in the case of the half dome shaped Dyn MD100 tweeter less of an issue than it's proximity to the mid-range. If I had elected to go with the 260 as opposed to the 360, I would have been tempted to use the ultra high end Esotar tweeter which has a different crossover freq. and may have made up for the absence of the MD140 driver. This might have made for a simpler install and avoided some of the configuration challenges created by the 3-way system. As it is now I have no need for a subwoofer. I am curious to know how Tech's frequency curve looks on the RTA. I noted a significant improvement in the SQ after tuning with 1/3 octave equalizers. "Re-tuning" the door enclosures also was very important and substantially improved the mid-bass and perceptually improved the deep bass although admittedly the repeat RTA was not dramatically different. There however is very little tactile resonance of the either the armrest or inner door panel. This is essential, particularly if you are going to use an 8" as your sole bass driver.

Regarding Speakerworks, yes they do excellent work, they are not inexpensive, and Eric Holdaway is the contact guy. He likes working on Porsches and rest assured you will be dealing with one of the highest regarded shop in the industry.

Rick

Tech-Law,

What about expanding the buy to the door panels as well? That should be pretty attractive since the fabricator should have molds already built.

Thanks.

Tech-Law

Door panels are ceratinly available as well. Any one interested should let me know.

I haven't gotten the car on an RTA yet. I want to let the drivers break in a bit.

YellowC4S

I'd be interested in the sub enclosures. However, minus the drivers and I have a pair if Image Dynamics 10"s

DrZ

Tech, Eric's ulta sensitive RTA shows that the low end pretty much drops off under 45Hz. Response above is near pertfectly linear. Bass nonetheless sound deep, and crisp w/o any hint of distortion or boominess. Dyn people tell me it should hit 35Hz but after full door enclosure wood to metal baffle, double layer of the best Cascade dampening sheets, 10" Cascade deflex pads, neoprene acoustic coupling at all contacts points, 400W Brax amp and 1uF Brax IPC I can't do any better! I would be interested to know if your enclosure goes lower. If so, do you really need a SW?

Tech-Law

I haven't spent any real time with the stereo. My car's been at the mechanics for over a month getting tweaked. But I did notice the upper midrange was a little muddy when last I heard it. I think it's because I'm asking the 8" drivers to act as sub, bass and midrange. Plus it just doesn't get as low as I'd like - this might change once the drivers loosen up a bit. The addition of a sub and a higher crossover point might take some stress off the driver and clean up the whole system.

I'm also just a nut for low, musical bass.

John H. in DC Area

I'm interested, however only if I can use my existing 8" drivers from Rod Birch, as they were selected to work well with my Butler Tube Driver amp. Also, the install looks clean in your picture, but it's hard to tell where the mounting points are for the rear enclosures (that's a good thing, a clean install). Can you explain how the enclosures are affixed, do they use the same screw points as the OEM panel?

Also, I would like to hear your report of the system once you've got it on the road. In particular, I'm interested in hearing that the mounting is rattle-free even during spirited driving or urban streets.

Thanks for sharing!

Tech-Law

That's actually not my sub install pictured above. It is a picture of my actual doors however.

We're using the above sub photograph simply as a "go-by" and trying to improve on the design/execution.

I'm sure the AKA guys will devise a creative and unobtrusive mounting system as they did for officemanager's subwoofer that clips into his rear seat and then fits perfectly inside the spare tire when you need to use the seats. Check the archives and I think you'll find some photos of that car - which was a Cab.

I can't comment on whether your existing sub will fit. The depth is the real issue. A call to AKA would likely answer the question.

I think any potential rattles would be dealt with via careful design, execution and padding of the rear of the enclosures.

The AKA team has built many, many award winning audio systems in all amplification classes and they are perfectionists. This leads me to believe that the end product will be likely be the best solution possible.

John H. in DC Area

Thanks for the response, Tech-Law, I think I'll wait to hear your first-hand report.

Rick

Tech-Law,

Can we get an approx price if we're able to arrange a group buy for the door panels? The only change I'd make is that I wouldn't be putting the tweeter in the door panel.

Thanks.

Tech-Law

I'll ask about price - although I think you're making a mistake leaving the tweeter in the stock location - if you don't want it in the door panel you should do a kick panel up front. IMO, putting the tweeter right next to the driver's ear is right up there with the decision to have Nokia design a "hi-fi" system in a $80,000 car...