Speedtoys

Most of the OE 6ch systems used a 4ch amp, just fed the far back speakers, from the back seat set.

Unless you're that really rare concours (Read Pebble Beach) where an insane amount of originality matters, skip em...and even so, I've never seen a judge as to operate and inspect each expected driver, even there. A PCA regional concour checks lights, doors, etc..Ive never been asked to make sure the cassette player works even...it does.

I would expect any respectable audio system architect to frown heavily on using the quarter window drivers too. Maybe they worked well for the adult back seat passengers that wanted to hear Vivaldi correctly at a stop light.

Kiwi928S4

Sage advice indeed - however now that the cars are fetching $2M originality will be highly prized?

Speedtoys

That was not a normal 928..rare is the movie where the car is arguably the co-star, in a generation defining movie...my car wont be that..it was well outside the 99th percentile sale.

Kevin in Atlanta

This raises an interesting question. For those who are not looking for audiophile performance can a decent system be put in place using modern speaker components?

Decent sound system that replaces the head unit, door speakers and uses coaxial 6.5 speakers in the B pillars.

Does sound really improve with separate tweeters and midrange speakers in the doors? Could a coaxial midrange fill the bill?

Not everybody needs a Hans level subwoofer in the rear. Can a spare tire subwoofer do the trick?

Just pondering. I've spent big bucks on audiophile home systems in the past. And not such big bucks on 928 audio systems. Though nowhere the level of Jeff/Speedtoys.

And this is from somebody who's daily driver has no radio (Boxster pocket in the space.) , no door speakers and does not miss them on all my short and long drives.

Instigator56

You definitely can improve the bass with a spare tire subwoofer. I used this one: https://www.crutchfield.com/p_109BAS...ub.html?tp=114

Speedtoys

Yes to all of your questions...mostly.

No head unit alone, has a decent amp built in, its a packaging and heat issue. You will always _be wanting_ with just the head unit.

DSP enabled multi channel AMPs are not that cheap...all the way up to $1100, this is where, IMHO, you should spend as much as you reasonably can.

I have Hans's front door drivers, and 20yr old MBquart rear speakers, and im sure a rather "generic" spare tire sub configuration would be just fine too...

Big $ is in custom fabrication if you want a bespoke project...but the HW itself doesn't have to be.

Separate drivers for specific ranges, shopped well, always outperform a single driver as well.


It's all a series of compromises when youre on a budget.

A decent set of drivers, a descent head unit feature wise (because you will never use its amp), and a sub with it's own amp (cant share this with the front four to eight (depending if you active or passively crossover each driver) cant do the sub as well in a compact package.

rexpontius

Yep, a good Head Unit, good amp a DSP and a nice sub is all you need.
In my 86.5 I have a Phase Linear 8" sub in the spare wheel well, a pioneer DSP, the Blaupunt retro headunit and the stock ITT tweeters and midranges.
Staging is perfect, and the ITT's actually sound pretty good!

Zero need for rear speakers.

chart928s4

Something went sideways in a couple of places I think.

First the more interesting one to think about: @Speedtoys I think your 1 foot/sec is correct, but (unmeasured guess) the left side tweeter is only about 18" from your head, and the so-called "woofer" is probably 1 foot. That makes it just 0.5ms of mud, which is not too bad. One the right side it's practically no difference in distance. So a 2 way in the back seems like it should be no problem.

However, with that said, I totally agree a time delay head unit will definitely help the sound and that a good coax 6.5" speaker will sound great. But of course even with time delay every driver is reflecting like crazy and you'll still get some mud.

On the crossover issue, unless you're using the wacky original amp, you will likely have 2 front and 2 rear full range speaker outputs. You should definitely wire the "woofer" to the rear full range, and then you can use a simple crossover at the woofer terminals to feed the tweeter on that side.

No?

Speedtoys

True, but i'm also measuring delay from the impulse source, to the microphone. Sorry if that wasn't clear. Without software help, you could just measure distances and be good too. Depending what hardware you use and the number of filters/etc, you will get 1-9ms delay in software too.

In REW you use the sound source (USB-C to TosLink adapter) as a loopback source internally so the software can time waveform genesis (input to system) to sound pulse at mic...yes, including the near speed of light paths.



Yes, there is echo, but..its not nearly as important as initial impulse timing. REW lets you view echo as well..it falls off in DB level pretty quick, and if your tweeters are not pointing straight across the car at a window..it's reduced quite a bit...the higher the frequency the more distinct the echo will be. Thats why I have damping on my closet doors at tweeter level in my living room only...don't need it where the tweeter cant fire.

Sit where you sit..and if you can see the tweeter with a mirror in that position, you need to treat -that- surface. High frequencies are super directional, and do not disperse very much. They are (in a small space) planar-like, they fire on a plane, as designed by the driver surface. The wavelengths are so short that the 'wave' doesn't disperse much in the room you have. the lower the frequency, the more spherical ACTING the waveform is, in a limited space. Of course, neither is actually planar...high frequencies are not a straight line like a laser pointer, but in a small space they act like it.

High frequencies also dont load up in corners either..they die quickly.




Hans' tweeter package points at the meat bags in the seats, not glass..the issue is moderately mitigated with passengers in the car.

The Forgotten On

Hans' tweeters basically aim the same as the factory 89+ 10 way system you have.

So you could try to find a tweeter that will fit into your existing cups or you can contact Hans and get a set of cups from him and install a set of Peerless NE19VTS-04 3/4 inch tweeters.

They sound great, especially when you factor in their affordable cost

chart928s4

@Speedtoys While I couldn't see the label on your giant home speaker I suspect it sounds pretty good (what is it?). I went a different direction and got bookshelf speakers + a huge sub for my tiny home theater, and it sounds pretty good too. So there is more than one way to get good sound.

From my perspective, improving the worst-performing component will make a better system than incremental upgrades to better performing components. Speakers are always the worst performing part of a stereo, and high quality drivers will, in my untested and humble opinion, give excellent sound with a 2 way in the back.

So back to the OP's post: What is proven to fit in the tweeter hole? Only the Peerless with Hans' adapters?

Speedtoys

The towers are Pols Audio SDA SRS 2.3TLs (Rebuilt 2019)
The side surrounds are Polk Audio SDA 2Bs (Rebuilt 2019)
Three SVS PC-4000 Tube Subs
2x MiniDSP DDRC-88A DSPs with Dirac
And then a B&W center, front atmos, and rear surround.
Sony 5000ES Receiver (Not doing any amplifier duty)

The amplifiers are
Sunfire Grand Cinema 400w x 5
Sunfire TGA 400W x7

...no way that fits in the car..


And youre right on with speakers...nothing can make a bad speaker sound good.