hans14914

It does make sense to me, and the way the factory grill is setup, the new proposed grills do cover the mounting diameter of the stock grills. The proposed tweeter grill is infact larger in diameter - so no issue there. On the midbass driver, the factory mounting ring (part that contacts with the door) is about 124.8mm, so the proposed 125mm grill will cover the 20+ year old stock indentation.

Thanks for the comments.

Hans

Bill Ball

Hans, great work. My greatest need is for a punchy 6.5. I actually believed that the original stock 6.5s were fine w/o a separate sub. They didn't rattle the windows but they had tight, usable bass (at one time) despite the essentially open chamber behind them. Still, I'll most likely buy a whole speaker kit even though I have some decent 4s and tweeters in front. I've just never been happy with any substitute 6.5s in the rear. Looking forward to your announcement of the kit(s) for sale.

sweet928

I just put in a new Nak MBV1head unit and have a unusual set up with 4" round speakers in the lower door (where the carpet is). I bought some JL Audio TR400-CXi's but they have a lot of gaps around the round cut out because they mount with 4 tabs instead of round woofers with 4 holes like what you seem to have pictured. I'm going to return them because gaps like that will make the speakers sound like ****. When will your speakers be ready and can you sell me just the pair of 4" speakers with grills? How much would they be? Got a picture of the grills?

hans14914

Bill,

there are a couple solid 6.5" options out there. We can chat via email or PM. I am sure I can recommend something that will work if my 6.5" driver does not go into production. Get in touch and we can figure something out.

Sweet928 - I am sure we can work something out on the drivers and grill package. I imagine you would want some kind of high frequency driver. These start rolling off pretty sharply at 7khz... they weren't designed to be a full-range solution. I have cad drawings/renderings for the grill. The tooling is being made now, and I wont have physical parts for some time.

Thanks
Hans

Speedtoys

Can I buy these now?

blazing928

What a fantastic job!! Well done, I will buy a set for rainy day or a second 928.
[My car is going all Brax, HT1 tweet, Matrix 2.1 & 6.5"s mounted in the lower door.]

Bill, a good free air 6.5" is a Rainbow Profi Kickbass, these thump hard from 80Hz to 180Hz.
They are specifically designed for doors etc which usually cannot be sealed. You would need the Rainbow cross overs. I am not sure how they would sound in the B pillar, it would pull the sound behind you, so not ideal. Other alternatives are DD, CDT, Hertz, but, if Hans is making specific speakers to suit the 928, then at this price point, these would be the better option by far.

Hans, you are educating about good sound and the pointlessness of the rear speakers, now to some sound deadening 101! +1 for Second Skin audio products!!

JPR928

Hi Hans!

Thanks for this super work!!!! I'm in for a set! How do you want payment and when will the goods be ready?

Two comments:

1.) I found a guy in Germany who will rebuild the original Bremen SQR 46's that were often shipped with the 928s. So, the cassette will work like new again. He can also modify the "Vorverstärkerausgang" to work as an input for an iPod!! I do intend to use your speaker set with the Bremen SQR 46. Do you see any problems here? Do I need to send you the details on the stock head unit? I actually don't know if the stock 928s with this head unit had a seperate amplifier or not. I doubt it though.

2.) Also, the grills will be slightly different in size. At least they will cover the old grills in so far as the indentations from the old grills will be hidden. Good. So, would the mounting be otherwise the same? How will we do this? I understand that the mounting points for the speakers and grill will be the same even though the grill is slightly larger, right?

Boy, this thread motivates me even more to move my *** and get a 928 GT ASAP! For long road trips, good music is a must!

JP

hans14914

Just got back from SITM. I took a set of drivers so people could take a look. Everyone seemed to be pleased with the execution.

Regarding availability, they have been ordered, but i was quoted a 90-day manufacturing window. So, between the actual time in production, shipping, and then packaging... etc, they will be ready to send to you by the end of summer.

I need to check on the grills today and see when they are slated to arrive. I will update shortly.

Regarding the grill and mounting, they use the same mounting points as stock, and they will cover the indentation of the stock drivers in the doors.

These drivers could be used with the stock headunit, amplifier, and crossover. They will fit and work, but you would be loosing quite a bit of the advantages of the new drivers. I would instead reccomend leaving all your stock wiring in the doors, and just fishing new dedicated wires through the door looms. This will allow you to use the purpose built crossovers, or power them actively, but still let you return the car to stock in a short amount of time.

You may want to reference my other parallel product the SharkWoofer for an easy way to add both a new 5-channel amplifier and subwoofer.

Thanks
Hans

Speedtoys

Hans:

Fantastic...cant wait to send ya $ for these once available.

Put me on the list..if yer keepin one.

royth

Hans,

Sounds fantastic and put me on the list as well .. you had me on board at SITM !!

Being a non-electronic guy will you have installation instructions for the wiring, connections etc ?

hans14914

Yes, documentation will be supplied. This is designed to be as easy as it gets for a 928 speaker replacement. Factory crossover can be used, but not suggested. Running new wire through the door loom for use with modern amplifier will be the suggested path (but not the only documented route).

Thanks for the interest. There will be an update to this thread tomorrow, with renderings of the custom grills and estimated delivery dates.

Thanks
Hans

JPR928

OK, so that means that you can tell us where to send the checks now, right? :-)

Tom in Austin

Great work Hans, I'm in for a set of these

hans14914

I dont quite have pricing nailed down yet. I still need to work out a few things on the crossover front.

However, here is where we are at on the project. The custom 4" drivers are in production, and should be completed between July 15 and July 20. After that, allow for a maximum of 40days for shipping, customs... etc. I should received everything by the middle of August.

Included in that shipment will be custom grills, for both the 4" driver, and the the tweeter. The tweeter grill is a very nice part, and is inspired by the 89+ version of the stock component. It angles the tweeter towards the occupants 20degrees, and it also angles it up 20degrees. Thus, the opposite occupant receives the far driver at approximately 30degree-off axis. The near driver will be approximately 50degrees off-axis. This is a HUGE improvement over the standard driver location on most cars. When I was at SITM, I noticed that lots of the later model cars had the tweeters replaced at some point with earlier models using the strait adapters. These place the tweeter in a way that in the best case scenario, the close driver is 80degrees off-axis and the far is about 45degrees off axis.

What this means is better imaging, perceived increase in volume, and better overall tonality, as the frequency response will be much flatter. The farther off-axis, the steeper and faster the roll-off of high frequency material. This translates into an easier crossover design (read less expensive) also it reduces the need for additional signal processing like loads of EQ. This is a custom part, exclusive to me, and designed for the 928 specifically. As mentioned before, it is designed to hold the 3/4" Vifa NE series tweeters. There are several dome formats to choose from, but I would recommend the standard aluminum or silk dome - depending on your tastes. I will design the crossover in a way that either tweeter can be used with a jumper selection (the silk dome is more efficient, and will need to be padded down to match the 4" driver. FS and other appreciable factors are very similar, so the same crossover can be used for both drivers).

You may look at the above passage and wonder why make custom tooling, and opt to use a 3/4" dome instead of say a 1" or even larger format driver. The 1" dome has become the mainstay of the autosound industry, and is now pervasive and deeply routed. It is not a bad format, but it does have several drawbacks, especially in 928 usage. If you look at the dispersion characteristics of a larger format dome, it has pronounced roll-off off-axis. The smaller the radiating surface, the more linear the driver performs the farther off-axis you are to the driver. In the 928, the drivers are always severely off-axis. Even with the custom tweeter mount, we still are far from ideal. So, using the smaller format driver assists in keeping a very linear response curve. Additionally, it has some added qualities inherent to having less mass - they are very fast and detailed. Finally, the efficiency tends to be a little less with the smaller format drivers - usually around a 2-3db drop in efficiency as compared to a 1" driver. While normally this would be a "bad" thing, in our application, it works to our advantage. The lower efficiency in the tweeter matches the lower efficiency of a 4" driver (again less radiating area) so we dont have to artificially pad the tweeter to bring its level down to match the 4" driver. The combination of the 4" driver and the 3/4" aluminum dome is very close in efficiency, and would not require any padding in the crossover design.

I will be posting pricing on the kit as soon as I can. I have fixed costs at this point for all the grills and speaker components - the only unknown is the crossover.

I have been working on an active crossover kit that will be an extension of the SharkWoofer product. It will have all the necessary mounting plates, wiring... etc, to use the suggested Kenwood XR-5S amplifier in a 2.1 configuration where the primary four channels are used to power the door components individually. This allows each channel to be actively processed, including time delay. The result of this configuration would be the best possible installation adhering to the principle of "do no harm" and not modifying the stock systems in any permanent and irreversible way. It is worth noting, that in this configuration, the other speaker locations would be left dormant. A subwoofer plus properly implemented and specified door speakers will yield the best system possible. More drivers arent necessarily a better thing. They collapse the soundstage, and if not actively processed, will just cause "noise" as the music will arrive at your ears at all different measurements of delay resulting in a very muddy sound.

For those who really want to have more speakers, I will have some suggestions on how to implement additional drivers.

So, after all that, here are some pictures and renderings of grill components. The grill mesh that I will be using is a standard round perforation. The hexagonal perforations shown are for a different project. While the tweeter cup is an exclusive part, I split the tooling cost of the 4" grill with the owner of the basket tooling that I am using for this project. That is also why the speaker in the rendering looks different than the posted pictures, it was a stock CAD file, and that driver has the same basket.

Thanks
Hans

blazing928

Hans, are these HAT speakers? or related?