Stock 10 speaker setup impedance?

[Eric]

Hi. Just resurrecting this thread, and possibly broadening it (I may also start a new one if the title seems to be misleading).

I've got a blown rear 10-speaker 4" midrange and need to replace it.

I've disassembled the speaker retaining shelf and taken measurements, and can see how a 5¼" midrange can fit easily, a 6½" maybe with a fair amount of ingenuity.

Looks like most component tweeters can be made to fit without much trouble in place of the 1½" unit that's in there.

So, here are my questions:

1. There is an adapter linked in a post above, model SAK-1203.
It appears to be only available in the UK and Europe (I can find nothing in the US, whether on eBay, Amazon, or just through Google searching).
Any idea whether I can get this in the US?
If not, it shouldn't be too hard to create an adapter with ¾" plywood, but a bolt-in solution would sure be nice.

2. Has anybody had either good or bad results with specific component speaker setups?
The Boston Acoustics SE-50s listed above are discontinued.
Obviously, most decent 5¼" speakers should perform about the same in this application, but my main question is about whether there are any that are particularly well suited to the crossover point used by BMW between the midranges and the tweeters - the feeds for both of these are separate, and are crossed-over at the amplifier, so it would be easiest to just connect directly to the car's wiring, and not use the included crossovers, especially since the midrange outputs will have no highs, and the tweeter outputs will have no midrange.

Any and all input would be welcome, before I spend my hard-earned cash.

Thanks,

- Eric

[zoner]

Eric-

The vendor for the SAK-1203 adapters is located in the UK, but I was able to purchase them and receive them within a couple of weeks (I'm in Los Angeles). The adapters allow a 5.25" driver to fit perfectly in the stock 4" location. Unless you get extremely creative, I could not determine a way to easily fit a 6.5" driver in this location due to clearance issues with the seat belt mechanism for the rear seats, or without having a portion of the speaker hang over into the parcel shelf area.

For the drivers, I used the Rockford R-152s component 5.25" drivers. Correct impedance and power range and while the sensitivity is a little lacking compared to other, more expensive drivers, they sound great and fit perfectly. You'd be hard pressed to find another 5.25" speaker with a rated low frequency limit of 58 Hz.! I took the tweeters from the package and used them in another setup. The only thing I wasn't especially keen about was the foam surrounds. While this is what helps give the speaker a 58 Hz. range, its longevity in an automobile environment is less than that of a butyl rubber surround. I think I paid about $89 for the pair, which was more than worth it, IMO.


SAK-1203 adapters

Rockford R-152s component system

[Eric]

Thanks, Zoner. I went back 30 of 88 pages in the "Interior and ICE" section, to 2008 (I find the Search function here a bit unwieldy - it likes to take a series of words as an "OR" search, which is fairly pointless), and found these four threads that had some relevance:
6½" speakers in stock rear bracket 4/26/08
busted speaker 2/25/09
Another Rear Speaker Upgrade... 5/24/11, and
4" Speaker Options? 1/14/12

In the last thread, PartsExpress is suggested as a good source of components, and I will admit that I have used them in the past, and forgotten about them.
One member suggests the Dayton Audio ND140-4 5¼" Aluminum Cone Midbass Driver, which actually looks like an excellent speaker for the location, with 4Ω impedance, up to 40W RMS power handling, 54 to 8k Hz response, and 85.3dB sensitivity.

PE also shows a Tang Band W5-1138SMF 5-1/4" Paper Cone Subwoofer, which looks like it would be great for the front kick panel woofer location, with 4Ω impedance, up to 40W RMS power, 45-1,500 Hz response, and 82dB sensitivity (so long as the amp crosses the woofers over low enough).

I know that some people have done some metal crunching and gotten 6½" speakers into the kick panel locations, but I will probably skip that, as I am not in the mood for major destruction.
I'm going to search and see if I can find anything about the kick panel woofers, other than to replace them with MB Quarts, before I place an order, but, as I have gone through five years of posts in the area and seen nothing, I doubt there will be much.
The key question is the crossover point. Driving those woofers at more than 1,200 to 1,500 Hz would sound messy.

I also have to search PE for 1½" diameter 8Ω tweeters, as I might as well do those, too while I have it all apart.

I will buy those English speaker adapters (Pip, pip! Cheerio!), as it'd be more than $30 of work for me to fashion something.

Thanks for the advice, and I will post information about how this all works out.

- Eric

[Eric]

A quick update:

Those Tang-Band W5-1138SMFs look nice, but they aren't right for this setup.
Aside from their depth of 3⅔" (specs I have seen seem to indicate about 2 9/16" with the sound deadening in place, a bit more without it but I haven't checked myself, as it's 10° out, with several feet of blowing snow), their response rolls off heavily after 1,500 Hz.

I used a handy iPhone app as a signal generator, fed it into my stereo, and swept it, while holding a pillow over the door tweeters, and had surprisingly loud sound out of the kickpanel speakers to at least 2,500 Hz, and a decent amount to 3k, so installing these using the stock amp's crossover frequencies would leave a big hole.

I've settled on the Dayton ND140-4s for the kickpanels. Their depth is 2½", and the tiny neodymium magnet won't interfere much even if it's a bit long. They're rated at 54-8k Hz with a sensitivity of 85.3dB, which will I think be enough. Looking at their response curve, they're pretty darned flat to 3k, and reasonably smooth to 5k, which should be fine.

I also bought a pair of Dayton RS125-4s for the rear midranges.
They're "5 inch" speakers, which means they're a bit smaller than 5¼s, so they won't work with the British adapters, but they look to be about the same size as the factory units, so I'll come up with a way of adapting them.

I picked them instead of 5¼s because their specs were just plain better, especially for a mid-bass unit. They've got a really smooth response, which starts really low with about 80dB at 50 Hz and 85dB at 75, then hits 90dB at 200 Hz, and basically stays there to 3k.

Dayton also makes an RS124P-4, which is supposed have slightly improved characteristics, but it was slightly less efficient, with slightly more variability starting around 1,400, where it is still crossed in in the BMW system, so I skipped that one.

I also bought a pair of Pioneer TST15 tweeters, which I will take apart and fit (probably hot-glue) into the original rear mounts.
These are 4Ω speakers, and I believe the originals were 8Ω, so I've bought a few 1, 2, and 4Ω 10W resistors (10Ω potentiometers are about $20 apiece ) - if they're too bright, I can put an ohm or two in series and tone them down a bit.

This stuff won't show up right away (kick panel speakers are backordered), but I'll report back on how it all worked.

- Eric