bose 901 driver surround repair replacement

[adason]

you are right mhtplsh
i was refering to parts exspress kit
ed

[stoolpigeon]

Why not repair and sell them? Surely you will get more than $50??

sp

[critofur]

Originally posted by adason
you are both poor in mathematics
link I gave you cleary states it is 10 surrounds for the price of $39.90
20 surrounds therefore is $80 unless you buy four kits and you get the price break
in my opinion those 901 speakers were junk than and are junk now, but one man's junk is other man's treasure.
i would like to see those far superior speakers for $80 you would build, ingvar, if that would include drivers and enclosure, it would be junk for sure

$80 eh?

Four of these midwoofers for MTM (perhaps dipole): http://madisound.secureserverdot.com...oducts_id=1757

Two of these tweeters: http://madisound.secureserverdot.com...oducts_id=1496

Two 8" woofers for "bass bins" lower low freq. cabinets, perhaps these?: http://www.partsexpress.com/pe/showd...number=299-826

The most expensive parts might end up being inductors, to save money, find some big AC motor being discarded (not too hard if you live in a big city and just watch the sidewalks for such things being thrown out) then salvage the wire and wind your own inductors. I know with the price of copper having gone up so much such things are harder to come by recently though. If you keep looking, eventually you can find some discarded copper wire...

Lots of people throw out furniture, you could use discarded drawer units/kitchen cabinets, etc. for the wood to build your cabinets to save money...

And, you could probably build something that sounds better than your typical $2,500 store bought speakers.

[mlise]

An old 901 is a great period piece. Especially if you have the funkey stands. I actually added Vifa 1" silk dome tweeters to mine and don't use the processor. They certainly don't have the fidelity of modern speakers so I keep them out in the back yard in the greenhouse. For a few bucks for foam surounds, latex glue and an afternoon, you'll have some rockin' party speakers. Remember, the flat sides go to the room and the 8 drivers on the back bounce off the wall.

[Inductor]

Originally posted by mlise
An old 901 is a great period piece. Especially if you have the funkey stands. I actually added Vifa 1" silk dome tweeters to mine and don't use the processor. They certainly don't have the fidelity of modern speakers so I keep them out in the back yard in the greenhouse. For a few bucks for foam surounds, latex glue and an afternoon, you'll have some rockin' party speakers. Remember, the flat sides go to the room and the 8 drivers on the back bounce off the wall.

If you don't use the processor how do you work out the boosted low frequencies from the 901s?

[sreten]

http://cgi.ebay.com/BEST-26-Pcs-BOSE...QQcmdZViewItem

/sreten.

[adason]

$80 eh? Four of these midwoofers for MTM (perhaps dipole):http://madisound.secureserverdot.co...roducts_id=1757 Two of these tweeters:http://madisound.secureserverdot.co...roducts_id=1496

that might work critofur!

[TICUL38]

Any further research/repairs done by the the originator on this thread?
FWIW, I recently listened to a pair of 901-II using both an Accuphase E-202 and a Mosfet moded Dynakit ST-120 Amplifiers...these clearly revealed the limitations in the 901 box/driver combo. Can't point any fingers to Bose, but need to admit the 70's technology/knowledge base on hand to put together sound boxes cannot compete with what you can do today with relatively less investment. Speaker design technology is now at the point where anyone so inspired can put together some pretty decent sound reproducers..question is how can one be certain of starting off with "good" drivers.
The Bose 901 series II drivers (all 18 of them from two boxes) are only good to experiment with. The ones I extracted from my boxes have been tested for TS parameters..since I plan to put together something different than the 901 style acoustic suspension box for these drivers. So far, I have just started considering what mods I need to make on the drivers...since these have cloth surrounds (Bose slightly sealed the cloth with a tacky substance), and paper cones that need to be sealed.
The listening session at the onset indicated a mid frequency boxy sound and lack of the high end response....both of which, IMO, should not be "improved" electronically using the 901 Active Equalizer (my ear-brain link does not like).
FYI, the drivers have Fs around 75Hz, Re=7.0 ohms, Vas=6 to 7.5L, Qe=0.34, Qm=1.6, Le=0.45 mH, ...these are average values
I will probably add weight to the diaphragms in search of a lower Fs (PVA coating and split lead sinkers as used many times by John Crawford reporting in Speaker Builder).
If interest appears, I will follow with progress in due time...I am running many rabbits (retiree)
Louis

[Inductor]

i'm interested in knowing the t/s parameters for one (of those) driver(s) only, and output/impedance in freq. (/graphs), for those people that want to find one to build a similar speaker. Thanks

[Luke]

adason was kind enough to post a link to the surrounds. We don't need to continue driving the Bose product into the ground do we?

yeah we do