bose 901 speaker replacement ideas

[req 5,000+ posts]

i have a pair of bose 901 cabinets from back in the eairly 70's that my dad wants to use, but all the surrounds in the cabinets (its a line array of 8 speakers on the back and 1 one the front) are totally thrashed and disentegrated.

here is a few shots -

EVERY speaker is destroyed because of non-treated supfoam surrounds :'(

and heres the crazy wiring diagram

says on the bottom "for normal recievers use only "+" and "-" terminals, see owners manual for use of "*" terminal."

now, my DMM ran out of batteries and was a POS so i dont have one at the moment. it SAYS on the internet they have a nominal impedance of 8ohms, so im guessing its some crazy weird way? i dont know if each driver is 16, 8, or 4 ohms.

i also cant find ANY T\S params for the speakers. i want to REPLACE EVERY DRIVER with something like the NSB's that wereon PE for $0.50\each, because we all know boston wasnt the greatest equipment ever.

the MOUNTING DIAMATER for the speakers is exactally 4-1\4 inches and i can fit about 5" speakers at the biggest. i was looking at these;

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-370

but they are 4ohm each, and as you can see the diagram shows that the stock speakers are ALL ran in series, and the only config that i can see for anything near nominal impedance of 8ohms is all 1 ohm coils in series. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

if i did all 4ohm coils, i wouldnt be able to hook up that front speaker, but i could get nominal of 8ohms, i would be able to run a set of 4 in series for 16ohms, and then the pair of 16ohm series arrays, in parallel for 8ohms.

how would i hook up that front speaker?

or better yet, can anyone find me some drivers that are manufacturered for CHEAP (im talking SUB $10\each and NOT a REFOAM kit?

thanks for the help - many minds are greater than one i always say //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

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[wilzyx 5,000+ posts]

if there are 8 drivers then they should be 8 ohms each

# of voice coils x impedance of voice coils / # of drivers = ohm load

8 x 8 / 8 = 8 ohms in series

these should work i guess they are the same ones you linked to but 8 ohms

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-372

 

[req 5,000+ posts]

there are NINE drivers if you read my thread.

8 on the back, one on the front.

http://www.the12volt.com/caraudio/boxcalcs.asp#ser

throw nine SVC 8 into the series calculator, tell me that its 8ohms.

 

[wilzyx 5,000+ posts]

oh ok, i was wondering what that extra circle was. why the hell would they put an odd number of speakers in? and have no clue on how to get 9 drivers to 8 ohms.

hmm this is quite a conundrum

 

[req 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

thanks for puttin your brain to work. i dunno what im gonna do. maybe if i got a 4 channel reciever and hooked something up wierd i dunno le-sigh.

 

[Prowler573 5,000+ posts]

The OEM drivers in that enclosure may have had a very non-standard inpedence that you won't be able to source in a commercially available replacement driver.

Additionally - you do not have to run all of whatever you put back in there in series, do you? I cannot see why you absolutely have to rewire it the way it used to be. Retrofitting isn't always putting things exactly back the way they were originally - things get changed to upgrade or enhance. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

So - with that in mind - could you do SVC drivers for the back 8 and a DVC driver for the front? Yes, on the same power source the DVC driver would see a different level of wattage than the rest but I'm just looking for ideas here...

 

[req 5,000+ posts]

well, i thought about that (see post before yours of mine)

and i could get a dvc 4 speaker or summin. the good part is each speaker has its own "enclosure" but the 8 speakers on the front are set up so that each set of 4" speakers use the same port. its some sort of weird T-Line-line array lol.

and the front speaker is like a normal ported enclosure with its own port and everything. so if the front speaker ended up having its own weird volume then maybe thats what would have to happen.

 

[Prowler573 5,000+ posts]

Bose speakers = Teh LOSE //content.invisioncic.com/y282845/emoticons/mad.gif.c18f003ab0ef8a0d9c27ca78d77a6392.gif

My wife has a pair of 501s that her mum gave her. Still intact and play fine - but no high end extension to speak of. They'll make nice bookends, I think.

 

[req 5,000+ posts]

lol, better than the television speakers, and he really liked them and spent a buttload of monies back in the day.

and nothing a tweeter and xover cant help lol //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Prowler573 5,000+ posts]

lol, better than the television speakers, and he really liked them and spent a buttload of monies back in the day.
and nothing a tweeter and xover cant help lol //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Yes, yes he did. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

I reckon springy will and I will keep hunting around online but manoman ~ You've presented us with a bit of a challenge, fella!

 

[req 5,000+ posts]

well thanks, ill keep my eyes open too //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

stupid bose 901 shizt.

 

[req 5,000+ posts]

cmon guys any idears?

ill do my best to get a DMM and find the resistance on those coils asap.

 

[BassAce 10+ year member]

How about this:

http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=3

My bad you said no refoam kit in big bold letters to catch attention in which I failed to look at. My bad.

 

[Darth Audio 10+ year member]

I think MCM has replacement drivers, but unfortunately my catalog is at work and the search I did on their site was fruitless. (Their search engine sux!) If you do not have a solution by Mon. I will look it up in my catalog for you.

 

[req 5,000+ posts]

i would really appriciate that, and if you can get me a price on each driver that would be sweet.

thanks mang.