Bose 901 series III PROBLEM!

c_corie

Bought some great shape 901s (for my dad), which have apparently been refoamed.

Hook them up, and anything with bass it buzzy distorted. Yes the EQ is hooked up. It seems like the 1 of the speakers in the back of each of the cabs, is either totally blown, or did not get refoamed right. Any tips on how to tell, they all look the same? Also what are the chances of the same speaker(location) in each cab getting blow? When looking from the back it seems to be the lower most left speaker(s). Any tips?

zarrdoss

push it evenly around the cone and see if the vc scrapes, pull the suspect ones and unhook them make sure the wires don't touch and see if it stops If the re-foam was not done right and the vc is not aligned properly it might be the problem.

c_corie

I don't see any screws/bolts, just holes? Did the series III have like a locking driver position? There doesn't seem to be anyway to get them out.

AudioGenics

Series III--1976 to 1978, Acoustic Matrix (ported cabinet) Drivers use 3 bolts.

zarrdoss

this might help could be glued in or the gasket is acting as glue, might have to pry on it gently

http://www.audiokarma.org/forums/showthread.php?t=148636

c_corie

It appears to be, on closer inspection. one group of the 4 back speakers. Which I hope is a wiring issue, cause how could 4 speakers next to eachother blow, but not that front, or other rear 4? I still can't get them out, maybe the guy glued them in, if he took them out to refoam them:(

zingo

c_corie wrote: »

Bose 901 series III PROBLEM!

It's because they are Bose 901s...

It does sound like a wiring issue if it is a group of drivers, but that still wouldn't account for the buzzing.

madmax

It would take a lot to actually blow any of the speakers. I'm guessing some were not lined up properly by whoever refoamed them. As said above, push them in and see if the voice coil is rubbing. I doubt (but don't know) if they have an electronic network of any kind in side so probably not a wiring problem.
madmax

kawizx9r

+1 with what everyone has said due to the voice coil rubbing. I mean think about it, if he had to refoam all of those drivers or even half of them there's always a possibility of him making a mistake. That or getting fed up after refoaming the 4th, 6th or even 12th driver and just not paying as close attention as you would after the first one.

c_corie

So voice coil rub would/is causing what sounds like a badly distored output especially on low freqs? The cabinets are in PERFECT shape for the late 70s, and so is the EQ, but my dad is now considering trading them in, for the Bose new 901 upgrade. They said something like $599, but I still feel terrible that I didn't notice these speakers were making that sound when I went to check them out for him. (Low volume and no EQ hooked up, so I figured that's what they sound like.)

So should I try to refoam, the ones that need it? It seems like it maybe around 8 of the drivers need it, just by listening to them speaker by speaker. OR should he just trade them up towards brand new ones at what still really is like a $500 discount (after factoring in buying the first set was $250.)?

kawizx9r

If its even 8 of them then I can't really say what the culprit here might be. As far as determining whether or not it IS the actual voice coils, you would have to get to each driver and apply pressure evenly on the cone. If you hear a "rubbing" noise of some sort from some but not from others, it means the voice coil is rubbing all because the cone wasnt sitting in its place properly while being refoamed. The surrounds could actually cause a little bit of "pulling" when the drivers show excursion. Test each one out as well to make sure none of them are blown, goodluck to ya anyway though with what you decide.

Keep in mind, even though one member mentioned they can handle huge amounts of power, if they were damaged I'd have to say possibly because they were being underpowered while being played at high levels.....that is if the issue were something else.

ctef

Hi, I see it's a little late for ansver of this quest, but if someone need, I can share my experience with BOSE 901-III.
I own 2 pairs of them,a EQ-IVs,a 550Receiver and Spatial Receiver.;)
And in the begining met similar problems...

bluecomet

I had those speakers and were not a big fan of them. I sold them and bought more vintage Polk speakers and never looked back. The bose 901 series 6 speakers are better then series 3 and don't have foam to rot. They do not compare to SDA speakers and are pathetic compared to SRS speakers.

ctef

Yes,I'm very far from the thought, they are the best speakers :-)
If I compare them, it can be only with full-range speakes.
Reading contrary opinions about 901s, I became very curious about them. That's why I decided to try 901s at home. In the begining met big difficultys. But in the time overcomed some of them and have some explanations...

Toolfan66

ctef wrote: »

Yes,I'm very far from the thought, they are the best speakers :-)
If I compare them, it can be only with full-range speakes.
Reading contrary opinions about 901s, I became very curious about them. That's why I decided to try 901s at home. In the begining met big difficultys. But in the time overcomed some of them and have some explanations...

Welcome to club polk!

CRESCENDOPOWER

TOOLFORLIFEFAN wrote: »

Welcome to club polk!

http://stores.ebay.com/Polk-Audio-Direct