Today's score!!-BOSE 901-III's-in the garbage!-PICS
- Thread starter GD70
- Start date
Hurst/Olds
Member
I'm not really a huge BOSE fan, but those things look very insane! They also look very menacing when all the speakers are showing. Now who would be crazy enough to set those out?
R-2-R
Super Member
There are probably only two types of individuals:
Any one who hates anything Bose. The other, one who simply doesn't know any better.
OP, Fantastic find-save-score! Those 901's are definitely worth restoring.
Keep looking thru CL for the Active Equalizer Series III, one is bound to show up for sale, maybe also a pair of classic Bose tulip stands as well, never know.
GD70
Lunatic Member
I wasn't either except for my 301's which I really like. I wasn't considering another pair of BOSE, though I have always been intrigued by the 901's as they are very cool looking with all those drivers. Only problem is they face the wall, so you wouldn't really see them. Those who have them, say they put out some seriously loud sound.
R-2-R
Super Member
Oh believe me they do indeed. With the right/correct/placement setup along with the right powerful amplifier and matching Bose Active Equalizer they'll kick out that sound.
Edit**two important things to keep in mind...1) Never use 901's for outdoor listening and 2) don't ever try them without the active equalizer because then you'll be very disappointed.
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GD70
Lunatic Member
Why?
Different compliance and damping/absorption of the wave when it reaches the edge of the cone.
I've refoamed two pairs of 901s for a friend, and its a major pain, even if you don't remove the drivers. So I'm keenly aware of the downside of foam. But designers use it because of its acoustical qualities.
Cloth can be treated with silicon compounds and such to give it better damping, but that silicon or whatever tends to migrate downhill over time, at the top, soaking the cone -- is that good? -- and, at the bottom, dribbling off, so its damping properties are lost. Not sure that's an improvement. But its better than the cone treatments that turn to rock -- I've had several Jensens that were unuseable for that reason -- or cone treatments that dry out and crumble off -- KLH and AR, for example.
I am not sure why people who perfectly happily change the oil in their cars a few times a year have a hissy fit when they have to refoam every couple of decades.
I've refoamed two pairs of 901s for a friend, and its a major pain, even if you don't remove the drivers. So I'm keenly aware of the downside of foam. But designers use it because of its acoustical qualities.
Cloth can be treated with silicon compounds and such to give it better damping, but that silicon or whatever tends to migrate downhill over time, at the top, soaking the cone -- is that good? -- and, at the bottom, dribbling off, so its damping properties are lost. Not sure that's an improvement. But its better than the cone treatments that turn to rock -- I've had several Jensens that were unuseable for that reason -- or cone treatments that dry out and crumble off -- KLH and AR, for example.
I am not sure why people who perfectly happily change the oil in their cars a few times a year have a hissy fit when they have to refoam every couple of decades.
A family friend brought me a pair of 901 series II (and equalizer) to restore. He'd found them in a thrift store for $20. Missing one front and one back grills, they smell like a damp ashtray, four of the drivers need replacing and the other 14 need refoaming. The only redeeming quality is that the wood isn't too bad.
My recommendation to him was for me to refoam the 14 drivers to clean up the parts and part the things out. To me they're not worth all that work - to enjoy or for reselling them. While I'm a confirmed Bose hater, I've owned 101's, 201's, 301's, 501's, 901's and several of the Acoustimass/Cube systems but they just don't do it for me. But that's just my opinion.
My recommendation to him was for me to refoam the 14 drivers to clean up the parts and part the things out. To me they're not worth all that work - to enjoy or for reselling them. While I'm a confirmed Bose hater, I've owned 101's, 201's, 301's, 501's, 901's and several of the Acoustimass/Cube systems but they just don't do it for me. But that's just my opinion.
GD70
Lunatic Member
I'll reserve judgement on their sound until they are refoamed and I have the proper EQ. If I don't like them, I'll sell them and make a few bucks, and I figure I'll learn something along the way working on them. Nothing ventured, nothing gained they say.
GD70
Lunatic Member
So I guess foam it is. I've resealed the cloth surrounds on all my KLH woofers with the correct sealer vintage-ar sells. The original sealer was mostly gone after 40-50 years, but there was no run off on the drivers or dribble at the bottom as you describe. I have seen this on JBL's though.
And that's the right reason to go down that road. Aside from my general dislike of owe products, every time another pair arrives I bring it in and give it a try - until this pair showed up.
GD70
Lunatic Member
My receiver is 60 wpc my amp 73 wpc. I'm guessing this should be enough power. If I have them refoamed before I find an EQ, I'll still hook them up to listen to them keeping in mind they will sound better with the EQ.
GD70 -- I was making a distinction between cloth surrounds damped with silicon compounds which dribble (ADC, some CTS, Leak Sandwiches (these surround also slide down the basket) and others), and cloth surrounds with different compounds that dry up and crumble off (AR, KLH etc.). Leaving aside the compounds that completely seize up, which I've seen on some Jensens (other identical drivers have completely supple surrounds) and an Oaktron.
My point is that no surround material is perfect, and none last forever. But who expected any speaker to still be in use for decades, and in some cases more than half a century, after its manufacture?
My point is that no surround material is perfect, and none last forever. But who expected any speaker to still be in use for decades, and in some cases more than half a century, after its manufacture?
Copa1934
My ears are bleeding
You live in NY. While you aren't absent of high temps, we have temps in the high 90's for months at a time. Living in the high desert of CA temps often reached 120. This does soften the treatment and allows it to run. Keeping in mind this is all subject to the temps inside your house, and not just because it's hot outside. Those that keep comfortable or moderate temps aren't likely to run into this issue. Pun not intended.
Now that I think about it, there is an astonishing enthusiasm for recapping (not an issue with the 901s at least until you lay your hands on the control box) which contrasts oddly with the indignation about refoaming. Both may be necessary (though the need for refoaming is at least easier to diagnose with certainty) and both are in the preventative maintenance category. The use of inexpensive electrolytic capacitors is basically price driven whereas the use of foam is tied up with what the driver designer is trying to achieve soundwise, but some people seem to get pretty upset with the latter but not the former.
GD70
Lunatic Member
With the KLH's, a re-cap does make a significant improvement in sound and bringing dead tweeters back to life since most used cheap made in Mexico caps. I've read AR's for the most part could benefit, though my 4x's haven't been touched except for a thin coat of sealer to the woofer surrounds. Seem's most 20+ year old speakers can benefit from new caps.
GD70
Lunatic Member
A bit of progress-Pics
I'm jumping back & forth between the LST & 901 restorations. It was too late to start gluing the veneer to the LST, so fiddled with the 901's a bit.
I removed all the dried out surrounds. They virtually turned to powder in my fingers. I also spent a little time sanding the veneer to get rid of the tape glue residue stains. I used 220 grit, by hand. The marks are almost gone as well as a few minor surface scratches. Good thing the veneer is fairly thick on these. I need to do a little more sanding , then I'll apply a coat of Watco Danish oil and see how they look.
Here's a few pics and one comparing the 901 and the AR-LST2 sizes.
Also, the surrounds were glued to the backs of the cones. Most I've seen are glued to the front surface.
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Before sanding.
The top surface after sanding.
I'm jumping back & forth between the LST & 901 restorations. It was too late to start gluing the veneer to the LST, so fiddled with the 901's a bit.
I removed all the dried out surrounds. They virtually turned to powder in my fingers. I also spent a little time sanding the veneer to get rid of the tape glue residue stains. I used 220 grit, by hand. The marks are almost gone as well as a few minor surface scratches. Good thing the veneer is fairly thick on these. I need to do a little more sanding , then I'll apply a coat of Watco Danish oil and see how they look.
Here's a few pics and one comparing the 901 and the AR-LST2 sizes.
Also, the surrounds were glued to the backs of the cones. Most I've seen are glued to the front surface.
Before sanding.
The top surface after sanding.
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GD70
Lunatic Member
The sticky residue is gone. I used Acetone, took it right off. The wood absorbed the moisture from the tape glue over time. So I have to take it down by sanding it off.
I'll try some alcohol just to see if it helps though.
Thanks, Glenn