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bose501
08-06-2009, 06:01 PM
Hello,

I'm hoping someone or some people with a greater knowledge of speakers can clue me in as to what may be bothering one of my Bose 501 speakers.

They seem to handle quite well. I like the bass(not suggesting by any means it's the greatest). I enjoy the stereo field but then I hear this fatigued almost distressed sound on the one speaker. I describe it as something is dying. A muffling sort of sound on the woofer and low volume on the tweeter.

This sound has been with the speakers since I picked them up. I don't have any 4 ohm receivers around so I had to try it out on a Sony STR 6065(which I believe is 8 ohms) and a Kenwood (90's era) which I think is 16 ohms.

Could they be causing a speaker to crackle?

I've tried switching wires around but nothing. Voice coil? It seemed to clean up a bit with more volume but now it's getting worse? Any ideas?

JohnMichael
08-06-2009, 06:26 PM
Hello,

I'm hoping someone or some people with a greater knowledge of speakers can clue me in as to what may be bothering one of my Bose 501 speakers.

They seem to handle quite well. I like the bass(not suggesting by any means it's the greatest). I enjoy the stereo field but then I hear this fatigued almost distressed sound on the one speaker. I describe it as something is dying. A muffling sort of sound on the woofer and low volume on the tweeter.

This sound has been with the speakers since I picked them up. I don't have any 4 ohm receivers around so I had to try it out on a Sony STR 6065(which I believe is 8 ohms) and a Kenwood (90's era) which I think is 16 ohms.

Could they be causing a speaker to crackle?

I've tried switching wires around but nothing. Voice coil? It seemed to clean up a bit with more volume but now it's getting worse? Any ideas?



Bose made several versions of 501's and the last was a thin tower with two small tweeters and a small woofer hidden within the enclosure in the middle of two air masses (acoustimass). The earlier speakers used one ten inch woofer and two three inch tweeters. If you could tell us which series you have that would help.

Also Bose used a device in the crossover to protect the drivers. I forget what they called it but it was like a small light bulb that would glow to absorb some of the power if you are over driving the speakers. This would cause the volume to reduce in the speaker or speakers.

While diagnosing the speakers I would make sure that you have the tone controls set without any bass or treble boost. If there is a loudness switch make sure the loudness boost is off. Check to make sure your speaker wires and interconnects are in good shape and have no shorts that might be causing problems. If you have other speakers check out your electronics to be sure they do not make the noise with the others.

harley .guy07
08-06-2009, 06:31 PM
Hello,

I'm hoping someone or some people with a greater knowledge of speakers can clue me in as to what may be bothering one of my Bose 501 speakers.

They seem to handle quite well. I like the bass(not suggesting by any means it's the greatest). I enjoy the stereo field but then I hear this fatigued almost distressed sound on the one speaker. I describe it as something is dying. A muffling sort of sound on the woofer and low volume on the tweeter.

This sound has been with the speakers since I picked them up. I don't have any 4 ohm receivers around so I had to try it out on a Sony STR 6065(which I believe is 8 ohms) and a Kenwood (90's era) which I think is 16 ohms.

Could they be causing a speaker to crackle?

I've tried switching wires around but nothing. Voice coil? It seemed to clean up a bit with more volume but now it's getting worse? Any ideas?


does the sound stay with the same speaker when you switch wires. and does the sound come just from the woofer or both the woofer and tweeter. If it stays on the same speakers and the muffled sound comes from both the woofer and tweeter then I would suspect that you have a blown crossover component possibly a capacitor.

harley .guy07
08-06-2009, 06:44 PM
Bose made several versions of 501's and the last was a thin tower with two small tweeters and a small woofer hidden within the enclosure in the middle of two air masses (acoustimass). The earlier speakers used one ten inch woofer and two three inch tweeters. If you could tell us which series you have that would help.

Also Bose used a device in the crossover to protect the drivers. I forget what they called it but it was like a small light bulb that would glow to absorb some of the power if you are over driving the speakers. This would cause the volume to reduce in the speaker or speakers.

While diagnosing the speakers I would make sure that you have the tone controls set without any bass or treble boost. If there is a loudness switch make sure the loudness boost is off. Check to make sure your speaker wires and interconnects are in good shape and have no shorts that might be causing problems. If you have other speakers check out your electronics to be sure they do not make the noise with the others.

I do remember that bose had those protection components in place for a while in their speakers because a friend of mine had a pair of bose 501's at his music store and kept having problems with them so he finally bypassed this circuit. After that he did not have any problems. He did have have to refoam the woofers after being played for 10 hours a day for years.

bose501
08-06-2009, 06:44 PM
Bose made several versions of 501's and the last was a thin tower with two small tweeters and a small woofer hidden within the enclosure in the middle of two air masses (acoustimass). The earlier speakers used one ten inch woofer and two three inch tweeters. If you could tell us which series you have that would help.

Also Bose used a device in the crossover to protect the drivers. I forget what they called it but it was like a small light bulb that would glow to absorb some of the power if you are over driving the speakers. This would cause the volume to reduce in the speaker or speakers.

While diagnosing the speakers I would make sure that you have the tone controls set without any bass or treble boost. If there is a loudness switch make sure the loudness boost is off. Check to make sure your speaker wires and interconnects are in good shape and have no shorts that might be causing problems. If you have other speakers check out your electronics to be sure they do not make the noise with the others.

Oh it's a 1977 Bose 501, the last version of the first series. Yes I've seen the light go on. I just tried using some quality speaker wire and still the same. It just sounds too weak out of that speaker when it is auditioned on one side only.

bose501
08-06-2009, 06:51 PM
Interesting. Yes I've had the bad speaker handle the bass side of mix and the treble. I've switched the wires every way they could go. One speaker(or box of speakers) sounds great. It's nice and strong with a nice low end for pop vinyl. The other just sounds like it doesn't want to get out of bed. I may have really blown it with the Sony Amp.

What you guys are talking about reminds me of the AR's I just sold. They had a notorious problem with their pots to the point the treble and mids would be lost causing the user to keep turning the volume up and then you start to get a woofer with asthma. One solution offered for them was to bypass the pots.

Grills come off easily?

harley .guy07
08-06-2009, 07:08 PM
Interesting. Yes I've had the bad speaker handle the bass side of mix and the treble. I've switched the wires every way they could go. One speaker(or box of speakers) sounds great. It's nice and strong with a nice low end for pop vinyl. The other just sounds like it doesn't want to get out of bed. I may have really blown it with the Sony Amp.

What you guys are talking about reminds me of the AR's I just sold. They had a notorious problem with their pots to the point the treble and mids would be lost causing the user to keep turning the volume up and then you start to get a woofer with asthma. One solution offered for them was to bypass the pots.

Grills come off easily?

the later model 501 the front tweeter grills came off but for the older models you have I am not sure. I was not actually there when my friend worked on his but I would say with the older models being of a standard looking model that they should not be too hard. I would take a close look at all the drivers first before opening up the speakers to make sure you don't have woofer and tweeter damage. other than that the problem has to be in the protection circuit or the crossover itself which would take further examination to determine the problem.

bose501
08-06-2009, 07:22 PM
the later model 501 the front tweeter grills came off but for the older models you have I am not sure. I was not actually there when my friend worked on his but I would say with the older models being of a standard looking model that they should not be too hard. I would take a close look at all the drivers first before opening up the speakers to make sure you don't have woofer and tweeter damage. other than that the problem has to be in the protection circuit or the crossover itself which would take further examination to determine the problem.
Seeing as I have little experience with these things it might be a lost cause. The grills to me appear to either be stapled or glued on. I didn't even attempt to take the AR speaker grills off before selling them. They were just glued in 6 points if I remember. The grill cloth on these speakers covers 3 sides. They show no signs of having ever been off since they were put on. I imagine a repair shop would charge a lot just to get inside. Then that begs the question is it worth it when my only intention was to resell them? They might be worth $75-$100. They weigh 40 lbs a pop too. Those speaker manufacturers are pretty crafty. Oh sure you don't want vibration so you glue everything up nice and snug but you also don't want anyone to be able to fix them so easily. If they were in more demand I'd sell as is but now I don't know if that's wise.

bose501
08-06-2009, 07:22 PM
Oh btw thanks guys for the quick responses!

harley .guy07
08-06-2009, 07:45 PM
Oh btw thanks guys for the quick responses!

If you are thinking they are not worth the trouble then it would put them up for sale as is and get what you can get. Then go on the prowl for some new speakers that will probably improve your sound anyway. If you need advise for looking for replacements there are some very good minds in this forum and some great reviews on this sight to guide you in picking the right speakers that will sound the way you like them to sound at a price that you are comfortable with. And remember my thoughts, GO HIGH END, DON'T GO BROKE.:16:

bose501
08-06-2009, 09:00 PM
If you are thinking they are not worth the trouble then it would put them up for sale as is and get what you can get. Then go on the prowl for some new speakers that will probably improve your sound anyway. If you need advise for looking for replacements there are some very good minds in this forum and some great reviews on this sight to guide you in picking the right speakers that will sound the way you like them to sound at a price that you are comfortable with. And remember my thoughts, GO HIGH END, DON'T GO BROKE.:16:

Yeah there's probably a cheery end to it. When both speakers are going they don't sound that bad or bad at all. You have to listen closely to hear that loss. I think I overspent for them at $20. $10 would have been my price. However I bet they'd sell tomorrow for $50 as is. I was just trying to get as much as possible. Just trying to pay bills.

As far as speakers go i just need some studio nearfields. Hopefully a couple of those(nice ones) show up at my local thrift store for $5(they tend to price things by size).

Thanks for the advice

harley .guy07
08-06-2009, 09:15 PM
Yeah there's probably a cheery end to it. When both speakers are going they don't sound that bad or bad at all. You have to listen closely to hear that loss. I think I overspent for them at $20. $10 would have been my price. However I bet they'd sell tomorrow for $50 as is. I was just trying to get as much as possible. Just trying to pay bills.

As far as speakers go i just need some studio nearfields. Hopefully a couple of those(nice ones) show up at my local thrift store for $5(they tend to price things by size).

Thanks for the advice

Yeah if you listen to your system very close to the speakers then nearfield monitors will probably work fine for you. I also would add that there are some great deals on bookshelf speakers out there in the used market. If you like the monitor type sound then a few brands to look at baring you cant find any nearfield monitors around is the Paradigm monitor bookshelf models or the Axioms. Both companies stress accuracy and are around the same size as most monitors and can sometimes be found used for a good price. Some people will recommend higher priced brands like dynaudio and Usher which are amazing speakers but are expensive. I have a neighbor that has a mac based studio in his house and he uses MA audio monitors and if you are sitting within their operating field normally around 4' or less they sound very smooth and detailed and are not to bad on the wallet. have fun searching and if you need any help you know we will be here.

bose501
08-07-2009, 03:59 AM
Yeah if you listen to your system very close to the speakers then nearfield monitors will probably work fine for you. I also would add that there are some great deals on bookshelf speakers out there in the used market. If you like the monitor type sound then a few brands to look at baring you cant find any nearfield monitors around is the Paradigm monitor bookshelf models or the Axioms. Both companies stress accuracy and are around the same size as most monitors and can sometimes be found used for a good price. Some people will recommend higher priced brands like dynaudio and Usher which are amazing speakers but are expensive. I have a neighbor that has a mac based studio in his house and he uses MA audio monitors and if you are sitting within their operating field normally around 4' or less they sound very smooth and detailed and are not to bad on the wallet. have fun searching and if you need any help you know we will be here.
I'll keep those things in mind. Compared to what I am using right now anything is better. I'm afraid though I'll have to find my speakers at thrifty prices. That Sony receiver I mentioned my brother got for cheap at either a thrift store or local auction is worth a pretty penny. now even if one doesn't think highly of it, others do. There for you find one of those(Ha!), sell it, and then buy say an Adams or something. I love these vintage speakers and equipment for their warm feel. I like the music they were intended for as well. I just can't afford to keep them. Today I'm going to find some AR3's in mint condition and then I'll be cooking ;)