Side benefits of walking your dog!

Bludsport

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View attachment 7250 View attachment 7250 View attachment 7251 This is my first post outside of the REW forum, but after walking my dog the other day, I thought it best to 'step out' (pun intended) and broaden my horizons a bit.

I was walking my dog Mia fairly early on Monday morning when she decided it was time to cop a squat beside one of those big metal dumpsters usually used for renovations and construction trash. Since she was taking a little more time than usual to complete her task, I decided to peek inside the dumpster. I'm not normally a dumpster diver and rarely pay any attention to them, but this particular yellow one was parked in front of the house one of my childhood friends used to live in. He and his wife went on a cruise last year and tragically, he had a massive heart attack and died in the sick bay of the ship. He had heart problems almost all of his life so it wasn't a huge surprise to anyone, but it's always hard when one of your old friends suddenly passes away. Although we had lost touch over the years, my recently deceased friend had been an electronics fanatic and audiophile nearly all of his life. It was a hobby that he loved and spent a great deal of time in the pursuit of, so hence my decision to have a closer look inside...and I'm glad I did.

Strewn throughout the big yellow metal container was the usual type of junk you'd expect to see when someone decides to rid themselves of the clutter they've amassed over many years, old broken chairs, stupid stuff you had to have while watching the home shopping network but never needed, old clothes, among other stuff, when something out of the corner of my eye caught my attention. It was black, shaped like a speaker cabinet and I could see a small portion of a woofer poking out of the other junk, so I took a look. Sure enough, it wasn't just a single speaker, but a pair speakers I could tell were a bit dated. After a closer inspection, they revealed themselves as a pair of stacked B&W speakers from the 1980's. I wasn't at all familiar with them so I looked at the labels located above the speaker jacks on the back panels. The lower speaker cabinet contained 2 small 5" woofers with a port centered between them and the label identified them as "B&W CM-2" and had a serial number printed on the label beside the name of the speaker. The upper cabinets housed another 5" speaker made from what looked to be woven Kevlar with a small tweeter above it. They were labeled "CM-1" and also had serial numbers.

When we got home from our walk, I jumped in my car and headed back to the dumpster and then jumped inside of it. When I was removing the dusty speakers from the dumpster, something else jumped out at me, an old Tektronix 475 2-channel Oscilloscope. I didn't have a clue whether it or the speakers even worked, but thought it was worth a shot, so I packed everything in my trunk and headed back home.

When I got home, I removed the front cover from one of the upper CM-1 speaker cabinets to take a look inside. The cabinet is made from some type of fairly thin plastic resin type material and the rear of is divided into a bunch of squarish partitions, each one being filled with foam dampening material cut to match the size and depth of each of the cavities. There was a crossover stuffed between the woofer and the tweeter, and from what I could tell, it looked to be in good shape. After a brief cleaning with soap and water, the cabinets and the speakers were in much better condition that I had originally thought. The lower cabinets are made from either MDF or plywood and are painted a sort of a dull matt black but were covered with scuffs and scratches from their run in with the dumpster. I took a small risk and decided to polish the dull black paint on them with a random orbital car buffer and some polishing compound. The CM-1 speakers that sit on top of them are also a dull black color, but they were in much better shape so I just cleaned them.
The woofers in the lower cabinets face the rear, so they really don't even look like speakers, more like pedestals, so I decided to see if I could achieve a gloss black piano finish on them. To my surprise, I actually came pretty close. When I was disassembling the lower cabinets and removing the speakers from them so they could be polished, my elation over what I had found began to fade a little. After removing the square plastic base plates where the crossovers were located, I could see that the crossovers were covered with a foam similar to the foam in the upper cabinets. When I tried to remove the foam to get the at them, it seemed to be stuck the them. I finally worked the foam free revealing a completely fried crossover in each of the speakers. I don't know what happened, but two white ceramic rectangular things (inductors?) on both boards apparently had caught on fire at some point and took out a couple of unfortunate capacitors living next to them. I don't know jack about passive crossovers and had to look all this stuff up online.

The good news is that all the drivers are in perfect shape and the original new old stock B&W crossovers are still available for around $150 each. Since speaker technology back in 1987 was not what it is now, I was wondering if I should pass on the B&W crossovers and maybe have someone design a better...smaller pair. Actually, I don't understand the whole crossover setup. Both upper and lower crossovers are interconnected. I always assumed that using one crossover for one for both woofers and tweeters was the norm. They actually sound really good sans the burned crossovers, but I'm hoping that they'll sound even better once I install either a pair of original or upgraded crossovers.

Oh yea, the oscilloscope...don't have a clue. I plugged it in, turned it on and the little blue screen lit up. Other than that, I have no idea if it works or not.
I couldn't find the coax looking leads that attach to it to connect it to some type of source, so I have no way of connecting it to anything. Should you see something like a wavy line or something on the screen when you turn it on if it's not connected to some type of signal?

Oh yea, I'll post some before and after pics of the speakers later.
 
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tripplej

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Life is always full of surprises and as they say, one man's trash is another man's treasure. :)
 

Matthew J Poes

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This is my first post outside of the REW forum, but after walking my dog the other day, I thought it best to 'step out' (pun intended) and broaden my horizons a bit.

I was walking my dog Mia fairly early on Monday morning when she decided it was time to cop a squat beside one of those big metal dumpsters usually used for renovations and construction trash. Since she was taking a little more time than usual to complete her task, I decided to peek inside the dumpster. I'm not normally a dumpster diver and rarely pay any attention to them, but this particular yellow one was parked in front of the house one of my childhood friends used to live in. He and his wife went on a cruise last year and tragically, he had a massive heart attack and died in the sick bay of the ship. He had heart problems almost all of his life so it wasn't a huge surprise to anyone, but it's always hard when one of your old friends suddenly passes away. Although we had lost touch over the years, my recently deceased friend had been an electronics fanatic and audiophile nearly all of his life. It was a hobby that he loved and spent a great deal of time in the pursuit of, so hence my decision to have a closer look inside...and I'm glad I did.

Strewn throughout the big yellow metal container was the usual type of junk you'd expect to see when someone decides to rid themselves of the clutter they've amassed over many years, old broken chairs, stupid stuff you had to have while watching the home shopping network but never needed, old clothes, among other stuff, when something out of the corner of my eye caught my attention. It was black, shaped like a speaker cabinet and I could see a small portion of a woofer poking out of the other junk, so I took a look. Sure enough, it wasn't just a single speaker, but a pair speakers I could tell were a bit dated. After a closer inspection, they revealed themselves as a pair of stacked B&W speakers from the 1980's. I wasn't at all familiar with them so I looked at the labels located above the speaker jacks on the back panels. The lower speaker cabinet contained 2 small 5" woofers with a port centered between them and the label identified them as "B&W CM-2" and had a serial number printed on the label beside the name of the speaker. The upper cabinets housed another 5" speaker made from what looked to be woven Kevlar with a small tweeter above it. They were labeled "CM-1" and also had serial numbers.

When we got home from our walk, I jumped in my car and headed back to the dumpster and then jumped inside of it. When I was removing the dusty speakers from the dumpster, something else jumped out at me, an old Tektronix 475 2-channel Oscilloscope. I didn't have a clue whether it or the speakers even worked, but thought it was worth a shot, so I packed everything in my trunk and headed back home.

When I got home, I removed the front cover from one of the upper CM-1 speaker cabinets to take a look inside. The cabinet is made from some type of fairly thin plastic resin type material and the rear of is divided into a bunch of squarish partitions, each one being filled with foam dampening material cut to match the size and depth of each of the cavities. There was a crossover stuffed between the woofer and the tweeter, and from what I could tell, it looked to be in good shape. After a brief cleaning with soap and water, the cabinets and the speakers were in much better condition that I had originally thought. The lower cabinets are made from either MDF or plywood and are painted a sort of a dull matt black but were covered with scuffs and scratches from their run in with the dumpster. I took a small risk and decided to polish the dull black paint on them with a random orbital car buffer and some polishing compound. The CM-1 speakers that sit on top of them are also a dull black color, but they were in much better shape so I just cleaned them.
The woofers in the lower cabinets face the rear, so they really don't even look like speakers, more like pedestals, so I decided to see if I could achieve a gloss black piano finish on them. To my surprise, I actually came pretty close. When I was disassembling the lower cabinets and removing the speakers from them so they could be polished, my elation over what I had found began to fade a little. After removing the square plastic base plates where the crossovers were located, I could see that the crossovers were covered with a foam similar to the foam in the upper cabinets. When I tried to remove the foam to get the at them, it seemed to be stuck the them. I finally worked the foam free revealing a completely fried crossover in each of the speakers. I don't know what happened, but two white ceramic rectangular things (inductors?) on both boards apparently had caught on fire at some point and took out a couple of unfortunate capacitors living next to them. I don't know jack about passive crossovers and had to look all this stuff up online.

The good news is that all the drivers are in perfect shape and the original new old stock B&W crossovers are still available for around $150 each. Since speaker technology back in 1987 was not what it is now, I was wondering if I should pass on the B&W crossovers and maybe have someone design a better...smaller pair. Actually, I don't understand the whole crossover setup. Both upper and lower crossovers are interconnected. I always assumed that using one crossover for one for both woofers and tweeters was the norm. They actually sound really good sans the burned crossovers, but I'm hoping that they'll sound even better once I install either a pair of original or upgraded crossovers.

Oh yea, the oscilloscope...don't have a clue. I plugged it in, turned it on and the little blue screen lit up. Other than that, I have no idea if it works or not.
I couldn't find the coax looking leads that attach to it to connect it to some type of source, so I have no way of connecting it to anything. Should you see something like a wavy line or something on the screen when you turn it on if it's not connected to some type of signal?

Oh yea, I'll post some before and after pics of the speakers later.

Long white ceramic things are wirewound resistors. It is very likely that these could be repaired for 10-20 dollars in parts. Do you know how to solder? With pics, we can probably help. I can help you identify the part values and replace them with appropriate pics. As long as the values on them are not totally destroyed. If they are, it is possible that B&W would share a schematic or repair manual.

Up to you, but personally, I would not buy replacement xovers for these. That is a lot of money. Maybe at least look on ebay first to see if any are available there for less.

That Oscilliscope is old, but there are people who would possibly buy them.

Exciting finds for sure! around me walking my dog would net me no such exciting finds. Just a need to carry his poo in a bag for a 1/4 mile.
 
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