Speaker replacement question

[leehljp]

I have a couple of 12 inch Radio Shack speakers that I bought in the early 80's. I haven't used them for the past 12 years and had them in storage.
I recently pulled them out and found that the foam support for the speakers had crumbled, or at least crumble with a touch.

These are the Opitmus 50 speakers, with 4 in mid range and 2 1/2 tweeters and have mid-range and high frecquency adjustments.

The Boxes are walnut veneer of the quality only available on very expensive units today or more common back then.

I hate to throw these away and wonder if I speaker kits are available for replacement. Before I start looking here (in Japan) I wanted to get some input from you speaker builders.

Any advice? IF speakers replacement are advisable, do I need to buy new crossover networks or will the current be fine if I purchase the right speakers?
Is there difficulty in finding speakers with the same values that will fit the old crossover networks?

I sure would hate to get rid of such well veneered housings.

Thanks for your input.

[BigguyZ]

WWW.Partsexpress.com sells replacement surrounds.
http://www.partsexpress.com/pe/showd...number=260-930


Parts Express also sells drivers, so you should be able to get some there for not too much $$ if you decide just to replace them all together.

Ideally, the drivers in a speaker are matched to the cabinet and the cross over of the speaker. speakers SHOULD be designed as a cohesive whole, with one design/ driver choice affecting the other aspects of the speaker's construction. SO- to make a long story short- you normally don't want to just grab another driver the same size and plop it in there. Now, these are Radio Shack speakers- so I'm going on a limb and saying you probably won't notice much or a change. If you do replace one of the drivers, make sure you replace them in pairs (both L&R) so that they match.

EDIT: I Googled the speaker, and found a link that has a phone number and part number to order replacement parts from Radio Shack.
http://support.radioshack.com/suppor...oc23/23177.htm

[Knottscott]

The surround replacement kits are usually under $30. They seem a bit steep for what you get, but are still the least expensive option for replacement, and will get closer to the original parameters than a substitute driver.

Good luck!

[leehljp]

Thanks Guys. Ahh surround kits, I didn't realize that they were available. I will give that a try for sure.

I will also check on full replacements, if they are not too expensive. I will be checking with RS also.

Thanks!

[Ken Massingale]

Hank,
I'll share my recent experience with audio and speakers. A few years ago I replaced an old technology Tecnics receiver/amp with a then up to date Pioneer Dolby unit. I opted to keep our massive Pioneer speakers, thinking that the newer small speakers couldn't compare to the big honkers.
A few months ago the oldest daughter, a true audiophile, surprised us with an Onkyo HT-540 system.
I really hesitated using the small speakers that came with the system. But, LOML insisted and I did.
The sound from these little suckers blows the old large Pioneers out of the water. I would think that in Japan you can find great small speakers with excellent sound for less than here. Just a thought.
ken

[LCHIEN]

Thanks Guys. Ahh surround kits, I didn't realize that they were available. I will give that a try for sure.

I will also check on full replacements, if they are not too expensive. I will be checking with RS also.

Thanks!

Hi Hank.
If you want to repair the speakers, there are MANY comapnies who sell surrounds and surround repair kits (with instructions and glue as well).
You can go to eBay and search for "Advent surrounds" and you will get lots of hits for companies selling the foam surrounds and kits. These companies will also be selling surrounds for many other brands of speakers as well as advent - Advent of course was a very popular speaker in the 70's (mine are on their third set of surrounds now). Some of them go for a lot less than $30 (ea.)
often sold as a kit in pairs for generic 12" speakers with glue and instructions. Once you find the sellers go to their websites and see whats available.

[leehljp]

I am kinda partial to these units because of the great walnut veneer, the good sound that they used to have, and it was my first "good" set of speakers. When I retire, I would like to use these with a turntable, amp and my 30 / 40 year old albums.

I have a good set of the small surround sound speakers purchased here (for our TV) and they do sound great on the TV, but in all honesty, I enjoy some of the sounds of old! I don't know what it was with just plain stereo, but it was much more mellow. Only recently have I heard the mellow sound on digital.

I also have a set of Pioneer S-99T that retail for about $450.00 for a pair. Those are huge, one meter tall, almost a foot wide and 15 inches front to back and HEAVY. Got them for free last summer when someone was moving. In spite of this, I still want to restore my old RS Optimus. The cases are just constructed so well and heavy as well as the quality job on the veneer.

I think I will go with the surround repair kits and install it myself. If it doesn't sound good after that, then I will probably junk them or think of something to do with the carcass.

[LCHIEN]

I am kinda partial to these units because of the great walnut veneer, the good sound that they used to have, and it was my first "good" set of speakers. When I retire, I would like to use these with a turntable, amp and my 30 / 40 year old albums.

I have a good set of the small surround sound speakers purchased here (for our TV) and they do sound great on the TV, but in all honesty, I enjoy some of the sounds of old! I don't know what it was with just plain stereo, but it was much more mellow. Only recently have I heard the mellow sound on digital.

I also have a set of Pioneer S-99T that retail for about $450.00 for a pair. Those are huge, one meter tall, almost a foot wide and 15 inches front to back and HEAVY. Got them for free last summer when someone was moving. In spite of this, I still want to restore my old RS Optimus. The cases are just constructed so well and heavy as well as the quality job on the veneer.

I think I will go with the surround repair kits and install it myself. If it doesn't sound good after that, then I will probably junk them or think of something to do with the carcass.

Another option is to remove the woofers and send them to a speaker repair place. A lot of the stores (not all) selling the surrounds will do them fro you for a reasonable price - it is a little tricky. I know you are in Japan, but maybe there are some speaker repair shops there that can do it also; I know the japanese can be fanatics about stereos, too.

The surrounds were made from polyurethane foam and had excellent acoustic characteristics but suffered from age rot (~10 years). Pity the poor souls who had the Bose 901s - these were the 5-sided speakers called "direct-reflecting", they had like 9 4" woofers per speaker (18 per stereo system), four each in the two rear facing faces and 1 in the forward face. They were quite expensive (all Bose stuff seems to be) at the time and if you kept them for 10 years you had to replace all 18 surrounds!

[Knottscott]

... Pity the poor souls who had the Bose 901s - these were the 5-sided speakers called "direct-reflecting", they had like 9 4" woofers per speaker (18 per stereo system), four each in the two rear facing faces and 1 in the forward face. They were quite expensive (all Bose stuff seems to be) at the time and if you kept them for 10 years you had to replace all 18 surrounds!

I fixed two pairs of 901s for customers. It was cheaper to replace all 18 woofers than to pay the labor to repair the surround. Both customers contacted me after and thought they sounded better than new....IIRC, the cost was about $340/pr back in the late 80's.

[LarryG]

Advent of course was a very popular speaker in the 70's (mine are on their third set of surrounds now).

Loring, how hard a job is it to replace the foam surrounds? I have a set of the original large Advents (circa 1973, when they were called simply The Advent Loudspeaker) and although I mostly listen thru headphones while at home these days, I wouldn't mind getting them back into service. Fussy job? Time-consuming job?

[LCHIEN]

Loring, how hard a job is it to replace the foam surrounds? I have a set of the original large Advents (circa 1973, when they were called simply The Advent Loudspeaker) and although I mostly listen thru headphones while at home these days, I wouldn't mind getting them back into service. Fussy job? Time-consuming job?

Larry - I've got Four Original Advents. I've used them in the "stacked position" Double Advent configuration which was quite famous at the time. I got a pair in 1971 and another pair in 1975. Usually the date of manufacture is stamped on the tweeter frame.
Right now they are doing left and right mains position flanking my 70" projection screen. They went down to 39 Hz which is still quite good compared to those little tiny speakers you see, altho mine have been relieved of duty below about 50 Hz - my SVS sub goes down to 16 Hz, flat with 325 W amp. The Advents are still sweet speakers.

back to the original question, I have replaced a lot of Advent surrounds.
The first time I did not know better and bought a whole new Advnet woofer, tossing the original. I soon learned they would all get it and had a shop replace the surrounds in the other three. 10 years later I did it again, but I found ads in teh back of Audio magazine offering surround repair kits.
another 10 years and I have the internet, found a place offering kits.
Just last year I replaced all four again, from kits on ebay. At one time my dad had a pair, too, I think he had them long enough I had to have his repaired, too.

So I would say, its tricky but not that hard.
You have to remove the old surround, it mostly falls off.
You are supposed to cut off the dust cap on the coil in the center and shim the coil to the magnet.
Then you have to glue the new surround to the edge of the cone and finally to the frame. This is tricky because the cone wants to move forward and backward, its hard to get a full bead of glue in there and then get it closed and mated without getting glue all over the place. You have to be creative about sticking stuff behind the cone to get it first out of the way and then back into final position
Finally you have to remove the shims and reglue the dust cover into position.
I did a couple without cutting the dustcap and they came out alright. However I have done it and ad the coil and magnet rubbing (because the cone just floats free and went to the side.) and it sounded real bad. I had to cut the glue joint and then cut the dust cap and start all over again. Figure on spending and hour or two with each.
Your glue joints need to be pretty much air tight (no gaps). You need to have a ball of plumber's putty to seal each woofer to the speaker frame.


Here's a link
http://mlug.missouri.edu/~igor/advent.php

you can find lots of info on advents on the internet
they sold tons of them. I hear there's guys who just go to garage sales, and thrift shops, buy them for $5 a pair and fix them up and resell them to eager audiophiles wanting the classic advent sound.

[Knottscott]

Loring reminded me of an old improvement tip. If you replace the surrounds as Loring suggests, once you're done with the plumber's puddy, spread a bunch of it on the back of the frame to deaden vibrations. It's one of many little tricks that are barely audible in and of themselves, but if you do a few of them, it can make a very audible difference combined.

Some of the other tricks are upgrading the original speaker wire with some decent oxygen free copper wire made specifically for sound...it'll be made up of small strands....Monster Cable is the big name, but there are many others that will be comparable. If the wire to the speakers isn't at this level, get enough to run it to your amp as well.

While you're at it, the stock capacitor's aren't very high quality. You can replace with a polypropylene cap of the same uF value....the voltage is nearly irrelavent. This should make a fairly audible improvement if the rest of the system is transparent. I like to bypass any fuses or circuit breakers to clean up the sound too....doubt you'll need them at this stage of your life!

You can also add a bit of wool, poly fiber fill, or "acousti-stuff". It's best to ball it up and put it in an old stocking and tuck it out of the way.

If you get ambitious, you can add a simple cross brace to help deaden the cabinets.

You'll be surprised what you can hear when you remove layers of fog. Have fun!

[wdreamsmaycome]

Loring, how hard a job is it to replace the foam surrounds? I have a set of the original large Advents (circa 1973, when they were called simply The Advent Loudspeaker) and although I mostly listen thru headphones while at home these days, I wouldn't mind getting them back into service. Fussy job? Time-consuming job?

I replaced the foam on my old speakers a few months ago, took about maybe 3-4 hours start to finish, most of that time spent waiting for the glue to dry: I used the kit from parts express, and if you follow the instructions it's not hard at all, you just need to be aware to center the coil with the provided shims before you start the gluing job.

I also didn't completely remove the dust caps (the provided ones in the kit wouldn't have fit), I just very carefull cut them about 80% around and flicked them inside out so they stayed out of the way while I was shimming the coil: once I was done I flicked them back and glued the circumference, you can't see the cut at all once the glue dried, and they sound as good as new.

[LarryG]

Thanks, Loring and WDMC. I think I just may give this job a go.

[JimD]

For those wanting to listen to old albums, there are now turntables that will put out signals so that you can make CDs of the album. I haven't pulled the trigger on this yet but for irreplacable vinyl, it might be a way to listen to them without damage (or minimal damage from the one playing).

Jim