Technics Speakers

[pauliachi]

I just picked up a pair of Technics SB-L51 speakers at the SA for $14 Canadian. Does anyone know anything about them? They seem OK to my untrained ears, but I know Technics speakers aren't very well regarded by audiophiles. Thanks.

 

[kermit z]

Here is a link to Technics speakers. They are ok. If they sound good to you, then thats whats important

http://www.vintagetechnics.info/loudspeakers.htm

 

[5_Star4TGF]

I know this thread is pretty much dead, but these are very well built speakers. Cabs are built very well, they have a crossover with magnet wire and seem to sound very nice.

 

[pumablues]

I just picked up a pair of Technics SB-L51 speakers, based on some of the warm reviews I found here. Unfortunately, I bought them off of CL locally, and as I keep discovering, either people are willfully leaving out details, or they genuinely don't notice things... one speaker has the upper range mostly absent. I'm guessing the caps are shot, since these are circa 1983. The low sounds great, and given their age, the one speaker that still has midrange and upper sounds pretty nice. Does anyone happen to know what I need to order for repairs for these, or do I just need to crack them open and find out first hand?

 

[RTally]

I just picked up a pair of Technics SB-L51 speakers, based on some of the warm reviews I found here. Unfortunately, I bought them off of CL locally, and as I keep discovering, either people are willfully leaving out details, or they genuinely don't notice things... one speaker has the upper range mostly absent. I'm guessing the caps are shot, since these are circa 1983. The low sounds great, and given their age, the one speaker that still has midrange and upper sounds pretty nice. Does anyone happen to know what I need to order for repairs for these, or do I just need to crack them open and find out first hand?

It is always best to open up speakers to verify the crossover before ordering parts. There are many cases where the factory makes changes during a production run. It is best to replace like for like instead of relying on factory information that may never have been updated to reflect changes.

It is also good to determine if the parts are original or if someone has been in there before.

 

[pumablues]

THank you @RTally ! I'm starting to consider you my Vintage Audio Obi-Wan Kenobi!

 

[pumablues]

I did a quick opening of my Technics SB-L51 speakers yesterday, to see if I could figure out what capacitors I needed to replace to hopefully fix the missing highs on the one speaker. One nice thing about these speakers is that the spring terminals on the back can be unscrewed and pulled out to reveal the crossover (I assume this is the only crossover, though I haven't pulled out the woofer yet).

The crossover seems to consist of a small PCB, with 4 components and wiring. The components are:

1. One 2.2uf 50v bipolar radial capacitor
2. one 1.2uf 50v bipolar radial capacitor
3. 8.2 ohm resistor
4. and one.. round thingy... looks like red wire wound around a cylinder, covered in some kind of glue or plastic? Anyone have an idea what this component is?

The caps are soldered into the PCB, with some glue thrown on to really hold things in place (ugh). Seems pretty straightforward, esp. since the caps are bipolar (meaning either end can be placed in either position.. no defined polarity, I believe). Photos attached, in case its helpful to someone else down the road.
These cap values, in the radial form, were not readily available on PE, so i turned to the 'Bay and ordered some there that match up exactly. Given the very small PCB, and my general ignorance about crossovers still, I didnt want to risk trying to use some caps that would turn out not to be good replacements.

View media item 18986View media item 18985View media item 18984

 

[pumablues]

Here's some additional technical information from https://vintagetechnics.audio/showi...zYi1sNTEiO2k6MTtzOjEyOiJsb3Vkc3BlYWtlcnMiO30=

Model: SB-L51 Loudspeakers ('Linear Phase')
Years: 82-83
Enclosure type: Bass reflex
Woofer dia. : 8.625 inches
Midrange type and dia. : cone, 2.5 inches
Tweeter type: Horn
Frequency response: 51-25
Sound Pressure Level (SPL): 92
Dimensions: 13" x 9" x 24"
Weight: 16 pounds
US MRSP at time: $200.00
Cabinet: MDF wrapped in wood simulation vinyl
Speaker wire connection: Spring terminal

 

[classic carl]

Have you tested the tweeters with a multi meter so check if they work? If so, just replace thec capacitors and you'll be good to go. I always recap one crossover first and then do an A/B listening test.

 

[pumablues]

Have you tested the tweeters with a multi meter so check if they work? If so, just replace thec capacitors and you'll be good to go. I always recap one crossover first and then do an A/B listening test.

I.... have not. In fact, I don't even know how to use a multimeter. I think I picked one up at one point... thanks for the tip; I'll see if I can YouTube it and give it a shot! Also, I like your idea about recapping just the one... right now, only one has lost its upper, so this is a viable A/B test scenario.

 

[dzkfraser]

[*]and one.. round thingy... looks like red wire wound around a cylinder, covered in some kind of glue or plastic? Anyone have an idea what this component is?
[/LIST]
It's an inductor - wired into the woofer circuit most likely, kinda hard to tell from the pics. You can trace the wires to see what goes where. no need to replace that, but the caps are relatively inexpensive to replace - just make sure they are bi-polar

 

[pumablues]

So! I replaced the old caps with new matching caps (sooo much smaller though!) And it turns out @classic carl was dead right -- the mid Tweeter is blown. And it just bummed me the hell out that my first soldering attempt was fruitless.

I hate to Chuck these -- one speaker sounds pretty nice. Any advice on replacing that mid Tweeter?

 

[pumablues]

PS. Any advice on what I be of multimeter o should buy to test this stuff? I found one online for about 11 bucks with good reviews...will that get the job done, or should I invest more ? Thank you all!

 

[classic carl]

I've always used a cheapo DMM from Harbor Freight.
So, is the midrange not working or is it the tweeter? I doubt that you'll be able to find a replacement, but you never know unless you look.

 

[RTally]

So! I replaced the old caps with new matching caps (sooo much smaller though!) And it turns out @classic carl was dead right -- the mid Tweeter is blown. And it just bummed me the hell out that my first soldering attempt was fruitless.

I hate to Chuck these -- one speaker sounds pretty nice. Any advice on replacing that mid Tweeter?

Bummer about the bad driver.

The auction site has some Technics midranges. Do search on the part number on the midrange driver and see what you find. Chances are that mid was used for several different models of Technics. Technics also manufactured speakers sold under the MCS name. You may have luck searching with the driver part number.

 

[RTally]

I've always used a cheapo DMM from Harbor Freight.
So, is the midrange not working or is it the tweeter? I doubt that you'll be able to find a replacement, but you never know unless you look.

I second Harbor Freight for an inexpensive mulitmeter. If you check the sales, you can pick one up for a few bucks or even free. They are not top quality, but they are fine for checking resistance and voltages.

 

[pumablues]

Sorry, yes -- it appears the mid-range is shot, not the actual Tweeter.
Thanks again to you both. I'll check out the part number tomorrow.

 

[pumablues]

so, thanks to the tip from @RTally regarding the part number, I was in fact able to find an exact replacement part for the mid-range -- and it was used in a different speaker model, just as RT suggested I got it in the mail, and besides a tear in the maerial surrounding the cone, it worked beautifully. So, that speaker (lets call it The Left) has replaced caps and a working mid-range, and it sounds pretty fantastic. I played the pair together, moving the balance back an forth... and i actually think the new caps might be making The Left speaker sound a tad warmer/clearer.. does that make rational sense, or am I imagining this?

At any rate, now I feel like I need to replace the caps on The Right, so they're completely matching. And then, after that, I might attempt to make some new grill covers... bought some wood trim pieces, and I'm attempting to think through how I'd assemble these.

Given that these speakers seem to not get much love, I actually think they're sounding really good now that they're almost in perfect working order. Certainly better than I had hoped. I'm glad I found this thread with the positive reviews. Oh, and @RTally -- I haven't given up on my Genesis Model II project. I'll be working on those next

 

[pumablues]

Incidentally, since this is a "technics speaker" thread... i was poking around on the Goodwill Auction site, and found a pair of Technics speakers, very complex, large, and intense looking... and they were going for in excess of $1000. Apparently they did have some "winners" with a cult following still out there? could be

 

[sealy]

Technics made some incredible speakers, including a horn-loaded speaker. Most of the great ones were made for the Japanese market. You may get lucky on the other hand. The odd one pops up in the States.