Not GR Speakers, Sonos SP100's, tweeter not working

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skeeter99

Danny, I know these aren't your speakers but I've found the people in this circle to be some of the most knowledgeable I've found so hopefully this is ok here! If not, please feel free to move to a more appropriate Circle ...

So, my wife and I dropped off a bunch of stuff at the local Goodwill so I thought I'd run in after and see if someone had donated anything cool. I rarely ever find anything there but did find a set of KEF C55's that were surprisingly good a number of years ago. Anywho, I ended up spotting a set of Sonos SP100 speakers, did a quick search online and found some decent reviews so I figured, for 10 bucks, they were worth a shot. The cabinets are in really good shape and all the drivers looked nice with no blown coils on the woofers.

I got them home and hooked them up, one sounded really good and the other, not so much. Put my ear up to the tweeter and no sound  :duh:  So I proceeded to take out the drivers and test them individually with a volt meter and they both tested at 4 ohms. Connected a small battery to each terminal and they both produce sound so I know the drivers are still good.

Next I went to work on the crossovers testing the paths and found that one of the capacitors (a 5.6uF 100V) was not passing voltage. So I went to the local electronics store (Vetco) and picked up a new cap and thought I'd replace the other since I was at it (a 22uf 100V). I did that yesterday and boom, still no sound from the tweeter  :scratch:  So my guess is that the network board itself is bad.

I contacted Sonos and they refuse to help. They won't get me crossover specs (I found out through their forum its a an 1850hz filter), won't sell me a new crossover and won't let me send in the crossover for repair. Gee, thanks guys.

So ... all that said, I'm hoping someone can help me figure this out and get these puppies playing!

Attached are pictures of the crossover and speaker.








HAL

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #1 on: 1 Feb 2018, 02:05 am »
Do both the resistors and coils show values close when you use an ohm meter?  Might be one of those is open on the tweeter side.

Good to see you around.

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #2 on: 1 Feb 2018, 02:11 am »
Do both the resistors and coils show values close when you use an ohm meter?  Might be one of those is open on the tweeter side.

Good to see you around.

Hal,

I didn't check the values of the resistors and coils, just whether or not current was passing through them. I don't know how to check the values, I'm guessing I can with a volt meter? When I check the cap I get no continuity so that's why I was guessing the cap was bad but when I replaced it I still got no continuity. I was checking on the bottom of the network putting my volt meter on each contact and seeing if the noise was made or not ... Maybe I did something wrong, lol!

And thanks, it's nice poking my head in once in a while :) I peruse from time to time but haven't posted in I don't know how long!

Scott

HAL

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #3 on: 1 Feb 2018, 02:32 am »
Scott,
Caps will not show continuity.  If they do they are bad.  Also depending on where they are in the circuit you might be reading other component values. 

If the voltmeter has a Ohms mode, set it to the lowest one and test the two resistors.  The values are marked on them from the picture.  See what happens.

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #4 on: 1 Feb 2018, 02:53 am »
Scott,
Caps will not show continuity.  If they do they are bad.  Also depending on where they are in the circuit you might be reading other component values. 

If the voltmeter has a Ohms mode, set it to the lowest one and test the two resistors.  The values are marked on them from the picture.  See what happens.

Ahh ok! Didn't know that about caps :)

The lengthwise 2.2 oh is reading 2.3 ohms so pretty close and the width wise one that's supposed to be 4.7  is reading 5.1 ohms

S Clark

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #5 on: 1 Feb 2018, 03:05 am »
I'm not yet convinced that the suspect tweeter is good.  Just for grins, take the 22 uF cap and put it in line with the tweeter, then hook it up and play it.  The cap should provide enough protection, and you should be able to play to moderate volume.  If you get sound, then you are back to your crossover.  If not, your tweeter (probably voice coil) is bad. 
Now, maybe you get lucky.
If the tweeter plays, then I'd replace all the resistor and the caps with better components.  Don't go crazy, but you can upgrade pretty cheap.  2.2 ohm and 4.7 ohm resistors, are cheap, and inexpensive poly caps are also easy to come by- I think I've got extras if you need them.  I'd be shocked if the coils are bad... nearly never happens.  $20-30 buys parts. 

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #6 on: 1 Feb 2018, 03:21 am »
Ok tried the tweet with the cap inline and the tweet worked fine so it's definitely crossover related.

So get new caps and resistors and do both crossovers?? What happens if the board itself is the culprit ...

HAL

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #7 on: 1 Feb 2018, 03:46 am »
Check the soldering joints on the rest of the rear of the board.  Use a magnifying glass.

The connections might be loose, so that is what you are looking for to check the board.

S Clark

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #8 on: 1 Feb 2018, 03:47 am »
Ok tried the tweet with the cap inline and the tweet worked fine so it's definitely crossover related.

So get new caps and resistors and do both crossovers?? What happens if the board itself is the culprit ...

Good tweeter is good news.
Now, HAL is right. Wiggle each component with music playing to see if you've got a bad solder joint.  The board is probably good.  On the small chance that the board is bad, one of us old retired guys can rebuilt it point to point for you, or just jump a wire to replace a bad trace.  It's really not likely though. 
If it is a bad component...   Disconnect the woofer, put the volume down LOW, and short across the leads on the back of the board, taking each component out of the circuit.  If you short across the bad one, you'll get music in the tweeter. 
What you are doing is removing each component from the crossover circuit, one by one, looking for one that is breaking the path. But you are also removing protection for the tweeter from low frequencies, hence the advice to make sure you are at low volume.

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #9 on: 1 Feb 2018, 03:48 am »
Check the soldering joints on the rest of the rear of the board.  Use a magnifying glass.

The connections might be loose, so that is what you are looking for to check the board.

Ok will do, just need to find a magnifying glass!

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #10 on: 1 Feb 2018, 03:51 am »
Good tweeter is good news.
Now, HAL is right. Wiggle each component with music playing to see if you've got a bad solder joint.  The board is probably good.  On the small chance that the board is bad, one of us old retired guys can rebuilt it point to point for you, or just jump a wire to replace a bad trace.  It's really not likely though. 
If it is a bad component...   Disconnect the woofer, put the volume down LOW, and short across the leads on the back of the board, taking each component out of the circuit.  If you short across the bad one, you'll get music in the tweeter. 
What you are doing is removing each component from the crossover circuit, one by one, looking for one that is breaking the path. But you are also removing protection for the tweeter from low frequencies, hence the advice to make sure you are at low volume.

Oh wow that's a great trick! Off to the bedroom to try that out!!

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #11 on: 1 Feb 2018, 04:56 am »
Ok tried bridging the contacts for the caps, resistors and coils and it wasn't making any difference but I noticed there was a TINY bit of sound coming out that was muffled by the woofer playing at normal volumes before. While looking closely at the board I noticed there's a crack in the board that goes from each side toward the middle. I tilted the board up and the tweeter started playing at normal volume so its for sure, the board is bad. I may be able to jerry rig the board back in place but it'll probably be a temp fix.

Ideas??

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #12 on: 1 Feb 2018, 06:11 am »
So I ended up flexing the circuit board to open the crack further, shoved super glue in and around the crack and then flexed it back so sound was coming out. I let the glue dry and then braced the board with a couple strategically placed zip ties. We'll see how well it holds. For now, it's working. They sound decent. There's not a ton of bass but the mid-range and treble all sound pretty good. Not giant killers but definitely good for 10 bucks!

Thanks for all the help!!

Scott

Captainhemo

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #13 on: 1 Feb 2018, 06:38 am »
So I ended up flexing the circuit board to open the crack further, shoved super glue in and around the crack and then flexed it back so sound was coming out. I let the glue dry and then braced the board with a couple strategically placed zip ties. We'll see how well it holds. For now, it's working. They sound decent. There's not a ton of bass but the mid-range and treble all sound pretty good. Not giant killers but definitely good for 10 bucks!

Thanks for all the help!!

Scott

Just  do  a point to point network for each speaker.    If you can't  draw yourself a schemeatic from the  original  boards, one of the guys here will likely help or even build you some networks  as mentioned above, always lots willing to help  8)

Glad  you have found the issue and know there is a solution   

jay

gregfisk

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #14 on: 1 Feb 2018, 07:14 am »
Glad you found the problem. I would just bypass the bad trace on the board, so you are basically doing point to point like Jay mentioned, but just doing it on the bad trace. Enjoy you good find, it's always fun to find this kind thing at the thrift store. Not often something comes along but it's like finding a treasure when you do.

Have fun!

Greg

S Clark

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #15 on: 1 Feb 2018, 01:52 pm »
A crack!  OK, now we're getting somewhere.  I'd try drilling the board on both sides of the crack, scraping a bare spot around the holes, and soldering in jumper wires across the cracks. Then epoxy it heavily for support.  If that doesn't work, build new ones with better components and point to point wiring.

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #16 on: 1 Feb 2018, 02:48 pm »
Thanks guys for the tips on fixing the board and offers to remake the boards for me! I may take you up on that depending on how these last. Or ... I may just do it regardless :) Watched a bit of TV on them last night and their pretty forward, not overly so but definitely more so than the AV123 ELT525M we have been using. I think a nicer point to point crossover with nicer components will help some of the chestiness that they have. The cabinets are solid and nicely dampened so I'm guessing its crossover related. I'm going to rerun Audyssey tonight after work and see if that helps as I didn't rerun it before using the speakers, just kept the ELT525M settings. So we'll see if that helps.

But overall, definitely a good thrift store find. Who knows, I may end up just keeping the cabinets and putting one of Danny's sets in them, making a template for the tweeter from the existing tweeter so they fit nicely. That's what my wife suggested so we all know, my wife is ALWAYS right :D

I'll keep you all posted!

Scott

Danny Richie

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Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #17 on: 1 Feb 2018, 06:23 pm »
Quote
Danny, I know these aren't your speakers but I've found the people in this circle to be some of the most knowledgeable I've found so hopefully this is ok here!

Yep, lots of people post stuff like that here rather than the general forums because our customers are some of the most knowledgeable and sharing guys in the industry.  :thumb:  Your questions were answered and problem solved before I even saw the post. The guys that hang out here are the best.  :thumb:

skeeter99

Re: Not GR Speakers, Sonos SP100's, tweeter not working
« Reply #18 on: 1 Feb 2018, 06:25 pm »
Yep, lots of people post stuff like that here rather than the general forums because our customers are some of the most knowledgeable and sharing guys in the industry.  :thumb:  Your questions were answered and problem solved before I even saw the post. The guys that hang out here are the best.  :thumb:

Yes they are! Thank you for letting the thread stand :)