SDA CRS+ Crossover recap
DeRod
Posts: 230
I got a pair of SDA CRS+ a while back and just now got around to checking them out. One had something rattling around inside. Once I got them opened up I found the crossover had come loose. The large inductor separated from the board and two other inductors on the board suffered some damage. Seems to all be cosmetic but still sucks.
Before ordering caps was looking for suggestions as far as the 2 polys and the resistor.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb.
Comments
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Replace the broken plastic standoffs with metal hex standoffs.
Are you asking about the polyswitch? If so, replace with a 0.5 ohm resistor. Vishay-Mills resistors are my choice.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Hi F1, thanks for the response.
Yes, I was talking about the poly switches.. looks like there are 2 … replace each with a .5 ohm resistor ?
I already have some hex stand offs left over from a previous project."Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Yes, I was talking about the poly switches.. looks like there are 2 … replace each with a .5 ohm resistor ?
Yes. Using a higher wattage resistor is a best practice as well. .5ohm 10 or 12 watt resistor instead of the 5 watt. -
Ok, so the 2.7 stays the same and the 2 poly switches are replaced with 2 .5ohm resistors, correct?"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb.
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There's only one polyswitch per crossover. S1 is the polyswitch.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
What's that little brown one in C4?"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb.
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Bypass cap, just remove that and do not replace- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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Any resistor on the board would benefit from increased wattage. If the other resistor is a 2.7 ohm 5 watt, increase them to 2.7ohm 10 or 12 watt resistors. Cheap insurance.
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VR3 and F1 answered my question/confusion. I thought that little brown one was a poly switch as well.
I will delete the bypass cap and replace the poly switch a .5ohm resistor
@pitdogg2 I got some mills 2.7k MRA12w left over from another project."Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
I’m still waiting on the caps to arrive so I went ahead and added hurricane nuts, JB Welded the woofers and added Dynamat.
Then I decided to make an SDA cable. I read here somewhere that the Cinch/Jones plugs work .. kinda think I’m gonna re do this ghetto looking cable I made and use the plug ends 😂"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
My cable for my pin/blade socket I also used RCA plugs with the ground ring removed, it worked well. If you're not using a dreadnought then there's no need for the blade. If you're going to use a dreadnought then make the switch to speakon connections.
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For the moment I just want to listen to them thus the ghetto cable. I have an Adcom GFA-545 that's from 1989, same as the speakers, that should pair up well.
In the future building a dreadnought looks fun. I have some class a mono blocks that should work well with that set up.
My tube amp isn't even grounded so that one is probably not a good choice for these speakers.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
What wire did you end up using, did you do the DH Labs Silversonic stuff? Doesn't look ghetto at all with that sheathing
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Mygatti Pro series speaker wire 14awg OFC - Amazon speaker wire
25FT $18.99 ... the wire looks cool it's the ends I made that look ugly. You can't really see them when they are plugged in though.
I think that DH Labs cable was $18.99 per FT 😜"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Mygatti Pro series speaker wire 14awg OFC - Amazon speaker wire 25FT $18.99
I think that DH Labs cable was $18.99 per FT
Not too bad. They say 99.99% Cu.
https://www.amazon.com/Speaker-Durable-Conductors-Oxygen-Free-Surround/dp/B0D977DJ5F/ref=sr_1_4
PS: AND it has a "sleeve to prevent your cat from chewing" 🤣George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
New capacitors and resistors arrived today. Wow .. I didn’t really think about it before hand but that 40uf is pretty big.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Creativity, the word of the day.
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I thought that big 40uf was going to be a problem … turns out, it’s the other 2 caps I can’t figure out how to fit properly.
My creativity has run out for the night 😂
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
I think you have to either stack the 20 and 12 or do an over the board/under the board combo.. I've only seen others do the stack IIRC but maybe the oval shaped 20 can be sort of diagonal or vertical with long axis of the oval and the 12 on the V-block formed between it and the PCB ? Other option might be long axis of the oval horizontal and just piggyback the 12 on top of it with some foam tape between them? I suppose yet another option would be to go vertical with both of them and foam tape between them like a couple toy soldiers for want of a better analogy lol.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
That’s what I came up with. Best I could do with my limited creativity 😂 It would have been easier if the leads on the capacitors were slightly longer.
@Gardenstater I didn't even notice that 20uf was oval till you mentioned it. That actually helped a lot.
BTW - that’s the board that had come loose and was rattling around inside the cabinet. Notice the broken plastic on the inductors. It also has some scratches on the circuit board that look superficial. Will the scratches affect anything?"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Run a bit of hot glue over the inductors before you re-install the boards.
I'm assuming you may have removed it during the fix. -
Yes and perhaps a bead of hot melt on top between the 20 and 12 AND a couple blobs underneath at the ends.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Ok 👌 glued and reassembling.. Black and Blue are positive ? I forgot to pay attention to the woofers when I removed them .. I assume black/white wires to the black/white labeled woofer and the pink woofer to the colored wires ?
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Terminals with the Red dots (if you can see that after dynamat) go to Black and Blue.
Those cabinets look very nice.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
They had very little damping inside. Just that small wad rolled up between the woofers and behind the tweeter. All in all though I’m super impressed with build quality of these for 1989. These are super nice even by today’s standards.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
I had the woofers reversed 😂
Got everything back together and I’m very happy how these sound.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
No toe in!Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Wow .. that made everything sound bigger 😂
@F1nut thanks for pointing that out .. I didn’t know and it does make a big difference.
These are a lot of fun so far.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Rookie....
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You are welcome.
Additional tips for SDA speakers:
5 to 6 inches off the wall. Half an inch will make or break the results of the bass performance.
6 to 8 feet apart.
At least 3 feet from a side wall.
Again, no toe in.
Other performance enhancements for your situation:
Stands should be mass loaded.
Stands should be on spikes.
Speakers should be isolated from the stand. Rubber pads work well.
One more thing, no speaker behind another speaker. 😎Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk
