SDA1c x-over problem

sheathensemble

Hi , I recently replaced my poly switches thinking that they were the source of the problem. I was wrong; the tweeters in one of my speakers only work when you apply a little bit of pressure to the crossover in the top left corner. The tweeters seem to let some of the sound through with light pressure and with a little bit more they open up full. I stuck something under neath the bottom right corner to apply forward pressure on it (this seems to work as well). I sat back to have a quick listen to be sure that it was sounding how it should and it was sounding perfect. I tried some different material and all was sounding good until I played a jazz piece with a really dynamic piano player. I noticed that when keys were hit with a higher velocity it caused a distortion sound to come from the tweeters (only in the speaker with the Problem [the piano was not panned] ). Then the tweeters started to cut out again... I am really confused as to what is happening here. Once again the speakers no longer have poly switches.

I hope I described this in a way that makes sense... If anyone has any idea what could be happening here, let me know!

Thanks for your time and Cheers!

thsmith

Sounds like youi have a cold or cracked solder or cracked PCB. In either case I think you will need to pull the xover and look.

sheathensemble

The pcb looked fine when I had it out. I don't really no what to look for when it comes to looking for cold solder connections. Any advice on how I can check them?

thsmith

Hopefully the more enlightened will provide some input but I would start with a ohm meter and test for continuity starting at tweeters.

Mr. Bubbles

I agree with thsmith here. it definitely sounds like a cold solder joint or possibly a cracked trace. Traces don't normally just crack nearly as often as the joints dry out and get brittle. A good solder joint should be kind of bright and shiny with no sign of line or edge at the connection point between the solder and the leg of the component that is connected at said point. If the solder is dry and dull looking or if you see an edge or line where the components lead comes through the solder, look closer, wiggle the tip of the lead, or just re-solder to be safe. The solder should flow fairly smoothly from the board to the lead, if it doesn't appear to flow it is probably not as good as it could be.
Good luck.
Another way I use sometimes on hard to find cold/ broken joints is to get to the back of the board and with the speaker active use the end of a small screwdrivers PLASTIC handle and rub across the board in different locations. many times when you hit the bad solder joint it will slightly bend the tip of the lead sticking through the solder and make it work. You can then look more closely at the joints close to that area with a magnifying glass if necessary.

sheathensemble

Knock on wood... I think I fixed it. I found a nasty solder on the tweeter output and resoldered. Looks good so far! Thanks for all the help guys! and I will be back if it decides to crap out again.

Cheers!

thsmith

Excellent ! Let us know when you are confident the issue is fixed.

sheathensemble

Well I am still getting a little bit of distortion on sustained notes. I will rip her open again tomorrow and have another look. Right now I have them hooked up to an sx 3800 though... maybe not the best unit to be running these either. I am going to get them hooked up to my alpha 450 tomorrow and beta pre. Should make for a better setup. I will post again tomorrow when I take another look.

Thanks again Smith and Oliver!

Cheers!

SDA1C

I think that's a dandy little receiver. It's age might be giving some static in jthe knobs or switches. We just had this issue with a sda1c cover board. Check all the resistor solder joints and resolder just for shots and giggles. I had a set that the resistors were literally held in place with the curl on the end of the wire. Rather common on these it seems.

sheathensemble

LOL (sarcastically): Vintage audio is really letting me down right now... right channel on the sx3800 just dropped out. I am still having problems with my left sda1c. And I just read online that my alpha 450 isn't common ground. I am sitting here starring at my sda1c's just thinking about how awesome they will sound when I get this sorted out.

So an update: after my last solder job the tweeters seem to work better and more consistently. They seem to be making a sort of popping sound now... and dropping out for durations of time you would measure in milliseconds frequently.

Anyone have any ideas?


I am currently using my lame pioneer 1019 7.1 receiver to power them. So it looks like I am going to have to get a AI-1 cable now before I can use a my proper amp.

---

> Does anyone know where and how I can get one? I have read:"Ken" that works for Polk makes them... How can I contact him?


Cheers!

sheathensemble

BUMP ---- Anyone?

F1nut

Yeah, you still have a connection issue somewhere, could even be an issue in the tweeter. Swap the left with the right tweeters to see if the problem follows. If it does, the problem is with the tweeter(s). If the issue remains in the left speaker, it's time to go over the board and connections again.

headrott

sheathensemble wrote: »

LOL (sarcastically): Vintage audio is really letting me down right now... right channel on the sx3800 just dropped out. I am still having problems with my left sda1c. And I just read online that my alpha 450 isn't common ground. I am sitting here starring at my sda1c's just thinking about how awesome they will sound when I get this sorted out.

So an update: after my last solder job the tweeters seem to work better and more consistently. They seem to be making a sort of popping sound now... and dropping out for durations of time you would measure in milliseconds frequently.

Anyone have any ideas?


I am currently using my lame pioneer 1019 7.1 receiver to power them. So it looks like I am going to have to get a AI-1 cable now before I can use a my proper amp.

---

> Does anyone know where and how I can get one? I have read:"Ken" that works for Polk makes them... How can I contact him?


Cheers!

You need to check to make sure your 1C's can use the AI-1. Not all of them can if I am not mistaken. You need the pin/blade SDA cable connection and there may be other requirements that other may be able to chime in with. That said, I may have one for sale (an AI-1) after I put my second one together using Larrys case for it. It may take a little time though (a month?) to finish it though. I will then put the one I am currently using up for sale if you may be interested in it. It's made with very good components.

Greg

sheathensemble

F1: Great Idea! Never thought of that! Really appreciate the input!

Headrott: have the pin/ blade cable...
I Am located in ontario Canada... pm me if you're still interested.

Thanks again Guys~!

sheathensemble

I plug them into the xover from the right speaker and they're fine. I fixed my sx3800 so now i have something to drive these 1c's. still lost, so frustrating hahaha.

drumminman

sheathensemble wrote: »

I plug them into the xover from the right speaker and they're fine. I fixed my sx3800 so now i have something to drive these 1c's. still lost, so frustrating hahaha.

That's good, you're isolating the problem. Unless you can see a visible flaw, it might be best to get some high quality solder and resolder all the joints. Of course, as long as you have to do that you might as well go ahead and replace the capacitors and resistors :cheesygrin:

It'd be no more work, and you'd be doing an upgrade at the same time you fixed the problem. :cool:

So easy to spend money :cheesygrin: but it will be worth it if you really want to hear what the 1C's can do.

TennMan

sheathensemble wrote: »

...So an update: after my last solder job the tweeters seem to work better and more consistently. They seem to be making a sort of popping sound now... and dropping out for durations of time you would measure in milliseconds frequently.

Is that a problem you are still having? If so you could have a capacitor that is breaking down. Does it make a popping or clicking sound starting after everything has time to warm up? That is a common problem in '80 and '90 car radios. Replacing the caps is the fix for the radios. It might solve your problem as well.

thsmith

TennMan wrote: »

Is that a problem you are still having? If so you could have a capacitor that is breaking down. Does it make a popping or clicking sound starting after everything has time to warm up? That is a common problem in '80 and '90 car radios. Replacing the caps is the fix for the radios. It might solve your problem as well.

That is what I was thinking.

Where are you located ? Maybe a local Polkie could take a look just to make sure.

nspindel

If you are going to resolder all the joints, may I make a suggestion. Head to your local Rat Shack and spend $10 on a de-soldering iron. Nothing will make the job of removing all the old solder easier. Then get some good solder like Cardas and have at it. As others have said, there won't be a better opportunity to upgrade your caps than right now if this is what you're going to do.

sheathensemble

Visually everything looks fine and in place.

I guess if it is a cap; I might as well upgrade everything. Thanks for the input, It will be the next thing I investigate!

PS The problem temporarily corrects itself when I give the cabinet a good smack :redface: , And don't worry I am not in the business of hitting speakers :cheesygrin: .


I am located in Toronto, Ontario.

If I make any progress I will surely post it.

Thanks guys! Cheers, Sheath

thsmith

You have a loose connection or bad solder joint. WIsh you were closer. If you are not comfortable you could take the Xover out and send it to someone to diagnose.

I am sure this is frustrating but be patient and you will be rewarded.

sheathensemble

thsmith wrote: »

You have a loose connection or bad solder joint. WIsh you were closer. If you are not comfortable you could take the Xover out and send it to someone to diagnose.

I am sure this is frustrating but be patient and you will be rewarded.

Ok I think my next step is to resolder anything pertaining to the tweeter, Since this problem is isolated to the tweeters. Can anyone recommend what parts I should resolder. Any recommendations on solder? I will most likely be buying it from radioshack (the source).

Thanks again Smith

thsmith

I will look later, at work now but if you go to the vintage speakers section and look for the SDA schematic sticky and find the one for 1C SDAs you will find what you need. If not sure how to read it I will pull it up later and look.

Cardas silver solder is my recommendation.

Make sure the plug coming in from the binding post on the inside is connected good on the PCB too.

sheathensemble

thsmith wrote: »

I will look later, at work now but if you go to the vintage speakers section and look for the SDA schematic sticky and find the one for 1C SDAs you will find what you need. If not sure how to read it I will pull it up later and look.

Cardas silver solder is my recommendation.

Make sure the plug coming in from the binding post on the inside is connected good on the PCB too.

Well I just resoldered the whole board. Tried her out and all was good until about 3-4 minutes into play time when the poping sound started. So I guess it is a bad cap? I think I had a contact issue as well some where... cause the tweeters didn't drop out just this poping sound. So I guess I am going to upgrade the caps and resistors... the stock inductors are fine right?

Well if anyone can give me a parts list of tried and true cap and resister replacements (values/ size as well) it would be appreciated.

Cheers, Sheath

sheathensemble

thsmith wrote: »

Make sure the plug coming in from the binding post on the inside is connected good on the PCB too.

Well I just soldered the wires straight onto the crossover ( bypassed the white plastic connectors) and went over the solder connection again and IT WORKS!

I just had my first real sda listen with the 1c's. Sounds like magic! Made it through 4 whole songs without a snap, crackle or pop!

Thanks everyone for all your help!

Cheers, Sheath :cheesygrin:

thsmith

Great that you stuck with it and congrats !

nspindel

They will only get better if you do the mods/upgrades as suggested on this site - tweeter replacement, caps/resistors, etc. If you ever do get around to upgrading, I'd suggest you find replacements for the quick connects and reverse the fix you just did. Obviously you had a bad connection in one of those quick connectors. Removing them and hard-wiring fixed your problem, but it also makes it very difficult to remove the crossover if you ever need to. Now you'll need to start pulling tweeters and drivers and pulling the cabinet wire all the way out along with the crossover. Painful....

sheathensemble

I was just wondering if these caps would be ok for a upgrade. From what I have read; Just getting newer caps and resistors is worth the work. I have not yet found an exact parts list to redo the xovers yet. But everyone says it cost around 120-300 depending on the parts you use. I was hoping to get new caps, but cheaper ones...

For example...

I am wondering if I could replace the 4.4 with this...

http://solen.ca/pub/cms_nf_catalogue_fiche.php?id=1371&recherche=&numRows=&manufacturiers=&niveau1=1&niveau2=3&niveau3=26

The cap type is: FAST CAPACITORS 250V PA SERIES METALLIZED POLYPROPYLENE

would this work? do you need a specific type of cap? If it would work do you think it would be considered an upgrade?

Excuse my ignorance if this is a stupid question..

The thing is that I am currently placing an order for parts to rework my Kinima G3 crossovers and at this price point I figured I might as well order the caps and resistors for the 1c's

Cheers, Sheath

sheathensemble

QT PART # DESCRIPTION MANUFACTURER PRICE
TOTAL

WWSQP10J2R7 2.7 Ohms 10 W Taiwan 0.27 $ EACH (2 of these)
0.54 $
Remove from cart
WWSQP10J7R5 7.5 Ohms 10 W Taiwan 0.27 $ EACH (4 of these)
0.54 $
Remove from cart
PA2000 20 mfd 250v 28x43 France 9.30 $ EACH (6 of these... double them up to replace the 40uf ?)
55.80 $
Remove from cart
PA430 4.3 mfd 250v 18x28 France 3.32 $ EACH (2 of these)
6.64 $
Remove from cart
PA1200 12 mfd 250v 23x38 France 6.48 $ EACH (2 of these)
12.96 $
Remove from cart
TOTAL

76.48 $CA


Would that work? I can'y find 40uf

F1nut

If you're going to upgrade, do it right. Those are really cheap resistors and Solens have no business in a crossover.

At a minimum, get Mills 12 watt resistors and Sonicaps.

http://www.soniccraft.com/

sheathensemble

F1nut wrote: »

If you're going to upgrade, do it right. Those are really cheap resistors and Solens have no business in a crossover.

At a minimum, get Mills 12 watt resistors and Sonicaps.

http://www.soniccraft.com/

Thanks! I think I will just wait until I really feel the urge and do it right. I am in canada and solen seems to be about all we have hahaahaa