vintagenut

vintagenut

Hello All, This is my first post here, Forum looks very interesting. I am somewhat of a collector of vintage HI FI. I just purchased a set of SDA 1Bs and already love them. I had to purchase the interconnect from Polk to get them up to speed. I have now discovered that 2 of the tweeters aren't working, also the ones in the speaker that I checked out had 3rd replacement wrote on them. To make a long story short, where can I get replacements? From Polk ? Why did they blow now for the 4th time? I would say overdriving with a low power amp .And will a Pioneer SX 950 drive them comfortably? 85watts per channel. Any info would be greatly appreicated. Thanks

F1nut

How did you verify that the two tweeters are bad? In case you didn't know, the tweeters in your speakers are a progessive point source. Therefore, the bottom tweeter does not play as loud or the full frequency spectrum.

RuSsMaN

Polyswitch Jesse?

Bottom line, he needs more clean power, and RDO's, right?

F1nut

All four would be dead unless it's two in one speaker. We need more info.

Absolutely!!!

nadams

Are both tweeters active in the 1b's when the interconnect is missing? I know when I had both tweeters hooked up in my 2's, the outside "sda" tweeters wouldn't function if the interconnect was unplugged.

heiney9

nadams wrote: »

Are both tweeters active in the 1b's when the interconnect is missing? .

Yes.

SDA 1's and 1A's with side by side tweets need the interconnect for the outer tweet to function. All SDA's with vertical tweets are progressive point source and have nothing to do with the SDA circuit.

We need more info from the OP to diagnose correctly.

H9

Joe08867

It sounds like you were a little to crazy with the volume and blew a couple of tweeters.

The SX950 is a nice sounding piece but not exactly the strongest in the Pioneer arsenal and may have issues of it's own since it is over 20yrs old.

I would replace the tweeters with the RD-0194 and take it easy on the volume until you get a source with better high volume power..

heiney9

Joe08867 wrote: »

The SX950 is a nice sounding piece but not exactly the strongest in the Pioneer arsenal and may have issues of it's own since it is over 20yrs old.

You mean more like 35+ years old. :biggrin:

At 20 years old that would mean it was made in 1991, that's a little late for the SX950

H9

Joe08867

heiney9 wrote: »

You mean more like 35+ years old. :biggrin:

At 20 years old that would mean it was made in 1991, that's a little late for the SX950

H9

You got a good point there. :biggrin: Good thing I am not an accountant!:eek:

vintagenut

Wow great discussion, Thanks all. I just purchased the speakers about a week ago, and have driven them very easily, kinda just playing with them, checking them out. The previous owner was the overdriver. I just noticed no sound coming from the bottom tweeter, so I swapped the bottom for the top one and now the bottom one, same driver as before is working. So it seems that all wires are hot, but at least the tweeter I checked is dead. The dead tweeter also is very dark in the middle part where the other one is clearer, Haven't tried the other side. The interconnect seems to be working after doing the checks as described in the owners manual. I haven't hooked them up to the SX 950 yet, It will soon be totally restored and just wondered how the two will match. I listen to mostly classic rock, with one favorite being anything Dire Straits, Just eniough volume to rattle whats very loose around the house. THANKS AGAIN.::rolleyes:

vintagenut

It's the bottom one on each side........ F1nut, I really like your definition. Thats funny, I don't care who says different.

rromeo923

Getting nutty in here

wingzam

vintagenut I have a little experience with these 1B's.I started off the audio hobby with these speakers and went thru alot of trial and error and Club Polk questions before I finally figured out what was going on.

The poly switches had built up resistance and were causing the speakers to go into protection mode at lower and lower power levels.Thought I had amp problems.After three different amps (the first two were high output.but kind of old and clunky) I found a post by Darqueknight about the poly switches and bypassed them with a resistor which I can't remember the value of...

This fix solved one problem,but created another.I no longer had the protection limiting the speaker volume,but I started blowing tweeters.

My Adcom GFA-5800 puts out 400 watts into 4ohms and the 1B's will just eat that up without distorting.It's hard to figure out when to stop turning up the volume knob!So I went thru 2 sets of tweeters before I decided to upgrade to the RDO194 tweeters.Not wanting to pay for anymore tweeters I take it a little easier now.

This has caused what must be an audioholics disease where one experiences a mania related to wanting to turn up the volume,with the anxiety of fearing to blow tweeters.I think it's called Volume Related Bi-Polar Disorder..VRBPD..or Verp for short.When one is in the middle of such an episode it's called Verping!When you get to that volume limit it causes one to get Verpy..and if you exceed the limit and blow a tweeter - you're Verped!

Schurkey

vintagenut wrote: »

I have now discovered that 2 of the tweeters aren't working,

wingzam wrote: »

I decided to upgrade to the RDO194 tweeters.

The 194s are a direct replacement. You can do better, however.

Replace the 4.4uf capacitor in the high-frequency crossover with a 5.8uf cap, (one per speaker) and order the RD0198 tweeters from Polk.

Same price except for the added capacitors. The caps will need to be replaced anyway, unless that's already been done.

The 198 tweeter is considered superior to the 194; which is superior to the SL2000 tweeters the speaker was originally equipped with.

There's a multi-page-long thread about all this; it doesn't get good until near the end. Bear in mind that the SDA-SRS2 (blade/blade) is essentially the same speaker as the SDA 1B except for a larger cabinet, bigger passive radiator, and one resistor in the crossover.
http://www.polkaudio.com/forums/showthread.php?t=74946&highlight=SRS2

MY 1Bs have 198s in the top position, and the original-style SL2000s in the lower, restricted-frequency position. I'm too cheap to replace functioning tweeters...

wingzam

Schurkey wrote: »

The 194s are a direct replacement. You can do better, however.

Replace the 4.4uf capacitor in the high-frequency crossover with a 5.8uf cap, (one per speaker) and order the RD0198 tweeters from Polk.

Same price except for the added capacitors. The caps will need to be replaced anyway, unless that's already been done.

The 198 tweeter is considered superior to the 194; which is superior to the SL2000 tweeters the speaker was originally equipped with.

There's a multi-page-long thread about all this; it doesn't get good until near the end. Bear in mind that the SDA-SRS2 (blade/blade) is essentially the same speaker as the SDA 1B except for a larger cabinet, bigger passive radiator, and one resistor in the crossover.
http://www.polkaudio.com/forums/showthread.php?t=74946&highlight=SRS2

MY 1Bs have 198s in the top position, and the original-style SL2000s in the lower, restricted-frequency position. I'm too cheap to replace functioning tweeters...

Thanks for that Schurkey.Just ponied up for the 194's and am too cheap to go any higher.But you do raise an interesting possibility if I do blow two of the tweeters.I'll do another partial upgrade as per your suggestion!

thsmith

vintagenut wrote: »

Wow great discussion, Thanks all. I just purchased the speakers about a week ago, and have driven them very easily, kinda just playing with them, checking them out. The previous owner was the overdriver. I just noticed no sound coming from the bottom tweeter, so I swapped the bottom for the top one and now the bottom one, same driver as before is working. So it seems that all wires are hot, but at least the tweeter I checked is dead. The dead tweeter also is very dark in the middle part where the other one is clearer, Haven't tried the other side. The interconnect seems to be working after doing the checks as described in the owners manual. I haven't hooked them up to the SX 950 yet, It will soon be totally restored and just wondered how the two will match. I listen to mostly classic rock, with one favorite being anything Dire Straits, Just eniough volume to rattle whats very loose around the house. THANKS AGAIN.::rolleyes:

A freshly tuned up 950 will drive them. I would save the money on tuning up the 950 and sell it. Pick up an anthem pre 1l and anthem amp 1 or a nad pre and amp. You will be miles ahead.