Polk SDA 2.3 - HELP Need information on crossover upgrades

prosuite

Hi, New to this site but long time Polk SDA/audio enthusiast.

I currently own a pair of very beloved Polk SDA 2.3 speakers (not TL) in need of some repair. I have been holding on to them for far to long in hopes of getting the budget to fix them properly. I believe the issue is with the crossover. Unfortunately I know very little about the workings of the crossover networks and am left at the mercy and knowledge of the people on this forum to direct me as to what to buy in order to make these work properly once again. Im hoping the new parts won't change the sound drastically from what the original sound would be.
I intend to have someone local upgrade the crossovers with the parts i purchase myself with help from this community. this will prevent **** hardware from ending up in my cabinets. I'm have to keep the cost below $300 (parts only).

Ever since I have owned these there has been an issue with the 'brightness' of the pair. tweeters seemed to be cutting in and out. The issue seemed to have gotten worse when a dynaco amp I was using had a total **** and died with a large, loud, high pitched buzz through the speakers. (this was a common ground amp). This must have done something to the internal workings of the speakers since now the high end of the cabinets is very dismal compared to the SDA CRS that sit atop of the SDA 2.3's. Any suggestions on what may have occurred would be appreciated.

Thanks very much for your information. I truly appreciate these and thank the community for support in getting another pair of the scarce series back in good shape.

Serial - SDA SRS 2 2837

[Deleted User]

Hello,
The tweeters cutting in and out could be related to the tweeter protection devices, called polyswitches, tripping. One of the things people decide during crossover upgrades is to either keep them in the circuit (putting in new ones) or eliminating them. But, from your examples of what happens with a failed amplifier keeping them might be a good idea?
Regards, Ken

F1nut

Serial - SDA SRS 2 2837

Your quote above indicates you have SDA SRS 2's, not SDA SRS 2.3's.

As Ken suggested, your polyswitches are giving you problems, but you may have also cooked the tweeters. However, that would be a blessing in disguise as no matter what new crossover components you use the SL2000 tweeters will still be bright. There is a solution, Polk sells a replacement tweeter, the RD0194-1 that is far superior, so no more brightness. You'll still want to upgrade the crossovers as the original caps are way past their useful lifespan.

prosuite

Thanks for the information guys. Im aware of the new tweeter upgrades. My issue isn't that they are too bright, rather that they have nearly no high end at all. Im not sure I want to do the tweeter upgrade at this point until I have gotten them working properly to see what I think of the existing tweeter.

I assumed they were 2.3 judging by the fact that they looked like other 2.3s out there. I suppose they are just SDA SRS2's

Thanks Ken, I wonder how these switches work? Do they trip once and need replacing?

Does anyone know where I can get a whole new batch of hardware for the crossovers including the polyswitches? I don't know about this stuff so I will need specifics or someone who can help me get all the hardware.

F1nut

prosuite wrote: »

Thanks for the information guys. Im aware of the new tweeter upgrades. My issue isn't that they are too bright, rather that they have nearly no high end at all. Im not sure I want to do the tweeter upgrade at this point until I have gotten them working properly to see what I think of the existing tweeter.

You said, "Ever since I have owned these there has been an issue with the 'brightness' of the pair."

I assumed they were 2.3 judging by the fact that they looked like other 2.3s out there. I suppose they are just SDA SRS2's

If the ones in your avatar are yours, then you do have 2.3's. Not sure why your serial number tag says otherwise.

Thanks Ken, I wonder how these switches work? Do they trip once and need replacing?

It's a thermal reset device, which becomes hyper-sensitive from being tripped.

Does anyone know where I can get a whole new batch of hardware for the crossovers including the polyswitches? I don't know about this stuff so I will need specifics or someone who can help me get all the hardware.

The forum is full of that info, use the search feature.

chandler9a

My 2.3's also just say SRS 2 on the back, not sure why but they are definitely 2.3 non TLs.

Sounds like your poly switches have tripped and tweeters need to be replaced, well worth it as it IMO, especially if you are going to do the crossovers.

I am saving up, and have been for years, on rebuilding mine but I can assure you, from upgrading other SDA's that I still own, you won't be disappointed.

Schurkey

Grab an empty cardboard core from a roll of paper towels. You could use a fresh roll of paper towels, but it's bulky and ungainly.

Play music you're familiar with, and which has decent high-frequency content at a normal volume level. Put your ear to the hollow center of the paper-towel core. Put the other end of the core very near each tweeter, in turn. You will be able to tell if each of your tweeters is producing sound.

Keep in mind that the three-tweeter array is a "progressive point source", so one tweeter should be fairly loud, the next will have less volume as it is frequency-restricted, and the third will have even less volume, being still-more frequency-restricted.

NONE OF THEM SHOULD BE SILENT, assuming you're playing music with reasonable high-frequency content.

First Guess: At least one tweeter in each cabinet is dead.

Get back to us with the number AND POSITION of dead tweeters.

Do you have an AC voltmeter that can register from a couple of volts downward to the millivolt range? If so, you could remove "dead" tweeters, and test for voltage at the driver leads, once you disconnect them from the tweeter(s) Voltage but no sound = dead tweeter. No voltage = dead crossover (which could include a failed "polyswitch" tweeter-protection device.)

As said, those crossovers are long past their expected service life.

prosuite

Thank you for your responses. There is a Welth of knowledge and experience here. This is starting to make sense...

- I suppose I should have mentioned the issue with the 'brightness' is that it's not bright enough.

- KennethSwauger - I diddnt know about the Polly switches. This could very well be some or all of the issue.

- f1nut, thanks for the info. If these are hyper sensitive I'll sort it out and get back to you.

- Schurkey, I'll try those tests and get back to you! The fact that these teeters are a 'progressive point sourse' is a huge bit of information I diddnt know. I wondered why all tweeters diddnt seem to sound the same so this puts that issue to rest. Does anyone have any more information on this? Three tweeters handling different frequencies is something I haven't heard of.

With regards to the crossover component upgrades I was hoping to open the discussion to experiences out there. Do we know a reliable source for hardware? Was the sound altered from what should be the original sound from these was like? Is the progressive point source altered? Was the SDA effect altered? Are some of these crossover upgrades overkill and not really needed to maintain the speakers, etc.

Thanks allot. This has already been very informative. Eagerly awaiting input so I can get some hardware.

F1nut

With regards to the crossover component upgrades I was hoping to open the discussion to experiences out there.

The forum is already jammed full of those discussions, get your search on. I will tell you this, there isn't one person that has upgraded their crossovers that wanted to go back to the original junk.

txcoastal1

http://forum.polkaudio.com/search?Page=p1&Search=sda+upgrade

PolkieMan

Also I suggest that you read the SDA Handbook. that way you will already have a basic understanding of what questions to ask.

http://vr3mods.com/uploads/SDA_Handbook_2011_Rev2.pdf

AND

http://www.gimpod.com/sda-id.html.
and

http://vr3mods.com/LCSDAUpgrade.php

Plan on replacing all your tweeters with the new ones, you will thank us so much!

The poly switch is nothing more than cheap tweeter protection.

Parts Express has them they are $1.50 each.

A lot of people remove it and just put like 0.22 ohm 12 watt mills resistor or even just a jumper wire.

If you have kids or wild parties you may want to keep it.

What is said about the tweeter array is correct and guess which one blows first the one that handles most of the sound.