SDA 1A Tweeter / Cut Out Issue

chuckeroo

Hello, and thank you for reading...

I recently purchased a pair of SDA 1As (actually the SDA 1 Signature Conversion), and they sounded great until I tried to push them a bit last week - didn't go really above 50% volume on a 100w amp, so figured would be no problem. Now, when ever I turn the volume up past about 25% or anytime there is any significant bass the sound cuts out for a second, then clicks back on. After the click, the tweeters on my right side have a loud hissing noise. I can turn the system off then on again, and at low volume everything sounds fine, then turn it up a little and same issue again. Do I have a bad tweeter? Is this the tweeter "fuse" or polyswitch thing cutting out? It's wierd because I am using a pioneer sx1010 which is only about 100 watts, which I would think is actually low for these speakers. I still have the 1000 tweeters in there, and will upgrade sometime, but would like to track this issue down first.


Any ideas or responses are really appreciated, and please let me know if I can provide any other info.

Thanks!
Chuck

halo71

Is it the outside tweeter(s) doing that or the inside?

halo71

For some reason I could not edit the above post.....but anyway.

Here are some links about the 1A that were posted in another thread recently that I found interesting.

http://www.polkaudio.com/forums/showthread.php?80470
http://www.polkaudio.com/forums/showthread.php?81321
http://www.polkaudio.com/forums/showthread.php?71487
http://www.polkaudio.com/forums/showthread.php?81206
http://www.polkaudio.com/forums/showthread.php?117784
http://www.polkaudio.com/forums/showthread.php?80916
http://www.polkaudio.com/forums/showthread.php?54342

Phasewolf

You are most Likely clipping the amp and tripping the polyswitch. Or the polyswitch is bad which happens over time. Do a search on polyswitch and read up.

heiney9

What is an SDA 1 Signature conversion?

I know what the SDA 1 Signature is, but what is the conversion?

H9

halo71

Takes a SDA1 to 1A specs.

heiney9

Phasewolf wrote: »

You are most Likely clipping the amp and tripping the polyswitch. Or the polyswitch is bad which happens over time. Do a search on polyswitch and read up.

Depending on generation these more than likely don't have poly's. Those didn't come until later. Without photo's of front and back there is no way to tell what he has. And if it has been converted (as he states and whatever that means) who knows what parts are in there.

But you are correct, if by some chance he has poly's in whatever x-over he's using, they are probably worn out. Typically SDA1 and SDA1A's had fuses.

H9

heiney9

halo71 wrote: »

Takes a SDA1 to 1A specs.

Ummmmmkay, don't know what that means. There is a lot of variation between the 1 and 1A and the 1A Signature Ed. is different as well. Just saying you have one or the other doesn't really settle it because of all the crossovers between the early SDA's. In this early period there was not a clear delineation from one model to the other. Truly using up parts bin pieces.

With out detailed photo's it's very hard to tell what he actually has.

H9

pitdogg2

Phasewolf wrote: »

You are most Likely clipping the amp and tripping the polyswitch. Or the polyswitch is bad which happens over time. Do a search on polyswitch and read up.

I don't think those have a poly switch. I have some SDA1 signatures and both tweeters are fused. These are power hungry that pioneer is like filling a giant swimming pool with your garden hose. Take a look at you tweeters very closely I had one of mine doing some very strange things and then one day it just up and quit. I found that the pole piece glue had completely let go and pinched the voice coil. So my thinking was that it was close enough to the coil to make nasty sounds until it completely let go and grabbed the magnet and VC.

That click your hearing could be your pioneer going into protection mode for a brief second these are 4ohm and really tax a receivers power supply.

chuckeroo

Thank you all for the responses! I will try to answer some of the questions here:

@halo71: It is the inside tweeter primarily making the hissing noise it seems

@heiney9: I guess SDA 1 Signature Edition is the technically correct name. I just said "conversion" as I have sort of read that it is an SDA 1 Cabinet modified by covering tweeter ports and using the 1A crossovers and wiring. I could easily be wrong though too. I definitely have fuses as there are holders on the back for extra fuses.

@pitdogg2: did you get new tweeters? did you get the 194s? did that fix your issues and did you see a big improvement?

Does this sound like a blown fuse issue? It does sound like it could be the amp clipping, because it happens on both speakers, and cut out occurs on both the tweeters and drivers, everything at the same time. I'm bummed that my amp won't be able to drive these things, I knew they prefer more power, but it sucks that I can't hardly turn the speakers up at all now. How much should I be looking for in an amp? 250 - 300 watts? I guess I should start looking at an adcom or something, can't really swing for too high end right now. Any amp suggestions would be awesome...

heiney9

If the fuse blows then the sound goes away until you replace the fuse, it won't cut in and out. Unless the fuse is somehow loose in the socket, maybe bass notes can cause it to cut out, I highly doubt that's the issue though.

My guess is the receiver is going into protect mode, most likely from overheating, and once it cools down it cuts back in until it overheats and goes into protect mode and cuts out. Older SDA's are much harder to drive so an amp is definintely in order.

H9

halo71

So its not the dimensional tweeters making noise, they are the outside ones. Your original post did not say it was the tweeters and drivers cutting out. At least I didn't comprehend it that way. Yeah I to think its your amp. I am supposed to be getting a pair of 1A's this coming Saturday. And will be driving them with an Integra M504 power amp at 165 wpc. So I shall see how they like that amp soon.

chuckeroo

Thanks again for the replies guys. So yeah, sorry for the confusion, the tweeters on only one speaker hiss, but everything cuts out when the clipping occurs. Man, the speakers sound so good, especially when I had them going loud for a bit, sounded like a guitar amplifier, really clear and loud at the same time. The amp search begins, the wife isn't going to like this at all.

halo71

Well in the meantime turn 'em down a bit and enjoy! I can't wait till this Saturday, they will be my first SDA's. I know it may not be much to many SDA owners. But I feel like a kid waiting on Christmas! lol

pitdogg2

chuckeroo wrote: »

@pitdogg2: did you get new tweeters? did you get the 194s? did that fix your issues and did you see a big improvement?

I still have SL1000 tweeters I will get some new tweeters when funds get more plentiful. The RDO-194's and SL2000 tweeters do not fit as well as i would like. the faceplate for the SL1000 is a hair smaller and the SL2000/RDO-194 will be right up against the stereo and dimensional drivers and a little covered by the top frame of the grill. I would like to inlet them into the front bezel so that in turn means a complete breakdown to route that out. For now I have plenty of SL1000 and SL2000 tweeters so it's not a burning desire.......Yet