SL3000 Kaput - need replacement

[William Finch]

OK so I have had this SDA SRS 2.3TL speaker set for longer than I can remember. I just did some modifications to the stereo system (new amplifier), swept out the cobwebs (literally) and tested everything. Alas, one of the SL3000 tweeters is kaput.

I'll order a replacement on Monday. I understand that the SL3000 replacements use a silk dome rather than the earlier trilaminate material. I suspect this will be a little brighter than the original but I doubt that it will make much difference. I suspect that any difference will be swamped by room acoustics.

Of course I could purchase a pair for balance, but I'll try just one at first. Any advice?

Also, why do tweeters quit in the first place?

[trubluluc]

If you're going with the newer design I would suggest doing a pair to keep things balanced. Not sure why one tweet goes and the other continues on..and on..and...

-Luc

[F1nut]

If you want some original SL3000's in minty condition, contact me.

[Tour2ma]

Welcome to the Club, William Finch (if that is your real name)... Always nice to see another, proud SDA owner join the fun.

A modest percentage of 3000's seem to have had a problem holding their "water" for more than a decade or so. It's happened to a few folk here.

FYI, F1 is not swooping in on unsuspecting prey. Deal with confidence, if an original replacement is the route you wish to take.

If you go the Polk replacement route, get a pair and be sure to mention you are a Club member...

[DarqueKnight]

Originally posted by William Finch
Of course I could purchase a pair for balance, but I'll try just one at first. Any advice?

I did a comparison of the SL3000 and its replacement by installing four of them in my right SDA SRS 1.2TL speaker and setting my preamp to "mono". The first thing I noticed was a very slight "hollow" or echo like quality to the sound. Another forum member had mentioned this "hollow" sound to me prior to my purchase. I let the speakers play continuously overnight and the next day the hollow sound was gone.

After the short break-in period, I could not hear a difference between the SL3000 and the replacement on instumental music. I could hear a difference on well-recorded vocal music, particularly female vocals. The replacement was smoother and slightly more detailed.

If you are only replacing one tweeter, the other five tweeters will probably mask the small difference in sound of the replacement. Let us know how it works out.

Originally posted by William Finch
Also, why do tweeters quit in the first place?

As Tour2ma mentioned, some SL3000 tweeters have developed leaks in the compartment that houses the "ferrofluid" cooling liquid.

[William Finch]

OK, so I contacted the service guys and they sent a replacement tweeter. The currently available replacement is an SL2500 ($48 club price). I bought just one. I took out old defective tweeter (SL3000) from right speaker - ohmeter shows open - so far so good. The new tweeter went in with no problems - the plus and minus leads are different sizes - no way to screw up here.

I hooked up a pink noise generator and listened in stereo and just to left (three sl3000 tweeters) and just to right (two sl3000 and one sl2500 tweeters) speaker from a mid position and from in front of each speaker and with ear to each tweeter. Initial conclusion - sl2500 is louder than SL3000s (5 remaining).

Next test - put on five favorite test CDs and listened from various positions at various loudnesses - enjoyed the music and forgot that I was being critical - this souds really good.

I think I'm satisfied for now. I don't need to buy a second SL2500 for left speaker to balance the right.

Next I set up a real time spectrum analyzer and calibrated 1/2 inch condesor microphone (B&K). I played mono pink noise and measured each tweeter - 1 cm from each dome. Result - frequency spectrum same from each tweeter - sl2500 is + 2dB above sl3000s.

Next I set up mic at listening position and equalized (soundcraft 10 band equalizer) left and right chanels for room acoustic peaks and dips - then put on test CDs and ABed between equalized and unequalized.

Conclusion - everything sounds damned good. Equalized is probably closer to the control room sound but unequalized sounded great also.

I am happy. Polk customer service is great!

[F1nut]

SL2500???

"Initial conclusion - sl2500 is louder than SL3000s (5 remaining)."

What position, top, middle or bottom did you install the new tweeter because they don't play at the same volume level.

[William Finch]

The new tweeter is in the top position.

Tell me more.

[VR3]

The 3rd tweeter down is the MAIN tweeter

And, If I am not mistaken - at LOUDER volumes is the only one playing, or is playing the most...

[F1nut]

Sid wrong, Sid bad.....we're talking about SDA 2.3TL's. The top tweeter is the main one.

William,

If they sold you a SL2500 then they sold you the wrong tweeter. The new replacement for the SL3000 is the RD0198-1. The tweeters desend in volume from top to bottom, there by creating a point source. If they all play at the same level you've got something wrong.

I'm not trying to sell you, but you could have some very nice minty SL3000's from moi and not worry about matching. :D

Jesse

[DarqueKnight]

According to the invoice for my RD0198 replacement tweeters, the RD0198 is listed as a replacement for both the SL2500 and the SL3000.

[F1nut]

Hmmmm...news to me. Mine didn't say that, but anything is possible.

The Polk Parts List makes it even more confusing:
PART Qty PART# RETAIL CLUB
PRICE
SL3000 ea RD0105-C $80.00 $64.00
SL2500 ea BD0108-C $60.00 $48.00

[DarqueKnight]

Here's a scan of a portion of my invoice.

[DarqueKnight]

Originally posted by F1nut

The Polk Parts List makes it even more confusing:
PART Qty PART# RETAIL CLUB
PRICE
SL3000 ea RD0105-C $80.00 $64.00
SL2500 ea BD0108-C $60.00 $48.00

These are part numbers for the original tweeters rather than the replacements.

[VR3]

WHOOPS! Sorry Jesse...

*Ducks for cover*

[F1nut]

Exactly Raife, that's why I said it's even more confusing.

Sid, LOL

[Tour2ma]

Yup, I'm confused...

If it's one replacement tweeter for both models, why the two different prices?

[William Finch]

If all else fails, read the (2.3TL) schematic, which I just did. The crossover network for the tweeters does indeed feed each tweeter differently. I'm not quite sure why but each tweeter has a slightly different frequency spectrum. What's this all about?

It would seem to my simple mind that if the three tweeters were all fed the same signal the phantom image would be from the center tweeter.

Is it possible that a different spectrum for each tweeter is used to correct for spectral deficiencies of the individual SL3000? I'm sure the real explanation is more complicated.

Also, the replacement being sold now for the SL3000 is called the SL2500 and does cost $48 (club polk).

Also, the speakers really sound good with just one SL2500 in the top right position. Perhaps in an anechoic chamber I could learn more, but the "real room" effect swamps fine distinctions.

[F1nut]

Originally posted by William Finch
I'm not quite sure why but each tweeter has a slightly different frequency spectrum. What's this all about?

Point source.

Also, the replacement being sold now for the SL3000 is called the SL2500 and does cost $48 (club polk).

No, it's the RD0198-1, which evidently is sold to replace both.




Glad you're enjoying your speakers again.:)

[Tour2ma]

Originally posted by William Finch
It would seem to my simple mind that if the three tweeters were all fed the same signal the phantom image would be from the center tweeter.

I thought by the time they got around to the tl series, that the tweeters were out of the SDA business...

Or was that just in other SDA models?

[DarqueKnight]

Starting with the third generation SDA's (SRS, SRS 2, 1B, 2A, CRS+), the dimensional effect was limited to the frequency range between 200 Hz and 1,000 Hz. Most human directional hearing cues are contained in that frequency range.

While developing the SRS, Polk found that limiting the bandwidth of the dimensional driver arrays enhanced the width of the soundstage.

[dorokusai]

The recent SDA2 aquisition, with the SDA tweeters, is officially weird to experience. It's a little odd to me beings I am accustomed to the later SDA array.

It's very obvious at lower volume, and not as much as you go incremental.

[Tour2ma]

doro,
Put a few more words around "weird experience" if you can...

DK,
Ok, along the lines of what I thought.
But was just thinking about the sounds of the coins hitting the register tray (and other effects) in the opening of PF's "Money". Would have thought it had a many HF elements >1kH, but yet most of them are way outside the speakers...

[dorokusai]

I will when I get some sleep.