SL2500 Tweeter ULV Fluid???

[rskarvan]

QUESTION:

Does the SL2500 tweeter ULV magnetic fluid ever dry up?
My tweets are now 11 years old. They don't sound quite
as nice as either the SL2000 or the SL3000. Are they at
all perishable strictly due to age?

Curious.

----------------
Catalog Quote:
Featured in the Monitor 4.6, 5jr+, 5, 7, 10 and 12, the SL2500 tweeter makes a major contribution to the improved performance of the Monitor Series 2. Sharing much of the technology of the incomparable SL3000 tweeter used in the Polk flagship SRS series, the SL2500 is a highly refined, technically advanced driver.

The voice coil, wound around an aluminum voice coil former, is cooled by an exotic ULV (ultra-low viscocity) magnetic fluid. This material, which has a viscocity close to that of water, enables the SL2500 to exceed normal listening levels without loss of performance or reliability. The resulting dynamic range is dramatic, indeed unique for speakers in this price range.

[DarqueKnight]

Ron,

The tweeter is sealed. Under normal circumstances there should be no way for the fluid to dry out. It is possible that a crack in the seal has occured and allowed fluid to leak out over time.

I know it is hard to remember what something sounded like 11 years ago, but do the speakers sound bad compared to what they sounded like 11 years ago, or do they sound bad compared to the SL2000 and SL3000?

[rskarvan]

Raife,

I bought these used from Scott Trigg.
I replaced all the mid-drivers. The tweeters were "good".
But, these tweeters don't sound nearly as good as either
the SL2000 or the SL3000. So, I was wondering if they have
aged too much.

I've heard that an upgrade for the Monitor 10 would be to
install SL3000 tweeters and change a capacitor in the x-over.
This would be a nice upgrade - me thinks.

The SL2500's don't sound horrible. But, likewise, they don't sound nearly as good as either the SL2000 or SL3000.
At first look, I thought the SL2500 was a cheap plastic tweeter
that Polk introduced as some sort of cost-savings. Evidently, judging by the writeup above, that isn't the case. So, I'm wondering if mine might be sub-standard.

On a positive note, its interesting to note that the tweeters still work after 11 years - when the drivers had (evidently) failed.
That may say something positive about the durability based upon that ULV fluid.

- Ron

[nascarmann]

I think the 2000 and 3000 tweeters sound better than the 2500's new, old or what ever....IMO

[DarqueKnight]

I remember listening to the new Monitor series when they first came out. I had a pair of Monitor 10B's at the time. I recall that I did not like the sound of the new Monitor 10's as much as much as my 10B's. I can't remember the particular sonic characteristics of the new model 10's that turned me off.

Polk customer service might have some technical literature on the SL2500 that could shed some light.

[wangotango68]

hay ron if you are looking to get rid of your sl2500's give me a shout. i could use a set of them.

scott

[nascarmann]

Yeah....go ahead and send them to him....he will pay you later

[rskarvan]

Scott, I'll trade you even for a pair of new SL3000's.
No problem there.

Seriously though, I'm going to have to wait a little while
before I attempt to upgrade the Monitor 10's. I'll keep you in mind though.

Hope all is going well in family-court for you. Glad to see you come clean on sending back the amp cash.

[wangotango68]

i get to indy more offen then before maybe i could stop by if you decide to get rid of them.

scott