RTA-15T (tweeter replacement)

heiney9

There really is no confusion because despite what the x-over shows there never was a RTA15T. All TL models used the sl3000 tweeter and all Series II Monitor's used the sl2500 tweeter. Both model tweets were successor's and better tweets than the original sl2000 tweeter.

Hope this helps

H9

dorokusai

Yeah, what he said is spot-on. There was never any confusion on this end.

skrol

heiney9 wrote: »

No such thing as an RTA15T, they were all TL models, as prior to the introduction of the new tweets there wasn't an RTA15 model, just the RTA8 and RTA11 both which come in T and TL flavors.

H9

Sorry to differ but the RTA15TL was originally the RTA15T, yes with the SL3000 Tri-laminate tweeter. Here is an interesting tidbit of information regarding the RTA15T that came from the designer when I asked him about the RTA15T vs TL. They were likely renamed as the RTA8T and RTA11T were upgraded to TL and it may detract from RTA15T sales. It is interesting what goes into choosing a name. From the designer:

"...I guess marketing changed the name later to TL. ... Original RTA8 and RTA11 had different tweeter ... new tweeter SL3000 came up just before I started design on RTA15T. So RTA15T started with tri-laminate tweeter ... but 8 & 11 went from T to TL when they were upgraded. Your assumption is correct RTA15T and RTA15TL are the same.

RTA15 was originally being scheduled and introduced as RTA14, I worked on it as RTA14 ... we had some literature printed ... when one day national sales manager came and said stop, stop, can't call it RTA14 ... he learned from Asian distributor that number "four" means in Chinese "death" and that we wouldn't sell any speaker ... (after RTA11 we didn't want to call it 12 because of Monitor 12, didn't want to call it 13 because of western superstition, couldn't call it 14 because of Chinese superstition and the next number was 15)" (ZSP)

Some of the early releases were labeled "RTA15T". http://www.polkaudio.com/forums/showthread.php?t=80049 See photo in link.

You are correct though in that they RTA15T and TL only had the SL3000.

heiney9

Thanks Stan for sorting that out. I sold Polk at the time and to the best of my recollection never had an RTA15T in our store, but who knows, I just remember all the "TL" series to have the sl3000, but that was a long time ago.

H9

maxilla

Mine.

ben62670

It's still a TL

maxilla

Fantastic.

dorokusai

skrol wrote: »

Sorry to differ but the RTA15TL was originally the RTA15T, yes with the SL3000 Tri-laminate tweeter. Here is an interesting tidbit of information regarding the RTA15T that came from the designer when I asked him about the RTA15T vs TL. They were likely renamed as the RTA8T and RTA11T were upgraded to TL and it may detract from RTA15T sales. It is interesting what goes into choosing a name. From the designer:

"...I guess marketing changed the name later to TL. ... Original RTA8 and RTA11 had different tweeter ... new tweeter SL3000 came up just before I started design on RTA15T. So RTA15T started with tri-laminate tweeter ... but 8 & 11 went from T to TL when they were upgraded. Your assumption is correct RTA15T and RTA15TL are the same.

RTA15 was originally being scheduled and introduced as RTA14, I worked on it as RTA14 ... we had some literature printed ... when one day national sales manager came and said stop, stop, can't call it RTA14 ... he learned from Asian distributor that number "four" means in Chinese "death" and that we wouldn't sell any speaker ... (after RTA11 we didn't want to call it 12 because of Monitor 12, didn't want to call it 13 because of western superstition, couldn't call it 14 because of Chinese superstition and the next number was 15)" (ZSP)

Some of the early releases were labeled "RTA15T". http://www.polkaudio.com/forums/showthread.php?t=80049 See photo in link.

You are correct though in that they RTA15T and TL only had the SL3000.

Marketing didn't change the name. The TL, tri-laminate was simply the tweeter...and that's from the rest of the designers. As far as the rest, it's solid information. The stickers never make much sense. The Monitor series should be proof enough of that.

skrol

I guess whoever made the name change is not certain but it did make naming consistent with the RTA8TL and 11TL and the SDA's. The RTA15T had the Tri-Laminate SL3000 from the beginning. It is even in the "Addendum For RTA 15T Owners" http://www.polkaudio.com/forums/attachment.php?attachmentid=38817&d=1236963951 . It is also in the all the posted schematics and diagrams for the RTA15T (TL) in the forum sticky.

A few RTA15T's have shown up on the forums too. http://www.polkaudio.com/forums/showthread.php?t=77214&highlight=RTA15T
http://www.polkaudio.com/forums/showthread.php?t=79635&highlight=RTA15T


Looking at the schematics, there was a cross over redesign that eliminated the poly-switch and increased the R1 value to 2ohms. This may have marked the transition to the TL. I'll ask about it next time I see him.

Ricardo

Who cares what tweeter or xover was in it, who named it, and why the name was changed. I've seen boxes, stickers and literature with RTA-15T. Isn't this enough to accept that there really was a RTA 15T?

heiney9

"T" models had the sl2000 tweet; "TL" models had the sl3000.................end of story and that's all that matters. The "TL" was a designation given because of the tri-laminate properties of the new series of tweeters. The 15 never came from the factory with an sl2000 tweet. Therefore, based on the tweeter it was manufactured with, it's a "TL" model by default. There was no transition from "T" to "TL" model since it used the sl3000 from day one. It was just a label.

H9

skrol

Ricardo +1

AudioGenics

you'll always will be exposed to tweeter failures
under high power , distorted, clipping conditions.

just need to improve the crossover, turn it down,
or have some protection

practice safe stereo !

( keep alot of spare parts available too )

LPN

jvc wrote: »

you'll always will be exposed to tweeter failures
under high power , distorted, clipping conditions.

just need to improve the crossover, turn it down,
or have some protection

practice safe stereo !

( keep alot of spare parts available too )

... or buy a better speaker component. I could never have imagined the RTA-15 TL's being that wimpy in the tweeter.

warlocks1

It is not a wimpy tweeter. I had 15TL's hooked up to an Adcom 555 (200 wpc) for years and could crank it so half the block heard them without damaging the tweets. Crappy electronics belong with crappy speakers. Good speakers need good components. Sell them to someone and by some cerwin vega speakers. You can then crank it all you want. After all, it doesn't matter how good they sound, only how loud they can play. Enjoy!

ben62670

Ouch!

I agree, but I would have been a wee bit more tactful.

LPN

warlocks1 wrote: »

It is not a wimpy tweeter. I had 15TL's hooked up to an Adcom 555 (200 wpc) for years and could crank it so half the block heard them without damaging the tweets. Crappy electronics belong with crappy speakers. Good speakers need good components. Sell them to someone and by some cerwin vega speakers. You can then crank it all you want. After all, it doesn't matter how good they sound, only how loud they can play. Enjoy!

Quite likely I'll replace the tweeters (again) and kick 'em out cheap. If they can't handle simple requirements ... adios amigo.

Cheers, Barrie.

F1nut

You simply don't get it.

[Deleted User]

LPN wrote: »

I suppose ... but keepin' the wife happy thing? How's that go?

Cheers, Barrie.

Basically agree with everything she says, accept all blame and do what you want to anyway. :cool:

skrol

LPN wrote: »

Quite likely I'll replace the tweeters (again) and kick 'em out cheap. If they can't handle simple requirements ... adios amigo.

Cheers, Barrie.

Kick 'em out cheap, eh. I wonder how much shipping would be from BC?:rolleyes:

AudioGenics

LPN wrote: »

... or buy a better speaker component. I could never have imagined the RTA-15 TL's being that wimpy in the tweeter.

I know what you mean.
However I would be interested to see what exactly failed
in the tweeter.

A discolored voicecoil will certainly indicate a prolonged heat / power use.

I haven't heard that ferro-fluid is being used but it was to help keep the coils cooler over very heavy power demand usage.

Also substantially increasing the gauge of your speaker cables could be beneficial ( now I've done it ...opened up a can of snakes ! ).

You still need to ensure that your amp is not clipping. That really chews up speakers.

heiney9

LPN wrote: »

Quite likely I'll replace the tweeters (again) and kick 'em out cheap. If they can't handle simple requirements ... adios amigo.

Cheers, Barrie.

Hey man, do what you want, but you are dead wrong about why they fail. Obviously not a good fit with your gear or your listening habits. Bose or Cerwin Vega are probably more your style.

Too bad, because when you sell them you'll be missing out on a great sounding speaker.

H9

pitdogg2

LPN wrote: »

Quite likely I'll replace the tweeters (again) and kick 'em out cheap. If they can't handle simple requirements ... adios amigo.

Cheers, Barrie.

I have some Cerwin Vega D7's that have a much better tweeter made by peerless from Denmark That I'd be happy to trade you. Ran them with my TFM 45. They get very loud but have two forms of protection that sounds like you could use.

What ya say shall we trade? I'd even let you send them to me with the fried tweeters.....what say wanna trade???

skrol

jvc wrote: »

I haven't heard that ferro-fluid is being used but it was to help keep the coils cooler over very heavy power demand usage.

More pealing of the Polk onion...

The SL3000 uses what they call Ultra Low Viscosity (ULV) Magnetic Fluid to provide cooling of the voice coil. Compared to conventional Ferro Fluid, it is much less viscus. This allows free coil excursion of the coil and thus improved efficiency and better transient response. According to the Technical Information issue from Sept. 1989, the ULV magnetic fluid combined with the silver-bronze braided lead out wire allows the SL3000 to operate at over twice the normal power and acoustic output levels without degraded performance.

AudioGenics

yes ... ULVMF ... neat name Ultra Low Viscosity

I remember as a kid adding ferrofluid and other "stuff" finding out
that some incompatible material that wasn't designed for it in the driver quickly failing.

Also coating the paper cones with more stuff and all kinds of goop.

Don't know if you want to try drilling vent holes probably too drastic
or adding a heat sink like from a CPU chip.

Had to stop experimenting cause my Dad got peeved
I was destroying so many speakers playing around.

Anyways....there are many solutions to the problem.

maxilla

LPN wrote: »

Quite likely I'll replace the tweeters (again) and kick 'em out cheap. If they can't handle simple requirements ... adios amigo.

Cheers, Barrie.

Just leave him alone. He's just trying to be provocative... and a nuisance.

skrol

jvc,
I knew a guy who was experimenting with zinc doped epoxy to improve heat conduction of voltage regulators to their heat sink. It worked very well but I wonder how it compares to some of the stuff on the market today (ie. Arctic Silver and the like).

Great to hear of others who used to like to experiment as a kid. I was playing with speaker phasing (ie. stereo but having the opposite channel present on either side but 180 deg out of phase). Then I heard about Polk Audio's SDA and abandoned the project.

If only my dad knew that I was doing with some of his stuff.

I seem to have a lot of ideas like that that come up independently, only to find that someone has beat me to it. Another example is an automotive breaking system that detects when you are approaching an object too rapidly and applies the breaks automatically. Thank you Volvo.

I have a few more that I'll have to run past my friend at the US Patent Office.

AudioGenics

that's really cool.
Your friend at the Patent Office must see all kinds of neat ideas !

well anyway I hope the Original Poster has gotten the idea of fixing his
speakers' tweeters. Of course he/she can burn them too

http://www.youtube.com/watch?v=gbb50hRUCWM&feature=related

LPN

pitdogg2 wrote: »

I have some Cerwin Vega D7's that have a much better tweeter made by peerless from Denmark That I'd be happy to trade you. Ran them with my TFM 45. They get very loud but have two forms of protection that sounds like you could use.

What ya say shall we trade? I'd even let you send them to me with the fried tweeters.....what say wanna trade???

Sounds interesting ... too bad there's such a distance between us and an international border, not to mention the cost associated with shipping.
I've got a local shop that I should let them have a look at these and perhaps make some needed changes / upgrades etc.

Cheers, LPN.

F1nut

Any local shops up there that dispense common sense?