Can you swap RT25 tweeter with RT25i?

TCK

I thought I read somewhere that you can directly replace the rt25 ( I think it's the SL 5507) with the RT 25i tweet ( not sure the model # ). I was going to look for a replacement for my RT25 & figured might as well upgrade them while I'm at it. Thanks

rooftop59

Did the 25s have the black silk dome tweets? In either case, the answer is yes you can, but I don't know if the crossover values changed. I actually replaced the silk dome tweets in a pair of rt15is with the tri-lam domes from rt25is since I much prefer the tri-lams, and it sound much better to my ears. They are, however, outdoor speakers (under a covered patio) and do not receive any critical attention. So take all that with a grain of salt...

TCK

rooftop59 wrote: »

Did the 25s have the black silk dome tweets?.

Yes, they are black. I attached a pic. Thanks for the info. I thought the crossovers were very close if not identical but I could be wrong. Seems like an easy & obvious upgrade

rooftop59

Yep you can switch them out. Its only an upgrade if you like the tri-lams better, which I do.

heiney9

I compared the RT20 xover to the RT25i (no RT25 x-over is posted) they are quite a bit different. It uses a 2nd cap in the tweeter array and a very large cap in the woofer section.

I'm sure they are physically the same, but the older "black" tweeter is a different material than the "silver" tri-laminate used in the RTxxi series. I'm sure they are electrically different. How that affects the sound is anyone's guess.

Why not just replace with correct parts or buy a pair of RT25i's?

heiney9

I guess my point is on the RT20 they use a cap and resistor in parallel in addition to another cap in series for the tweeter.

The RT25i, they use a single resistor in series with a high value electrolytic cap, bypassed with a mylar cap in parallel with said electrolytic cap.

Two very different approaches, so I'd say the tweeters aren't all that compatible to each other.

H9

heiney9

rooftop59 wrote: »

Yep you can switch them out. Its only an upgrade if you like the tri-lams better, which I do.

What are you basing this recommendation on? Just that they physically fit?

H9

heiney9

The RT25i uses the SL 6505 or 6506 tweeter, IIRC.

rooftop59

heiney9 wrote: »

rooftop59 wrote: »

Yep you can switch them out. Its only an upgrade if you like the tri-lams better, which I do.

What are you basing this recommendation on? Just that they physically fit?

H9

I know nothing about the crossover components, so I won't pretend otherwise. But the rt20 and the rt25 are VERY different speakers. RT20s have two 8 inch woofers and the first tri-lam dome tweet, the rt25 has one 5.25 woofer. The RT25 is the same configuration as the RT25i, the only (visible) difference is the black silk dome vs silver tri-lam, and the gray vs blue woofer. As with the rt55 v rt55i, there has been much debate as to whether there were any changes in crossover, and I do not know.

My suggestion is based on sound. I have done the same thing myself and prefer the sound of the tri-lam tweets in those speakers.

heiney9

The RT20 (not 20P) schematic only shows a single woofer. I couldn't remember if it was a bookie or floorstander.

So you have done the swap yourself, so then that's where the advice is coming from, cool beans.


H9

TCK

heiney9 wrote: »

Why not just replace with correct parts or buy a pair of RT25i's?

I thought the RT25i had a better tweeter. It's the same concept as replacing a SL2500 with RDO-198. If it's not a direct swap, then I will just replace with an RT25 tweet.

rooftop59

TCK wrote: »

heiney9 wrote: »

Why not just replace with correct parts or buy a pair of RT25i's?

I thought the RT25i had a better tweeter. It's the same concept as replacing a SL2500 with RDO-198. If it's not a direct swap, then I will just replace with an RT25 tweet.

It is, I have done it, I say go for it!

heiney9

If someone has successfully swapped them, then go for it. I was just playing a bit of a devil's advocate. If I really think about it, they are probably a close match. Still if it were me I'd look at the crossover values of the two models and be sure there aren't any huge variations.

H9

TCK

Thanks H9, I do appreciate looking at all angles. I would hate to put them in only to find they don't work right. I think I will call cs & see if the replacement is the same for both models. May have to go that route & just get new ones. They can't be that much, there is not much to them. They have a magnet the size of a few nickels stacked together

rooftop59

FYI, I have two SL6501s that would work in these. They are a bit discolored but work fine. I would ship them for $35 if you are interested. You could see if you like the change for not much dough...

TCK

Very generous offer @rooftop59. These are my daughter's & here's the thing...she is happy with them. She doesn't understand why I want to mess with them & I agree, they do sound ok as is. The reason I was looking for a replacement tweeter, is that when I was listening to them one day, I noticed one tweeter a tad bit quieter than the other one. I took it out & swapped it out with the other one & the problem followed over to the other speaker. I figured I might as well upgrade as I said before.
So I will take them, thank you. She never takes the grills off anyway.

rooftop59

Sounds good, shoot me a pm and we'll get it worked it.