Try this all-aluminum project: the TRS-80

[Undefinition]

Hey, if you have the parts laying around, or just want to try a 2-way using the RS180 that's off the beaten path, I say, "Go for it!"

http://undefinition.googlepages.com/diy-trs-80

[lunchmoney]

I'm confused about big TM's... started a thread about it on the PE forum... care to share your thoughts there?

http://techtalk.parts-express.com/showthread.php?t=208674

[Paul Ebert]

I notice that the D25 is, currently, $2 more expensive than the XT25. How would you compare them from a sound quality perspective?

I'm planning on building a set of HT speakers using the RS180 and RS28. I may modify this for the RS28 (already have them). It seems like an excellent design.

[Kevin P]

Sorry, just had to do this.... :B

TRS-80

[ThomasW]

Sorry, just had to do this.... :B

That was my first thought as well ..

[---k---]

I must be too young. This was the first one I remember using:

[seattle_ice]

Ok, too funny. I remember in junior high walking down to the Radio Shack in the mall and playing this weird grid-based Star Trek game on the TRS-80 display in the store. And there it is in the pic above!

[Curt C]

Hey, if you have the parts laying around, or just want to try a 2-way using the RS180 that's off the beaten path, I say, "Go for it!"

http://undefinition.googlepages.com/diy-trs-80

Looks nicely done Paul, and a good write up as well. :T

C

[Undefinition]

First off, thanks guys for chiming in with the nerdiness. It gave me a chuckle.

Oh, and thanks Curt for the encouragement, once again. I promise this will be the last Vifa D25 design I do!

I notice that the D25 is, currently, $2 more expensive than the XT25. How would you compare them from a sound quality perspective?

I'm planning on building a set of HT speakers using the RS180 and RS28. I may modify this for the RS28 (already have them). It seems like an excellent design.

It is a bit strange that Madisound is selling the XT25 as a "special." I hope they're not planning on taking it off the market or--gasp--moving production to China. (Note: to my knowledge, Vifa has already done this with the D25AG, so Madisound is charging you a "Danish" premium for a Chinese-mfr'd driver. If that's the case across the board, this is one time I'd go for Parts Express over Madisound, who seems to have kept the price comparatively "low")

I am a big fan of Vifa's ring radiator tweeters. I've heard the XT25 and XT19 in several designs and each time, I thought the design had an "extra-deep" soundstage. I don't know why. It's all psychoacoustics anyway. :W

The XT25 is a wonderful tweeter, and I've considered trying it out in this cabinet (the flange is the same size, even). I DO know, however, that crossing the XT25 this low will require an LCR shunt filter to flatten the impedance spike... this will definitely price it above other options. But still, I have no doubt it would sound really good.

The RS28 would work fine in this application, as many designers have proven (although I cross higher than them). So I say try crossing it with my LP filter for the RS180 and see how it sounds. If you need help, I have a pair of RS28a sitting in a closet.

[Jed]

It is a bit strange that Madisound is selling the XT25 as a "special." .

Availability of Vifa/Peerless drivers are pretty unpredictable. Drivers are getting phased out left and right. I heard the 7" exclusive is on the chopping block. The Nomex 4" Peerless is gone, as is the poly version. The non double magnet tweeter XT25 might be for OEM only as well. Who knows what the future will bring. Even if the nice new Vifa drivers are released, how long will they be around? Long enough for us to design a speaker and see it get phased out? These are questions we'll have to ask ourselves in the future.

Madisound suggested to me that we are safe with SEAS. That doesn't give me a lot of hope for a lot of the published designs that use other drivers.

Looks like the Vifa D26 is safe again- taken off the discontinued list. But will it change in a few months? . .. only time will tell with that company. Interesting thing is madisound frequently gets Scan Speak drivers in stock.

[JonP]

Yeah... kind of wonder myself what happened over there. A big merger/reorganization, a well known, knowlegable guy heading up the tech side who was DIY friendly, a "summit" meeting with Zaph and other DIY representitives... and then before a year is up they've turned over the new guy and possibly much of the team that was there...

Wonder if anyone knows what happened? Too much optimism in a cooling market? Company couldn't afford the intended R&D budget? Bean counters won a war and fired the engineers for a better bottom line? Who knows? I just hope whatever is going on in there, they get things back in balance so they can return to a more stable state, and we can depend on good drivers available into the future...