Installed the FST tweeters in to my RM40's

Tyson · « **on:** 27 Apr 2004, 07:06 pm »

Mike came over thes past weekend to finally put in my FST tweeters in the RM40's, replacing the dual spiral ribbon tweeters. I'd had the FST's for almost a year, waiting for trim plates, but after a year I lost patience and Mike agreed to make some for me. Lucky me, the wood he found to make them out of matches the veneer on my 40's exactly (white birch). Mike did a great job getting them cut to the correct dimensions, a little sanding to them and they fit perfectly. Doing the cutouts to make room for the new tweeter was the hardest part of the job.

The crossover modifications weren't too hard, at least not for Mike, how is a very experienced solderer and electronics builder. Basically it consisted of adding a bit more capacitors to the network, and an additional air-core inductor (basically a low pass on the mid panels so that the play to 7khz instead of 10khz). Oh yes, we also took the mid/highs switch out of the signal path, since I never use it (always bi-wire or use an external jumper in my setup).

After a few hours, everything was done, speakers were put back together but Mike had to leave before I got the PR and base screwed back on. Let it run in for a couple of hours and then sat down to give it a quick listen.

It was a jaw-dropping improvement. Imaging and "air" and ambiance were a big, big, big improvement. I've compared the 626R with Spiral tweeter to a 626R with FST tweeter before, and it was an improvement, but not on the magnitude of this. There seems to be an extra synergy between the multiple mid panels and the FST on the 40's.

In addition, bypassing the switch seems to have tightened up the low bass nicely and given the upper bass some more kick. Add to that an additional transparency to the mids (you can hear very small details, like the smacking of lips when a singer opens their mouth to sing, fingers on fretboards, etc), and you have the result of a very, very big grin on my face. Overall effect was to impart an additional sense of "liveness" to the suond, more of the illusion of the person standing "right there" and singing/playing away. Even my wife said "That sounds amazing" when listening to one of her CD's. Me very happy

John Casler · « **Reply #1 on:** 27 Apr 2004, 09:40 pm »

Quote

and you have the result of a very, very big grin on my face.

I know what that's like. In fact I just had a "dose" (case) of it a few minutes ago, in front of the 626Rs w/Larger.

Spun up Steely Dan's "Two Against Nature". If you looking for ways to "test" and enjoy your new FSTs plop that on if you have it.

Man, what a 3-D soundstage.

And I might also offer that Ginkgo Biloba (check spelling

) also helps you hear better.

Wish it helped you "hair" better, but that is another story

JoshK · « **Reply #2 on:** 27 Apr 2004, 09:46 pm »

Congrads! I wondered when you were going to get that done. I remembered you had said you ordered it but then heard nothing more. I still haven't ordered mine because of house buying situation. Will get done eventually. I can't wait.

audiochef · « **Reply #3 on:** 27 Apr 2004, 10:41 pm »

Awsome Tyson,

can't believe you waited a year.

What caps are you using?

Tyson · « **Reply #4 on:** 28 Apr 2004, 12:38 am »

John,
hair isn't necessary when you are in that good a shape

I've been meaning to correct the spelling of Ginkgo in my sig, but keep forgetting.

Josh,
Think I never said congrats on the new house, so congrats! You going to have a dedicate listening room in the new digs?

audiochef,
yep, a whole year, I'm a pretty patient guy, be even I have my limits. I got the Auricaps, I just couldn't find the budget to get the TRT's.

audiochef · « **Reply #5 on:** 28 Apr 2004, 01:20 am »

Right on Tyson,

same caps that I use, I needed the beter than stock caps cause my system was succeptable to grain. But after the Auri and mid rebuild, no more grain ,then there came into notification was glare. NO. 2 on my list of unacceptable nasties.

Fortunately for you, apparently you've never had these anomolies.
Since all my recent upgrades, my system , though I now think is rather uneventfull, but in a good way . I guess. No glare or grain, just music.
Before, I allways noticed the weaknesess. And there was something to strive for.

Is this called musical? If it is , it's overated ,because by VMPS owners nature is to tweak till it's perfect. Well it is now as perfect (natural?) as I've ever heard any system, but with slamm! Of course.

Good luck fine tuning your system. If you don't mind , please do tell what rest of your system consist of.

Thanks , Stan

mgalusha · « **Reply #6 on:** 28 Apr 2004, 02:56 am »

Really glad to know they sounded good once you had a chance to listen to them. Hopefully you toasted them with some fine scotch.

I'll have to try and make it by for a listen with the new setup.

Josh, if you do order the FST tweeters the material I made Tyson's trim plates from was 3/32" birch plywood. This can be sourced from most hobby shops, especially those carrying R/C planes.

I have to say the speakers looked compltely different with the new tweeters. Another DAM member has a pair of RM-40s with the FST tweeters but since they were built that way the ribbons are right next to the tweeter. Tyson's look quite a bit different as the mid panels are about 2 1/2 to 3 inches from the tweeter. Kinda cool actually.

mike g

Tyson · « **Reply #7 on:** 28 Apr 2004, 04:11 am »

Yes, a serious thank you to Mike, this simply would not have happened without his help.

By way of saying thanks, I bought something for you

tkp · « **Reply #8 on:** 28 Apr 2004, 04:22 am »

Tyson,

Can you post some pictures? I have been wondering about the upgrade for some time but not sure I am up to the task. I don't have any problem with the soldering iron but wood working is another story.

Tyson · « **Reply #9 on:** 28 Apr 2004, 03:22 pm »

I wish I could, but I stupidly forgot to take any pictures of the upgrade

JoshK · « **Reply #10 on:** 28 Apr 2004, 04:01 pm »

Tyson,

Could you take a picture of the now upgrade RM40's? Just for ideas for us?

As for as the house, thanks btw, we have a July 1 closing date. I intentionally did this so that is would be a couple weeks after my CFA exam so I have time to scramble before closing after the exam.

The house is relatively small by standards outside the greater NYC area, but within close proximity to NYC is relatively large. It has yet to be decided for sure whether I will get the dedicated listening room or not. So far so good but things could change once we are all moved in and compromises have to be made.

I am mostly excited about the shop I am going to set up in the basement that will allow me to do some of the more involved DIY projects I have wanted to attempt.

I have some ideas on things to do and try out with my RM40's as well as other things I will not yet disclose.

Marbles · « **Reply #11 on:** 29 Apr 2004, 03:31 am »

Tyson, remember this?

Quote from: Tyson

Dammit Marbles, you cannot have speakers as good as mine, I've got to upgrade to the friggin RM/X's now

Sounds like your getting close to my 40's....when you upgrade to TRT's and add lambswool, you'll be there

Glad you like the new tweets. Enjoy!

Tyson · « **Reply #12 on:** 29 Apr 2004, 04:00 am »

There is one local guy that IS getting the RMX's, but it's not me

Everytime I think that your speakers are better than mine I just start drinking more scotch. Pretty soon after that I've achieved a non-speaker-envy bliss-like state

Hell, with the $$ I've spent on scotch I probably could have afforded the RMX's, hehe.

Josh,
I left out a small amount of stuffing when I put the 40's back together. When I open them up to put it back in I'll take some pics of the crossover. And once I get some urethane on the trim plates (so they fully match the rest of the speaker), I'll take some pics of the whole speaker too.