RMAF 2007 findings

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Midnite Mick

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Re: RMAF 2007 findings
« Reply #20 on: 24 Oct 2007, 12:00 am »
I think I saw photos of the Consonance room with a single driver Fostex as well.  Anybody listen?

panomaniac

Re: RMAF 2007 findings
« Reply #21 on: 26 Oct 2007, 09:59 pm »
Hi Jim!  Thanks for the kind words on the Little Grass Shack speakers and my electronics.
Nice to meet you, nice to talk to you.  RMAF was just too busy for me to get around to many rooms, so it was great to meet the folks who did stop by the room.

You  know we really should not have presented such a fresh speakers at the show, it takes a long time to get a new design dialed in.   The Little Grass Shacks will be much better when the backs are solidly mounted and the stuffing is done right.  I came back into the room at the end of day Sunday and the boys had changed some stuffing, it helped at lot.  This is a very promising design with the Hemp FR8c driver.  I know I want a pair for my living room, hope you build or get a pair yourself.  Despite not being really ready, the LGS got a lot of favorable comments.  It's always nice when visitors to the room get "stuck" and don't leave. A real compliment.   :D

I do agree with you on the problems the T-Amps have in the upper bass/lower mid.  That's what I've been working so hard these past years to improve.  An amp with the beautiful lower mids of a tube amp and the amazing detail of the Tripath chip will be a real winner.  Should be there soon, it's really the only fault left with these chips.  Just like tubes, how you implement them makes can make a big difference.

Thanks for your reports on the other rooms.  I wish you had been able to hear the EnABL'd Lowthers, they were really much smoother.  Still, pretty amazing what a good  full range and two 10s can do on an open baffle, eh?

Aloha,
 Michael

jrebman

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Re: RMAF 2007 findings
« Reply #22 on: 28 Oct 2007, 03:28 pm »
Hi Michael!

Welcome to the single driver forum!

Yes, the LGS' were really very nice to listen to, even in their rough, unpolished form.  I'm glad that you did decide to show them, and believe me, you weren't the only one at the show with speakers that had been assembled for the first time at the show, but I think most experienced listeners can tell the potential in a speaker, even if it isn't in final form.

I saw the announcement on the Audio Magus site for these and will be staying tuned for these and the other things to come from Lotus Acoustics.  I did find a web site, but it appeared to be mostly in German, so not sure I found the right one, but I hope you'll let us know when everything is live.

As for the t-amps, I've never heard a Trends -- stock or one with your mods, but a local guy has one and wants to bring it over to do some work on it, so I'm sure I'll get to hear one sooner or later.  In the long term, I can imagine a next, or future generation of tripath amps that are a little more configurable in terms of their sonic signature, simply by manipulating the various parameters and algorithms used in their internal signal processing feedback loop.  Which is all to say, that I see that there could be potential for maybe something like a "personality module" or uploadable personality profiles to store in CMOS or some similar thing.  Imagine a tripath amp that you could plug in a 45/2A3/300B/6550/ whatever, sonic profile, or even one with interactive controls that let you tune the sound to your speakers, room, and taste.  Theoritically at least, it looks possible.  Then we wouldn't have to mess around with fancy power supplies, tubes and all their supporting circuitry, etc., and just keep the amp circuit as clean, simple, and noise-free as possible and be able to experience all the best attributes of tubes and SS in a single amp that can run on a battery and won't require an air conditioned listening room. :D

Again, welcome, and I look forward to your forthcoming announcements.

-- Jim

P.S. -- And if your wife ever convinces you to move stateside, maybe we'll be neighbors :-)


panomaniac

Re: RMAF 2007 findings
« Reply #23 on: 29 Oct 2007, 09:45 pm »
Hi Jim,
 Good to be here on the single driver forum with all you crazy purists!   8)

My first "serious" pair of speakers were a single driver TQWT that I built over 20 years ago.  17 cm Triangle driver + Technics super tweeter.  It was a rather famous design by my old buddy Gerard Chretian published in the French mag "Revue de l"Audiophile" back in the 80s.  Sweet speaker.  My neighbors often thought there were musicians in my apartment.  I miss those little speakers.

As for the T-amps and Trends, what you heard driving the Little Grass Shacks with the Hemp 8" was the Trends amp with my modifications. The Mardis signature edition.

I think the good things you heard where due about half and half to the nice Hemp driver and the EnABL process.  The EnABL just makes a good driver even better.

I would tell you about my next speaker project with a buddy here on Maui - a Diatone 6.5" on open baffle with a Selenium 15 inch "bass helper" - but as it's not true "Single Driver"  you guys would kick me out!

jrebman

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Re: RMAF 2007 findings
« Reply #24 on: 29 Oct 2007, 09:57 pm »
Michael,

Oh, my mistake -- I thought you told me that it was a KingRex amp playing at that time.

I just scored a pair of Fostex F120as today, so will probably be looking into the smaller brother of Demetri for those.

-- Jim

panomaniac

Re: RMAF 2007 findings
« Reply #25 on: 30 Oct 2007, 08:08 am »
Oh, my mistake -- I thought you told me that it was a KingRex amp playing at that time.

Could have been.  But probably the KingRex preamp and the Mardis Mod Trends.  That's the combo that sounded best.

Fostex f120?  Hmmmm.... Don't know that one.  Demetri has a little sister called Mileva - for the FE127
http://www.planet10-hifi.com/boxes-fostex.html#mileva

You might ask Dave if it's suitable for your 120s.  Same style box as the Demetri design that led to the "Little Grass Shacks" , just smaller. Please let us know what you do!

planet10

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Re: RMAF 2007 findings
« Reply #26 on: 10 Nov 2007, 08:34 am »
I had a chance to hear a pair of modified Fostex FE166 based Demetri's this past summer at the local DIYfest. They sounded very good driven by a gorgeous 300B SET diy amp, with killer bass extension, and this was outside!

These were actually FE167... they look a bit odd in Demetri ... the 8" drivers suit the cabinets better.

A Demetri with the back not glued on will have relatively no bass...

dave

richidoo

Re: RMAF 2007 findings
« Reply #27 on: 22 Nov 2007, 01:39 am »
I'm new to this circle, but glad to find it. I have a pair of Feastrex D5nf, gradually experimenting with various enclosures to find a happy home for them.

I agree with Jim's assessment of the Feastrex room at RMAF. It was good at most things, exceptionally great at a very few (Basie big band on 9" driver, solo guitar) and lousy on a few (any large orchestral music.)

Linn is right about things improving through the weekend. The D5nf sounded better to me in both cabinets in which it was played, counter intuitive considering it is less expensive.

I have built one cabinet for them so far, dave's new design called "Freddie Chang." It sounds better than the Feastrex boxes and maxxhorn with same driver, IMO, but it still has issues, mostly due to my ignorance of how to build a speaker. It was originally just a pine box with no bracing. Then adding random dowel braces, it got too bright. There is a dual horn version being developed now "Maiko", so I will try that hopefully with better building technique. But the Freddie does sound pretty good on everything, and is much less of a chameleon than boxes used at the show. Considering the price difference is almost 3rd order of magnitude it is a little surprising. Sorry for the tangent, looking forward to learning something in this circle.
Rich

floobydust

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Re: RMAF 2007 findings
« Reply #28 on: 22 Nov 2007, 04:36 am »
 Hi Rich,

 I'm also building the FC enclosure for the D-5nf drivers, but in red oak. I'll be adding a cross-brace for the rear of the driver and probably sealing and filling the lower triangle section. Should have them done in 2-3 weeks. I might try some of the blackhole products... used them in a simple ported box for the F120A, good stuff. I have an initial drawing for a TL but want to use the FC boxes for break-in and give me some time to build a prototype.

 So have your drivers opened up with some time? Any noticeable differences?

 Regards, KM

richidoo

Re: RMAF 2007 findings
« Reply #29 on: 24 Nov 2007, 02:45 pm »
Hi KM
Yes, they opened up a lot in the first week. Settled down by 3 weeks, playing a few hours a day. Apparently, the glue has to harden over time to reach full potential, plus mechanical loosening of course. I look forward to your impressions, and how the oak works out. It's a lot stiffer, so should self damp better than solid pine, at least on lower freqs. Was reading about black-hole again last night. They say it has equivalent air displacement of only 3/8" inches, which might be OK in the FC if used sparingly. The volume of the driver box is critical to the bass reinforcement as one might assume. Putting too much damping inside mine killed off the bass. I probably reduced interior volume by 1/3.  :o  It's how I learn.

I will build the new two horn version being designed now, gonna be called Phat Freddie. I hope it is ready in the next week or so, I'm itchin to start it. I would be interested in a TL design also, based on what Ed's been saying. The only one I've seen is here:
http://parkwestlake.com/nopw/rich/thackeray.gif
I've not built it yet, kinda small so I assume bass will be limited? A friend says it sounds very nice indeed, comparable to his single 8" driver OB.

Try a couple amps on them too. At a recent gathering I set them up with a Cary SLI-80 which was handy. The D5s sounded fine on two other amps, but the Cary was unlistenable. The Cary sounds fine on all my other speakers, but apparently doesn't like the high impedance for some reason. A friend who was over tried to explain why, but I had too many beers to follow. I had great luck with Snappers 100w tubes, and also the Altmann BYOB. The bass is better on the 100w amp. I measured -6dB at 60Hz with the Altmann and no damping or bracing. Dead flat on up to 290Hz.

Also, tighten the phase plugs securely, they will rattle if not tight. Also, protect the gap from debris falling in. Magnetic ferrous bits gettinginto the narrow gap have claimed a couple drivers already. Face down or sideways  or covered is better than face up like a funnel.
Good luck, and enjoy!
Rich

floobydust

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Re: RMAF 2007 findings
« Reply #30 on: 24 Nov 2007, 09:10 pm »
 Hi Rich,

 Thanks for the feedback on the drivers... glad to hear they've gotten better. I'll also post some feedback once the oak enclosures are completed and I've got some time on the drivers. I also looked at the TL Ron designed.... was interested at first but did some napkin math and I get the impression that Ron never really had a D-5nf in hand... the line square area where the magnet assembly sits is actually less than the cone square area. In effect, the concept of a tapered line is compromised as you immediately have a restriction before you actually get past the driver to the line itself. Obviously caused by the massive magnet casing.... I don't doubt that it may sound pretty good, but I don't think it's a proper design based on the physical driver characteristics.... but I could be wrong.

 As for amplifiers... I only have those of my own design and build... I started a prototype using the 20-watt SE iron from Hashimoto and will be driven by a WE300B. Design spec is 6-watts output which should be plenty. All I need now is a pair of 300B tubes....

 Regards, KM

planet10

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Re: RMAF 2007 findings
« Reply #31 on: 27 Nov 2007, 08:44 am »
I will build the new two horn version being designed now, gonna be called Phat Freddie. I hope it is ready in the next week or so, I'm itchin to start it.

Rich,

If you want i can email you the Phat Freddie as it exists at the moment... enuff info for someone to build them. We have been holding off with a full public release until Chris W issues a set of updated data.

dave

richidoo

Re: RMAF 2007 findings
« Reply #32 on: 27 Nov 2007, 01:40 pm »
Rich,
If you want i can email you the Phat Freddie as it exists at the moment... enuff info for someone to build them. We have been holding off with a full public release until Chris W issues a set of updated data.
dave
woohoo!!! Thanks Dave....

jrebman

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Re: RMAF 2007 findings
« Reply #33 on: 27 Nov 2007, 05:12 pm »
Rich, Now how did that happen?  Somehow we never mentioned this circle in conversation?  Ah well, glad you stumbled on it.  Welcome, my friend.

Can I ask you guys to start another thread on enclosure designs for the Feastrex drivers?  Just to keep things somewhat organized.

Kevin,

I'll be very interested to hear what happens with the oak enclosure, as will Mike L. -- who interestingly enough lives just down the road from me (i.e. Maiko).

-- Jim

richidoo

Re: RMAF 2007 findings
« Reply #34 on: 27 Nov 2007, 05:31 pm »
I am the world's worst hijacker - sorry. :oops:

I just never noticed this circle before, but glad to finally find it.

mwyatt

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Re: RMAF 2007 findings
« Reply #35 on: 21 Dec 2007, 07:45 pm »
Hi all...

Just wanted to introduce myself and let you know that we have completed the final version of the Little Grass Shacks. With the backs secured, stuffing worked out, and proper back-to-the-wall placement, the low end is amply and pleasantly present. We are extremely pleased with them (and tip our hats to Dave for a great design with which to work.) They will be on the website within a few days and available as soon as our custom drivers arrive (with a nice natural cone color.).

We have another another design based on the LGS in the works, incorporating, among other changes,  a suprabaffle and the option of a super tweeter. Will have 8" and 4.5" driver versions, all EnABL treated. More info to come as we move forward...

Mike Wyatt

Scottmoose

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Re: RMAF 2007 findings
« Reply #36 on: 22 Dec 2007, 12:38 am »
:^) Nice one Mike.

jrebman

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Re: RMAF 2007 findings
« Reply #37 on: 22 Dec 2007, 06:59 pm »
Mike,

Welcome to the AC single driver circle!  This all sounds really good, and I'll be looking forward to hearing from the first owners of the LGSs.

Can you comment on what sonic characteristics the bamboo ply brings to the final sound?  Obviously people think it looks great, but I think a lot of us are interested in hearing firsthand what it's particular acoustic properties are, and any other design considerations that have to be accounted for.

Any ballpark guesses on pricing?

And when are we going to hear about the Lotus DAC and when they'll be for sale?

You guys are doing some interesting things there.

-- Jim