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06-01-2009, 01:56 PM
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Senior Member
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Join Date: Jun 2008
Posts: 123
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It's Alive! DIYDC
After a couple of missed years, I'm reviving the DIY gathering in Washington, D.C. (well, Bethesda, MD). It will be a modest affair with no competition--just a show and tell and a very interesting demonstration of crossover slopes by Neil Davis. I'll let him describe exactly what he's planning. I'll have the recently introduced Salk HT4's on hand, which feature an 18 Hz bass module by Jeff Bagby, a quasi open-back mid module using the $500 per FAL flat driver, and a virtually free standing RAAL OEM ribbon tweet. And my passive variant on the Linkwitz Pluto will also make an appearance, using an upfiring
5" revelator midwoof and the Neo 3 planar.
This won't be anything to rival the Iowa or Ohio DIY's, but maybe the food will be better. The date? July 18th, 10:00 AM. The place? 5214 Wehawken Rd, Bethesda MD 20816. Please PM me, Dennis Murphy, if you can attend or have any questions.
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06-01-2009, 02:06 PM
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Senior Member
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Join Date: May 2008
Location: manassas, va
Posts: 645
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Re: It's Alive! DIYDC
ALL-FREAKIN'-RIGHT!!!!!!!!
I'm there!
__________________
Insurance is like marriage. You pay and pay but you never get anything back.
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06-01-2009, 04:15 PM
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Senior Member
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Join Date: May 2006
Location: Iowa
Posts: 815
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Re: It's Alive! DIYDC
Hmmm, I would love to be there but I bet that the odds of that happening are about zero.
Have a good time Dennis and you never know I just might make it. I have some family in the area.
Doug
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06-01-2009, 07:30 PM
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Senior Member
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Join Date: Oct 2005
Location: Little Chute, WI
Posts: 358
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Re: It's Alive! DIYDC
Hey Doug,
When Dennis was at the Iowa event did you take him to Casa Margarita? No? I didn't think so....
Let's not be dissin' Iowa food! 
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06-02-2009, 09:31 AM
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Senior Member
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Join Date: Mar 2006
Posts: 163
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Re: It's Alive! DIYDC
Ah C'monnnn. I hope there's more interest than this. Maybe people are just sending PMs and not posting.
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06-02-2009, 11:55 AM
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Senior Member
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Join Date: Jun 2008
Posts: 123
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Re: It's Alive! DIYDC
Quote:
Originally Posted by ericy
Ah C'monnnn. I hope there's more interest than this. Maybe people are just sending PMs and not posting.
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The replies are trickling in. But there's room for lots more. Did I mention that I have a remote-controlled A-B preamp that lets you instantly compare up to 4 sets of speakers at the same volume level? And there will be food? And a golden retriever?
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06-06-2009, 01:39 AM
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Junior Member
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Join Date: Jan 2007
Location: Northern VA
Posts: 23
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Re: It's Alive! DIYDC
For a preview, here is one of my very limited edition Plutoesque octagons, with Dennis' crossover.

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06-12-2009, 02:17 AM
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Junior Member
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Join Date: May 2008
Posts: 1
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Re: It's Alive! DIYDC
I'd like to exhibit these at DCDIY.
This speaker was built in 2005 and two of the drivers I think are now discontinued so that the speakers are basically not replicable. Despite their one of a kind limitation , I think that they are worth a listen and perhaps a critique as well.
Dennis Murphy designed the crossover and he hasn't heard them in stereo yet so I thought that after all his efforts he should at least hear the results of his work.
The bass is the venerable Peerless CSX 10", mid a Seas Excel w15CY and the tweeter is the Raven R1 ribbon.

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06-12-2009, 01:52 PM
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Senior Member
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Join Date: Jun 2008
Posts: 123
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Re: It's Alive! DIYDC
Quote:
Originally Posted by cfbuck
I'd like to exhibit these at DCDIY.
This speaker was built in 2005 and two of the drivers I think are now discontinued so that the speakers are basically not replicable. Despite their one of a kind limitation , I think that they are worth a listen and perhaps a critique as well.
Dennis Murphy designed the crossover and he hasn't heard them in stereo yet so I thought that after all his efforts he should at least hear the results of his work.
The bass is the venerable Peerless CSX 10", mid a Seas Excel w15CY and the tweeter is the Raven R1 ribbon.

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Thanks very much for the post, and I hope you'll be able to make the long trek. I'll look forward to hearing that design again--it's the only one I've done with the Raven, which is an exceptionally smooth driver. Although the Peerless woofer is extinct, I've revised my MB0W1 3-way using the replacement woofer, which is almost as good. So I'm sure this design could be modified successfully as well.
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06-12-2009, 10:39 PM
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Join Date: Aug 2006
Posts: 92
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Raal vs ?
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06-13-2009, 01:09 AM
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Senior Member
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Join Date: Sep 2005
Posts: 137
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Re: It's Alive! DIYDC
Quote:
Originally Posted by mtbiker
For a preview, here is one of my very limited edition Plutoesque octagons, with Dennis' crossover.

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Nice! What is the approximate cost in drivers and crossovers?
Jason
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06-13-2009, 01:37 AM
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Junior Member
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Join Date: Jan 2007
Location: Northern VA
Posts: 23
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Re: It's Alive! DIYDC
Probably $700+ for drivers and crossovers...
The monetary cost isn't the real story. It's the time required to make an absurd cabinet like this. Of course there are a few things I would do differently if I had to do this all over again.
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06-13-2009, 05:19 AM
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Senior Member
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Join Date: Sep 2005
Posts: 137
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Re: It's Alive! DIYDC
Dennis or mtbiker....
Any comments on listening impressions, on it's own or as compared to the original Pluto?
Thanks,
Jason
Last edited by jasonb; 06-13-2009 at 05:20 AM.
Reason: My typing sucks!
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06-13-2009, 12:05 PM
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Join Date: Jun 2008
Posts: 123
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Re: Raal vs ?
Quote:
Originally Posted by sendler
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That's easy--it's virtually perfect, although the last sample I got wasn't quite as flat, and I suspect the tensioning of the ribbon element is critical and subject to QC issues. But the response without a baffle (which is how I use it) is the best I've seen, both on and off axis. And the distortion products in the 1500-3000 Hz range are much lower than with other ribbons I've measured. I crossed it at 1800 Hz on the new Salk speaker with no problems. On very well recorded material with lots of bells and whistles, the sonic superiority is readily apparent in an A-B test with the best ribbons and domes. When money's not an object, it would definitely be my tweet of choice.
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06-13-2009, 12:16 PM
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Senior Member
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Join Date: Jun 2008
Posts: 123
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Re: It's Alive! DIYDC
Quote:
Originally Posted by jasonb
Dennis or mtbiker....
Any comments on listening impressions, on it's own or as compared to the original Pluto?
Thanks,
Jason
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I haven't had extended experience with the new Pluto, but I had the original version in my house for almost a year. The Orion is one of my favorite speakers, but the 1st Pluto--not so much. The lower treble and upper midrange sounded blurred to me, particularly on brass. There was just too much output. That didn't show up on the usual one-meter measurement, however. And when I first designed the crossover for Mt. Biker I went for a flat measured response. But it sounded just like the Pluto. My read is that the very short measuring window wasn't picking up on the woofer's rear radiation output. But, of course, the ear would as soon as the 1st reflections came rolling in. I took some room measurements and experimented with the on-axis profile in the crossover region, and finally came up with something that sounded accurate to me (but it measured with a pretty deep depression centered around 2 kHz). Jamie can update me on this, but when he got the thing home, he tried it in two different rooms, one quite reverberant, and the other very damped. It sounded fine in the reverberant room, but he could pick up on the hole in the middle in the dry room. So these things are tricky.
Last edited by framus; 06-14-2009 at 11:37 AM.
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06-13-2009, 04:16 PM
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Junior Member
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Join Date: Jan 2007
Location: Northern VA
Posts: 23
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Re: It's Alive! DIYDC
Dennis is correct. The octagons live in a painfully reverberant room and they sound great there--really fantastic. However, they are "my wife's speakers" which means that they are never asked to play anything complicated, loud, or compressed. When I put them in the basement, which is an acoustically damped room, I could hear the hole in near the crossover point. Ordinarily I think narrow holes are OK since you often don't know what you're missing, but since this extended downwards in the midrange, it really affected speech intelligibility just watching TV. This was a lesser problem when I listened to complicated, loud, and/or compressed music in the basement, where they maintained their clarity despite the hole. So I'm not sold on the arrangement or the crossover for myself, but they work great upstairs. It will be interesting to hear them at DIYDC.
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06-14-2009, 08:52 AM
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Member
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Join Date: Aug 2006
Posts: 92
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Too bad we can't buy the Raal oem
Quote:
Originally Posted by framus
That's easy--it's virtually perfect, although the last sample I got wasn't quite as flat, and I suspect the tensioning of the ribbon element is critical and subject to QC issues. But the response without a baffle (which is how I use it) is the best I've seen, both on and off axis. And the distortion products in the 1500-3000 Hz range are much lower than with other ribbons I've measured. I crossed it at 1800 Hz on the new Salk speaker with no problems. On very well recorded material with lots of bells and whistles, the sonic superiority is readily apparent in an A-B test with the best ribbons and domes. When money's not an object, it would definitely be my tweet of choice.
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Great. Now if only we could buy them.
Ever try the Raal 140-15?
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06-14-2009, 11:38 AM
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Senior Member
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Join Date: Jun 2008
Posts: 123
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Re: Too bad we can't buy the Raal oem
Quote:
Originally Posted by sendler
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Great. Now if only we could buy them.
Ever try the Raal 140-15?
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Of course not. Why would I try something relevant?
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06-19-2009, 01:31 PM
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Member
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Join Date: Oct 2005
Posts: 60
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Re: It's Alive! DIYDC

Quote:
Originally Posted by framus
After a couple of missed years, I'm reviving the DIY gathering in Washington, D.C. (well, Bethesda, MD). It will be a modest affair with no competition--just a show and tell and a very interesting demonstration of crossover slopes by Neil Davis. I'll let him describe exactly what he's planning. I'll have the recently introduced Salk HT4's on hand, which feature an 18 Hz bass module by Jeff Bagby, a quasi open-back mid module using the $500 per FAL flat driver, and a virtually free standing RAAL OEM ribbon tweet. And my passive variant on the Linkwitz Pluto will also make an appearance, using an upfiring
5" revelator midwoof and the Neo 3 planar.
This won't be anything to rival the Iowa or Ohio DIY's, but maybe the food will be better. The date? July 18th, 10:00 AM. The place? 5214 Wehawken Rd, Bethesda MD 20816. Please PM me, Dennis Murphy, if you can attend or have any questions.
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Great news on the return! I`ll be planning on coming with a couple of speakers. Thanks for hosting.
Steve.
Last edited by castlesteve; 06-19-2009 at 01:37 PM.
Reason: adding pics.
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06-19-2009, 11:59 PM
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Join Date: Mar 2009
Location: West Virginia
Posts: 56
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Re: It's Alive! DIYDC
I'm very interested, if nothing else to come and listen to everyone's hard work.
I don't know if I'll have the Magna C Laude's done in time, but then again, they won't compare to most of what is showing up. 
__________________
Reciever: Onkyo TX-SR706
Fronts: Magna Koom Laudes
Surrounds: Cambridge Soundworks Model Seventeen (soon to be replaced with some little Magna design)
Subwoofer: Who needs a subwoofer when you have 4 twelves in your mains?  [ I do, apparently  ]
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