[pinkfloyd4ever]

Nice! I'm definitely excited about this one.

When you say the weekend after Thanksgiving, do you mean Nov 29-Dec 1? Or Dec 7-8? I could do Dec 1, 7, or 8th.

December 14-15 works for me but it might be a little too close to Christmas for a lot of people?

[dcbingaman]

I am thinking the weekend of Nov. 28-29 OR Dec. 14-15.  I have a couple conflicts on Dec. 7-8.  I'm good for Saturday or Sunday - let me know what works for you guys.

[dcbingaman]

Check that - I meant the extended weekend of Nov. 29-30.  I have an SLSO Concert on Sunday Dec. 1st, and a Wash U. concert on Dec. 8th.  (How time flys by !!)

[pinkfloyd4ever]

Wow no one else is interested in this?

I could maybe do the 14th or 15th, but it might be best to wait till after the holidays at this point?

[popthinker]

I'm up for after the holidays sometime.

[dcbingaman]

Hi, guys.  I am now thinking after the Holidays in the New Year.  Everybody is too busy between now and the blessed event.

I should have everything soldered and calibrated by then.  I am thinking maybe Jan. 4th, 11th or 18th.  Let me know what works best for youse guys (and gals !!).

[Blackmore]

I’ll chime in first by choosing the 11th.  Thanks

[chalmersiv]

if this is open to everyone I would like to do 12-11...gordon

[pinkfloyd4ever]

Not sure what my schedule in January will look like at this point, but probably pretty open, so I think any of the above dates should be good.

[dcbingaman]

Hi, guys and gals (AKA Major Dudes and Dudettes).  Based on all the recent craziness, I have settled on Saturday, Jan 11th, 2020 from 2:00 pm until whenever for my Open House.  Audio food and drink will be provided.  Please PM me to RSVP and for directions.

Attractions: Speakers: Magnepan LRS, Pass SLOB and Spendor SP1 speakers, Vandersteen 5.1 HT with new Sony 4K projector.  Amps: First Watt J2, PassDIY Sony VFET, Dynaco Stereo 70 Block 3, Pass Aleph 5, PassDIY F5 Turbo V.2. Preamps: Pass Nutube, Broskie Aikido, Vinyl: Denon DP-75 / Jelco SA-750 + Ortofon SPU, VPI HW-19 Mk. IV / FR-64fx + Koetsu Urushi Gold, SOTA Sapphire / Sumiko "The Arm" + Miyajima Shilabe.  Digital: various sources with Meridian DAC's.

[SteveFord]

And then what happened?

[pinkfloyd4ever]

And then what happened?

It was a great time and the LRSs were freaking awesome! I haven't been able to stop thinking about them since. Really been trying to figure out how I could make them work, but I just don't have the space, or a powerful enough amp.

Don, were you running your LRSs with subs when we were there? And with the J2 or or the Aleph 5? I thought it was the J2, but from what I've been reading a 15 wpc amp would never be near enough power to make those sound as good as they did.

[Wind Chaser]

Really been trying to figure out how I could make them work, but I just don't have the space, or a powerful enough amp.

And that's the rub. A lot of people will continue to find this out the hard way.

[smargo]

And that's the rub. A lot of people will continue to find this out the hard way.

right - you def need at least 100 watts - dont even be on the fence on this one - but wind chaser if you do have the right wattage

their awesome

[dcbingaman]

Hi, guys.  I was running the LRS's with an Aleph 5.  An Aleph 4 would be even better.  These babies dig current !  Also they were crossed over at 50 Hz to a single Outlaw Audio 12" subwoofer and balanced using an RTA.  Great combination.

[dcbingaman]

Hi, Guys. Since the Bat virus is making everyone Bat $hit crazy, I, like ya'll, am cooped up in the House for the next few months.  I decided to see if Wendell Diller was up to anything good with this "30.7 for Condos" idea of using stereo dipole dynamic woofers in place of the large bass panels on the regular 30.7 model.  It doesn't take a rocket scientist to figure out that a 30.7 midrange and tweeter panel is essentially a larger version of an LRS.  The missing element is the dipole woofer.  Wendell supposedly has a 4 x 6.5D" woofer array on an open baffle of some geometry which nobody is allowed to photograph.  Things that make you go Hmmmmm.....???

Rather than try to guess and duplicate that, I decided to use a proven setup from Siegfried Linkwitz for his LX521.  Madisound has knockdown cabinets for both the dipole woofer and the rest of the speaker, but they will sell you the dipole woofer cabinet separately.  The drivers Siegfried specified are rather expensive (two SEAS L26ROY 10D' drivers), so I looked at alternatives and found an 8 ohm, 10" aluminum cone driver from Dayton Audio that is better suited than the SEAS driver for the open baffle - the RSS265HF-8.  It has a Vas 50% greater than the SEAS driver and it has a flatter response below 100 hz.  Here's some pics.






DSP - I acquired a miniDSP 2x4 HD which has two inputs and four outputs and has 24 bit / 96Khz A/D, processing and D/A.  Very cool and easy to program.  I am using Linkwitz's curves for the woofer EQ and crossing over to the LRS panels at 80 hz at 24 dB / octave.  Bass boost at 20 hz is about 12 dB.  I am using a Emotiva A-300 for the woofers (300W into 4 ohms - the woofers are run is parallel) and my Pass Aleph 5 for the LRS's (~100W into 3 ohms).  I am still working on the second dipole woofer so I haven't hooked it all up yet. 

When I get to the audition stage I will give you an update.  I am using a calibrated mike, a pink noise CD and a RTA app on my iPhone to set the levels - works pretty good with the Outlaw audio sub I am using now with these wonderful little LRSes.  I'd love to have you guys over to hear these again, but the social distancing thing will keep us apart for a few more weeks.  I CAN post RTA images here as soon as I get them done.  Stay tuned !!

[pinkfloyd4ever]

Nice! Looks interesting and I bet it will sound awesome. Definitely looking forward to this social distancing/shelter-in-place being over but I'm afraid it may be a longer than we're hoping.

Yeah I'm getting pretty close to digging out the parts for some projects that I had given up on ever actually completing with all the time at home. Maybe I'll finally get started on restoring my Fisher 500c!

[dcbingaman]

OK guys, I have some major news.  Jeff McCabe and I have built the first pair of Little Dipole Woofers (LDW) for Magnepan's wonderful Little Ribbon Speakers (LRS).  This is a slot-loaded dipole which sits right behind the panel on MagneRiser stands and radiates through a 3" x 10" slot underneath the panel.  The 10" Dayton Audio driver is powered by a Dayton Audio 250W amp with built in DSP  with a high pass for the LRS - similar to Wendell Diller's "30.7 for Condos", but better integrated geometrically.  I am halfway through tuning, but I have gotten a flat response down to 32 Hz and they integrate so well with the Maggies you can't hear the transition.  They give the Maggies Cajones like a cone speaker, but preserve the magic Maggie lower midrange with no boom or mud in the response.  You've never heard an acoustic bass sound this realistic in a loudspeaker - they are that good.

Here's a picture....more soon, but Jeff and I intend to build these in production for LRS owners via direct sales.  Availability and price TBD, but affordable !!

[Blackmore]

Nice work Don!!!!!!!

[Jon L]

Here's a picture....more soon, but Jeff and I intend to build these in production for LRS owners via direct sales.  Availability and price TBD, but affordable !!

Very niiccee... There is no reason you can't use these dipole subs with other Maggies or other dipole speakers, right?