Magnepan LRS

dcbingaman · « **on:** 12 Oct 2019, 09:41 am »

Just got a pair of these from Magnepan. Pretty freaking awesome. Youse guys need to come over sometime to hear these things. Its like a 21st Century Quad ESL-57.....its really that good in the midrange. A couple caveats - they need a lot of current to drive them. My Aleph 5 works, but just barely. The second is they run out of poop at about 50 hz. I tied them to an Outlaw subwoofer and they work pretty well, however. Definitely a speaker that needs some augmentation, LOL.

Let me know when you major dudes and dudettes would like to come hear these things. I can haul them over to Dave S.'s place if that works - they are relatively light weight.

popthinker · « **Reply #1 on:** 12 Oct 2019, 11:18 pm »

Sounds very intriguing. Count me in...wherever the audition is!

wedweb · « **Reply #2 on:** 14 Oct 2019, 12:54 am »

I've never heard any panels live before. So, I'd be up for a meet.

Bo

pinkfloyd4ever · « **Reply #3 on:** 18 Oct 2019, 03:26 pm »

Oooo heck yes I too have never heard Maggie (or any other ribbon/panel/electrostatic speakers). I was watching a Steve Guttenberg video about the LRS and I'm definitely interested in hearing them.

I wish I could offer to host but our house is tiny and my listening space is not too good

SteveFord · « **Reply #4 on:** 18 Oct 2019, 09:29 pm »

Never heard planars?
Hold onto your wallet, they're kind of addictive.

thunderbrick · « **Reply #5 on:** 19 Oct 2019, 03:56 am »

If GASsers want to hear large panels, I'm up for a small gathering down I-44.
Bob

SteveFord · « **Reply #6 on:** 19 Oct 2019, 09:22 am »

Stay away from Thunderbrick's place, once you hear what he's got you're doomed.

Saturn94 · « **Reply #7 on:** 19 Oct 2019, 01:17 pm »

Quote from: SteveFord on 18 Oct 2019, 09:29 pm

Never heard planars?
Hold onto your wallet, they're kind of addictive.

At least with the LRS the hit isn’t too bad.

Blackmore · « **Reply #8 on:** 19 Oct 2019, 03:57 pm »

Hey Don,
Any ideas on a listening session for the LRS? Sundays aren't good for me but I've got a lot of Saturdays off and would love to hear your pair

Mark

mjmsound · « **Reply #9 on:** 9 Nov 2019, 01:34 pm »

"Stay away from Thunderbrick's place, once you hear what he's got you're doomed."

Heard Thunderbrick's setup. Sounds great, should not miss it.

dcbingaman · « **Reply #10 on:** 9 Nov 2019, 11:13 pm »

Hi, guys, I am actually waiting to do a two-fer for you guys. The SECOND speaker pair may be more impressive than the Maggie LRS speakers. I am in the process of finishing up a pair of Pass / Linkwitz SLOB's - that is Slot-Loaded bass augmented Open Baffles. This speaker design combines a full-range 8" Cube Audio driver set in a 20"W x 40"T open baffle and a 15" Eminence super woofer which propagates through a 3"T x 16"W slot just below the baffle board. This is Pass's reference speaker and only about 2 pairs exist - Herb Reichert of Stereophile heard it about 8 months ago in Sea Ranch, CA and said it was the best audio transducer he has ever heard.

Here are some pics of the cabinets which master carpenter Jeff McCabe is finishing for me, and the drivers. The speaker is bi-amped using a Pass Aleph 5 on the bottom, and a First Watt J2 SIT amp on the top. I will receive the cabinets from Jeff in about 1 week. The only change I made from Pass's design is the use of a 1/2" thick piece of clear acrylic instead of 3/4" birch plywood. (The acrylic has a much higher density but lower modulus - great for damping.) The crossover is under construction at Casa de la Binger and should be ready in a couple weeks. It includes equalization to flatten the driver response out to +/- a couple dB from 40Hz to 20KHz.

I am also looking at adding a dipole set of Coles Supertweeters at 8Khz and up to improve the Cube Audio driver's high frequency polar response. The last picture is a 2001: a space odyssey inspired layout of the drivers. I expect to be ready for an audition by about Thanksgiving time. I will set a date (probably a Sat. afternoon / evening) in about 1 week.

Blackmore · « **Reply #11 on:** 10 Nov 2019, 12:40 am »

Can’t wait to hear both of these. Which Eminence woofer are you using?

Mark

dcbingaman · « **Reply #12 on:** 10 Nov 2019, 02:56 am »

It’s a Definimax 15 - 8 ohm version.

The star is this crazy Cube Audio 8” FC8 Driver - it is the most innovative direct radiator / voice coil driver I’ve ever seen. Very linear and no hysteresis. It uses a spider made of phenolic “leaf springs”, but shaped like a set of spiral galaxy arms. Very cool.

Blackmore · « **Reply #13 on:** 10 Nov 2019, 02:57 am »

Nice!!

dcbingaman · « **Reply #14 on:** 17 Nov 2019, 10:58 pm »

The SLOB's are assembled ! All I have to do is wire them up to the speaker terminal and finish the crossover. When do youse guys want to get together ? I'm thinking the weekend after Thanksgiving or the weekend of Dec. 14/15, 2019. Lots of fun stuff to show you !

genestl · « **Reply #15 on:** 18 Nov 2019, 03:31 am »

I will bring bier.

rollo · « **Reply #16 on:** 18 Nov 2019, 06:35 pm »

They look sweet. You guys have fun. Nice work BTW.

charles

MickeyBoy · « **Reply #17 on:** 18 Nov 2019, 10:52 pm »

I have a pair of LRS speakers that just did not work out in my room. I have had a pair of Magnepan MGIIIa's for over 25 years, so I know & love Magnepans. I am planning to return them to Magnepan under the home trial arrangement. I hate to do this & make such a good company "eat" them. So I am willing to sell them for $600. There is nothing wrong with them, cosmetically or otherwise. To the contrary they are typical Magnepan quality, broken in about 30-50 hours.

I can deliver them during Thanksgiving as I will be in the STL area then. I live in Columbia, MO. I don't want to wait too long to return them.

dburna · « **Reply #18 on:** 19 Nov 2019, 12:40 am »

Quote from: dcbingaman on 17 Nov 2019, 10:58 pm

The SLOB's are assembled ! All I have to do is wire them up to the speaker terminal and finish the crossover. When do youse guys want to get together ? I'm thinking the weekend after Thanksgiving or the weekend of Dec. 14/15, 2019. Lots of fun stuff to show you !

Am curious -- is there a crossover to the SLOB speakers? Or do both woofer and full-range connect directly to the speaker terminals? It is not possible to tell based on these photos if there is a crossover involved.....or what kind it is.

Thanks, -dGB

dcbingaman · « **Reply #19 on:** 19 Nov 2019, 09:48 am »

The speakers are bi-amped. The active crossover was custom-designed by Nelson Pass and had EQ for each driver, as well as a 2nd-order Linkwitz-Riley filter set. The crossover frequency is about 80 Hz. The drivers are connected to the amps in positive phase. The Cube driver is quite efficient and is driven by an SET or a JFET power amp like a First Watt J2. The low pass is driven by a suitable 60-100W power amplifier like a Pass Aleph or First Watt F5 Turbo (about 140W).

The crossover has stereo pots for both low and high pass. The pots are set using a pink noise source (CD), a calibrated mike and an RTA.