[dcbingaman]

Maggie LRS fans - with 10,000 pairs sold in 14 months and more on the way, the LRS is a HUGE hit.  Wendell Diller's experiment with dipole woofers for the "30.7 for Condos" indicates this speaker has an even bigger future with the right bass augmentor.

Introducing the Little Dipole Woofer (LDW) by VPE Aerospace !  This is a dedicated dipole woofer with a Pass-inspired slot-loaded port which exits under the panel sitting on MagneRisers, and with the driver itself radiating rearward.  The speaker uses the excellent Dayton Audio 10" woofers that Duke LeJuene uses for his Audiokinesis SWARM subwoofers, and the Dayton Audio 250W DSP amplifier.  The DSP is tuned to work with the LRS and provides seamless bass extension to 32 Hz.  I am still tweeking the tuning, but I have gotten flat response down to 32Hz on my RTA with a calibrated mike, and this combination gives the best reproduction of standup bass I have ever heard.  Jeff McCabe and I intend to
put these in production for LRS owners to buy direct
or through MagneRiser. Availability and price TVD, but they will be affordable.  They will be on an audition tour soon.  More to follow !!

[dcbingaman]

OK, guys.  The LDW DSP calibration is done.  Here are the results.  The top plot is the basic LRS with no woofer driven with Pink Noise and measured with a calibrated mike plugged into an RTA app on my iPhone (works great).  Pretty smooth, but it falls off like a rock at 60 Hz, and Magnepan put a "BBC Bump" in the 80-100 Hz region to make it sound like it has more bass than it does (second harmonic area for the low notes on a string bass or a piano).  The second plot is the LRS + LDW with EQ using a Pass Aleph 5 for the LRS.  Pretty smooth and provides flat DIPOLE response down to the Dayton Audio free air resonance point of 27 Hz.  The Aleph amplifier is an ideal match to the LRS and puts about 100W into the LRS load. 

The third plot is the LRS + LDW with a typical Class A/B amp, the Emotiva BasX A-300. Not quite as smooth but close.  I tried the Emotiva to see if a simple change in the LDW gain setting could offset an increased or decrease in the high pass amplifier gain.  It does, but the DSP needs a little more tweaking to tame the "BBC Bump" in the basic LRS response.

The LDW's are going on the road to show selected listeners how well an LRS-based "30.7 for Apartments" can work.  All I will say is I have been an audiophile for 40 years and am a big admirer of the Maggie 20.7.  I have NEVER heard a string bass sound as realistic as what the LRS + LDW combination provides.....and it is (relatively) dirt cheap.