Subwoofer best suited for electrostats

[MGH]

Hi, I've never heard a dynamic subwoofer that mates well with an electrostatic speaker. I heard conventional cone woofers (Martin Logans and Sound Lab Pristine) and transmission types (Innersound Eros). The Innersound has better integration than ML or SL, but I can still hear discrepancy between the different transducers. I've also heard standalone subwoofers from Vandersteen, Thiel, Veladyne, M&K mated to electrostats, but still I it bothered me. I've heard dipole subwoofers are better suited in this application. I know there were some discussions about dipole subwoofers but I don't recall anyone trying to use it with electrostats and comparing to other types of subwoofers. Anyone have any success? Thanks.

[AJinFLA]

Start here:
http://www.euronet.nl/users/temagm/audio/dipolesub.htm
The best possible match for a dipole main speaker - is a dipole subwoofer. I use a dipole sub using 2x12 for music with very satisfiying results .http://www.linkwitzlab.com/proto.htm#PW1
For very high output, ultralow bass - like pipe organ tracks or HT, I also use a sealed sub below 35hz in conjunction with the dipoles to extend output below 20hz at high levels. 95% of my listening is done with the dipoles only.
The dual woofer H-frame version of this is pretty much like mine and might work for you also: http://www.musicanddesign.com/craw.html

cheers,

AJ

[MGH]

Thanks! Has anyone ever built a tower dipole subwoofer system (ie, to match the hight of the electrostat line source)? Although this would be expensive, it would be more like a line source like most electrostats and provide more extension the a dual woofer design.

[JonFo]

Originally posted by MGH
Thanks! Has anyone ever built a tower dipole subwoofer system (ie, to match the hight of the electrostat line source)? Although this would be expensive, it would be more like a line source like most electrostats and provide more extension the a dual woofer design.

Well not quite dipole or a sub, I am building a line array mid-bass bolted to the top of an infinite baffle sub matted to a Martin Logan SL-3 panel as my new center. See details on this DIY Audio thread
That concept could be extened by a couple more drivers and some greater length to do frequencies down to 30Hz or so.

As for the best sub to match ESL’s, my opinion is that a good infinite baffle is the trick.
My IB delivers outstanding results with my all Martin Logan system. Here’s a pic:



The key is the crossovers and phase matching. Use a good high-end speaker processor like the Drive rack 260 and tune it to your system /room and presto, audio nirvana.

[Calvin]

Hi,

just built a dipole tower... result:
...
...
...
....forget everything else
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


ESELman

ps: the bass below the panel isn´t used

[AJinFLA]

That is exactly the approach I would take. Good job Calvin. Looks nice ! I would run the box sub below 40hz and use the dipole a array above. Can't hear it, but I know its sounds good . What woofers did you use?

cheers,

AJ

[Calvin]

Hi,

thanks for the praise
The box blow the panel will be replaced by a smaller box, that will only house the electronics. But with enough volume to have a 2-channel digi-amp and active crossover built in -future plans-.

The system runs the woofer drivers from app. 35Hz to 250Hz, where the panel takes over. The panel is crossed over with a 2nd order butterworth filter with a Q around 2 to counter the falling freq-response and a notch on its ground resonance (160Hz). Acoustically this gives app. 4th order chebycheff.
The woofers are filtered with a 4th. order chebycheff and the acoustical behavior is the same. So both channels experience equal slopes -different slopes, i.e different group delays is imo one of several reasons why most hybrids integrate bass and panel so badly.
The bass channel is completed with a subsonic and bass boost (0-10db @ 35Hz..I run it at app. 6dB).
The drivers are bought from a sell-out. I knew them before and that they are able to be used in dipoles, but the sound-experience I have now is far better than I believed could be possible in my room. Playing a double bass like in Rebecca Pidgeon´s Spanish Harlem led to strong booming at distinct frequencies. Now I have clear and highly precise bass without any tendency to boom at any frequency at all.
What surprised me even more -and I don´t know any explanation for this- is, that the exceptional bass quality leads to even better mid-highs!!
Though I´m absolutely happy with the results, I´m a bit ashamed that both towers -as You can see them on the pics- costed about 200€


jauu
Calvin

[Dabler]

Nice work Calvin. This is just the kind of project that I had in mind for my SL3s, using GR Research's new XBL^2 drivers (in development) that are meant to be used open baffle.

Any pittfalls I should know about?

I plan to use my Dbx Driverack PA as the crossover for the open baffle line array, running it between 250hz and about 80hz, where my subs will take over.

What do you think?

[RobWells]

Linkwitz used 8 x 12" per side in W baffles to get down to 20Hz at good spl in the Beethoven grand

A good starting point

Rob.

[JonFo]

Originally posted by Dabler
Nice work Calvin. This is just the kind of project that I had in mind for my SL3s, using GR Research's new XBL^2 drivers (in development) that are meant to be used open baffle.

Any pittfalls I should know about?

I plan to use my Dbx Driverack PA as the crossover for the open baffle line array, running it between 250hz and about 80hz, where my subs will take over.

What do you think?

Good choice for the DriveRack. I would recommend around 315Hz as the crossover for the SL3.

I also highly recommend bypassing the passive crossover in the SL3.

I posted full details on how to mod the SL3 crossover and a bunch of measurements of my DriveRack based SL3-eXtreme Center speaker over on the Martin Logan club
.
5 pages of build and test chock full of pics and graphs.