DSP filter: how does it work in commercial speakers like Martin Logans?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi,

currently I'm building a hybrid electrostatic loudspeaker: a combination of a magnetic woofer and an electrostatic mid / high panel. I use an external MiniDSP 2x4 HD and two seperate power amplifiers and one pre amplifier to power this loudspeaker.

If I'm correct, the hybrid Martin Logans (for instance) use an integrated power amplifier for the subwoofer together with an inegrated DSP to filter frequencies to esl panel and subwoofer. But when looking at the pictures, I only see two regular loudspeaker input terminals, so I would guess you can only connect them to the output of a integrated / power amplifier. (not line-level)

I was wondering how DSP takes place? Is the power / amplified signal used for the subwoofer and if so, does it pass a DSP? I hope my question makes sense as I'm interested in a similar solution for my own DIY hybrid loudspeaker, just to make it more compact.
 
1) Sources to preramp which has volume pot and input select - AVR or stereo (pre)amp with line out that follows volume setting
2) RCA line level to Minidsp 2x4HD inputs (L/R)
3) minidsp settings take care of signal splitting, gain adjustment, eq and crossovers
4) RCA line level to main amps (two stereo amps or four mono amps which can be similar or different for bass and ESL)

You can as well use full fixed 2V signal from sources to minidsps and use it's remote to set volume. This way noise level should be lower.

More info in many sources, and minisp homepage
Stereo 2 Way Xover
 
Last edited:
But about Martin Logans ESL, they obviously do just some eq and xo, no delay etc. with dsp - and only for bass unit. Speaker level input is convinient for end users' old habits and amps, many commercial subwoofers can take it too.

MartinLogan Masterpiece Renaissance ESL 15A loudspeaker | Stereophile.com

ESL Masterpiece has better step response than Reneissance, looks like dsp sets some delay for the electrostatic panel.
 
Cardiod pattern is not mentioned, but to some extent yes, with CLX and Neolith versions

CLX DualForce™ Bass and Dipole Phase Stabilization
CLX's unique DualForce double diaphragm, triple stator dipole low-frequency electrostatic transducer delivers deep, dynamic bass with twice as much force as a standard ESL. Additionally, CLX's low-frequency dipole stabilization technology reduces low frequency rear wave cancellation inherent to dipole transducers. This is accomplished by increasing the air path length behind the CLX and delaying the out-of-phase back wave. The resulting decrease in low-frequency front-wave cancellation increases overall output while minimizing total harmonic distortion at low frequencies.

MartinLogan | MartinLogan Bass Advances

Lots of fancy "technologies" trademarked, but impossible to me to tell what happens in each speaker model! Factory secrets...

Martin logan CLX mods
 
Last edited:
"The Vojtko crossover allows the woofers to remain in phase below 100Hz and radiate omnidirectionally. Woofer phasing is shifted slowly between 100 and 160Hz so that the front and back woofer output becomes dipole-like above 160Hz"

Finnish forum talked about summit x model couple days ago, it has front firing and rear down firing drivers.
What i've listened my front and rear firing drivers cardioid or kinda dipole makes most sense soundwise, only delay of rear driver changes
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.