Pro Audio Design Forum

I found a second way to do this externally as an insert to the MS matrix. The circuit I'm testing right now is second order with a high cutoff. There is virtually no separation below 200 Hz; at 1 kHz its about -25 dB. On a lot of material - already mastered - I can't hear it working which I suppose ...

VAB84 Description and Schematics I found the English technical description and schematics for the VAB84 and it confirms the different method it uses over prior generations of "Elliptical Equalizers." https://proaudiodesignforum.com/images/jpg/Neumann_VAB84_Matrix_Block_1.jpg Nuemann VAB84...

I'll post links to the full schematics. I want to re-tile the E77. I'm finding out what a "Swiss Army knife" the MS board is. It looks like everything up to the VAB84 was 6 dB/octave and by virtue of blending cancelled LF Side information rather than fold it into Mono/Mid like the VAB84. I...

I've looked at the VAB84 again and realized that it is a completely different animal than the LF blending of earlier Neumann "elliptical equalizers." Phase and polarity differences (Left relative to Right) are what make stereo. Pan something hard Left and the Side information will be the ...

the old school phono carts had 20-30 dB L-R separation. I think those are reasonable numbers. Lets use -30 dB to keep numbers round. I think I may have seen a 35 dB figure quoted once in a review and was astounded. The 20 Hz -3dB filter in the OP provides ~ -42 dB of separation at 1 kHz. An 80 Hz f...

I don't think the 150 and 300 Hz labels were the -3dB frequencies... I'm thinking those panel markings may have been "x" amount of separation at the marked frequency. That high a frequency (for a -3 dB point) and at 6 dB octave there would be no mid-band separation. I did see one post wher...

This particular speaker was a 5 way with active crossover. One of the mid-range drivers had mis-wired polarity on both sides smack in the vocal range. Dunno if they changed the standard but JBL woofers forever made positive voltage on the red connection suck the driver in. I suppose that goes back t...

...There may actually be some modern tracks with hard panned low bass. Old school recording knew not to do that (or they should have known). I cited an article in another thread (somewhere around here) about the modern requirement to have center-panned low frequencies for proper ear bud translation...

I remember Russ Berger seeing a similar response from some SOTA monitors that had been installed in the 80's at Tele-Image in Dallas.
One driver had the wrong polarity in both the left and right monitors.
They had been QC'd that way by SOTA.
It had the exact same bump.

John - The application is for a low frequency "crossover" to mono for disc cutting. (I think this is sometimes called "vertical crossover" due to the sum/difference mechanical vectors.) So not a crossover in the speaker sense, but mono blending to prevent large difference informa...