Some questions about bass integration and XOs (Oris Horns)

by Don Reid, Rural Northwest Georgia, USA, Thursday, December 20, 2007, 01:24 (5966 days ago) @ Bert
edited by unknown, Thursday, December 20, 2007, 04:41

Hey Bert,

I beg to differ with your opinion regarding digital crossovers, room correction, time alignment, phase correction, etc. The first time we discussed the efficacy and sonics of the DEQX you stated that you had only listened to it once, that being in a system at the Rocky Mountain Audio Fair. Have you ever taken time to give it a relaxed listen in a carefully aligned arrangment in a system featuring your own speakers?

I have corresponded on another forum and by e-mail with the two installers who set up the system with the DEQX at RMAF. They told me that thirty-six hours before the show opened they had never seen a DEQX or any of its documentation. The learning curve on this very complex component and its PC software is far too steep for that to provide sufficient time for a proper job to be done. It took me two weeks, and I'm a frigging genius.

The follow is an excerpt from the posts from back in 2005 which may be reached by the link provided below.

" I recently installed a DEQX PDC-2.6 digital processor/crossover in my system. It was a chore for me to learn how to install it. Speakers are AER MD3s in Oris 150 horns and the bass corner horns of Klipschorns. The DEQX (pronounced DECKS) allows me to program a linear phase, 160 Hz crossover with the high pass to the Oris 150s rolled off at 78 dB/octave and the low pass to the Klipschorn bass bins rolled off at 96 dB/octave. The diaphragms of the AER drivers are about six feet in front of the 15" woofers in the Klipsch. The DEQX time aligns them to within 1/8", or less than one-one hundredth thousandth of a second. Passes the WE tap dance test. Calibration and calculation of correction filters similarly correct speaker phase and frequency response,room resonances, etc.
The AER MD3s in Oris 150 horns coupled to Klipsch corner horn woofers were, before the DEQX, splendid speakers in many ways. They were not imaging champs. I hadn't ever expected them to be. Installing the DEQX was a revelation. My beloved horns now imagine better than any speaker I've owned, a considerable number, with the exception of a pair of floor to ceiling full range electrostatics I owned up until 1988.

The image not only retains its three dimensionality and verisimiltude to outside of the Oris horns but even through and outside the side walls which are quite near the Oris. It just blows my mind. The image has good depth and height and precise localization of voices or instruments is at least pretty good.

I never had any idea how well my horns could image before the DEQX. Those who have never tried it or a similar digital crossover, phase, time, frequency response, room correction processor might be very surprised to find out how well their speakers can image. I sure was.

Since this is a response to a question about amplifiers and imaging I'll mention that I use a pair of Cary Audio Design 2A3 SET monoblocks (5 watts/ch.) on the 112dB/W/m sensitive AER drivers in the Oris horns and a highly modified New York Audio Laboratories Moscode 600 tube/ss hybrid amps (300 watts/ch.) on the 104dB/W/m sensitive Klipsch bass corner horns. My patch cords and speaker wire are mostly DIY of my own design."

This post, the RMAF installers responses, etc. may be perused beginning at: http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=82193&highlight=Don+Reid+and+DE...

The DEQX features 32-bit, floating-point, 240-MFLOPS sustained processing with dual SHARC DSPs and has 96/192kHz generation 24-bit ADC (2 channel) /DAC (6 channel) converters. A digital signal input directly into the DEQX from a good quality disc player with no down conversion needed and then manipulated as desired before being converted to analog and input directly into the power amplifier (or even taking a digital output from the DEQX directly into a digital amplifier) for each driver with no fallible coils or capacitors intervening in the signal between amp and driver is superior to the analog alternative. Remember the best sounding capacitor of all is no capacitor at all. I do not have the physics and psychoacoustic sophistication to understand all the technical specifics involved, but at the time I originally calibrated the DEQX to function with the Oris 150s and Klipsch bass horns I had remarkably good hearing as tested by a professional audiooligist and over forty years of very careful listening as an audiophile and musical performer (piano, saxophones, oboe and kazoo) and over thirty years experience building loudspeakers, usually of my own design.

Unless you listen only to LPs and analog tapes you obviously have some fondness for digital audio. Why, if you find 1s and 0s capable of storing and recreating a musically satisfying sound, is it such a stretch to think that with the use of a PC, a good calibrated microphone, a good set of ears and thoughtful listening and diligent effort that a digital signal could could not be crossed over, phase and time corrected, etc. without the sort of degradation you describe being the inevitable result.

Dear Stephan (aka: madprofessor), I don't know what sort of pulse response the DEQX has, but I have e-mailed an inquiry to the manufacturer. I will apprise you of any response.

Bye Y'all,
Don Reid

P.S. I hope the forum members have an appreciation of self deprecatory humor.

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