Gonk,
I may not have found all the resources that you know of. Could you list a few regarding what to do in the analog realm?

As I have said, the main thing I am worried about is that, since the output level varies with the volume control, rather than staying at a fixed level, the equalizer will be operating over a very wide range of signal levels. To me, this sounds like it will introduce noise, and therefore might be an inappropriate application. So, I have two questions about analog:

1. Without divulging any trade secrets, would it be possible for me to (voiding my warranty, of course) tap into an analog signal before the volume control? For this to work, I assume the path would be 7.1 analog to the volume control and then directly to the output jacks.

2. If I had the volume control maxed, is there a musical, balanced and affordable 7.1 infrared controllable volume control that you know of?

The digital solution is interesting, but certainly not possible with the current model. HDMI would be cool, but there would certainly be DRM issues complicating matters. FireWire would be good too, after you paid your royalties to Apple.

The professional stuff from Beheringer and others uses AES/EBU for digital, but I don't know much about it. I think it is only two channels. The voltage levels are different. The connector is bulky, but a high density connector with a conversion cable would do the trick.

Equalization seems to be the only major piece missing from the 990. It would make much more sense to integrate the capability than provide a connection for outside processing. It would be a heck of a selling point to have the features I need for the Behringer incorporated. It has a 1/3 octave graphic equalizer, plus 10 parametric channels. It has a real time analyzer and pink noise generator to automatically or manually EQ the room.

I would certainly pay twice the price for the 990EQ.

As for resources, Behringer's feedback destroyer (BFD) has been a favorite among subwoofer tweakers for years now - I never investigated them closely, but have seen numerous discussions of them in places such as HTF. One recommendation is the BFD Guide site (formerly called Snapbug, since that was the old domain name), which some consider the definitive source for BFD information.

Finding a way to tap the analog signal internally, pull it out to process it externally, and then plug it back in would be a pretty major undertaking - I suspect that Outlaw would be leery in the extreme about coughing up information like that. It would probably qualify as a case of "if you can figure it out without asking and don't care about the warranty go for it, but otherwise forget it." As for the IR-controlled 7.1 analog volume control, I have no idea. Folks have suggested that Outlaw (or somebody) build a purely analog surround processor on occasion - mostly as discussions of ways to improve the ICBM, such as adding multiple inputs and/or volume control so it could act as a 7.1 switcher or even a 7.1 analog pre-amp - but I don't think anything has really appeared on the market.

I don't see why you are so worried about having your EQ after the volume control and before the amps. Every speaker (except the LFE) in my system is run this way (ie. each speaker has a dedicated 10 band parametric equalizer associated with it) and that alone introduces no added noise, problems, or distortion that wouldn't have been present using a fixed line level. Seems to me that mucking about by splicing into a circuit somewhere is inherently more problem -prone. Or maybe I missed the point of the originl post?

Jeff Mackwood

Jeff,
You are absolutely right that messing with the 990 could be a bad idea. It wouldn't do my warranty any good either.

My concern is that I am asking the equalizer to cover a very wide dynamic range by asking it to handle the range of the source material plus the range of the volume control. The equalizer is 24 bit, which is about as good as it gets. I just think that the chance of introducing artifacts would be decreased when doing an analog/digital/analog transformation if I was only dealing with the dynamic range of the source material.

I haven't even hooked up the equalizers yet, so maybe the best thing to do is just listen. I do tend to get too wrapped up in theory.

Thanks to you and Gonk for your valued input.

For subwoofers, I've never seen mention of anyone having trouble with using the unit downstream of the volume control - it's the standard location for a BFD among sub tweakers. For your full range speakers (which I'm not as used to seeing fed through an EQ like this), the best bet is to let your ears be the judge. I saw a mention on the BFD Guide site to a bypass button on the Behringers - that would be an excellent way to test the influence of the unit on the signal path.

Oh, anybody else notice the newsletter ? You know, the one that Scott just posted that announced this goodie ?

I just purchased a SMS-1 from another vendor, and it is awesome. It is one of the best additions to my home theater yet. I would recommend it to anyone, especially those like me with limited room placement options.

So do we think that this means there will not be some room eq functionality added to the 990???

Personally I can not afford a 990 and a SMS-1.


Regards,


Charlie

It seems unlikely that the company would offer the SMS for sale and then "cannibalize" sales by adding similar functionality to the 990. If the SMS works as advertised, it sounds like a nifty little box. I'll have to consider checking one out for my dual LFM-1 setup.

Cheers,

.

I largely agree with and affirm the points made and conclusions reached by Wayne.

The only exception I will respectfully take is that I believe a single test position is not sufficient for subwoofer signal modification. While the lower frequencies do not provide perceived directional cues to the listener, bass frequency ‘standing waves’ in a room with mild, moderate, or strong resonances make reliance on a single test point a poor choice.

Let’s say that a given room has a large resonance response at 48Hz. There are still places in the room where, by moving about with one ear covered, one ear open, or with an SPL meter, 48Hz is perhaps 10dB over the average and other places where 48Hz is 10dB under the average. Unless the measurement microphone is placed in a position where 48Hz is at an average, the adjustment for 48Hz will be off. But then if the measurement microphone is in an average position for 48Hz, it doesn’t mean it is at an average position for all other subwoofer frequencies. Granted, there are test signals that are better to use than sustained sine waves, but normal source material will have some frequencies sustained for long enough periods to result in standing waves and resonance in the room, so it is good to 'observe,' among other tests, what happens when standing waves are present.

It is not realistic for me or anyone to expect a flat and properly time-aligned response everywhere in the room no matter what forms of analysis and correction are applied. While this would be ideal, I cannot afford the pursuit of that goal to the nth degree of what is actually possible. But short of that nth degree, I can still measure and take note of differing response in different areas of the listening environment and make reasonable adjustments to: the signal (including internal EQ or external devices like the SMS-1, if present), the placement of transducers and room treatments. Personally, I would never rely on a single, or even just a handful, of measurement points if I want the best overall experience for all listeners present.

If the signal modifying equipment allows for several presets, one could have a saved setting for the ‘sweet spot,’ another for an ‘alternate sweet spot,’ another averaged for ‘small group near the sweet spot,’ and yet another for ‘best average for a large group.’

Enjoy finding what works for you!