I don't have any pictures online but basically the room was built as a dedicated theatre, and is about 21' x 30' with an arched ceiling. The power amps for the main LCR speakers is all vacuum tube. The front left and right speakers are bi-amplified (apart from the sub woofer path) with a 1,200Hz crossover. The frequencies above 1,200 Hz are amplified by a single-ended triode power amp. The subwoofers and surrounds are powered by solid state power amps. There are four surround speakers, left and right side, and left and right back for Dolby EX. Currently I'm using the Smart "circle surround" EX extractor box for the back surrounds. There are four 18 inch subs, two per side, in stereo. These are next to the front left and right speakers. The screen is 10 feet wide in a 16:9 aspect ratio. The projector is a Sony LCD 16:9 native unit. The whole system has two signal paths: a "home theatre" path which takes it's signal from my (currently) Sony EP9ES 5.1 processor, and another path taken from my mixing console which in turn is fed from a ProTools 24 bit digital audio workstation, along with sundry outboard processors, analong tape decks, DAT deck etc.

Any analog crossover introduces phase shift at the crossover point, whereas doing it digitally *can* be done without any phase shift. The actual "at-the-ear-in-the-real-world" sound of analog is *generally* more pleasing than doing it digitally. Every time you use an analog "tone control" on a preamp, or every analog equalizer on a mixing console introduces phase shift, but to the ear, the effect is more pleasing than a digital equalizer or filter. I realize this is a controversal issue, but all I can do is point to the overwhelming popularity of analog outboard equalizers in use in recording studios, which to most ears sound more natural than digital equalizers.

I have heard phase shifts (which can't be avoided with a passive analog crossover) can be pleasing to the ear, but most people tell me accurate phase makes for more accurate sound reproduction.


[This message has been edited by Will (edited August 14, 2002).]

Are these the same people who just happen to have a digital crossover they want to sell you? (-:
Seriously, it comes down to application. Sometimes, such as in a recording studio where you want a vocalist "to sound really good", an analog unit is reached for, even one that uses *really* old technology such as inductors and capacitors. In speaker crossovers, the phase shift is generally agreed to be a bad thing in a passive crossover. In a signal path that is meant to be as transparent as possible, digital is the way to go. In a home theatre setup, I personally would rather have the more warm sound of an analog crossover, if for no other reason than to counteract the harshness of almost all film sound, which is almost universally done with a completely *digital* signal path!

I'm not sure adding a phase shift in the low frequencies where a subwoofer crossover occurs (with an analog crossover) counteracts harshness in the higher frequencies where harshness generally occurs.

The sound studios can tweak the sound using filters (and reverb etc). But I want to play back what the studios put on the recording, without adding filters (or reverb etc) in my listening room. But to each their own.


[This message has been edited by Will (edited August 14, 2002).]

Adding phase shift in the low frequencies would do nothing for the highs, as you said. But dubbing stage speaker systems have analog active electronic crossover networks, analog 1/3rd octave equalization, and use horns for the high frequencies. The mixing engineers hear the sound through this system and mix accordingly.

[This message has been edited by soundhound (edited August 14, 2002).]

I personally don't know how a phase shift could ever be a good thing.

Basically, any phase shift at a particular frequency or range of freqs involved with a crossover between two drivers, would result in a decrease of output for the freq involved. Bingo, no more flat frequency response where the phase shift has occurred.

Now, *usually* crossovers are used at lower frequencies, 60 - 120 Hz or so. Digitally, that is a piece of cake, due to the typically high sampling rates involved (compared to the crossover freq).

I would always prefer it be done in the analog domain too, simply because of the "continuity" (digitally, no matter how high a sample rate is still discrete), but at these frequencies, I doubt *anyone* could tell the difference.

I plotted frequency response of my system a bunch of times once. Every Hz from 98 to 20 Hz. Crossover set to 80 Hz. Really interesting in that I could get the sub in phase with my mains at *either* 60 to 90 Hz, or 20 to 30 Hz. Chose the higher simply because there is more content there. (Obviously a phase shift between the 2 somewhere.) Phase in a HT is a really interesting thing that most people don't fully understand.


[This message has been edited by Kevin C Brown (edited August 15, 2002).]

Kevin, I agree with most of your points.

The processing steps needed for full 5.1 or 7.1 bass management have less loss of information when done in the digital domain than in the analog domain. There's more than just crossovers to consider. There's summing multiple channels (to, for example, the sub), time delays, etc. These things are done more accurately digitally than the old days where analog adders did sums, and analog bucket brigades did delays.


[This message has been edited by Will (edited August 15, 2002).]

Dear Outlaws:

As we have often stated, all of the Outlaws read all of the posts in this Forum, but we also refrain from interfering with the flow of the threads so that the discussion in not tilted in one direction or other by us. However, some of the recent posts have brought up a subject that I felt merits my personal intervention.

Some of you have complained that the August Update was a bit light on new information. We realize that, but given the promise to release something (a commitment that many of you were taking us to task on) we wanted to at least issue some statement. Laugh if you will, but we said that an Update would go out before the end of the week of the 5th, and it did. (In typical Outlaw time!)

That having been said, I’d like to provide some additional thoughts given the current discussions
As a member of the Outlaw team I am privy to the day-to-day flow of data between our engineering teams in Taiwan, California and New England, as well as the factory in Maylasia. I am confident that we are extremely close to resolution to the issues that have impacted the Model 950, but if we were to release daily updates it will only confuse matters and create more, not less frustrated customers.

To sum up: the discussions that I have been involved with in the last 96 hours since the Update was released -- indicate that we are really close. We have a plan ready to activate, and once we get the word from the factory, we will start to get the corrected Model 950s in your hands very quickly. I believe it, and the rest of the Outlaw's believe it. As a matter of fact, one of the Outlaws never went to bed last night as he dealt with engineering and production teams in Taiwan and Malaysia to nail down a “pesky” technical issue. (He stumbled into his day job this morning, only to pick up where he left off at 5:00 AM this morning!)

Bottom line: Nothing is more important to all of us than to get the 950 going again and we literally are working around the clock on it. However, we will do it right and that unfortunately takes time.

A final note: Those of you, who have come to know me over the last couple of years, know that I am dedicated to providing the quickest most accurate answers and service possible. It has never been my, or any other Outlaw's, intent to provide less than this. I was Outlaw’s first full time employee. I was excited to join the company then and am even more excited today about our future plans.

Sincerely,

Scott Jackson

The phase shift of an analog crossover most certainly isn't a good thing, but it's something that's taken into consideration in speaker designs for instance. If you have satellites speakers with a woofer and tweeter, you almost certainly have a good old analog passive crossover in there. The designer of the speaker takes the phase shifts into consideration in the design of the speaker, to yield the best results. My original point was just that the best tool for the job should be used, be it analog or digital. One factor in including digital filters in preamp/processors etc is that they are *cheap*. Aside from the software design, there is no parts count involved, really. There can still be good and bad implementations of a digital filter; it's up to the skill of the software engineer.