digital eq/room correction trade-offs

If you listen to CD, digital is a given, as is the processing of same prior to conversion to analog. Digital equalization degrades nothing and is of considerable benefit in adapting speakers to a specific environment. The straight wire with gain folks had the upper hand as long as equalization was done in analog, but this doctrine no longer makes any sense for CD. For a real improvement, get a digital preamp and skip an analog stage instead.

I think you're hearing so much about it right now mainly because there are a TON of new products out in the past few years, and this is a result of some new directions in the OEM (chip-level) DSP products. It used to be that fast DSPs in general were all Harvard-model processors with fairly limited memory, so the code written for them had to be clean and concise, and thus it wasn't easy to quickly configure them for different processing arrangements. Nowadays, there are many Von Neumann-model DSPs available, with much more memory, which makes it MUCH easier to write the code . . . and many of the IC manufacturers have developed "modular" programming environments with huge chunks of common applications pre-written.

So for end-user applications, especially in professional sound, there are likewise tons of multi-configurable products that are replacing dedicated boxes. For i.e. a typical simple church sound-reinforcement application, instead of an analog mixer, analog equalizer, analog (active) crossover, and analog peak-limiter(s), you can buy a product like a dbx "Driverack", Ashly "Protea", Rane "RPM-88", etc. that do it all in the digital domain in a single box, all configured however you want it, via a PC. And this is (in general) better, cheaper, and more flexible.

The consequent of this is that if you don't know how to properly tune a system with all the analog stuff . . . suddenly finding the digital equivalents with far more virtual "knobs" to tweek isn't going to make things any better. Some of the consumer products try to get around this by automating the process . . . but IMO very, very few of these approaches hold any promise.

In general, if you get past the whole "it's better because it's new because it's digital!" thing . . . it's all just signal processing. Digital and analog products are somewhat different tools, but the thing that makes it good or bad ALWAYS comes down to the quality of the tool, the skill of the person using it, and its suitability for the intended application.

Thanks Kirkus and Samujohn. I agree that it's all signal processing and it's all how well you can use the tool. I guess my thinking is that these systems are supposed to self-configure, but my understanding is that they don't do that very well. So you end up tweaking them. And even with lots of experience running mixing boards in live sound situations, I'm not convinced that I wouldn't just be winging it with these new systems. Not to mention the problems introduced with additional jitter as the signal gets switched back and forth from digital to analog to digital to analog.

To Samujohn's point -- I get the idea of elimminating an analog stage and going with a digital pre, but that's going pretty far out on a limb before I even know what the technology can do, and given how many more options there are for nice analog pre's versus the handful of digital ones. The answer is probably a home audition of one of these systems to see how it works for me...

If you can get a home audition--hearing for yourself in your system is always the best way to decide. Every room and system (and listener) responds differently and priorities differ.

My experience with digital room correction (RCS) has been very positive. A friend brought over a Tact preamp and we set it up and it was as if a blanket had been removed from the speakers. I also though I had a good room, but measurements (especially in the bass) showed otherwise. My speakers have changed twice since then, but the RCS remains (Tact 2.2x and two 2150s).

Main benefits are in frequency response. The bass humps and suckouts that most of us have learned to live with are gone, which creates a subjective experience of opening up the mids. And time alignment helps add clarity, depth and realism to the soundstage. The only trade-off is a slight lack of warmth and bloom. These are very slight IMO, and insignificant compared to the advantages.

A year ago I thought maybe I was missing something with the likely recent advances in digital conversion, so I bought a $5K tube DAC and $4K amp to substitute for the Tact amp. Yes it was slightly more liquid, but less open and detailed so they were quickly sold (actually, I kept the amp for another system). There is a wonderful advantage to keeping the signal digital all the way to the speaker.

If analog or SACD is your main thing, the trade-offs with RCS might not be worth it -- hard to say. For me it wasn't and I sold my SACD, as my CD with RCS sounded about as good overall as SACD without. Depends on your room and listening preferences.

The presets are quite good by themselves, but heck, we're audiophiles and we like to tweak. I've tweaked my correction curves to fit my listening priorities, and also to have alternate options for different recordings (ie, some have too much bass for my taste, etc.) I've also got power supply, etc. mods to the preamp and amp which further increase the fidelity and minimize the digital conversion artifacts, but I could have happily lived without these.

In the end, different strokes for different folks -- but try to experience it in your system. You may be surprised. Products from Tact and Lyngdorf and Behold, etc. have really upped the ante.