SVS AS-EQ1 Thoughts... - Page 2

It's always possible to make something better, but in this case I don't know whether the benefit would be noticeable. At least in my situation, where the multiple seating feature is not a factor.

The SMS-1 is a terrific device, and it made a tremendous improvement in my 16-46 PC-Plus based setup. My only disappointment is that the infrasonic filter is not defeatable. Seems like an odd choice, given that potential buyers are almost certain to have subs that already have their own infrasonic filters. I can't even update to the 5Hz software, because it requires a PC with an RS-232 port and I have neither.

Other than that, it exceeded my most hopeful expectations.

Still, competition is a good thing, so I welcome SVS's entry even though I'm not about to give up my SMS-1.

You MUST know someone that has an old laptop laying around that has an RS232 port on it.

You can also buy RS232 cards for next to nothing. (<$10)

I would be getting that update... especially with a 16-46.

-Eli

Actually, I don't. (At least, not well enough to inquire.) I'm surrounded by Mac lovers like myself.

I'm thinking about shipping it back to Velodyne so they can update it, but I'm so addicted, I hate to give it up for a couple of weeks. Eventually, I'll bite the bullet, I suppose.

In the meantime, I've managed to tweak it to largely offset the infrasonic filter, at least above 15Hz.

IMHO, i think in most rooms the rolloff of the SMS-1 isn't even an issue, since there should be plenty of room gain down low. Not to mention that most of the other electronics start rolling off around 5-8hz or so...My IB is flat to 15hz and that covers the vast majority of movies that I watch, and I am more than satisfied with the response.

As far as the finer resolution that some of the newer EQ's might offer, I can't help but think that all that is wasted in most rooms where a small change in any direction of the mic can make a big difference in the response.

Sure, there are peeps that will benefit from 1/24 octave resolution and a lower HPF, but I would think it's going to be a pretty small number and in most cases the BFD, PE17, or SMS would work just as well.

I wouldn't mind checking out the SVS eq, but I certainly don't think an extra few hz is going to justify that extra expense when I could easily double my IB for that price.

I always keep one of these laying around for some of my legacy devices...

http://www.ramelectronics.net/html/usb_serial.htm

it's worth the price of admission.

The one thing about the new Audessey that has piqued my interest is whether its multi-seating equalization will make much difference. I've taken multiple seat measurements and tried inputting blended settings into an SMS-1, a BFD, and a DEQ2496. For all the time and effort I didn't think the blended response made any difference compared to taking one measurement in the middle of the seats. I have to qualify this statment because I run multiple subs so FR will be more uniform anyway. Of those three I favour the SMS-1 for ease of use and performance.

Yes, I was thinking of trying one of those, although Velodyne expressed doubts that it would work. I'll probably give one a try before I pack my SMS-1 off for an upgrade, though.

check your local computer store (BB, CC, CU, etc) and you can always return it if it doesn't work.

Yes, that was my experience, too, although my serious listening area is confined to one small couch.

The difference between the "best" and "worst" reading there is ~+/- 1dB, not audible under most circumstances. That may or may not be unique to my room though. I don't know.

Or even if it does, considering it's a one time use!

( Joke. I wouldn't cheat the store like that if the converter did the job, so no one should get upset.)

I'm sceptical there is an audible difference. People who tried Velo's multi measurement mic setup said much the same thing. I guess Audessey needed something to try to differentiate this unit. But with no display, I don't think it can compete with the practicality of the SMS-1. That's the main reason my DEQ 2496 stays in the box.

Yes, unless one prefers to just let the automation do the job, the display seems essential to me. But I like to tweak manually.

I had an ART 351 connected to a second sub in my room. I spent hours smoothing out response as well as I could with an RS meter and test tone disk. 5 minutes with the SMS-1 display, and I made very significant improvements to my previous settings. Adding in the SMS-1 adjustment got the whole two sub setup ruler flat across the entire display range. The only ripples are in the top 1/3 octave, outside the SMS-1's operating range.

Music is tighter than I could have imagined possible, and movies have punch they never had before.

Yes, I gotta' admit the display features of the popular SMS-1, especially the immediate visual representation of levels & ranges, are not only practical but most desirable & quite addicting once you have experience it. A picture is truly worth a thousand words and it is all too easy to get spoiled by that feature.

Having said that, the upcoming AS-EQ1 sounds very intriguing. Although the primary focus of the AS-EQ1 & SMS-1 may be somewhat different, I look forward to seeing how they stacks up against each other in terms of their auto setup vs manual tweaking features, practicality & ease of use aspects, and most importantly their real-world SQ/frequency curves/integration end results.

I am guessing the SMS-1 is about 2 years old. The price reflects the fact that it includes a microphone and a measurement system with its own OSD. The unit operates in an auto mode as well as a very sophisticated manual mode. The only improvment I would like is an option for a higher resolution display of the measurement data.

The Pro software is no more, nor any less, automatic than the XT. The additional features are the off-loading of the calculations to the PC and, depending on the hardware, the ability to take more measurements and implement more filters.

There are serial-to-USB adapters.

It all depends on HOW you combine the measurements, according to Audyssey.

True, but Velodyne isn't sure they'll work. According to my computer engineer daughter, it depends on how the software was written. I intend to give it a try, though.

Of course, that applies to just about all things audio doesn't it? Regardless of how they write their algorithm Audessey is making assumptions regard how much deviation in FR they want and likely rerunning sweeps as it effects the compromises. If you go through the long manual process of measuring across the seats and tweaking settings it amounts to much the same thing. Velodyne's addon 5 mic device for the SMS-1 is another similar solution. Its not the rocket science being suggested by Audessey/SVS.

I would use caution here. I fried an SSP while attempting to upgrade by using the "wrong" type of serial cable. I have heard that the USB to Serial adaptors work, but I managed to find an old laptop with a serial port and used the recommended Serial "Mouse Extension" cable to upgrade a DD-18 with no issues.

Part of the answer is in the AS-EQ1 tearsheet, where it mentions measuring in the time domain (how long a sound lasts) and not just the amplitude domain (how loud a sound is).

If you move a SPL meter from seat to seat, you'll notice that the same frequency that is too loud in the sweet spot can be just right or too soft in other seats. Using the SMS-1 to bring down that peak will make it better in the sweet spot but can make it worse elsewhere, especially if that frequency was already close to flat in another seat.

Instead of only measuring how loud the sound is in your room, as the SMS-1 does, suppose you also measured how long it takes sound to decay. And suppose it turned out that your side walls were just the right distance apart for a particular frequency to bounce back and forth much longer than adjacent frequencies.

That lingering frequency could mask other sounds that immediately follow, not only giving your subwoofers a one-noted sound but also obscuring detail and articulation at all frequencies. Since the sound is bouncing back and forth between the walls, any seat between those walls will hear the problem. As you would expect, if you move a SPL meter around, you'll find the ringing frequency will vary in loudness from seat to seat. But that means that any system that only looks for the largest peaks could miss the problem, especially if the measurement was taken from a seat where the ringing frequency wasn't very loud.

Now suppose you used the AS-EQ1 to measure in the time domain and correlate data from multiple seating locations. You could target the frequencies with the longest decay times, whether they showed up as the largest peaks or not, and then dial them down. Since the problem was audible from multiple seats, correcting it will likewise be beneficial for more than one seat. This could be one of reasons why SVS "weren't that happy" with the SMS-1 and instead looked for a solution from Audyssey.

Sanjay

Thanks for the warning. Velodyne never mentioned that possibility. And I certainly would never have thought of it.

Guess I'd be wiser to ship it back to them for an upgrade after all.

Fixing combined time domain/FR problems with electronic correction is a tricky proposition. It reminds me about the many early lofty claims made by avr manufactuerers about their auto-correction programs, audessey included. I have rarely heard one which actually set auto-equalization/delay correctly for subwoofers. The physics involved make it very difficult for an automated program with limited processing power to do well. Its actually refreshing to buy equalizers (DEQ2496) with auto-programs where the manufactuer(Behringer) specifically warns not to use such programs for frequencies less than 100hz. To date those issues are best dealt with judicious use of manual equalization, room treatments, bass traps and processor delay. Even the SMS-1 performs best with manual tweaking. I am reserving judgement but at this point without knowing more about the technology I remain sceptical.

How can it? How did you weight each reading? Were the weightings applied equally across all frequencies? Did you just average the corrections?


Right. It ain't rocket science but it is a proprietary algorithm which is not a simple average. Consequently, unless you have inside info or remarkable luck, you cannot come out with the same combined data. That's not to say that what you do is better or worse, just not the same.

I believe the simple average is your idea. Every algorithm involves propritary approaches, assumptions and iterative formulae. You miss the point in that the physics involved make a combined time/FR auto correction near impossible even with huge processing power. It is at best a compromised solution which cannot be ideal in every room. I presume it will allow for manual tweaking which may be where its real power lies.

Yeah, sure, but the point is that you cannot say, as you did, that "If you go through the long manual process of measuring across the seats and tweaking settings it amounts to much the same thing." All we have are varied imperfect approaches to a nigh insoluble task.


One hopes that the SVS system will allow more manual tweaking than the extant Audyssey implementations. At the moment, the most flexible (and most frustrating) LF EQ I've used is the MRC in the Meridian 861.

I bought one of the RS232 to USB adapters that came with a software disc to upgrade my SMS-1. Worked like a charm.

Absolutely it amounts to the same thing. If you stop and think about it, you will realize that conceptually its much the same as what Audessey or any auto program is trying to do. Sweep,Measure, Adjust, Sweep, Measure, Adjust,.. repeat as many times as you want...a long manual yet iterative process involving continuous incremental adjustments in both domains. Anyone who has used sweeps and an equalizer goes through it, the main difference is you are now having to consider more measuremnts at more locations. I've spend several idle afternoons optimizing response across six seats this way using the SMS_1 display and delay on the processor . I very much doubt an auto program could optimize the tradeoffs involved as well. But being open minded to new ideas I would pleased to be shown otherwise. However without a huge dedicated processor attached it ain't gonna happen. Maybe one day with more powerful chips but not with current technology which is why I am quite cynical about the claims.



On this we can agree.

Indeed, which is why better ones (Meridian, Lexicon) limit their scope to only addressing long decay times, that too only for frequencies below 250Hz. Neither one claim they're attempting flat bass response, instead recommending passive treatments for that.
Of course. Audyssey never said they achieved perfection in every room. The goal is to improve the sound in most situations. If the AS-EQ1 does more harm than good in your particular room, then I'm sure you'll be able to return it to SVS. But I doubt they're introducing a product that makes the sound worse for most users.

Sanjay

From a purely mathematical point of view, how you do this makes a difference. The iterative and subjective process you describe is one way. Executing a program that automatically combines data from multiple measurements based on an algorithm that objectively weighs amplitude and decay is another. I never said that one was superior, just that they are not the same nor will they generally result in the same endpoint.

I've spend many hours with the SMS-1 in several systems and, in fact, have used it to monitor the operation of other EQ systems. It's only real flaw is the limited display resolution and, in that regard, may fail to distinguish audibly different corrections.