SVS AS-EQ1 Thoughts... - Page 3

you could use a laptop with line-in and TrueRTA, hook it up to the outputs labeled THRU on the SMS and capture the original input that the SMS is seeing...so that you don't have to rely on the OSD.

Sure. In fact, I've done that and also used ETF to look at the effect of the SMS-1 PEQ on decay times. But then, you've paid for the OSD of the SMS-1 already........

That said, I like to see more information detail even though, in general, the SMS-1 display is good enough for the task. Higher Q nulls/peaks are probably not worth trying to correct unless one has time domain info to assist.

Well then you know that when you first ran the auto function in the SMS-1 it produced a better FR but it also did unwanted things such as boosting nulls excessively because the program was following a predetermined set of rules as it ran its sweeps, measured and adjusted amplitude. It took your own tweaking to lower the bars and shift the filters to where they were needed most based on your analysis of the visual data. You likely applied your own sense of what Q was necessary or ran RoomEq to compute it for you. Your manual adjustment process though it followed the same process as the auto program, involved a level of sophistication and adaptation that no program can match and in this case we are only talking about the frequency domain.

Now lets look at the Audessey MultiEQ which reportedly uses fuzzy logic to not only adapt as you did with the manual settings but proposes to also do it simultaneously in the time domain across several seats. Keep in mind that fuzzy logic also uses a set of someone else's rules to solve problems which you may not want solved. Its chic today to say that fuzzy logic can substitute for human decisionmaking and simplify control processes like we are doing when we try to optimize FR and time delay issues. If you consider the scale of the problem of dealing with directed and reflected long wavelength in a closed room with a sub which will likely have some group delay, I fail to grasp how someone's simplified rules in a fuzzy logic based algorithm will optimise my acoustical problems in space and time.

" MultEQ uses Finite Impulse Response (FIR) filters for equalization that use several hundred coefficients to achieve much higher resolution in the frequency domain than parametric bands. Furthermore, by their nature, FIR filters simultaneously provide correction in the frequency and time domains. FIR filters had been considered to require too many computational resources. But Audyssey solved this problem by using a special frequency scale that allocates more power to the lower frequencies where it is needed the most."

So rather than rely on the required computational power which is not available in the device, and in any event cannot approximate your adaptive response to the measurements, it uses a "special" frequency scale. Its no surprise why the Denons that I have seen have made a hash of low level equalization in the two rooms I investigated. How can a special scale with a predetermined set of rules adapt to everyone's unique acoustics? The only light I see in this long narrow tunnel is that the marketing sheet makes reference to using the device in conjuction with a personal computer. I hope what that is referring to is using the computers processor to augment the chip in the AS-EQ1 for an exponentially larger number of iterations. Based on my experience the Audessey in the Denons and what has been described in the marketing literature , I do not see anything in the materials which would lead me to believe it can outperform your manual tweaking without a huge boost in computations.

The more I dig into this the more I appreciate Uli Behringer.

I'd like to see Balanced XLR connections (or TRS 1/4" balanced at least) on the SVS unit...or the Audyssey unit. Every piece of gear we have in our demo system is XLR balanced.

Understood and I sincerely hope that goal is attained but bass frequencies and wavelengths pose a more formidable challenge which requires more than chic fuzzy logic and inadequate processing power. The auto funtion should help in some rooms but not in all. Moreover in the rooms where it is helpful it will require manual tweaking to optimize the results. Hopefully, there will be more user control than in the AVR implementations.

How can predetermined algorithms do better than a skilled and adaptive user? Depends on the skill of the user.

This problem splits into at least two limbs. More sophisticated users, including professionals, will get excellent results with analysis/EQ tools implemented with skill and patience. Most users, however, are not interested in and/or capable of the informed iterative and interactive process, even with the SMS-1. For them, the imperfect but fairly effective Audyssey processes are advantageous, especially if they resist doing anything about physical room acoustics.

The quality of the results I got with the Audyssey SEQ were superior to what I got with the Denon 4806. In fact, I believe that a careful user will get better results with the Audyssey Pro (in a PC) than will most so-called trained installers who will usually have one eye on the clock and who will not tweak it over the span of days. Of course, there's no substitute for care, intelligence and knowledge, regardless of the approach.

If you look at the graph on the second page of the SVS flyer (uncorrected/corrected) it appears that MultiEq does not try to boost nulls, but instead lowers everything to the level of the dip. I wonder what it would do with a very nasty null. I know this is only a marketing tool, but it is worth asking about.

John, you keep referring to inadequate processing power. How are you coming to that conclusion about the Audyssey? With todays imbedded processors, you can build significant horsepower into an relatively inexpensive appliance. If the application is written in low-level machine code, you can get good performance out of a less than stellar CPU. I'm not saying you aren't correct, I just haven't seen anything that indicates what kind level of processing power is in this.

True, they should either include video output capability or include a version of the Pro kit.

The price of the boost is the loss of overall gain. Trade-off. Others have mentioned this.


This is a real limitation since, regardless of the low-cost of such hardware, the processing power in consumer receivers is defined by the DSP devices chosen and the other tasks they must perform. Audyssey designers have commented often on the constraints imposed by them. While the stand-alone SEQ has much more processing power for EQ than there is in the AVR versions, they still off load the calculations to a PC that is better suited for it.


Sure but there's not much interactive capability anyway.

Hi Randy. To elaborate further Audessey makes use of "Finite Impulse Response (FIR) filters for equalization that use several hundred coefficients to achieve much higher resolution in the frequency domain than parametric bands. " So far so good because this approach theoretically provides more resolution by calculating hundreds of data points on the measured FR curve and applying them to create digital filters. The equalization filters used by Audessey require solving complex differential equations in the space and time domains in an algorithm that models a "finite impulse response" based on those calculated data points. I am just glossing over the complexity of the calculations and the model employed since not all details are contained in the description, but one can see by virtue of this approach how computational intensive it has to be to solve many iterative simultaneous equations in two domains.

To do this right you need a hell of a lot of processing power which is not practical currently or in the box presented. So Audessey uses several compromises to get around this formidable problem through pre-determined rules, a "special frequency scale" and (I'm speculating now) a set of assumed co-efficients in the model rather than have them algorithmically derived.

That's why using a powerful outside home computer with it will likely make this a formidable equalization technology but on its own with limited processing like you find in an AVR or this box ...limited less optimal results. Its actually a very good concept but it needs much more powerful chips to achieve what it is claiming in an auto-program . Hence why I suggest a tweaker with time and patience will get better results and why the best thing for now in the absence of the processing power should be more user control . But auto-programs aren't about user control are they?

It will be interesting to see if they allow the device to connect and rely on another computer to do more advanced processing. That's probably asking too much for the $750 suggest price.

If the Audyssey "Pro" label is on it, it will connect to the external PC. In fact, many current AVRs are now being upgraded to the Pro capability to off-load the calculation of the filters.

Thanks for that. The previous post had me spooked!

Re processing power, Audyssey in a receiver is handling 10 oct X 5 ch (or is it 7) = 50 oct, whereas if the AS-EQ1 is handling 80 to 10 Hz, that's 3 oct x 2 ch = 6 octaves.

So it seems like it ought to be able to do a pretty good job.

Does anyone have a feel for how much memory it takes to store a set of EQ parameters?

Maybe it's a lot more for Audyssey w/its time domain correction than other brands'; even the standalone unit doesn't store more than one setup, whereas Pioneer and the new HK's do (don't know about Yamaha).

SVS has done more than any other company I know of to both inform and educate customers on the necessity of 'setting up a room' for bass, a task for which AutoEQ is not designed.

How will a customer use auto-eq to determine null positions for seating?
How will a customer use auto-eq to determine optimum driver locations?
How will a customer document their systems performance?
How will a customer determine the best placement for room treatments?
And my favorite:
How will a customer document the performance of their AutoEQ system?

Why, by using manual equipment of course!

How will a customer suddenly gain the skill to use measuring equipment properly and the knowledge to analyze the results correctly?

Sanjay

By reading?

Reading what?

Sanjay

The problem with where you are going, Sanjay, is that the in-room physics will occur regardless of whether the customer wants to read about it or not.

If, for example, Yamaha were to include frequency sweeps and an RTA display in their DSP, do you think a customer would be unable to point and click PEQ's into place? Such a manual method would also allow the customer to address the questions I raised...
as would Audyssey providing similar functionality.

The AS-EQ1 will feature a version of the Audyssey "pro" software, which has considerably more computational power in the bass regions than the consumer version used in AVRs. There will simply be a cut-off (which does not hamper performance in any other respect) which prevents it from being used as a full-range EQ solution.

While it has the ability to connect to a PC (for a GUI, etc,) there is no additional computing power derived from same - it can do everything just as well with the face plate controls.

This is being marketed as a simple to use, highly-powerful auto-EQ for a single or dual subwoofer system. Market research indicates our intended buyer demographic does not want to spend hours manually tweaking in order to optimize the FR; they want a "plug-n-play" solution.

Also, do not confuse in-room modal ringing due to standing waves, peaks in the response, and a lack of bass traps/treatments with the FIR filter technology uses in Audyssey's latest Adaptive Low Frequency Correction Technology (ALFC) software. IIR filters can cause ringing in the time domain, and FIR filters do not. It would be more accurate to state the Audyssey ALFC system doesn't create problems in the time domain by virtue of its operation, unlike a conventional IIR-based PEQ.

Ed,

"The AS-EQ1 will feature a version of the Audyssey "pro" software"

That's great! (FYI, the picture of the unit on your site says "MultEQ XT" right on the front panel)

Is it as effective in the bass as the Audyssey standalone unit?

"Market research indicates our intended buyer demographic does not want to spend hours manually tweaking in order to optimize the FR; they want a "plug-n-play" solution."

Does this means it comes with a mike and the purchaser can do their own setup?

Does it have memories for more than one EQ setup? I listen to audio in a different seat than I watch video.

Any estimate of when it will be available?

Thanks

You still haven't explained how the typical SVS customer will suddenly gain the knowledge and skills, not to mention the actual measuring equipment, needed to do the manual adjustments you are suggesting. It's easy to be smug when dismissing automatic EQ systems ("Why, by using manual equipment of course!"), but you're being rather vague when it comes to suggesting a viable alternative that the typical SVS customer will want to use.

There's no argument that in-room physics will occur, whether the customer wants to read about it or not. So, as an alternative to the AS-EQ1, what reading list and "manual equipment" would you recommend to deal with in-room physics? How long do you think it will it take the average SVS customer to learn low frequency acoustic theory AND become profecient in using the manual equipment?

Many new receivers come with automatic calibration (not EQ) systems that set up speaker levels and distances using a supplied microphone. For the vast majority of the receivers sold, the alternative to auto-cal wasn't manual calibration with a SPL meter and tape measure; the alternative was no calibration at all.

The Audyssey unit won't keep moving your subs around until it finds the optimal placement in the room. No one ever claimed it would. But once your subs are placed (whether based on acoustics or convenience or decor), the AS-EQ1 can address low frequency problems and help improve the sound. For the majority of SVS customers, the alternative isn't manual measurement and manually setting filters on a PEQ; the alternative is no EQ at all.

Sanjay

In my review of the JL f113, I suggested (with tongue in cheek) that someone marry a measurement system with a RoomBa so that the system could find the room position for best response all by itself.

I guess it could simultaneously clean the listening room. That would send WAF off the scale.

Sanjay

Hi Noah:

Yes I know about the graphic on the front panel - it's a functional prototype and final graphics are subject to change. Probably the most accurate way to describe this unit is that the algorithms and DSPs are proprietary to this application and the ALFC hardware/software is definitely more powerful than the full range consumer version you see in AVRs, and it's the latest and most effective subwoofer correction technology currently offered by Audyssey.

Per the cut sheet on the SVS website:

"It applies frequency and time domain correction and has the capability to individually delay each subwoofer for better blending with the main channels. It can do this for a maximum of 8 positions to cover a wide listening area. Basic configuration can be performed from the front panel. More advanced setup can be achieved by running the system's calibration application on any PC. A dedicated microphone is included to ensure optimum results."

Expected release date is 2nd half of 2007 - sorry I can't be more definitive.

Ed

Sounds like a winner, thanks ED (and my bad for not reading more carwefully).

Oh, what about memories?

Is there a release date on this yet?

Wow, I could have just read 2 threads up. Dropped the ball on that one.

I just wanted to bring this topic back up to the pile. I really hope SVS might release this earlier than expected as the AS-EQ1 sounds like a winner.

Has anyone heard any news? I too heard 2Q07 3 or 4 months ago.

Chris

Onkyo 905 and Denon 4308ci have MultiEQ XT which is supposed to be same as SVS ASEQ1. I am going to get 905, so do I need to spend $ to get additional SVS ASEQ1?

Cannot be the same. The SVS is a bass-only EQ which, it is likely, will use all the DSP filtering in that range. The other MultEQ xt units are full range with filters across the audible range.