"Official" Audyssey thread (FAQ in post #1) - Page 10

I agree completely - the "Pro" eq is exceptional. I sold my SEQ because the 9.8 will have it on board and I hope that the 9.8 has similar filters available for the program to set as the SEQ or I might be looking to get another one.


Personally I really like what it does for the bottom end - the bass resolution is incredible and having four curves to choose from, plus the option of midrange compensation, gives you some choices for the top end based on your tastes. I read that one AVSer, preferred flat in his room I preferred the Audyssey's roll-off with no midrange compensation - two rooms, two tastes, two happy campers.

There is, in fact, no greater user control with the Pro setup; it merely lets the user choose one of 4 target curves and/or a midrange compensation. There are no storage or saving or adjustment options beyond what you get in the Integra or the Denon consumer setups. Tweaking is verboten.

Audyssey does a nice job. It could be much better with little effort on their part, it's like having air conditioning but with no control over the temperature.

IMHO, it's possible that allowing user changes like folks here seem to want isn't easy to do. I'm not saying that it can't be done, just that it may not be practical. Stay with me here for a moment. Audyssey's goal is to make every seating position in an HT sound the same, right? To do this, they use calculations that operate on data gathered during the setup routine. Fuzzy logic is applied to group the measurements according to certain parameters, then filters are calculated to produce the different built-in curves. Yada, yada, yada. Now, changing those curves on the fly could be a lot more daunting than we assume them to be in terms of both the math and the hardware involved. For instance, it might require entirely different fuzzy logic or calculations for the filters depending on what frequencies were boosted or cut, because of changes in phase, etc. Audyssey has done the math to find the fuzzy logic routines and filter equations that produce their specific curves, and packaged them in a form that can be built into DSPs. On-the-fly changes to these might require far more computing power than is currently practical or affordable in mass-market CE gear.

I think the key here is the math needed to maintain equal sonic goodness for all the seats in your HT. Anything else isn't Audyssey. In that case, one might as well just use a parametric EQ.

Again, this was just my opinion. YMMV!

I do not disagree but let me suggest two modifications that would make the product much more attractive to me and, perhaps, others.

1. Allow the user to set a target curve. Currently, Audyssey Pro supports 4 pre-determined target curves. The measurement results are applied to these curves and the resulting filters can be loaded, compared to bypass and, if they satisfy, stored. Adding/substituting a user-defined curve (or letting the user select one from a larger assortment of curves) would still leave the basic Audyssey operations intact.

2. Allow the PC (which runs Audyssey Pro) to store two or more EQ results. I can get variable results from Audyssey Pro but, when I achieve a good one, I am deterred from attempting to improve on it lest the next result be inferior. If so, I cannot recover the previous usable one. This does not flaut Audyssey philosophy or secrecy but would allow the user to optimize its use. (N.B.: The promised Wisdom Audio controller utilizes Audyssey Pro and has multiple memories.)

3. Allow the operating device (AVR, pre/pro, SEQ) to store more than one set of EQ results. This would allow the user to have different EQ settings for, say, alternative seating arrangements and/or alternative speaker arrangements. It would also implement the function discussed above in (2).

The instructions I've seen point out that the microphone should be pointed up to take a "grazing" reading, as opposed to pointing at any speaker. I understand the purpose there, however I have a less than ideal room situation that results in my sitting areas being up against the back walls, and therefore my rear surrounds are ceiling mounted above the seat positions and facing mostly down. Therefore, having the mic face up will allow for a grazed reading of all speakers except the rears. I'm thinking that the best option would be to angle the mike forwards in a compromise position that would have it pointed to the ceiling towards the front of the room, such that the angle from each speaker and the mic was as equal to all speakers as possible.

Thoughts?

Darin,

The microphone surely does have a different sensitivity depending on the direction of the sound wave hitting it, or Audyssey would not be so adamant about the orientation. Audyssey has optimized the use of the mic, taking its characteristics into account in the filter calculation software so your question is well founded.

Because the back wall is a significant issue and greatly affects your mains and center, and those are the most critical channels, I would suggest using the recommended vertical mic orientation. Surrounds are generally recommended to be mounted three feet above ear level and so will often have the direct wave hit the mic from somewhat above the horizontal (just not at the near 90 degree angle you have). Additionally, the sound from the surrounds is supposed to be diffuse and if there is some less than optimum calibration that occurs from the surround test tones hitting the mic at a high an angle, it will probably have little impact on sound quality.

In a nut shell, while your rear surrounds are not ideally placed, I wouldn't let them influence the optimization process for the other channels.

You might try orienting the rears differently, maybe kicked in at 45 degrees so they partly face each other (sound still going down the back wall, but not directly downward).

You might experiment with mic orientation. But, if you see it affecting any of the settings or "before" room anomalies for the mains and center, or it affects the sound from the mains and center in any way, I would go back to the vertical orientation.

HClarkx

Kal, does the Pro software store one set of measurements to disk, i.e. can you restart the program and the measurements are still available? If so, you should be able to manually copy the files to another folder and restore them if necessary.

Nope. The only thing it stores is an encrypted version of the results suitable only for upload to Audyssey for their own purposes.

Well that's sure a crock!

Yeah. I even sent the file to a guy who was fairly confident he could break the code but he could not, given a short time and effort.

Thanks for the input! It's really a shame they give you no way to view the measured results, or even the adjustments that are made. Unfortunatley, that means I need to do separate measurements after the adjustments are made to confirm what's happening (and without software to do it, that's very tedius with a test disc, sound meter, and paper/pen.). Guess I need to get an automated way of running and measuring sweeps.

You are right but you can get the software free. It is called Room EQ Wizard.

Darin,

doing your own tests is a very tedious process. Audyssey tweaks both gain (or SPL) and phase (or "timing") of the sound in each of the 512 or 1024 bands. Much of Audyssey's advantage over traditional EQs is the timing correction. Timing (phase) is very difficult to measure, and without doing that and doing it well, you will have difficulty evaluating what you've got.

With the Sound EQ Pro, you do see gain/SPL and transient response before and after, but not timing, probably because that is very difficult to chart given that adjustments at the higher frequencies are very small even though they can result in a large change in phase. The timing is less critical at the higher frequencies, but is hard to measure even at lower frequencies.

I would hope that mic orientation is a second order effect and if it is, it will be difficult to measure even with the best of instrumentation.

But, good luck if you try it. Let us know how it works.

Hclarkx

I will be setting up my first 5.1 system this weekend. I will pick up my Onkyo 805 on Saturday and Audyssey is included with the 805.

I was told that the wire on the Audyssey microphone is only 8 or 10 ft. long. I will be sitting about 16 ft. from the Onkyo and my L&R read speakers will be 18 or 20 ft. from the Onkyo.

My speakers are Mirage OMNI 550's.

My questions are:

(1) If I need an extension cord for the Audyssey microphone, so it can adjust the rear speakers, can I buy one at Radio Shack?

(2) If I can buy the extension cord at Radio Shack what do I ask for when I get there to insure they sell me the correct item?

(3) Should I wait about 100 hours of use for the speakers before I use the Audyssey?

This is my first attempt at having a great sound system so I can use all of the help you guys can give me.

Thanks in advance for any help.

Jim

Oh definitely... I don't mean to suggest I could accomplish the same things manually, just that if I could see the response, or even just the adjustments made, I could quantify how much effect various mic orientations make. And fwiw, I don't have the Sound EQ pro... I have MultiEQ XT in my receiver.

As luck would have it, my 875 just arrived this evening. I just pulled out the mic, and I would say the cord is at least 20 ft. I'd be REALLY surprised if the 805 and 875 came with different mics. But fyi, it's a standard 1/8" mini plug, so I would expect a 1/8" M-F extension would work just fine if you needed something longer.

Thanks for the really fast answer and that takes care of one worry.

Jim

Darin,

I knew you didn't have the Sound EQ, but mentioned it for those that might go in that direction and for interest sake.

But, while I doubt you will be able to pick out the effects of tilting the mic forward, you should be able to measure the before and after effects of the Audyssey system. That will be fun and educational, even if you only look at the sound power level. Heck, you can do that fairly well with just a test CD and a $50 SPL meter from Radio Shack. My system had 10db more SPL at 50 Hz than it did at 100Hz and above. Audyssey's correcting that bubble around 50 Hz was quite obvious in both listening and simple checks with an SPL meter. The more uniform SPL among the sitting positions was also evident though total correction in that regard is not possible. Incidentally, even the Sound EQ software only tells you the "after" as an average of all measurement positions.

BTW, as to the wall behind your listening positions; as you indicated, it is an undesirable situation. I've seen that problem before and I'll offer my thoughts for what they might be worth.

Sound coming from your mains hits your ears then travels on back to the wall behind you and then bounces more-or-less forward, passing by your ears again. At the frequency where the distance from your ears to the wall is 1/4 wave length, the sound wave that bounces off the wall will pass by your ears out-of-phase with the sound wave that caused it. That will give you reduced SPL at that frequency. If the wall were a perfect reflector and only the incident and reflected waves existed, you would have a perfect null. Likewise, at higher frequencies, e.g., 1.5 times that frequency, the same thing will happen. You will have a series of "dips" in the SPL, depending on how hard the surface behind you is. Audyssey can help, but not fully eliminate these effects (it will do so best if all of your listening positions and hence your measurement positions are equidistant from the back wall).

But, to my point. I've always wondered how effective it would be to make the surface behind you highly absorbent. If much of the SPL were absorbed behind your ears, the effect would be much like having a longer room where you were sitting well away from the back wall. In a larger room the sound passing by your ears would decay and be fairly weak when it got back to your ears just as it would if much of it were absorbed by a closer wall.

Ideally, the whole back wall should probably be absorbent, but I'd bet that just a 2 foot high panel a bit wider than your sitting area centered at ear level would do fairly well. Hanging a heavy multi-layer quilt behind your seats and a few tests with a test CD and an SPL meter might indicate the benefit.

I'm just thinking out loud here. I've never tried this. Getting sufficient sound absorption might be difficult. Any critiques would be interesting.

Hclarkx

"With the Sound EQ Pro, you do see ... transient response before and after"

Could you elaborate on that?

Only 8 outputs

Would Y cables work for bi-amping?

They are provided, but are something you would want to ask your installer about. Even he might not want to get into them. They get rather complex. He will probably tell you that since Audyssey largely takes care of room transient response or ring-down issues, one doesn't need to worry about them. And he would be right.

HClarkx

Can the Audyssey only equalize a specified range? Would it be able to equalize if I shut off the tweeters?

Never mind all I need is a preamp which I have found.

I don't think any of the Audyssey implementations have any way for you to control the frequency range that is treated in the filters, other than to assign one or more channels to be subwoofers (applies to the Sound EQ only). If you disable the tweeters, it will probably try to drive the mid-range or woofer so that it is flat up into the tweeter range. But, if there is still a crossover in the circuit there is not much it can do (it's limited to about 10 db in any event as I recall). But, that 10 db boost in the crossover range will not dovetail well with the tweeter when you turn the tweeter back on.

Hclarkx

Thank you I think I got it now. It is just a theory however.

Yes, I agree that it's a very problematic situation, just not a big enough one to make me want to move to alleviate it. But we do have similar thoughts on the matter... I do have a large (about 6' high) thick tapestry against one wall directly behind one of the seating areas. The other is less easy to deal with, as there's a window there, but I've put multi-cell cellular blinds up there, which was the best I could do to add some absorbency to glass without making it look like a college dorm. And as much as many purists would shun this, another method I've used to alleviate the poor layout situation is using a second DPL II receiver to break up the rear channels into even more channels along the back wall. May not be ideal, but I'm happy with the results given my situation.

And more back on topic... I may have spoken too soon in pointing out that my new receiver only has MultiEQ XT. From the Onkyo firmware update thread:

Good. However, I think I did not clearly state what I was thinking. Audyssey will probably try to boost any missing sound, so will push up the SPL not just in the crossover region where there is some spill from the woofer or mid, but there will be added gain across the tweeter region and you will hear that when you reconnect the tweeter. Earlier I was thinking the tweeter circuit would bypass the Audyssey EQ system in which case you would have separate control over the tweeter, but would have some boost on the other drivers where the filters try to compensate the dropping SPL in the crossover region but can only actually do so where there is some signal. Yikes. I think I'm less clear now. But it seems you've got it under control in any event.

Anyway, have fun.

Hclarkx

Link please?

Click me!

Spot on. In one of my systems, the listening couch is more than 10 feet from the rear wall and the bass is pretty even. In the other, the couch is up against the rear wall, so that my ears are about 2 feet from that wall. Installing 2"thick 2'x4' OC703 panels (off the wall by another 2") made a huge difference in that room, even before the implementation of Audyssey EQ.