"Official" Audyssey thread (FAQ in post #1) - Page 991

thanks for this Larry. It sharpened my understanding as to what Chris was alluding to earlier.

I don't see this being an issue for me, as all of my trims are -8 to -11. Nevermind the fact that I'm currently running a Denon 3310 (until my "last" upgrade for a long time, lol) and I'm consequently prolly less vulnerable to the condition altogether.

thanks again all,
James

Hi Jeff, I was going to take a look at the room calculator but it asks for a user ID and password... Do I need to register with Harman to use this?

That's odd. I just clicked on the link in your post and the spreadsheet opened in Excel on my computer. Maybe it's a Canuck thing?

Try this link.

Jeff

It opens but you cannot change the room data without a password.

"Save As"

It opens in ready only by default because it is opened from cache. Saving it locally allows it to be used.

That's curious. I was able to change the room data to match my room without entering a password.

You might have downloaded it to your hard drive before opening. Just clicking in the link, on most people's computers, opens it instead of saving it.

Nope.

Perhaps. Mozilla gave me the choice and I did download and save it.

Thanks! that worked just fine opened in Excel and was able to enter data and see the node points.

I would surmise that just as you wouldn't want to have seating positions at the null points, the microphone should be placed there either? (assuming your seating positions wern't located at those null points)

OK, you can only change the fields colored WHITE, i.e. the room dims.

Odd, you can change the speed of sound, too.

From the instructions:

4. If desired, you may also change the speed of sound, directly
below the dimension input fields. This is not normally
needed. However, if you are working at high altitude or in a
location where the temperature or barometric pressure is
very different from normal, this could be helpful.

The pros, especially when having the luxury of starting from scratch, will locate listeners HEADS so that they are in neither peaks or nulls in all three dimensions. Yes, row spacing front to rear, but also seat width, spacing and height. I seem to remember fifths and sevenths for spacing.

That is what I figured, although certainly not a 'pro' I do get to start from scratch when building my home theatre.

I have the luxury of a basement room, formally a family room that currently houses the equipment, my wife said once I finish the kitchen reno I get to remodel for a real 'home theatre'!

Good question on the mic placement and nulls. This is one for Chris ...

Audyssey can't fix nulls, but from my experience it can lessen their severity. But it can't correct what it doesn't know about, so I'm going to speculate that we should measure as if we know nothing about the room's modal distribution. The exception is to stay away from the walls...

That's cool. At this point, pro or not, you know enough to avoid room dims that are multiples, e.g. a room with an 8' ceiling should not have a length or width of 16' or 24', etc. And you probably know to avoid having seats at 25%, 50% or 75% of the length .. and width ... and height if you can avoid it.

Jeff

Now Jeff, if you fill up the entire volume of your room with wood (for example), the speed of sound will change, coz sound travels in wood at 3300 - 3600 m/s or 11,000 - 12,000 ft/s.

I take me...(you know what!)

Duh. In my inimitably devious ways, I was trying to change the dims. on the Modes page.


Great for us obsessives.

Now Jeff, if you fill up the entire volume of your room with wood, the speed of sound will change, coz sound travels in wood at 3300 - 3600 m/s or 11,000 - 12,000 ft/s.

I take me...(you know what!)




OK Guys, let's play with the idea a bit more (just for the sake of some fun, eh?).

Listening in such common solids like wood would surely have two great benefits:

1. 1st room modes would increase 10x, i.e. instead of some typical 30 - 60 Hz they would go up to the range of 300 - 600 Hz. Wouldn't that be easier for Audyssey to tame? Meanwhile the sub range would be free from nulls and peaks forever!!

2. Music would reach our ears 10x faster in wood!

Now I take me hat...!

I did email them, and the author wrote back saying:

"iPhone 4 mic is basically identical to iPhone 3GS."

According to the link Chris posted, it is pretty bad and a huge step down from the 3G. I should probably spend more time with REW and the calibrated mic I bought and not think about spending more $$ for a good looking, but unreliable app.

Jeff

What "link", can't seem to find on in the thread following my first post on this subject, can you include it? Thanks!

http://www.avsforum.com/avs-vb/showt...9#post19055429

The link is in the first word "here"

Geez, I must be going blind, and scrolled right past that post. Well, I'll read that page, I realize the tiny hardware in any phone is not going to be great. But since all I have now is an RS meter, I'm going to see how close each of them are with some pink noise tests etc. I looked at most of these kinds of SPL apps and while none of them may be as accurate as "real" gear, this one seems the best of the lot, in design in option settings etc. Obviously, if you have access to better gear, that's the way to go. I have yet to set any of my speaker settings by SPL feedback so it's just a tool I'm testing. Thanks for the interest and link.

Added this link to Freq. response charts, shows Iphone 4, 3Gs, and iPad, but NO 3G data, this from a dev that sells a $20.00 app called "SoundMeter", it looks full featured as well, but I can't buy em all to test.

http://blog.faberacoustical.com/

I'd be interested in hearing your comments on it if you use it. PM me perhaps?

Jeff

Awe shucks, that's an awesome spread sheet and I was able to get it to output my room waves and modes, but I don't know what to do with the data lol.

I think that having 2 subs and a single simple parametric cut available on each sub, I should just leave it a zero db and use the output as a guide of what spots to avoid measuring from and possibly adjust my seating positions. So do I avoid both wave and mode spots and/or their intersection? In other words I want to be where the arcs are their highest?

The calculator is most accurate in a closed rectangular room, but has some relevance to an open rectangular room. Shapes beyond rectangular are much more difficult to model. But to your question, you would want to especially avoid the bottoms and the peaks, if possible.

We still haven't heard from Chris on avoiding measuring in nulls, but you can safely avoid putting seats there.

I wouldn't like to be there where the arcs are at the top (boomy bass). IMHO, your graph shows to you the bare naked situation of your room without any treatment (acoustical or electronic). I'd like to be at an averaged point, and I think that's what Audyssey is going to do for you. You name the place (MLP= Main Listening Position) and it's surroundings (Acoustic Bubble) and Audyssey will take care of the rest.

Well I performed a 8 position Pro calibration on the weekend now that my NAD T-175 was serviced and the Am-200 audio card was replaced. The buzzing has now gone for the rear surround speaker when listening to a True-HD track with Dynamic EQ engaged.

Question for Audyssey. Does the NAD suffer from lack of processing power when the user runs and saves a Pro cal then engages Dynamic EQ or adds Prologic 11x and has audyssey on as well to a codec like True-HD? I'm finding the headroom reduced and finding I have to come close to reference "0" to achieve a desireable listening level. I know some Marantz models have limitations with processing and Audyssey, so does NAD fall into this catagory? The HD cards I have installed are the VM-100,AM-200. I find that when I've just performed a Audyssey XT calibration ,I have much more headroom and don't have to have the volume up as much (approx -8 or -10 depending on the movie).

Ideally, one would not want the mic in an infinite null, but since it's impossible to know that before starting we have to rely on the rules in the algorithm to prevent overboosting.

Also, while the calculator is nice to play with it really doesn't do much good for most home listening environments that are not enclosed by 4 rigid walls...