Difference Between Avia and DVE - Subwoofer Calibration (2 Viewers)

[Brian L]

I am with Ed. I did a very, very quick test yesterday afternoon using my older Sony 650D (It has a display that shows when the .1 channel is active.)

Doing my sub to center test, the LFE indicator did not come on. When I later ran the .1 channel sweep, it did.

I suppose it is a good way to author this test, since it will let you know straight away if your BM is working or not.

BGL

 

[Kevin C Brown]

Cool. I guess my BM is working then...

One thing that *then* doesn't make sense to me, is what if I have all large, sub on? Then the Avia test won't work right? But a lot of people could have their systems set up that way. (That's how I run for SACD & DVD-A.)

 

[Edward J M]

Correct, if you set your speaks to large, Avia will still play the rumble tone, but it will just come of that speaker.

Ostensibly, if the speaker is set to large, you don't need the subwoofer rumble tone anyway. You can still use Avia to calibrate and balance the 5 channels, regardless.

 

[Kevin C Brown]

OK, I'm going to ask another stupid question here, because there are some knowledgeable people here...

If the sub test of Avia is using crossed over info, wouldn't then the amount of sound (sound pressure level) change as a function of the crossover? I.e., I run a higher crossover, so more of the signal gets sent to the sub, so the sub *measures* louder? Or maybe I guess if the crossover is doing it's job, I get the same *measured* output no matter where the two parts of the signal end up? (Sub and main speaker.) But if you're not in perfect phase, then it still would matter anyway. And it's damn difficult to get every main speaker in perfect phase with the sub. ??

 

[Lewis Besze]

Yes there is a couple of DB difference,and I elected to use the left main,as it's the farther from the subs.

 

[Kinson_Y]

Edward: I don't understand why you're saying that one should calibrate their sub to 82dB when using Avia while the other "regular" channels should be done to 85dB? (My initial guess was that you were including a correction for a SPL meter's inherent error, but you've since stated above that 82dB is a corrected value.)

In any case, my confusion is because you've stated (and I believe you, BTW) that the Avia disk doesn't use a true/discrete ".1" subwoofer output for it's calibration signal; that some of the tone is coming from another speaker when it's running.

Given this fact, doesn't it make sense to actually calibrate the sub channel HOTTER than 85dB since regular DVD's have DD/DTS soundtracks that are "correctly" coded with a discrete ".1" channel that doesn't (unlike Avia) send the main speakers to play lower frequencies?

In other words, why doesn't it make sense to calibrate the sub channel 2 or 3 dB "hot" assuming that (for discussion's sake) the system in question is set up with the typical 80Hz crossover and all the regular speakers set to "Small".

Thanks.

 

[Kevin C Brown]

I'm not sure this is Ed's reason, but there is another reason to to drop the sub a few dB.

The Radio Shack meter is less sensitive to lower freqs. We all know that. So if you calibrate straight across at the same level for the sub as for the main speakers, you actually get the sub too loud to begin with.

For years, I calibrated everything to 75 dB. I always felt the sub was too loud for movies. (A sub doesn't play much of a role in 2 ch music.) Now I run -3 to -5 dB on the sub compared to everything else, and my system sounds much more balanced.

 

[Edward J M]

You must be referring to this quote: "And realize that 85/82 on Avia is running the sub FLAT at best (with the C-weighted correction factor included), or maybe even a little cool."

I could see where my statement might confuse - sorry for the poor choice of words. What I meant here is that 85/82 as read on the meter is considered "flat" (in reality 85/85) or maybe just a little cool (85/84), if you include the correction factor.

I run 85/82 (direct meter read) for HT and even a little cooler 85/80 (direct meter read) for music. I really like the sub to be nicely blended and unobtrusive on music.

 

[Brian L]

Above is a quote from a Guy Kuo article that I got here http://www.keohi.com/keohihdtv/exper.../avia_a2z.html

So, regardless of Ed's reasons, his method is right on the money.

BGL

 

[Stephen_F]

I just want to report that I get similar results to Edward, with the recently released "PAL" version of DVE. I posted in an Australian forum that I measured a difference of 13db between my surrounds and the subwoofer, but I did not know why. Thanks for this detailed information.

 

[Edward J M]

Yes, that sounds about right. What did you use to previously calibrate the subwoofer level before you tried DVE and got the 13 dB difference?

Ed

 

[Stephen_F]

I am using "The Ultimate DVD Platinum". The NTSC version, as there was no PAL version. I am still using it for speaker calibration. The DVE is great for picture calibration, but I felt I could not trust (or understand) the DVE calibration tones.

Does this look correct, this is a more recent attempt to calibrate with DVE:
I used the Tandy sound meter and used the correction table. Placed meter on a tripod at the listening position at ear level, facing forward at a 45 degree angle. Meter setting was C-Weighted, Slow. Receiver is a Yamaha 1300 with a volume range of -99db to 0db.

Platinum -
Set surrounds to 75db at receiver volume of -33db
Receiver -4db subwoofer level to get 75db

DVE -
Set surrounds to 75db at receiver volume of -23db
Receiver -17db subwoofer level to get 75db

I tried watching a movie with the DVE settings at -23db volume, but it was way too loud and the subwoofer was nowhere to be heard. I decided to go back to Platinum, as I did not know what was going on

 

[Edward J M]

That sounds about right. You required a 13 dB reduction in the subwoofer level to get the same SPL from the sub when switching between Platinum and DVE. Looks like the problem still exists, at least on your copy. And I agree - calibrate the sub with DVE and it's definitely "nowhere to be heard".

I like DVE for video and the calibrating the main channels (it does 6.1), and the video portion is nice. But the navigation is a bear, and the sub level cannot be trusted, so Avia remains my trusted choice for both video and audio basic calibration.

 

[Bill Mullin]

Just wondering, I have the original Avia which can be used to calibrate 5.1 audio. I'm about to upgrade to 7.1 - will the new Avia DVD support calibration of the 2 additional channels?

Thanks, Bill

 

[Edward J M]

I think it will support 6.1 (and send a dual mono signal to both rear surrounds). But I heard it will be really expensive (like $400) and geared to the professional.

I think the Ovation S&V disc supports 6.1 for under $20 from Amazon.com. Might be worth it just for that?

 

[Brian L]

Secrets has a review up of DVE here http://www.hometheaterhifi.com/volum...ls-3-2004.html

But its not a review at all....its just a run down of the features and functions.

Is it just me, or do others find this sort of thing extremely annoying. There have been legnthy threads here that brought up many issues with both the audio and video on the disc, yet every "review" I read is just a re-hash of the damn press release.

I wonder if the author actually tried to use it to calibrate his system? If so, and he missed the FUBAR LFE channel, it makes one wonder.

BGL

 

[Edward J M]

Agreed. Maybe it wouldn't hurt to send him an email and ask if they compared the sub level tone to Avia, S&V, the original VE, Platinum, etc.

 

[Stephen_F]

I was thinking about e-mailing them about the review, but these were the only addresses I could find:


For those who have not seen the official list of excuses:
videoessentials.com/DVEQ&A.htm (add your own www, as I am not allowed to post a url until I have more than 15 posts)

 

[GregBe]

I had some interesting findings with this disc. I will preface this by saying that my room is 19' x 19' which creates a very uneven frequency response. Originally I had my sub in the front corner of the room between the front speakers. I had the same results as everyone here. The sub calibration using DVE was way off compared to my receiver test tones. Because I was getting huge peaks and dips in FR, I moved my sub to the back of the room, near my seating position, and out of a corner and against the back wall. Now, my sub sounds great with a pretty even response. The funny thing is that last night I compared DVE and the receiver tones again, and DVE was only 3 db too hot. I remember reading that with DVE they authored it to compensate for the 3 db's that the SPL meters are off by (I may be wrong on that).
This goes along with what Joe Kane is saying about how the disc is correct, but the errors could be caused by the room. I wonder if this is more of a problem with this particular disc, or if all tones are subject to inaccuracies due to the room. If it is just this disc, it was a poor way to go, because most people don't live in a perfect room, and in turn would calibrate their sub wrong.

Greg

 

[Edward J M]

You could try placing the sound meter in a near-field location (like 2 feet from the sub), and test for volume differences before room acoustics take over. I'll do the same with Avia and DVE and report back.