Difference Between Avia and DVE - Subwoofer Calibration (1 Viewer)

[Stephen_F]

Before I calibrated with DVE, I positioned my subwoofer using some test tones. I ran a frequency sweep, with the separate tones below for the subwoofer and plotted the results in a spreadsheet. This showed me how the subwoofer was responding in my room.

Here is the spreadsheet: *snapbug.ws/subtestmodel.xls from the Behringer setup page: *snapbug.ws/bfd.htm

I made up my own CD of test tones from the same site:
*snapbug.ws/sinewaves

* - please add www to get to the site.

Just needed to download:

• 16 hz
  18 hz
  20 hz
  22 hz
  25 hz
  28 hz
  31.5 hz
  36 hz
  40 hz
  45 hz
  50 hz
  56 hz
  63 hz
  71 hz
  80 hz
  89 hz
  100 hz
  125 hz
  142.5
  160

and the 10hz to 100hz sweep.

Then I used Nero audio to burn them in order (so I did not forget which is which ) to a blank cd, so I could play them in my DVD player.

Using this method, I found that the front left side, slightly away from the corner was better than the right side/corner. The respose was flatter and I got rid of a null that was close to the listening position.

From the DVE site and I think there is a clue to why this is happening, but I still think there is something wrong with the tone:

 

[Sebastian]

Here is a FAQ quoted from JKP website. I think his answers are a bunch of crap and I probably will not buy another JKP DVD because of his cover up. I mean several and I mean several people including myself have encountered the same results Ed has. However JKP only states the LFE is only a couple of dB's off. Hmm, that is odd? room acoustic? I guess everyone's room acoustic are to blame? I think not Mr. Kane.
I wish he would fess up and say yeah, the LFE is really screwed up! "Sorry, I will send new DVD's out to everyone right away" Hehe, yeah right!

When I used DVE to set-up my subwoofer I could not even hear it anymore and the gain was almost turned off! Both on the amp and the rec!

 

[EdNichols]

I am confused by this 10 db on DVE error now. Using the DVE, if I calibrate my surrounds to 75 db. on my meter, then the sub. should be set on my receiver to -10db from my surrounds? Or, should the sub by set the same as my surrounds on my receiver so the meter reads 10db hot from my surrounds because the LFE channel compensates for this?

 

[Edward J M]

Set the 5 or 6 surround channels to 75 dB. Set the sub level in the AVR to around -5. Adjust the sub amp gain control so it reads anywhere from 85-90 dB on the RS meter. In my experience, that should be "about" right for DVE.

In my room, DVE is 13 dB off, and 88 dB for the DVE sub level results in a "flat" sub calibration, as verified with my TrueRTA test rig on an in-room FR sweep.

Your results may vary, and I would advise double checking against a disc like S&V or Avia.

 

[Marvin E]

This would explain why my new PB2-ISD at -10RL or at moderate listening levels sounds awful. I used Chapter 3-1 of DVE to calibrate my surround speakers and I used the LFE test signal for the PB2; all to 75 db. Even with my PB2 running about 4 to 6 db hot with sub gain at about 1/4, the bass response was horrible; no shake...nothing. I just ordered an AVIA. In the meantime, I going to try the 85 ot 90 db recommendation with the AVR sub level set to -7 (range is from -14 to +14).

 

[John Tami]

Just a note on the S&V disc, per Ovation (we discussed this at the HTS a month or so ago...and emailed Ovation for clarification) this disc is not to be used for Sub calibration. It was only designed to help polarity and verification, but not cal. The Tone is not at the same db as the separate speaker tone calibration page on the DVD.

I expect someone could measure the difference and come up with a offset chart. You up to that Edward?

PS, I just ordered DVE ($16.48 shipped at DeepDiscountDVD.com), have been using S&V for the past year +....

 

[Edward J M]

Yes, try 88 dB and see what happens. I'm betting the bass will fall into line just about perfectly. Then compare it to Avia and see what you get.

John - Thanks for the definitive tip on S&V. I won't recommend it anymore for sub calibration; only Avia.

As for offsets, I stand by 13 dB for my copy of DVE on my system, and it seems to be a valid number for many other users, too.

The only way to be absolutely sure is to ground plane the subwoofer (to eliminate the room effects) at the specified calibration level for each and measure the amplitude difference between the two response curves.

I'm not inclined to do that, but I did actually run a TrueRTA Quick Sweep from 10-20,000 Hz on my system after calibration with Avia, and the average system level from 30-200 Hz was constant. The sub only showed an increase below 30 Hz due to room gain.

If I recalibrated with DVE and remeasured the FR, it would show a huge sag below about 70 Hz, with the average bass level in the 30-70 Hz region being far lower than the average midrange level in the 70-200 Hz bandwidth.

 

[Jeremy Anderson]

I've read about how DVE is supposedly messed up with the LFE channel, so I got a copy yesterday. My SVS 20-39CS+ is EQ'd for flat response +/-3dB from 20-100Hz, system crossed over at 80Hz. At reference level, here's what I got for numbers:

Internal tones:
75dB mains, 72dB sub (to correct for SPL meter's C-weighting)

Avia:
85dB mains, 82dB sub (again, correcting for the meter)

DVE:
75dB mains, 75dB sub (since DVE's tone is pre-compensated for C-weighting)

So, have they corrected the disc or were people just having equipment/setup issues? On my system, all three methods get you the correct levels.

 

[Edward J M]

This is by far the more likely of the two. Too many people have experienced identical results with early editions of DVE for it to be equipment/set-up issues.

Nice to see JKP apparently rectified the problem. FWIW, I have consistently recommended that people compare to other sources in anticipation of eventual correction of the flaw.

 

[Stephen_F]

If they have corrected DVE, do you think it will be possible to exchange discs, or do you think they will want to keep it quiet?

 

[Edward J M]

Ask Joe Kane and see what he says.

FWIW, I'm keeping my bad copy of DVE as solid evidence that the problem existed.

If JKP decides to exchange defective copies for corrected ones, would that be perceived by some as a tacit acknowledgement that the problem existed, and that the disparity was more like 12-13 dB instead of 2-3 dB as they claim on the website?

 

[GregBe]

Well that is really dissapointing if they corrected it and did not offer an exchange or even make mention of it. My DVE was 7db's off from VE. I sold my VE when I originally purchased DVE. Once I realized the problems, I rebought a used copy of VE. It wasn't a ton of money, but dissapointing nontheless.

Greg

 

[John Tami]

Hmmm...I just got a copy last week from deepdiscountdvd.com (took a week to deliver..they are the slowest shippers around in my experience!) have not ran it yet....wonder if there is any easy way to tell:

1. If they did fix it.

2. How to tell the difference. Visual clue on box/disc/ or programming?

Test with my SPL meter I suppose is the only true test.

 

[Nick Breckon]

I doubt it. I got a DVE disc last month and the LFE is at LEAST 10db hot still.

 

[Stephen_F]

We need more input, as Jeremy Anderson said it was now perfect in his setup. So that means that either, they have corrected it, or Jeremy is doing something different to everyone else

 

[Edward J M]

Yes, clearly Nick's recent copy is defective - in his words still "at LEAST 10 dB hot". And Jeremy's copy seems to work perfectly. A conundrum, for sure.

Trust me, if you have a bad copy of DVE, you'll know immediately; it flat buries the meter on the sub tone and requires bumping the meter to the next scale just to read it.

 

[GregBe]

I am still wondering if DVE is more affected by room differences than AVIA and VE. It seems to me looking at multiple posts on multiple boards, the differences are all over the place from 3dB's off to 13dB's off and everything in between.
Does anyone know for sure what frequencies make up the rumble tone for DVE vs AVIA and VE. I find it hard to believe that DVE has the discs mastered with different info on them unless they made a correction. It makes more sense to me that the tones are simply different than AVIA and VE. My thoughts are that if the frequency of the tones are different, you would get different readings amongst the discs depending on how your room reacts to the tones in question. If all were authored with the same range of tones, you would get identical readings whether you use DVE, VE, AVIA or the receivers test tones.

obviously a lot of people have done comparisons of DVE to VE or AVIA. I am sure this has been done before, but has their been testing of AVIA vs VE in various rooms to see if they read the same no matter what the room is like?

Greg

 

[Stephen_F]

So DVE may have a subwoofer tone that is affected by your room acoustics, while the other calibration DVDs have tones that are not, significantly, affected? Now I am even more confused. Why would they use a tone that is affected, so badly, by room acoustics, that would make the tone useless for most people, who have less than perfect rooms. Maybe JK did make a mistake, just not the one we thought he did.

 

[GregBe]

Stephen,

I don't mean to confuse you, because I am much less knowledgeable than most on these issues. I am just throwing out my own theories hoping to spark a conversation and get some answers from the experts.

Greg

 

[Jeremy Anderson]

If someone can tell me a good program to do frequency analysis of mono WAV files, I managed to rip the LFE tone from DVE and the left front subwoofer tone from Avia. That way we can see the actual differences between them.

Or if someone more experienced than me would like to do it, give me an e-mail address and I'll send the two WAV files for analysis. If that doesn't get to the bottom of it, nothing will.