AA2.0 imposes a -6dB limit on mono recordings

[Phil M]

I would like to know if anyone can achieve any signal in -6 dB to 0 dB
range when recording to a mono track in Edit mode with Audition 2.0.

If not, are there any plans from Adobe to fix this serious recording
algorithm bug in Mono? Or I'm doing something wrong?

I'm using M-Audio 2496 sound card. I also tried with a SoundBlaster
Live and Realtek audio boards on a different computer. I tried it on
both Vista and XP with same results. While recording the AA2.0 meter
shows signal up to 0dBFS, but the waveform clips at -6dBFS.

I also didn't notice any FAQ or mention of this limitation/bug on
Adobe's site. Is there any undocumented -6dB pad for mono recordings
in AA2.0? Weird.

[Paul Stamler]

"Phil M" > wrote in message
...
> I would like to know if anyone can achieve any signal in -6 dB to 0 dB
> range when recording to a mono track in Edit mode with Audition 2.0.
>
> If not, are there any plans from Adobe to fix this serious recording
> algorithm bug in Mono? Or I'm doing something wrong?
>
> I'm using M-Audio 2496 sound card. I also tried with a SoundBlaster
> Live and Realtek audio boards on a different computer. I tried it on
> both Vista and XP with same results. While recording the AA2.0 meter
> shows signal up to 0dBFS, but the waveform clips at -6dBFS.
>
> I also didn't notice any FAQ or mention of this limitation/bug on
> Adobe's site. Is there any undocumented -6dB pad for mono recordings
> in AA2.0? Weird.

I assume your mono signal is going into only one channel of the card. What
AA does when you tell it to record mono is that it pads down both channels
6dB then sums the two of them. If there's nothing in one channel then you
get a signal that's 6dB lower than what you put in, and yes, if you put in
more signal than what it takes to reach -6dBFS, it clips.

The secret to making full-range mono recordings in AA is to make a stereo
recording, with one channel registering blank, then highlight the channel
with material on it an export it. It will automatically save as a mono file,
and you can get full scale on it.

Peace,
Paul

[Phil M]

I forgot to mention in my previous post that to reproduce this
anomaly, only 1 mono channel must be fed to the sound card. Left OR
Right. In this situation, AA2.0, in Mono/Edit view it will show a
signal in the -6 to 0dB range, but the waveform will clip at -6dB.

Moments ago I repeated the same test with Sound Forge 8. SAME
problem, HOWEVER, unlike AA2.0 the meters showed the -6dB limit!

In SF8, I then unselected selected "Microsoft Sound Mapper" and
selected "Microsoft Sound Mapper - Left" and Bingo, I got a full scale
signal!

Could there be a bug in the Microsoft Sound Mapper? If the bug is in
the sound Mapper, then why AA2.0 reads a Full Scale signal despite of
the "-6dB pad"? Although SF8 is also affected by this bug, it's meters
reflect the pad. Is there any way to select 'Microsoft Sound Mapper
Left' when recording mono in edit view in AA2.0? Or have this being
done automatically when in mono? I don't recall this anomaly when I
was using CoolEdit Pro...

I do radio broadcast/voiceover editing and Mono is extremely
important.

[Mark]

On Mar 31, 1:32 pm, Phil M > wrote:
> I forgot to mention in my previous post that to reproduce this
> anomaly, only 1 mono channel must be fed to the sound card. Left OR
> Right. In this situation, AA2.0, in Mono/Edit view it will show a
> signal in the -6 to 0dB range, but the waveform will clip at -6dB.
>
> Moments ago I repeated the same test with Sound Forge 8. SAME
> problem, HOWEVER, unlike AA2.0 the meters showed the -6dB limit!
>
> In SF8, I then unselected selected "Microsoft Sound Mapper" and
> selected "Microsoft Sound Mapper - Left" and Bingo, I got a full scale
> signal!
>
> Could there be a bug in the Microsoft Sound Mapper? If the bug is in
> the sound Mapper, then why AA2.0 reads a Full Scale signal despite of
> the "-6dB pad"? Although SF8 is also affected by this bug, it's meters
> reflect the pad. Is there any way to select 'Microsoft Sound Mapper
> Left' when recording mono in edit view in AA2.0? Or have this being
> done automatically when in mono? I don't recall this anomaly when I
> was using CoolEdit Pro...
>
> I do radio broadcast/voiceover editing and Mono is extremely
> important.

per the posts above, sounds like your best solution is to simply apply
your mono signal to both the left and right input...

you'll get a __theoretical__ 3 dB input stage noise reduction as well

Mark

[Scott Dorsey]

Phil M > wrote:
>I forgot to mention in my previous post that to reproduce this
>anomaly, only 1 mono channel must be fed to the sound card. Left OR
>Right. In this situation, AA2.0, in Mono/Edit view it will show a
>signal in the -6 to 0dB range, but the waveform will clip at -6dB.

That's a metering anomaly. The waveform you are seeing is the sum of both
channels, so if you use only one, you can only get to -6dB.

>Moments ago I repeated the same test with Sound Forge 8. SAME
>problem, HOWEVER, unlike AA2.0 the meters showed the -6dB limit!

The metering was different, then. Maybe it shows peak of each channel.
The manual should tell you.

>In SF8, I then unselected selected "Microsoft Sound Mapper" and
>selected "Microsoft Sound Mapper - Left" and Bingo, I got a full scale
>signal!
>
>Could there be a bug in the Microsoft Sound Mapper? If the bug is in
>the sound Mapper, then why AA2.0 reads a Full Scale signal despite of
>the "-6dB pad"? Although SF8 is also affected by this bug, it's meters
>reflect the pad. Is there any way to select 'Microsoft Sound Mapper
>Left' when recording mono in edit view in AA2.0? Or have this being
>done automatically when in mono? I don't recall this anomaly when I
>was using CoolEdit Pro...

No, what you are seeing is a side effect of Apogee actually following the
IEC standard.

>I do radio broadcast/voiceover editing and Mono is extremely
>important.

If you actually care about real levels, buy the RME or at least a Dorrough
digital meter and don't even THINK about trusting the metering on the DAW.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[hank alrich]

Scott Dorsey wrote:

> If you actually care about real levels, buy the RME or at least a Dorrough
> digital meter and don't even THINK about trusting the metering on the DAW.

Sonalksis is giving away a free metering plug-in that offers much more
than most DAW "meters", called FreeG.

http://www.sonalksis.com/index.php?section_id=99

--
ha
Iraq is Arabic for Vietnam