Topic: Edirol R-09´s AGC is a limiter and does NOT boost levels?

[Arni99]

http://www.amazon.com/Edirol-R-09-WAVE-MP3-Recorder/dp/B000FPQFKO

is this true?

Customer Reviews
Average Customer Review:
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  3 of 3 people found the following review helpful:

 Great - BUT automatic gain control not good, February 26, 2007
Reviewer: Charles T. Tart (Berkeley, CA United States) - See all my reviews
I'm charmed with this little gem, which I will use mainly for taping meetings. But the advertised automatic gain control does not work as advertised. It does limit high intensity sounds so the recording doesn't overload, but it does not automatically boost low level sounds. Indeed as soon as you switch in automatic gain control, the microphone sensitivity is lowered so you are less likely to pick up softer sounds. It's still great in many other ways, but they would have better advertised the R-09 as having limiting circuits, not as automatic gain control....
I thought at first that I had a defective unit, but Edirol tech support tells me this is the normal way the unit operates.
 

[lbgspam]

Does any taper actually use AGC?
Even from my D7 days the practice was that AGC was bad

http://www.amazon.com/Edirol-R-09-WAVE-MP3-Recorder/dp/B000FPQFKO

is this true?

Customer Reviews
Average Customer Review:
Write an online review and share your thoughts with other customers.   

  3 of 3 people found the following review helpful:

 Great - BUT automatic gain control not good, February 26, 2007
Reviewer: Charles T. Tart (Berkeley, CA United States) - See all my reviews
I'm charmed with this little gem, which I will use mainly for taping meetings. But the advertised automatic gain control does not work as advertised. It does limit high intensity sounds so the recording doesn't overload, but it does not automatically boost low level sounds. Indeed as soon as you switch in automatic gain control, the microphone sensitivity is lowered so you are less likely to pick up softer sounds. It's still great in many other ways, but they would have better advertised the R-09 as having limiting circuits, not as automatic gain control....
I thought at first that I had a defective unit, but Edirol tech support tells me this is the normal way the unit operates.
 

[Arni99]

Does any taper actually use AGC?
Even from my D7 days the practice was that AGC was bad

http://www.amazon.com/Edirol-R-09-WAVE-MP3-Recorder/dp/B000FPQFKO

is this true?

Customer Reviews
Average Customer Review:
Write an online review and share your thoughts with other customers.   

  3 of 3 people found the following review helpful:

 Great - BUT automatic gain control not good, February 26, 2007
Reviewer: Charles T. Tart (Berkeley, CA United States) - See all my reviews
I'm charmed with this little gem, which I will use mainly for taping meetings. But the advertised automatic gain control does not work as advertised. It does limit high intensity sounds so the recording doesn't overload, but it does not automatically boost low level sounds. Indeed as soon as you switch in automatic gain control, the microphone sensitivity is lowered so you are less likely to pick up softer sounds. It's still great in many other ways, but they would have better advertised the R-09 as having limiting circuits, not as automatic gain control....
I thought at first that I had a defective unit, but Edirol tech support tells me this is the normal way the unit operates.
 

if it was a limiter as on the rockboxed iriver´s "safety-clip" feature, it´s perfect for taping .
you set the starting level manually(let´s say +15dB for loud amplified rock shows) and IF clipping would occure it automatically reduces levels as needed but NEVER boosts them(as normal AGC does) afterwards;) .
kind of "brickwall-limiter" in rockbox.
you never need to check levels during the show and all my recordings turned out great!
I would NOT use normal AGC as we all know from MD recordings, cause it boosts low signals and reduces high signals.

[BayTaynt3d]

The safety agc on a rockboxed iriver is NOT a limiter.

[Arni99]

The safety agc on a rockboxed iriver is NOT a limiter.

well my safety clip IS a "limiter", as it never boosts levels(Mmmm´s build+REP 20070217).
of course it does NOT check the signal for possible clipping in a puffer before it´s written to the HDD, but it does the same as we all do when using manual level control => reduce levels when clipping occurs.
safety-clip does nothing else than the above.
Petur - rockbox developer - can confirm this .

[pgoelz]

When enabled, the R-09 AGC sets the record to a fixed level (not adjustable).  It reduces the gain as needed to prevent over recording but it does not increase the gain if the input level drops below the 100% record level. 

Two additional considerations.....

1.  The time constant of the AGC action is WAY too fast for most program material. 

2.  If you happen to have a unit with excessive DC offset, the AGC gain change steps can be very audible and objectionable. 

That said, I have used the AGC successfully to prevent over recording on applause.  But for this to work well, the normal progrm level has to be below the point where AGC activates.  Since that level is not adjustable (and since there is no indication when AGC has activated), it is a crap shoot. 

Paul

[Arni99]

i just bought the edirol r-09 and will tape my 1st show tonight in 2 hours ....in Vienna.
will use my sennheiser HLSC cardioids+bbox on MIC-IN starting at level 25/30 with MIC-SENS low, AGC off, LOW CUT off.
let´s see how it turns out.....

[Roving Sign]

i just bought the edirol r-09 and will tape my 1st show tonight in 2 hours ...AGC off, LOW CUT off.
let´s see how it turns out.....

Rah - but what does that have to do with this thread...?

[BayTaynt3d]

The safety agc on a rockboxed iriver is NOT a limiter.

well my safety clip IS a "limiter", as it never boosts levels(Mmmm´s build+REP 20070217).
of course it does NOT check the signal for possible clipping in a puffer before it´s written to the HDD, but it does the same as we all do when using manual level control => reduce levels when clipping occurs.
safety-clip does nothing else than the above.
Petur - rockbox developer - can confirm this .

Sorry, not trying to be a jerk at all, but you are incorrect, and I don't need Petur to confirm that. Rockbox safety AGC is NOT a "limiter." I'm guessing you may not know what a true "limiter" is? It means something very specific in the audio world, and safety agc isn't it. A real "limiter" is basically a special case of compression that typically uses a fast attack, and a very high compression ratio and threshold. The safety AGC turns the audio down after clipping occurs and it never turns it back up, whereas a limiter catches signals that go over a certain threshold and compresses the hell out of them to avoid clipping before it happens (and it does not lower the gain permanently, only temporarily in the moment the over is happening) -- these are two very different things. FWIW, I think it'd be a cool as hell feature for rockbox to have a compression capaibility for playback (not recording), but that's a whole different conversation.

[Arni99]

The safety agc on a rockboxed iriver is NOT a limiter.

well my safety clip IS a "limiter", as it never boosts levels(Mmmm´s build+REP 20070217).
of course it does NOT check the signal for possible clipping in a puffer before it´s written to the HDD, but it does the same as we all do when using manual level control => reduce levels when clipping occurs.
safety-clip does nothing else than the above.
Petur - rockbox developer - can confirm this .

Sorry, not trying to be a jerk at all, but you are incorrect, and I don't need Petur to confirm that. Rockbox safety AGC is NOT a "limiter." I'm guessing you may not know what a true "limiter" is? It means something very specific in the audio world, and safety agc isn't it. A real "limiter" is basically a special case of compression that typically uses a fast attack, and a very high compression ratio and threshold. The safety AGC turns the audio down after clipping occurs and it never turns it back up, whereas a limiter catches signals that go over a certain threshold and compresses the hell out of them to avoid clipping before it happens (and it does not lower the gain permanently, only temporarily in the moment the over is happening) -- these are two very different things. FWIW, I think it'd be a cool as hell feature for rockbox to have a compression capaibility for playback (not recording), but that's a whole different conversation.

why do you think did I use the " " when talking about the limiter .
i know its NOT a true limiter..."AGC-safety-clip" should be called different as "AGC" in this case will be misunderstood and generally has a bad image.

[dorrcoq]

i just bought the edirol r-09 and will tape my 1st show tonight in 2 hours ....in Vienna.
will use my sennheiser HLSC cardioids+bbox on MIC-IN starting at level 25/30 with MIC-SENS low, AGC off, LOW CUT off.
let´s see how it turns out.....

Why wouldn't you go Line-In?

[Arni99]

i just bought the edirol r-09 and will tape my 1st show tonight in 2 hours ....in Vienna.
will use my sennheiser HLSC cardioids+bbox on MIC-IN starting at level 25/30 with MIC-SENS low, AGC off, LOW CUT off.
let´s see how it turns out.....

Why wouldn't you go Line-In?

because guysonic(and i guess poorlyconditioned) said in his review that the mic in is almost impossible to overload and he was right .
the show was extreme loud in a small club(300 people).
i used:
manual level control starting at 25 but going down to 11.
recorded in 16bit/44.1khZ
bbox on MIC-in, no bass roll off.
some treble-boost in post is needed for the HLSC mics.

totally different levels accepted by the r-09´s mic-in compared to my sony mz-rh1.

great that the r-09 can handle high SPL on mic in perfectly .

thx for your help, arni