Topic: Brickwalled recordings

[Gutbucket]

Well that's really no different.  It's still happening earlier in the chain, its just that most or all of the chain is in one device.  In the case of any of these all-in-one recorders you have what used to be multiple boxes (preamp, ADC, recorder.. mics too) all in one unit.  When brickwalling happens in the R-09, the analog input preamp stage of the chain within recorder is clipping.

Of course in that case, we have no way of changing the gain staging between the components within the device itself.  That's Edirol's job in setting up the gain-staging when they designed the machine.  It can be strongly argued that allowing the user to set input levels below level 8 on that device is a design flaw.  After all they have all the components under their control.  But once we know not to use such low settings it's not a big deal. We just stay away from that region.  Similarly I don't run the gain up too high because noise becomes a problem.  I mentioned this elsewhere, but my comfort region on the R-09 is about 10-20 or so.  If I need more gain then that I use an external preamp or a sensitive mics.  If I needed less I'd use attenuators before the recorder's inputs or less sensitive mics.

[newplanet7]

So basically this is less likely to happen with separate components
rather than all in ones?
Basically because you get to monitor each stage?

[Gutbucket]

If you had actually had meters everywhere that would be true, but there usually isn't metering available on every unit.  Take pre-amps for example.  I have meters on the V3 but none on the MMA6000 or my Church Audio pres.  If I run the V3 in front of the R-09 I can check levels on both of those units.  Because the R-09 doesn't accept a very hot signal, the V3's meters only light up the first few lights when I set the r-09 input at 10 (the lower end of my comfort range).  That's OK, nothing is overloading, but I don't really need the meters on the V3 in that case.  It's sort of the opposite of the brickwalling, the V3 has way more headroom than needed in this case and is in no danger whatsoever of clipping.  But the V3 is a more professional piece of gear designed for higher levels and with more headroom in its analog sections.

I've thought about doing the math to figure out at what point I will be close to clipping those other preamps so that I actually know what's going on with the gain staging in my chain.  I know the sensitivity of the mics and have specs on some of the preamps, but the math part is a bit beyond my skills and I can comfortably run my gear without knowing exactly so doing that would be a bit academic.  That's something I'd need DSatz or one of the EE's on this board to help me through.

In actuality, all-in-one recorders should be less likely to have problems because the manufacturer is responsible for making sure all the components work together at appropriate levels.  Yet cost constraints manufacturing inexpensive recorders means that there is no budget for extra headroom for unusual 'just in case' scenarios and these types of problems can manifest with extreme settings.

[Ekib]

That's nice and all ...the difference between brickwall and clipping...thanks for the info...but...my question was is there any way to correct this with any type of software ? I have anto clipping in for example Nero Wave Editor and all it does is lower the volume. Not the distortion itself.
I am just wondering if there is any way to fix it.
A friend of mine compares it to scratches on a picture ...whatever isn't there can't be corrected he says . But I think it is the opposite. To me it looks like there is too much info ( for lack of a better word ). It's not like something's missing , it's just too much.

[newplanet7]

I don't think you'll be able to undo the distortion/saturation.
When I bricked I just deleted it.

[it-goes-to-eleven]

You can use the pencil tool to fix it by hand.   You might be able to use an expander to spruce things up but that's iffy.  Maybe in 5 or 10 years they'll be able to cure it with stem cells.  The fix everything!

Sometimes you have to accept it as a learning lesson and move on.   As long as the artist hasn't died and this was their last performance, etc, you'll get another chance.

[Gutbucket]

That's nice and all ...but...my question was is there any way to correct this with any type of software ?

A qualified yes.. see the first two responses to this thread.

[jlykos]

Sony Sound Forge has something called the Clipped Peak Restoration, which appears to me to be a kind of compression where it take s the signal and lowers it to a certain extent and then cuts it off at a user-defined limit.  I used it on a recent Mastodon recording where I accidentally knocked the -20 db switch to 0 and it improved the recording to a significant extent, but it does sound quite different (i.e. compressed) after the processing.

[Gutbucket]

I've only noticed the Samplitude version since that's the software I use, but haven't used the function.  All of the tools mentioned probably lower the level of the signal a bit to 'make enough room' to recreate the peaks, then use some sort of algorithm to guess the shape of the wave that should be there if it wasn't flat topped by clipping..  Sort of like enlisting a bevy of ompaloompas with pencil tools to redraw the tops and bottoms of the peaks like Freelunch mentioned.

Like most things the less you need it the better the results are likely to be, ala the 'conservation of goodness' law.

[newplanet7]

But would this really minimize the distortion?
I don't see how it could.
It seems that it would just lower the volume of the distortion.
I know when I bricked Sound Forge didn't do squat.

[jlykos]

But would this really minimize the distortion?
I don't see how it could.
It seems that it would just lower the volume of the distortion.
I know when I bricked Sound Forge didn't do squat.

My relative success with the Clipped Peak Restoration may have also been a function of using the limiter on the D50, which kicks in when the signal hits 0 and then reduces it around -12 db.  As a result, the distortion caused by clipping is not nearly as high as on other recorders.  There is still distortion present, particularly on the bass, but the recording sounds OK otherwise, even though it is quite compressed.

[newplanet7]

thanks jaime.
Now when you say clipped, you mean 0 right?
That, to my knowledge is the only way it will work in SF
because it looks for anything @ 0db.
I may be wrong though.

When I "bricked" I didn't have any peaks above -4.
Just squared off waveforms at -4db that were distorted.
Since then though I just run the pad on my 660 and all is well.
-todd

[jefflester]

They term "brickwalling" was used for years on DAT-heads, so not just around here. Though I suppose one could say the "taper community" which includes DAT-heads and TS. It was a problem with the Sony TCD-D7 and D8. The Sony TCD-D3 was the earlier generation small Walkman sized model and it was more tolerant of input level, the D7 came along as the next generation but was less tolerant.

Here's a vintage DAT-heads post describing the issue:
http://www.rockpark.com/d7/8_brick.txt
 

[newplanet7]

They term "brickwalling" was used for years on DAT-heads, so not just around here. Though I suppose one could say the "taper community" which includes DAT-heads and TS. It was a problem with the Sony TCD-D7 and D8. The Sony TCD-D3 was the earlier generation small Walkman sized model and it was more tolerant of input level, the D7 came along as the next generation but was less tolerant.

Here's a vintage DAT-heads post describing the issue:
http://www.rockpark.com/d7/8_brick.txt
 

thanks for the article link.

[Ekib]

They term "brickwalling" was used for years on DAT-heads, so not just around here. Though I suppose one could say the "taper community" which includes DAT-heads and TS. It was a problem with the Sony TCD-D7 and D8. The Sony TCD-D3 was the earlier generation small Walkman sized model and it was more tolerant of input level, the D7 came along as the next generation but was less tolerant.

Here's a vintage DAT-heads post describing the issue:
http://www.rockpark.com/d7/8_brick.txt
 

I have brickwalled recordings made with the TCD-D3 aswell.
Can't even remember how much battery trouble I've had with this recorder ! It broke down so many times.
I was glad I ws able to switch to the TCD-D7 and be able to use penlites...