Topic: MME users ----->

[THE NIZ BIAAAAACH!]

I always run the SL, if you do some tests IMHO you can hardly tell its on, unless you just peg the levels.  Set it up in front of your stereo and do some tests.  I also have a reference listening system, and can hardly hear the difference.

[Tim]

it does make a "pop" when you turn it on though. if you don't start with it on be careful about switching it on!

[whitenite]

As mentioned, i may use it for acoustic music but never for hard rock with high SPLs.  this is why i run a V3 in front.  you don't have to fool with the levels on the MME or with SL.  the pre is VERY sensitive.  gotta tame that bad boy to some extent..  the A/D, on the other hand, is second to none IMO.

[caymanreview]

it does make a "pop" when you turn it on though. if you don't start with it on be careful about switching it on!

excellent tip, i hadnt noticed that, or even tested to see if it did! big +T for that

thanks guys for all the tips! ive got some smaller acts to tape here locally coming up, i will definantly be doing some experimentation with the SL

[bearcobb]

personally i always leave the soft limit on (position 1) and never really pump the levels that high (vary rarely do i ever see a red, maybe 5 times in about 50 shows ive taped) as id rather have a greater dynamic range. it doesnt need to be pounding all the time, just turn the stereo up if you want it louder!

[Tommy E.]

I am under the impression that by running any piece of equipment as hot as possible, without clipping, you extend the dynamic range; not the other way around.

[marc0789]

I am under the impression that by running any piece of equipment as hot as possible, without clipping, you extend the dynamic range; not the other way around.

ding, ding, ding, we have a winner!

run it as hot as you like, occasional reds are meaningless. soft limit is only appropriate when taping acoustic music, when you want to hit nice levels during the music, but not clip during the applause. in those cases, run it so you are around -3 during the music, to avoid the soft limit from kicking in at -2.

[bearcobb]

I am under the impression that by running any piece of equipment as hot as possible, without clipping, you extend the dynamic range; not the other way around.

thats probably the case, but for some reason all those high peaks do look like clipping on the waveform, whether or not you can see it.

i just notice that a lot of shows ive had before and when i was a patcher that lots of people cranked the levels so high that everything sounded really saturated to me, maybe that was a better choice of words. in this case for me less is more.

[OOK]

I always run the soft limit.  The limiter only engages when approach say -1db.  What it does is round off the peak so you don't get an over.  You can't hear.  It is only measurable with test equipment.  It doesn't hurt the dynamic range at all.  I run my mme hot peaking around -4db.  The limiter is rarely if ever hit, But I am safe in knowing that I won't have an over if the signal does try to hit above 0db, the mme won't let it................As far as the SLC setting  that is for dialing in some compression.  Now this is not compression in the sense that a minidisc is compressed.  No, this is the type of compression that is used in a studio durring a recording session.  It is for soft signals that need addition gain.  What it does is basically multiply it siganl times  itself to make the siganl louder(thats the best way I can decribe it) I not sure of the exact ratio of compression at the moment.  But the first setting is soflimit with a real mild compression ratio. I don't even think you can tell.  It may be a boost of 1 db.  The second setting is what is called a soft knee setting,slc2.  This is a compresion ratio of about 2:1 at -18db.  and finally the 3rd is about 3:1 at -15db. the more compression you add the louder the siganl appears....and the range is tightened up a bit.  For concert recording you will never need to use compression setting.  only with acoustic music would I recomend using it and no higher than 2:1(slc2) when at a distant form the source.  I hope this helps......................

[Brian Skalinder]

In the interest of clarity, from the MMe manual:

Soft Limit is an analog process that acts as a guard against digital 'overs' that can result from high-level transients in the incoming audio signal.  When enabled, Soft Limit will round out peaks in the incoming signal in order to eliminate the undesirable effects of clipping the A/D converter chip.  This rounding will begin on peaks at about -4dBFs and gradually smooth them out up to 0dBFs in order to safeguard the audio signal.  This process will not only eliminate digital 'overs', but it will also help t oget a few extra dB of gain to tape or disk.  (see illustration in post attachment)

 

Push-IT is a unique gain control circuit consisting of a compressor and limiter that are integrated with Soft Limit.

So, Soft-Limit and Push-IT are two different functions.  The MMe has the option to use just SL, or SL + P-IT, depending on your selection.

The limiter only engages when approach say -1db.

Per the manual:  Soft Limit alone, without any compression, kicks in at -4dBFs - not -1.  (see manual reference above)

It doesn't hurt the dynamic range at all.

This simply isn't true.  Soft Limit, by it's very definition, reduces the dynamic range.  You may not find it audible, but it does reduce dynamic range.  Take a look at the illustrations in the manual - it's quite clear.  (see attachment)

I not sure of the exact ratio of compression at the moment.  But the first setting is soflimit with a real mild compression ratio. I don't even think you can tell.  It may be a boost of 1 db.  The second setting is what is called a soft knee setting,slc2.  This is a compresion ratio of about 2:1 at -18db.  and finally the 3rd is about 3:1 at -15db.

Unfortunately, Apogee doesn't publish the compression specifications.  (Why am I not surprised).  But the attached graph from the manual gives an indication of the end result.

[Todd R]

I totally agree with what Brian said.  And I should add, pushing your levels will not increase dynamic range.  (It'll decrease your dynamic range if you clip though.)  Dynamic range is the ratio of the loudest part of the music to the softest part.  If you capture the soundwave accurately (ie, you don't clip), the dynamic range will be the exact same whether you run your gear hot or not.  The dynamic range is determined by the band/soundman, not the taper.

Depending on the specifics of your equipment, you can improve the signal to noise ratio by running your gear hot.  For most equipment, this will be the case.  This might be what people are thinking of, but running hot will not help dynamic range.  And as Brian alludes to, use of the MMe soft limit can only decrease your dynamic range, not increase it.

Also, fwiw, running hot and risking clipping for the purposes of improving S/N ratio really isn't worth it in my estimation.  From a S/N ratio, getting to -4db to -2db is fine.  The amount of internal noise inside your pre/AD that you can reduce by running hot is totally swamped by the vast amounts of noise within the venue and coming from the PA system.  I run hot since I don't do post processing and normalizing and I don't want to have to turn my stereo way up.  This is a reason for me to run hot, but improving S/N ratio or dynamic range is not.

[rustoleum]

close, Todd... but not 100% correct.  Your definition of dynamic range is correct (the difference between the loudest point and the softest point measured in decibels), but pushing your levels will increase your dynamic range.   Here's why: 

In the digital world, each bit can represent 6 decibals... a 16 bit recording can hold up to 96 db of information.   So..... you peak at -12 db you're only using 14 bits and therefore only getting a theoretical dynamic range of 84 decibels because you're not using 2 of your bits.  Peak at -2 db and you're getting 10 more and using all 16 bits.

This is one reason 24 bit recording is where it's at... you don't need to push your levels as close to 0 to get a CD quality or better recording as you've got room for a theoretical 144 db of information.

Peak at -12 in a 24 bit recording and you've theoretically got 132 db of info.

I suggest you check out Dan Heend's fantastic 24-bit Field Recording FAQ (http://www.24bitfaq.org) for more information on this exact topic.

[F.O.Bean]

nice posts guys

i always assumed what rustoleum said

[Todd R]

Thanks Rust -- good point.  Though I'm still not sure that in our real world application of recording PA systems it matters, though there clearly is a difference in theory.  My understanding is that the point you make only would figure in if the noise floor of our taping system is more than the noise level of the PA system we're trying to record.  (I guess we could talk about recording the whole room, not just the PA stacks, but the noise of the people in the room, the HVAC system, etc would probably still lead to the same conclusion.)  Or perhaps stated differently, if the PA system is only providing 68db of dynamic range, it doesn't matter if we limit our recording system to 84db instead of 96db by pushing our levels.

Also, as you note, I don't believe there is even a theoretical difference in dynamic range in recording at -3dbFS peaks (or even -6db peaks) rather than 0dbFS or 0.5dbFS -- you still use that last bit.  And even less of a difference if you record at 24 bits and dither down to 16 bits.

So anyway, I agree with you on what you said, but I'm still worried that tapers who don't understand this all that well will start pushing the hell out of their levels and getting clipping (thus doing more to reduce the dynamic range).  All to get better dynamic range out of their recorders in theory, even though that given the noise level of the system they are recording -- representing the absolute level of dynamic range that is achievable -- is well within the limitation of their recorders whether at -12db or -6db, let alone -3db.  Bottom line, I still think that a few db's of headroom will make for better recordings, not worse.

[F.O.Bean]

but technically, 0db isnt an 'over' right

thats why i hit zero on the v3 at least a few times a show, because thats not an 'over'