MOTU 8pre vs. PreSonus FireStudio Project vs. Focusrite Saffire Pro 10 i/o

[Bitfiend]

As mentioned in a previous post i have a Mackie Onyx 1640 w/FW. going to get rid of it as it's way more and very different from what i need. Looking at the afore mentioned FW interfaces and wondering if anyone has had experience with any of them?

[admin]

What exactly do you need then, that the Onyx was overkill for?

[Bitfiend]

well it's a full 16 channels
the faders and EQ's DO NOT function with the FW option
So i have mic pre's, gain and conversion with only 2 channel stereo output not 16 i/o as you'd assume with a FW interface (sidebar, this has been a huge issue with unwitting consumers as 1. it wasn't clearly stated at first 2. then only in the literature in the box 3. now it's finally "known" upfront)

If i were doing live shows, it'd be a great mixing board.

i can ship it to Warren at Frontline (God know's what that'd cost) and for $399 he'll mod it so the faders and EQ's can be inserted in-front of the FW or not used via a pre/post button already on the board on each channel). So I'd end up prolly about $2500 into the board (maybe more once shipping is all said and done).

i just need 8 (7 actually) balanced inputs/outputs with pre's. with the afore
mentioned units, i'd spend $550 max. so i'd prolly come out about $1200 ahead when i sell the Mackie and can put that towards other more immediate gear (as in the monitors and converters we've previously discussed in other threads).
as of right now, the band records with my system as a scratch pad. This weekend we're booked into a professional studio here in Denver.
I don't see that changing until i get the studio situated and really learn all the gear, so the front end becomes the least important in the chain at the moment as there is only 1 conversion A/D then it's all ITB from there.
that first conversion is the killer. Knocks something like just over -3 dB out. So i'm thinking get a cheaper ADC for now, i'm not going to be doing 20 A/D D/A conversions, say, to OTB compressors, limiters, etc. (besides the converters in the Mackie wouldn't stand up to that anyway).

additionally if i decide i like using a control surface, i can't use the 1640.... so the behemouth sits there. This was bought prior to my knowing/understanding ANY of digital recording and in a whirlwind with my guitar player in a rush to
"record our next ablum". Yeah, what a joke....nothing like experience as a teacher....(tail between legs, and run away)

[admin]

Ok so you need 8 inputs and outputs of conversion with pres?

What do you you mean by knocking -3db out?

[Bitfiend]

Ok so you need 8 inputs and outputs of conversion with pres?

yep at the moment that is it. And i'd like to go the cheapest route at the moment as eventually it will be upgraded.

What do you you mean by knocking -3db out?

the first conversion you do A / D or D / A, instantly knocks off -3.0 dB in the dynamic range. after that, say you're running back out to compressors, limiters or other non-linear effects, the more times you convert the signal the more it looses. It's just nowhere near as much as the first time and actually the more times you convert, the loss gets less and less. But it has an accumulative affect over all.

[admin]

Where did you hear this -3db thing? I'd understand converters will add some noise which effectively does this, but so does most analog gear in one way or another.

[Bitfiend]

from Bob Lavry (Lavry Black box, Blue series and Gold).

"lets take dynamic range limitations, which are due to a random noise floor. Say we use one conversion as a reference point, calling it the 0dB referance point. Then the degradation in dB for 2-20 converters is:

2 converters -3.01dB
3 converters -4.77dB
4 converters -6.02dB
5 converters -6.99dB
6 converters -7.78dB
7 converters -8.45dB
8 converters -9.03dB
9 converters -9.54dB
10 converters -10.00dB
11 converters -10.41dB
12 converters -10.79dB
13 converters -11.14dB
14 converters -11.46dB
15 converters -11.76dB
16 converters -12.04dB
17 converters -12.30dB
18 converters -12.55dB
19 converters -12.79dB
20 converters -13.01dB

So the biggest loss is the first convertion. The second converter brings about a -3dB, which is the same as the COMBINED last 10 conversions in the chain. In fact, the difference between say convertions 19 and 20 is tiny. Now, if you compare one converter to say 16 converters, you have 12 dB "jump", which is 2 bits loss. And if you just add one converter at a time, starting at 10 converters and ending at 20 converters, the difference is 1/2 a bit."

[admin]

Just to note,you're not actually 'loosing' bits though, you're loosing dynamic range which is represented by bits. All the bits are there, but you've added noise above the inherent noise in the particular bit depth.

At the end of the day this is just a bit of noise way down below what you'll ever hear anyways, again not something to realyl worry about unless you're doing classical music.

[Rambunkcious]

Bit,

got to agree with jes, im running a bunch of a/d's, d/a's in the project studio setup and as mentioned the loss of dynamic range is actually an increase in your noise floor, and unless you are recording something that is super quiet and soft, like an orchestra as jes said, you'll be fine.

To combat the inherent raising of the noise floor by the amount of converters, just up your bit depth to 24 or even 32 if possible.

bunkcious

[admin]

Bit,

To combat the inherent raising of the noise floor by the amount of converters, just up your bit depth to 24 or even 32 if possible.

bunkcious

Careful as you're mixing two things here that shouldn't be.

No converters are 32bit so recording at 32bit doesn't solve anything due to noise coming from a converter, 32bit is for later, doing calculations.

Even 16bit has a very low noise floor, down to -93db or so. Even if you add a few db on top of that you're still in most cases below the noise of the source material.

For instance if your source mic has a noise floor of -70db, it's going to mask any of the noise of 16bit format which down at -93db, even with a few db added from the converters.

If you record a good signal at around -12 or so rms (with peaks around -6) you'll generally be just fine with 16bit.

Really guys though I've said it before, you can stop worrying about numbers. The impact it will have on todays music is pretty much nill.

If you can just forget that bits and noise floor etc.. exist you'll be a lot better off, unless you are really *abusing* your gear in either of these areas they don't contribute significantly to the final quality of a recording.

As I stated before I can convert a current pop or dance track to 7-8bits with dither, resulting in a noise floor of about -30db and you will still not hear it except for maybe the very beginning and ending of the track and even then it's not always noticeable.