Analog Summing - What for??

[taperocket]

Hi, I'm kind of confused as to what analog summing is and what it's used for, could some one offer me their insight? Thanks

 

[bennychico11]

summing is the combining of two or more signals. in audio this is usually done by taking two or more mono tracks and bussing them to a stereo track (although this can also be summed to a mono, 5.1, 7.1, etc. system). We don't have 24 speakers for each individual track, we just have two speakers to play back all the tracks. So we sum them together so they come out of the mixer in stereo.
Analog summing just means we do this in the analog world as opposed to the digital world. A lot of people will do this because they have a really good, expensive, mixing console that gives the sound that digital can't.

 

[taperocket]

ok so like the analog summing box from dangerous audio just imparts a more analog sound to a digital recording and that's why people use it?

 

[acorec]

ok so like the analog summing box from dangerous audio just imparts a more analog sound to a digital recording and that's why people use it?

No. The DAW digital summing has to make millions of calculations per second. The problem is with the rounding of these numbers when added, subtracted and divided. All these errors affect the sound in a negative way. Analog summing allows the DAW to only convert the individual tracks to analog with no further math involved. The tracks then can be mixed (summed) with no loss of information or errors. The end product is a generally cleaner mix that sounds "bigger" for lack of a better word. The tracks also gel together more naturally.

 

[mhelin]

Analog summing is for people who think computers make just errors . In fact the analog summing produces more distortion (in amplitude and phase) than the digital mixing, which usually is implemented in 64-bit floating point arithmetics, so the overload is impossible and the accurity is too large to be fitted on CD anyway. Analog summing may be useful if you want to process some of the tracks in analog domain and use much outboard gear. Also some people are used to analog faders to ride the gain of tracks when doing the mixup and use analog mixers with dedicated tape inputs (the line inputs in mono channels btw. usually go through the mic preamp section with the signal padded).

 

[acorec]

Analog summing is for people who think computers make just errors . In fact the analog summing produces more distortion (in amplitude and phase) than the digital mixing, which usually is implemented in 64-bit floating point arithmetics, so the overload is impossible and the accurity is too large to be fitted on CD anyway. Analog summing may be useful if you want to process some of the tracks in analog domain and use much outboard gear. Also some people are used to analog faders to ride the gain of tracks when doing the mixup and use analog mixers with dedicated tape inputs (the line inputs in mono channels btw. usually go through the mic preamp section with the signal padded).

That is one theory. There are dozens that are floating around in professional circles. The one I posed was from a phD in Digital theory and wrote the book on it. There is no one answer here but there certainly is a truth. Analog summing sounds much better than digital summing and is used in every major studio that records digitally that I know of. Truth or not, the pros sum analog through the Neve and SSL boards. I have used most of the DAW programs out there and analog summing trhough any analog console beats the **** out of digital summing every time.

 

[dwillis45]

The practical side of analog summing is that it seems costly to do right. You need multiple channels of AD conversion and a good analog mixing device. As far as I can tell, the cheapest way to get some of the benefits of analog summing is to shell out roughly five grand. That gets you something like the Dangerous 2-Bus and eight channels of "decent" AD conversion (Apogee, Mytek,etc.). Otherwise, you're talking about some very expensive pro consoles.

I suppose you could rely on a standard Firewire interface (like the MOTU 828) and one of the more afordable studio mixers (Allen and Heath, Soundcraft, etc.). But I don't have a clue as to how this type of analog summing would stack up against mixing "inside the box." Unforntunately, all the comparison info out there seems to be geared towards the pro consoles versus the pro DAWS. The 3d Audio DAW SUM sampler, for example, compares the following:

DAWS:CoolEdit Pro, Cubase, Digital Performer, Fairlight, Logic, Nuendo, PARIS, ProTools (LE, MIX+, HD and PT6), Pyramix, Samplitude, SAW, Sonar, Soundscape, Studio Vision Pro, Vegas

Digital Mixersanasonic DA-7, Sony Oxford, Sony DMX-R100, Tascam DM-24, Yamaha 02R96

Analog Mixers:
SSL9000J, Trident 24, Yamaha PM-2000, Manley 16x2 Line Mixer, Dangerous 2-Bus

 

[mhelin]

Analog summing sounds much better than digital summing.

That's why analog summing is used. The cleanest signal without 2nd harmonic distortion and noise doesn't sound as good as the clean signal. A/B tests have shown that humans prefer a signal with a little bit noise mixed in. But why buy something like a €2000 analog summing box when a €100 Behringer can do the same job? Yet something like Audient Sumo could be a nice box to have (http://www.audient.co.uk/Audient_Products.jsp?WhatToDo=SHOW_ITEM&CatID=22&ItemID=50) even though it can mix only 8 stereo signals.

You can still warm your sound in digital domain as well, use something like PSP Vintage Warmer or similar plugin. Sample the background noise of some vintage desk and create a noise track to be mixed with the other tracks.

 

[dwillis45]

But why buy something like a €2000 analog summing box when a €100 Behringer can do the same job?

You've shattered my faith in capitalism and market economics! I assumed, because of the price, that the Dangerous 2-Bus was 20 times better than the Behringer! Tell me it's not true!

 

[acorec]

That's why analog summing is used. The cleanest signal without 2nd harmonic distortion and noise doesn't sound as good as the clean signal. A/B tests have shown that humans prefer a signal with a little bit noise mixed in. But why buy something like a €2000 analog summing box when a €100 Behringer can do the same job? Yet something like Audient Sumo could be a nice box to have (http://www.audient.co.uk/Audient_Products.jsp?WhatToDo=SHOW_ITEM&CatID=22&ItemID=50) even though it can mix only 8 stereo signals.

You can still warm your sound in digital domain as well, use something like PSP Vintage Warmer or similar plugin. Sample the background noise of some vintage desk and create a noise track to be mixed with the other tracks.

Although some devices have reasonably low second-harmonic distortion, the ear is not very sensitive to 2nd harmonic. It's the 3rd and higher-order harmonics that create unpleasant "electronic" colorations. D.E.L. Shorter of the BBC Research Labs and Norman Crowhurst both proposed weighting harmonics by the square or cube of the order in to reflect audibility and annoyance-factor, and it's a shame their suggestions were never carried out. To this day, it's the 2nd harmonics that dominates THD device measurements, but it's the ones that are higher than that (even though they may be 20dB lower) that we hear. That's why a THD spec, without reference to the complete spectrogram, is essentially useless, and not only that, potentially quite misleading

Since most of the analog consoles out there are transistor in design (or IC based-same thing) then 2nd order harmonics and "noise" are more likely not the reasons that analog summing sound better than digital summing.

 

[mhelin]

Yes, the even ordered harmonics sound best. 100% 2nd harmonic distortion sounds like an octaver. In a recent finnish Hifi magazine the distortion effects were listened by using a distortion generator. One of the listeners liked the whole distortion generator removed from the signal path - even when it was bypassed by a switch it colored the sound negatively (same thing as with some guitar stomp boxes). If you're aim is to reproduce the reality (jazz, classic music etc.) go for digital and if you need some coloring use the analog gear. Digital summing does nothing to signal (except that it averages the overall volume which also the analog summing does after it's gone through the additional D/A and A/D steps). Problem is that it's so unforgiving, and you need a lot processing too. Reason why most producers like analog domain mixing is two-fold: It's more convenient because of the user interface issues and work flow, on the other hand it's just because these peoples are stuck with the old technology. For the same reason the new generation producers are attracted to old gear, digital is too clinical and uninteresting. I think digital is still on way to becoming what is it supposed to be. Maybe the new formats like SACD and DSD really give the life to the digital sound, let's see.

 

[NYMorningstar]

Problem is that it's so unforgiving, and you need a lot processing too. .

Using digital for mixing does not equate to needing alot of processing. If your mix needs processing it needs it regardless of whether you use digital or analog.

Reason why most producers like analog domain mixing is two-fold: It's more convenient because of the user interface issues and work flow, on the other hand it's just because these peoples are stuck with the old technology. For the same reason the new generation producers are attracted to old gear, digital is too clinical and uninteresting. I think digital is still on way to becoming what is it supposed to be.

Stating most producers like analog domain because of user interface issues and work flow is a big stretch and assumption. Digital has arrived. It is easier, more convenient and like it or not digital is being used in most studios now while the analog equipment is gathering dust.

I can't comment on your second reason why because frankly I don't know what you mean. Can you explain what

For the same reason the new generation producers are attracted to old gear, digital is too clinical and uninteresting.

means exactly?

 

[boingoman]

I think he meant processing as in processing power, for the number of calculations involved.

 

[acorec]

Quote:
For the same reason the new generation producers are attracted to old gear, digital is too clinical and uninteresting.

If anyone is going to reliy on a tape machine to get "interesting recordings" they have a serious problem with their recording methodology. Is it correct that in absence of a tape machine, one cannot make a good recording?

There are a whole ton of top level engineers recording grammy level recordings that are going to be dissapointed to hear this.

(Please don't tell them, OK?)