Differences between analogue & digital mixing?

[Tapehead]

I'm finding it harder to get digital mixes just as I like them, whereas I found analogue easy from the off, so I don't think it is purely a personal experience thing.

In particular the levels of different instruments seem to vary more when played back at different volumes on digital mixes

I don't mean the relative differences between loud and soft passages, it is noticeable across entire mixes.

Is this a compression issue?

I never used compression in my analogue recordings (nor yet on digital), would it be the compression inherent to cassette tape making the difference and what would be the digital compression parameters that equate to tape?

Maybe I'm barking up the wrong tree but something is something is different between the two processes.

Lets say we have a recording with guitar, vocals, keyboard & drum tracks

What would be a good max level for each before mixing digitally?

[DVDdoug]

Theoretically, it's the same. Mixing is done by summation (addition). Computers are pretty good at addition! An analog mixer is built-around a summing amplifier, and when two sounds mix acoustically in the air, the waves are being summed. i.e. If you reverse the polarity of one speaker you are "adding a negative" and you can hear the bass subtraction. You can hear cancellation at higher frequencies too, but room reflections and distance variations give you a spacey/phasey sound as different frequencies are canceled more than others.

In the real-world, Analog mixers typically have more headroom than digital formats. Since you are adding signals, you can easily end-up with clipping (distortion) when you mix digitally. Audacity works in floating-point (like most audio editors), so there is virtually no upper limit and Audacity won't immediately clip when mixing. But if you export to a normal integer format, or send the full-volume signal to your DAC, mixing can cause clipping.

Yes, analog tape can introduce some compression. That would show-up as a difference between what you are hearing "live" from the mixer compared to what ends-up on the tape.

The cassette is going to have more noise and frequency response variations that you don't get with digital recording... Those are the things you'd probably notice if for example you transfer a CD to a cassette.

P.S.
And, there may be some other difference between you digital setup and your analog setup... And, it's very unlikely that you are mixing & recording the exact same signals!

[DVDdoug]

...and what would be the digital compression parameters that equate to tape?

It's hard to do with a regular compressor/limiter. You can find tape simulation plug-ins, and that's probably the way to go if you want to simulate analog tape. Usually these simulators are designed to mimic particular high-end studio reel-to-reel tape decks, and I'm just not sure if you'll find a cassette simulator.

Tape acts like a limiter with a soft knee. But it gets more complicated because the recording equalization (high-frequency boost & low-frequency cut) means that high frequencies are saturated at lower levels than low frequencies. And, the playback EQ (high-frequency cut & low-frequency boost) tends to "soften" the distortion caused by saturation/limiting.

[Tapehead]

Gets complicated doesn't it? At least for me it does.

Thanks for taking the time to explain things doug.

Maybe you have covered it and I haven't gotten things but I'm still wondering though about the relative playback volume levels.

On my fuze mp3 player I have several tracks recorded and mixed on the computer and several recorded and mixed on tape and tranferred to the computer.

The tape sourced tracks sound fine at lower volumes, the digital ones don't sound so good at lower volumes. They're better when driven with more volume.

[kozikowski]

I think you're listening to a combination of tape characteristics and your ear's oddities.

Loud always sounds good. That's why the store makes the sound system they want to sell quickly louder than the others.

Tape systems are not linear. They have a graceful "S" curve and it's your job to keep the show in the more or less flat, straight portion in the middle. So the shows are "compressed." Sharp, high peaks are reduced and there isn't much you can do about it. And you may not want to do anything about it. That "distortion" sounds pretty good. Also remember when you edit tape, you're going through all the tape electronics multiple times.

You stopped short of a definitive test. Tape dub the same song back and forth six or eight times to really see what the machines are doing to it. If you do that to the digital version, little or nothing happens. Something is going to happen to the Audacity digital version. Audacity adds a dithering signal to the export to get around digital conversion errors, and that will eventually add up. But I think the analog show is going to fall apart way sooner than the digital.

I wonder what would happen if you applied one of the "tape effect" filters to your digital work.

Koz

[Tapehead]

My ears can be a bit odd at times, they are highly/over- sensitive, a legacy of having had Myalgic Encephalomyelitis. I don't care for a lot of current productions even when I like the song.

It'll be a month or so before I'll be reunited geographically with my tape deck
so will experiment with copying digital mixes to tape then. Not to see which format 'falls apart' first but to see what it does to the sound.

In the meantime I'm trying out vintage warmer. Thanks for the suggestions koz

[Tapehead]

I like vintage warmer.

After initial bafflement I found this tutorial and then winged it.
http://www.youtube.com/watch?v=m8qolGXbB7o

Fully functional 14 day Demo.

[steve]

I like that the video makes it clear that the Vintage Warmer is a "distortion" effect (albeit a very subtle one). Far too often "analog warmth" is wrapped in mystical reverence that denies that fact

[Gale Andrews]

Far too often "analog warmth" is wrapped in mystical reverence that denies that fact

When audio is played in a real environment it gets modified, perhaps even distorted. There are some elements of that real life modification that digital doesn't capture properly IMHO. That's probably why some people think analogue sounds more natural, warmer or whatever, even if it has other distortions that are perhaps unwelcome.


Gale

[steve]

There are some elements of that real life modification that digital doesn't capture properly IMHO

Which "elements" are you referring to?
What do you mean by "doesn't capture properly"?

even if it has other distortions that are perhaps unwelcome

Distortion is not always "unwelome" (as illustrated by the existence of effects like "Vintage Warmer").