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I want to deal specifically with the Round trip issue identified in other threads. We all agree that an ITB recording should not suffer from the phase issues of round tripping. This should be easy enough to test. There are several members who claI'm to be able to hear phase shift from "round tripping" easily. If I take 6 mixes of raw drum tracks and bounce some of them totally ITB with no processing and send others with each track round tripped with no processing and then bounce them you guys should be able to pick out which is which with nearly 100% accuracy.

I understand the quality of the conversion and the hardware gear( a relatively clean D&R console) will effect the test. It should make it easier for analog guys to hear the result.

Who wants to participate? Is there a better way to test this?

Comments

KurtFoster Tue, 01/07/2014 - 10:07

through all of this i have never said anything about phase. to tell the truth that is way beyond my pay grade. but what i do speak of is what i hear.

and again i am not speaking of simple file copy functions or bounces. that's not the question. the question is what sounds better when i mix.

so what i think you ought to try is doing a mix itb and doing a mix through your console. try to duplicate each element as close as possible but include dynamics processing, reverb and delay effects and time based effects. if you can use plugs on the itb mix of the same analog processors you have on the otb mix, all the better. listen to see if one sounds better than the other. i already know the answer. in fact i challenge anyone to make the analog mix sound worse. remember the goal of this exercise is to exactly match the 2 mix's.

my contention is using an analog mixer makes better mix's. the better the mixer or console, the better the results. that's all.

audiokid Tue, 01/07/2014 - 13:30

I have no idea is this is helpful for you:

Crane Song - The listening test

The files presented here are the first in a set of files that have controlled and repeatable amounts of jitter. There are many questions about jitter and until now no real way to know what it sounds like. It can have different sounds as you will find out. The goal is education.

Depending on the playback system and the level of ear training it may or may not be possible to hear the differences in the files. The level of jitter has been pushed a bit to help this experiment. You will need to down load them and play them in your listening room[="http://www.craneson…"]

[/[url=http://[/URL]]link to the Jitter Pages[]]link to the Jitter Pages[="http://www.craneson…"]
jitter_1[/]

http://www.craneson…

Paul999 Tue, 01/07/2014 - 20:20

[quote=audiokid, post: 409547]I've never thought about printing different 2-bus mixes to the capture like this, then summing those ITB . Seems like a lot of extra fuss but it has me thinking. What do you all think?

(Dead Link Removed)

My version of this is to loop a verse or chorus etc. and record automation using my controller as I go. Not the same but works for me.

mberry593 Tue, 01/14/2014 - 16:24

audiokid, post: 409657 wrote: Interesting thread about phase:

(Dead Link Removed)

Yes, that was of some interest....BUT I made a BIG mistake and looked at page 1 too.

Note to self: Don't go to Gearslutz!

Let me add some of my experiences with phase. I started out working for NBC in the 1960s. At that time both the radio and TV networks were distributed by AT&T using copper equalized circuits. Fairly soon after I started, they were both changed to carrier which was a big improvement.

Here's how the copper circuits worked. We fed a circuit with 600 ohm/+8. The phone company used a transformer to make it 150 ohms. The phone company offered several grades of service....
-non-eq
-5 kHz
-8 kHz
-15 kHz
This was obtained by placing a parallel resonate circuit tuned just above the upper frequency of interest across the end of the circuit and then amplifying the result. The natural phase shift of the rolloff of the circuit was not exactly the same as the inverse of the phase shift of the equalizer. In short circuits with only a few equalizers, this was pretty much inaudible (or visible in the video). Long circuits were a different matter!
The backbone circuits of the networks were all 5 kHz. Many stations had 5kHz local loops but many others only had voice grade service. The network was in two parts. The eastern half (called the RAC) was in a circle....NY to Cleveland to Chicago to Washington and back to NY. There was a reversable circuit from Chicago to San Francisco for radio called the PC. TV did Burbank instead of San Francisco. Anyway, in the east you broke the circle (aka 'Round Robin) when you wanted to feed. That meant you could hear yourself coming back. In this case we are talking about a very long circuit with maybe dozens of equalizers. The phase shift was really nasty. On speech, 5 kHz service doesn't sound that bad but the phase shift made a really terrible effect. I can remember what it sounded like - - -and it WASN"T good! I would really have trouble putting it into words.

All of that said, it just might be that the phase shift did some other terrible things too. I'm not sure, I'm saying this because of my experience of what it did to the video which was clearly visible on the scopes. In the video, it was necessary to make an effort to correct the phase problems with all-pass filters. If it wasn't corrected, it would result in either a rounding of the waveform on trailing edges or ringing after transients. To my knowledge, there was never any effort made to all-pass correct the audio. (I would love to hear if any other network ever fooled with that.) The move to carrier and diplexed audio made the whole problem go away.

So, the phase shift in this grotesquely large situation did matter - alot!

NEW TOPIC

All of this talk reminds me of the 1970s in home HiFi. Some people got very concerned with the phase response (aka group delay) of loudspeaker crossover networks. I remember reading of someone's (I can't remember who) tests in which he fairly confidently identified that this was a significant degradation. Unfortunately the cure was elusive. Putting all-pass networks after the crossover is the obvious answer but that is not without problems. The worst problem may have been trying to take into consideration the listening room and speaker position which also have effects. Also the all-pass networks do nothing good for woofer damping.

NEW TOPIC

At any rate, if you are interested in fooling with this stuff, take a look at two Waves plug-ins.

First is the In Phase.
[="http://www.waves.com/plugins/inphase"]Phase Correction Plugin[/]="http://www.waves.co…"]Phase Correction Plugin[/]

Get the full version, not the LT version.

Waves also has a zero phase eq:
[[url=http://="http://www.waves.co…"]Linear Phase EQ - Equalizer Plugin | Waves[/]="http://www.waves.co…"]Linear Phase EQ - Equalizer Plugin | Waves[/]
Although I do own and frequently use the In Phase, I do not own the Linear Phase EQ so I can't comment on it.

If you just want to fool around with these things, Waves does offer a free demo situation.

Sorry for the long post.