The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
Time Aligning Sound Console Mix w/Ambient Mics Recorders, Players & Tape Machines
Old 1 week ago
  #31
Lives for gear
 
crosscutred's Avatar
Quote:
Originally Posted by Samc View Post
Time alignment was always a "thing" and that's why all those recordings sound good...alignment is not just about using digital delay.

This is not just about personal taste, and the science behind the concept were well understood for a long time.
Oh yes, sure, I should have used the exact phrase "sliding tracks around in a daw to put one frequency in a complex signal into alignment with another track"

But it doesn't trip off the tongue.

Really it was rhetorical too, because I'm aware it became a thing when DAWs were invented.

I'm not a fan of doing it, not because of "personal taste" but because it's obvious that the result is a fudge at the best of times.
Old 1 week ago
  #32
Lives for gear
 

Quote:
Originally Posted by crosscutred View Post
...I'm not a fan of doing it, not because of "personal taste" but because it's obvious that the result is a fudge at the best of times.
...to me this sounds more like you haven't experienced a properly aligned signal or you're telling all system techs that their work is crap - maybe you're missing the appropriate tools?
Old 1 week ago
  #33
Lives for gear
 
crosscutred's Avatar
Quote:
Originally Posted by deedeeyeah View Post
...to me this sounds more like you haven't experienced a properly aligned signal or you're telling all system techs that their work is crap - maybe you're missing the appropriate tools?
I am not missing a DAW, which is the only tool you need for this.
If you move a track in the daw in time some of the frequencies will align (you choose which by either what the peaks look like on the screen or by sound) then other frequencies will be pulled out of a coherent phase relationship with the other mics in the DAW.
It is a compromise.
It is something that can be rendered unnecessary by placing your mics with care and attention.

To avoid confusion, which seems to be a feature here, I am not talking about time aligning speakers in the live environment or placing mics with time alignment in mind. Only about sliding them around in the DAW to try and compensate for badly placed mics in the first place.
Old 1 week ago
  #34
Lives for gear
 

Quote:
Originally Posted by crosscutred View Post
Oh yes, sure, I should have used the exact phrase "sliding tracks around in a daw to put one frequency in a complex signal into alignment with another track"
This is incorrect...sliding the track in the DAW does not just align one frequency as you claim.

Quote:
Really it was rhetorical too, because I'm aware it became a thing when DAWs were invented.

I'm not a fan of doing it, not because of "personal taste" but because it's obvious that the result is a fudge at the best of times.
You keep using the phrase as if this practice is just some arbitrary fashion statement...modern tools allow us to align recorded audio tracks easily and accurately. This means recording microphones can be placed exactly where they will be out of the way and/or offer best sound quality in a given situation etc., and then aligned after the fact.

If you're not a fan of doing it, maybe you can explain the method you use, and explain why doing it in the DAW results in an obvious fudge...?
Old 1 week ago
  #35
Lives for gear
 

Quote:
Originally Posted by crosscutred View Post
I am not missing a DAW, which is the only tool you need for this.
If you move a track in the daw in time some of the frequencies will align (you choose which by either what the peaks look like on the screen or by sound) then other frequencies will be pulled out of a coherent phase relationship with the other mics in the DAW.
It is a compromise.
You should use the right terminology so we can follow your arguments...

Quote:
It is something that can be rendered unnecessary by placing your mics with care and attention.
As long as there are two or more microphones all the information will never be in perfect alignment...the type of mic used and it's placement can reduce this unwanted effect.

Quote:
To avoid confusion, which seems to be a feature here, I am not talking about time aligning speakers in the live environment or placing mics with time alignment in mind. Only about sliding them around in the DAW to try and compensate for badly placed mics in the first place.
"Badly placed mics"...?
Old 1 week ago
  #36
Lives for gear
 

Quote:
Originally Posted by crosscutred View Post
I am not missing a DAW, which is the only tool you need for this.
If you move a track in the daw in time some of the frequencies will align (you choose which by either what the peaks look like on the screen or by sound) then other frequencies will be pulled out of a coherent phase relationship with the other mics in the DAW.
It is a compromise.
It is something that can be rendered unnecessary by placing your mics with care and attention.

To avoid confusion, which seems to be a feature here, I am not talking about time aligning speakers in the live environment or placing mics with time alignment in mind. Only about sliding them around in the DAW to try and compensate for badly placed mics in the first place.
there's a huge difference between TIME alignment which indeed can be done with a daw or any digital desk (and is 'good enough' on many occasions, meaning it yields a clear improvement over not aligning at all) but works for a specific frequency area only and PHASE alignment in multiple frequency areas which can be done with some of the more sophisticated speaker processors: they do not need to get used for alignment of speakers only but can be used for alignment of spot to (coincident) main mics as well.

you need an fft though running a capable analysis software and some experience how to interpret phase plots plus some dsp/speaker processor with enough allpass filters.

wondering which daw/sequencer can provides this?!

once you've heard (what i call) 'properly' aligned spot mics using the very same technique live sound has been using for at least two decades now (as sam pointed out), i'm pretty sure you wouldn't call the results 'fudge' anymore - obviously, you haven't...



[side note: sometimes i'm wondering why classical music recording/mixing engineers refuse to adopt technique from live sound (in a rather arrogant way); if i'd refuse to go the extra mile as a system tech when setting up speaker system on large productions and use but simple time delays, i'd get fired pretty soon!]
Old 1 week ago
  #37
Lives for gear
 
Roland's Avatar
Croscutred is partially right, in that you can’t completely line up two microphones, even on the same axis with a single point source sound. This is one of the reasons that speaker measurement is so difficult and even in the best conditions is open to a certain amount of interpretation. In the case of two microphones on a single axis, pointing at a single sound source, (for the point of original argument we will ignore reflections or extrenuous pick up), at higher frequencies the frequency response will vary due to the distance from the source relative to the wavelength. Move the mic forward or backward on that axis will effect ‘what it hears’. A good tool for trying to deal with these type of problems is the waves In phase, but even using this is not a perfect fix.

Going back to the op question, perhaps no time aligning is what is needed, perhaps it needs to be matched exactly to the main mix. This is something for post mix unless it’s a live broadcast. My suggestion for not delaying it to tape is that the original is preserved and if after careful listening in a controlled environment the alignment doesn’t work, the original is still available, not a situation of trying to find another best compromise.
Old 1 week ago
  #38
Lives for gear
 

Quote:
Originally Posted by Roland View Post
Croscutred is partially right, in that you can’t completely line up two microphones, even on the same axis with a single point source sound. This is one of the reasons that speaker measurement is so difficult and even in the best conditions is open to a certain amount of interpretation. In the case of two microphones on a single axis, pointing at a single sound source, (for the point of original argument we will ignore reflections or extrenuous pick up), at higher frequencies the frequency response will vary due to the distance from the source relative to the wavelength. Move the mic forward or backward on that axis will effect ‘what it hears’. A good tool for trying to deal with these type of problems is the waves In phase, but even using this is not a perfect fix.

Going back to the op question, perhaps no time aligning is what is needed, perhaps it needs to be matched exactly to the main mix. This is something for post mix unless it’s a live broadcast. My suggestion for not delaying it to tape is that the original is preserved and if after careful listening in a controlled environment the alignment doesn’t work, the original is still available, not a situation of trying to find another best compromise.
sorry, but this is rubbish: of course one can 'align' any two mics, regardless of characteristics, position, angle and orientation towards a source! alignment means nothing but moving one mic back in time, resulting in an effect as if the distance to the source would have been identical for both mics - no big deal, this can be done down to microseconds, good enough for our ears/brain.

when talking about alignment, using terminology such as 'completely line up two microphones' is misleading: of course it's not possible to make a more distant mic sound the same as the mic closer to the source and vice versa! but it is possible to get much better results regarding their phase relationship than just delaying the closer mic (see my previous post, tons of literature, videos on youtube etc.)

anyone not having spent enough time with smaart/lake cannot know what s/he is missing!

and no, speaker measurements ain't that difficult to do: difficulties only start with validity and interpretation of data or arguments over what shall and can be achieved with corrections. some things cannot be corrected, no matter what amout of dsp is available - choose design, positions, x-overs, delay, eq and phase corrections wisely...
Old 1 week ago
  #39
Lives for gear
 
Roland's Avatar
I’m not sure that you are saying anything different from what I was saying. My point was that two microphones at two given distances on a single axis can be aligned due to delay. BUT, there will still be anomalies due to wavelength, air damping, and this doesn’t take into consideration reflections, and other sounds picked up off axis. These are all reasons why even when alignment is done it doesn’t guarantee great results.

As you are familiar with Smaart and lake style dsp processing you are also aware of how a flat(ish) response close to a speaker may sound good, now produce that response at 100 ft and it sound subjectively way too bright. Are ears and brains are programmed to make these judgements. It is a complex subject and subject to interpretation as you allude to in your final paragraph. The suggestions that adding a delay during record will just fix the sound for the original poster are just plain wrong. It may, but it may not. Even with post production and the ability to ‘perfectly line up at sample level in a DAW doesn’t guarantee a great result. As in all things audio, it depends.
Old 1 week ago
  #40
Lives for gear
 

Quote:
Originally Posted by Roland View Post
I’m not sure that you are saying anything different from what I was saying. My point was that two microphones at two given distances on a single axis can be aligned due to delay. BUT, there will still be anomalies due to wavelength, air damping, and this doesn’t take into consideration reflections, and other sounds picked up off axis. These are all reasons why even when alignment is done it doesn’t guarantee great results.
Under normal circumstances and if the microphones are on the same axis, the single most important anomaly that will negatively affect the microphones will be reflections, and especially off axis reflections.

Air damping, temperature etc will not cause problems that can be heard in a mix, this is true even in the studio, no two microphones on a drum-kit will have the same exact information, but unless you do something really wrong it will not/shouldn't sound strange. Just nudging the audio in the DAW will sound a lot better than microphones that are more than 80' apart...as could be the case in the OP.
Old 1 week ago
  #41
Lives for gear
 

Quote:
Originally Posted by Roland View Post
I’m not sure that you are saying anything different from what I was saying. My point was that two microphones at two given distances on a single axis can be aligned due to delay. BUT, there will still be anomalies due to wavelength, air damping, and this doesn’t take into consideration reflections, and other sounds picked up off axis. These are all reasons why even when alignment is done it doesn’t guarantee great results.

As you are familiar with Smaart and lake style dsp processing you are also aware of how a flat(ish) response close to a speaker may sound good, now produce that response at 100 ft and it sound subjectively way too bright. Are ears and brains are programmed to make these judgements. It is a complex subject and subject to interpretation as you allude to in your final paragraph. The suggestions that adding a delay during record will just fix the sound for the original poster are just plain wrong. It may, but it may not. Even with post production and the ability to ‘perfectly line up at sample level in a DAW doesn’t guarantee a great result. As in all things audio, it depends.
i still don't agree with what you're saying regarding time alignment of two mics, unless the temperature and humidity is very different in the two positions (which may be the case in large venues/outdoors) or if the distance is that long that mic's cannot 'hear' anything from each other's source: mic's can be perfectly time aligned, regardless of pickup pattern, axis, reflections etc. - even wheather condition can be calculated in (not that i want to do this though...)

anyway, i'm with you that alignment of spot mics does not necessarily guarantee musically pleasing results! especially those who like a more blurred image from spaced omnis may not want to challenge/destroy the airy character of a recording/mix while i would expect those who prefer precise localisation from coincident pairs to prefer their spots to be aligned (also in different genre than classical music as sam mentioned in his example). - i guess ambis are more of a special case: on music with lots of sound coming from percussion instruments, i would at least try to align ambis; on softer music i often like the sweetening effect of distant mics without alignment (or replace them with efx).

when aligning spots, i recommend using all the tricks we have available: the realism which can be achieved when also taking into account phase behaviour in multiple frequency areas is just unparalleled!

regarding alignment of speaker systems, there is (hopefully) a difference between flat speaker response with pink noise (or sweeps) and response from the system with a band/ensemble playing: can't stand those mixes with flat response either! - a flat alignment of a speaker system measured at foh mostly translates to a response of a 3db drop per octave starting at 1khz with music from natural/amplified instruments (much different with all eletronics/playback tracks etc.)

besides housekeeping, i use dsp in studios to mimic some curves (although with a softer tilt) or to compensate for different listening levels - one cannot use b&k/smaart/lake enough!

Last edited by deedeeyeah; 1 week ago at 12:44 PM.. Reason: typo and edited
Old 1 week ago
  #42
Lives for gear
 

Quote:
Originally Posted by deedeeyeah View Post
i still don't agree with what you're saying regarding time alignment of two mics, unless the temperature and humidity is very different in the two positions (which may be the case in large venues/outdoors) or if the distance is that long that mic's cannot 'hear' anything from each other's source: mic's can be perfectly time aligned, regardless of pickup pattern, axis, reflections etc. - even wheather condition can be calculated in (not that i want to do this though...)
Unless one mic is indoors with the heater on full and humidity close to 100% and the other is outdoors in the middle of winter, I think it is improbable that that there would be an anomaly big enough to be heard... I've done arena and stadium gigs/tours and this was never a problem with ambience mics on either end of some very wide stages.

I don't understand why the room mics would be up to 80' away from the stage in the first place and what they are aimed at, this would seem to be the bigger problem as ideally the mics should be on the stage aimed at the room. sending the signal from these mics through the console via the matrix (to the recorder would even be better since it would be subject to the same converter delay as the mix...Anything else is begging for unnecessary complication and hence unnecessary trouble in my opinion.

Quote:
anyway, i'm with you that alignment of spot mics does not necessarily guarantee musically pleasing results! especially those who like a more blurred image from spaced omnis may not want to challenge/destroy the airy character of a recording/mix while i would expect those who prefer precise localisation from coincident pairs to prefer their spots to be aligned (also in different genre than classical music as sam mentioned in his example). - i guess ambis are more of a special case: on music with lots of sound coming from percussion instruments, i would at least try to align ambis; on softer music i often like the sweetening effect of distant mics without alignment (or replace them with efx).
In my opinion, room microphones are supposed to help the broadcast and/or post mixer (accurately) represent the experience of being in the room. Ideally, (in my opinion) room mics should be placed on the stage and aimed into the room and should be aligned with the most forward microphone...usually the lead vocal.

Being the closest to the front of the stage and (usually) also the loudest, it will most likely have more room information than the other mics on stage makes it a good reference point. Placing room mics at the mix position regardless of where they're aimed, is wrong on so many technical levels I can't think of a situation where it should ever be done.

In my experience, a single pair are often never enough for a really full, three dimensional sound...I usually use three or four pairs aimed at specific areas of the listening space to represent the depth and width of the venue.

This is course geared toward reenforced rock/pop band situations...stereo, acoustic recordings are a different thing altogether.

Quote:
Originally Posted by deedeeyeah View Post
when aligning spots, i recommend using all the tricks we have available: the realism which can be achieved when also taking into account phase behaviour in multiple frequency areas is just unparalleled!
Yes!
Old 1 week ago
  #43
Lives for gear
 

pretty much my thoughts on the use of room/ambient mics too, (except for) three things regarding the positioning i'd like to add:

- when recording classical music, it may be desirable to have a pair (or more) room mics as far away from the source (ensemble/orchestra/choir) as possible so these mics will pick up mostly diffuse sound/almost no direct sound or any unwanted noise from the stage. their tracks then can be used as a 'natural room efx' and as such don't necessarily need to be aligned to the main mics or even get additional delay - when recording live, crowd noise can rend them useless though so i try hanging them pretty high up/ from the roof if possible...

- when recording/mixing amplified music (jazz/pop/rock) or modern music for orchestra and electronics, i like setting up a stereo pair of ambis at foh and keep these tracks as a reference for the balance between amplified music and applause/crowd noise - i may not use them for postproduction though. if i do, i align them almost always and i sometimes feed these mics to the video folks in the venue.

- ambis on the stage can also serve to blend in some ambience for musicians wearing in-ear systems without risking a large delay between the aux mix (of direct signals from close mics) and ambis - during songs, ambis get ducked.



p.s. i so far only once experienced an atmospheric difference between two mics: a measurement mics in one of the delay towers was relatively close to a waterfall at the far end of the field while the measurement mic at foh was in the middle of the audience, standing/dancing on a concrete runway which lay in plain sunlight all day long:
difference in temperature and humidity was considerable so i could see a difference between the mics in the two delay towers on the analyzer. i could even watch the drift in sound propagation when it got dark earlier at one delay tower due to the sundown behind the mountains!
cannot remember though what the system tech suggested, if the delay towers could get adjusted separately nor what we did - tricky situation...

Last edited by deedeeyeah; 1 week ago at 05:53 PM.. Reason: p.s. added
Topic:
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump