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cheap DI vs. expensive DI
- Thread starter Juniorkimbrough
- Start date
For adjusting phase (time alignment in this case, not the same as phase reverse) differences when playing live between a DI and a mic use something like this
Phazer - Radial Engineering
In the 70's, you wanted this: Invalid Link Removed. Neat to see the old hardware.
Phazer - Radial Engineering
In the 70's, you wanted this: Invalid Link Removed. Neat to see the old hardware.
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Within reasonable freqeuncy bandwidth a ported cabinet shifts phase by about -90 degree at the top range and by about +90..180 degree at the low end.
The SPL is shifted by 90 degree versus cone movement cause SPL is the derivation of moved air.
A microphone shiffts output voltage roughly by -90 degree cause mic output voltage is the derivation of a magnetic AC field caused by mic membran movement.
Unfortunatelly mics shows 2nd order HPF characteristic and so the mic shifts the phase by (additional) 90 degree around f3
All of these phase shifts have in common that there is really no delay present between both lines which was caused by any phase shift. This means there is no way to align phase shift issues with additional delay.
Btw. there are lots of folks out there who are very picky with any kinds of phase shift issues. Personally I don't bother too much with those issues cause "some" amount of shift happens in real practice day by day anyway.
Almost always those phase shift issues remain unnoticed cause the presence of phase shift "issues" is unknown.
That's the reason why we don't read any discussions about these "issues".
For example a parallel fx loop may split the signal to wet and dry path. The "wet" signal may be boosted at the mids with the EQ of a pedal board and then send back to the parallel fx-return. The wet (at the mids phase shifted) signal will be summed with the dry (none shifted) signal.
As (average) folks dont know about these phase issues they don't feel any need to discuss issues they don't know.
This delay or latency issue have absolutely nothing to with phase issues.
There is no way to align phase issues with delay.
Furthermore there is no way to align latency/delay issues with phase correction.
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Phase shift versus delay.
If a total signal was phase shifted by 90 degree then every Harmonic of the signal will be shifted by 90 degree.
Phase shft does NOT cause any delay. Even phase response of cabs does NOT cause any delay.
If a total signal was delayed by 2msec then every Harmonic of the signal will be delayed by 2msec.
Delay does NOT cause any phase shift. Even with pro audio software its not possible to shift the phase of a signal with "only" delay.
If a total signal was phase shifted by 90 degree then every Harmonic of the signal will be shifted by 90 degree.
Phase shft does NOT cause any delay. Even phase response of cabs does NOT cause any delay.
If a total signal was delayed by 2msec then every Harmonic of the signal will be delayed by 2msec.
Delay does NOT cause any phase shift. Even with pro audio software its not possible to shift the phase of a signal with "only" delay.
svtb15
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- Mar 22, 2004
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- I play it all. Whatever works for the gig. Q+
Honestly. Doesn't affect me. I only care if it works for my liking or my employers liking.. F3, F6 etc if fine for paperwork or creating a product.
Doesn't mean anything to me when in a session or on a gig.
I've been blessed to work with the biggest names in engineering and producing in the world the past 45 years. Roger Nichols who everyone knows did some stuff that doesn't seem right on paper. But it works in session and for Grammys..
HOnestly, I'm simply a guy that plays bass and tours for a living. I let the eggheads that know how to number crunch do what they do best..
I was on a gig with Jimmy Iovine years ago,while he was still producing records. The stuff that would make tech heads brains burn because it wasn't right on paper, didn't matter to him..
In fact he told me when i first worked with him back in the 70s when i was a kid in NYC sessions was "There are No RULES"... With the exception of measuring overheads with equal distance from kit center.
Doesn't mean anything to me when in a session or on a gig.
I've been blessed to work with the biggest names in engineering and producing in the world the past 45 years. Roger Nichols who everyone knows did some stuff that doesn't seem right on paper. But it works in session and for Grammys..
HOnestly, I'm simply a guy that plays bass and tours for a living. I let the eggheads that know how to number crunch do what they do best..
I was on a gig with Jimmy Iovine years ago,while he was still producing records. The stuff that would make tech heads brains burn because it wasn't right on paper, didn't matter to him..
In fact he told me when i first worked with him back in the 70s when i was a kid in NYC sessions was "There are No RULES"... With the exception of measuring overheads with equal distance from kit center.
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svtb15
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- Mar 22, 2004
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- I play it all. Whatever works for the gig. Q+
And it MIGHT sound good.. depending on what the overall product is.
I was in session NYC years ago.. Just spectating..Blondie was recording demos..
It doesn't have to be mathematically perfect to create a great sound picture that lasts for decades .
Room mics, Bleed and Console crosstalk bleed all create imperfections that work out great.
I have noticed that many DAWs now have CONSOLE emulations. To recreate/ SIM what the old consoles did back in the day and still do. Even the best consoles seem to have some level of channel bleed. Some worse that others. Funny thing is i NEVER noticed it back then.. But engineers knew it.. And now i notice it ..
Not sure if it was console crosstalk or adjacent 2" tape channel bleed. But it worked out just fine somehow
Nothing is pristine perfect.
I was in session NYC years ago.. Just spectating..Blondie was recording demos..
It doesn't have to be mathematically perfect to create a great sound picture that lasts for decades .
Room mics, Bleed and Console crosstalk bleed all create imperfections that work out great.
I have noticed that many DAWs now have CONSOLE emulations. To recreate/ SIM what the old consoles did back in the day and still do. Even the best consoles seem to have some level of channel bleed. Some worse that others. Funny thing is i NEVER noticed it back then.. But engineers knew it.. And now i notice it ..
Not sure if it was console crosstalk or adjacent 2" tape channel bleed. But it worked out just fine somehow
Nothing is pristine perfect.
The idea for this post was just to explain that sound engineers adjust pure delay "issues" if they add some delay to the DI line versus the mic line. Some (particular) phase issues (if present) between mic and DI can't be aligned with delay.
Reverse polarity issues (180 shift to the total signal) in this regard is a very different animal. these issues can be easily fixed with the revverse polarity switch
The real world solution is to time align the waveforms, you immediately hear an improvement and comb filtering isn’t generally an issue with bass. It can be with guitars and vocals.
At the very high frequencies there can be some phasing sounds after time alignment, even artifact type chirping in the very high frequencies. If it’s an issue, these can be eliminated with a stratiegically placed low pass filter. An alternative is some dedicated frequency specific processing or compression. The best solution depends on the case.
At the very high frequencies there can be some phasing sounds after time alignment, even artifact type chirping in the very high frequencies. If it’s an issue, these can be eliminated with a stratiegically placed low pass filter. An alternative is some dedicated frequency specific processing or compression. The best solution depends on the case.
Interestingly Jaco Pastorius was used to use a delay with very short delay time which could give him a "chorus like" and very "fat" sound.
I think that Jaco's sound is pretty much in contrast to what somebody might expect with phase/delay issues.
As long as it sounds good then its good. No need to claim "science" issues.
I recall that many bass guitar and 6-string players used short time delays to "enrich" the total sound of the instrument in the 80's and 90's of the last century.
I did it just the same way for some time with a Korg A3 (about 10..20msec delay) but, in the long run the sound was not fully convincing me for my soundgoals I did with a fretted bass guitar.
Here you are with the extraordinary "fat" sound that Jaco did with delay, at 51:50 he chimes in with solo playing
I think that Jaco's sound is pretty much in contrast to what somebody might expect with phase/delay issues.
As long as it sounds good then its good. No need to claim "science" issues.
I recall that many bass guitar and 6-string players used short time delays to "enrich" the total sound of the instrument in the 80's and 90's of the last century.
I did it just the same way for some time with a Korg A3 (about 10..20msec delay) but, in the long run the sound was not fully convincing me for my soundgoals I did with a fretted bass guitar.
Here you are with the extraordinary "fat" sound that Jaco did with delay, at 51:50 he chimes in with solo playing
True, but I have learned a very lot about "accurate" numbers since I joined TB. For example its common pratice to call a 2.67 Ohm cabinet a 2.67 Ohm cabinet rather than just call it 2.7 Ohm although the rounding error does not matter.Yeah, but when looking at orders of magnitude and sonic applications, that stuff pretty much falls away as a rounding error
Just the same is for 5.33 Ohm cabinets instead of 5.3 Ohm
- Feb 12, 2006
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- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
Phase deviations is generally only a real issue when combining parallel signal paths. It's especially an issue where the paths contain essentially the same signal plus a phase shift, for example, if the phase shift happens to be 180 degrees between the signals the results would be astonishingly bad...
Given the error/variation inherent in the impedance numbers, I'm not sure that two significant figures is warranted.
In regards to phase:
Back in the day we didn't have these new fangled computers to line up tracks, correct pitch, or deal with phase issues.
You had to play and sing in time and on pitch; I know, most of you weren't alive then. It was a magic time in the music buisness.
I was taught that if a combined input for a single instrument sounded bad, move the mic a few inches to a few feet one way or the other until it sounded best.
True confession. I was recording a rock album and had the snare double mic'd.
We cut the first 3 rhythm tracks with the top and bottom snare mics in phase (when one should have been 180 degrees out of phase).
It didn't sound bad but we recorded the next song with 2 snare tracks, one in and one out of phase.
We went with out of phase for the rest of the record; back then sampling was in it's infancy.
The difference was EQ'able and very hard to hear the difference; producer and band were fine with the outcome.
Some mistakes you never forget.
Back in the day we didn't have these new fangled computers to line up tracks, correct pitch, or deal with phase issues.
You had to play and sing in time and on pitch; I know, most of you weren't alive then. It was a magic time in the music buisness.
I was taught that if a combined input for a single instrument sounded bad, move the mic a few inches to a few feet one way or the other until it sounded best.
True confession. I was recording a rock album and had the snare double mic'd.
We cut the first 3 rhythm tracks with the top and bottom snare mics in phase (when one should have been 180 degrees out of phase).
It didn't sound bad but we recorded the next song with 2 snare tracks, one in and one out of phase.
We went with out of phase for the rest of the record; back then sampling was in it's infancy.
The difference was EQ'able and very hard to hear the difference; producer and band were fine with the outcome.
Some mistakes you never forget.
svtb15
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- Mar 22, 2004
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- I play it all. Whatever works for the gig. Q+
I did some sessions with producer Roger Nichols.. Of Steely Dan fame and Donald fagan. He alerted me to a few 'mistakes
" that were left on a Fagan record..
Roger, R.I.P. was METICULOUS. He invented WENDEL too. But some mistakes are golden.
The stories that he and his assistant shared were inspirational and priceless...
He also invented a low cost nuclear clock that he used to sync recordings. IIRC.. He has stories!
" that were left on a Fagan record..
Roger, R.I.P. was METICULOUS. He invented WENDEL too. But some mistakes are golden.
The stories that he and his assistant shared were inspirational and priceless...
He also invented a low cost nuclear clock that he used to sync recordings. IIRC.. He has stories!
I don't play covers that often but if Jean Jeanie is on the list, you've got to play that trainwreck bass part!
svtb15
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- Mar 22, 2004
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- I play it all. Whatever works for the gig. Q+
When this thread started the Noble hadn’t hit yet but at this point it deserves mention. I sold the REDDI I swore I’d never part with for one.
When covered without those mixtakes, something sounds not quite right. Raw playing with timing errors and mistakes can help make the song.
Here’s an example.
They sure can be bad but some can do a fine job down at the bottom end. You just need to know where to look.
This works great for a utility active DI
D.I. Boxes
And this is a great, simple 2 channel that can also be used as a splitter/combiner when needed. I use this one for keyboards or drum machines pretty regularly.
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