Topic: CAD e70 - Great Budget Mic's (Samples Inside)

[Neilyboy]

Chris,

This sound any better to ya? I tried inverting the left channel of my aud source. Then laying them down over each other again..

http://www.mediafire.com/?sharekey=604c8a120c42ec8975a4fc82078ae6c8e04e75f6e8ebb871

Neil

[chris319]

Neil -

What I observed is not a stereo left/right problem. The problem is, you are picking up the same source on more than one mic. In simple terms, whenever this happens, unless the sound waves arrive at each mic exactly in phase, you're going to get summing and cancellation at various frequencies and it's going to sound bad. To make matters worse, your room mics are picking up the lead vocal off the P.A. system and your board mix, I assume, is picking up the lead singer directly. This is going to happen whenever you try to combine room mics with a closely-miked mix and the results are likely to be unsatisfactory.

Your latest mix sounds better but I suspect I am hearing much more of the board mix in this version. I still hear a lot of noise from the crowd.

[ArchivalAudio]

^^^^^^^^^ I think what Chris is trying to say
is that the speed of sound travels slower than the sound thru the wires to the FOH mix (soundboard) if you are further back then say 25 feet (right now I am not remembering the milliseconds)
but if you run mics from further than 25 -30 feet away from the source and mix it with the board  you need to apply a delay to the board feed
either with a specified delay time
or
it is possible for you to align the waves forms  in a four track   situation
you'll need to physically move the  Soundboard feed  forward in time so the waveforms line up exactly, this can be done if you zoom in  while the 2 track of the soundboard are selected physically drag them to the right- or forward in time, and match the waves.

btw - I have not listened to the new "matrix" samples, but I saw you were like 45 feet back- which would cause a horrible delay fromt eh stage sound to where the mics in the audience are

one easy to avoid this is to place the mics on stage, or at the stage lip, you'll avoid that horrid delay - I think sound travels at 300 feet per second (I'm sure someone will correct me), but thru the wire it's "instant" or at least much lees of a delay.

phasing usually refers to when sound waves line up on th e opposite -= causing cancellation, which is not really what would be happening if the mics were 45' from stage, you'd be hearing one source first (the soundboard) and then you'd hear the mics just a few milliseconds after it causing a boomy echo like sound.

make sense?

hopefully
-- Ian

[Neilyboy]

Sure I understand but I have zoomed way in on the tracks in audacity and matched them up exactly which is what is confusing me. I will have to try it again but I am sure its aligned spot on.. is a delay filter different than just moving the audio right/left in my editor? Should I get it all lined up and then run a delay filter on the sbd feed of about .045?

or if anyone else has any good tips I could try out im all ears as I do want to make as best of mix as possible with this as the sbd feed sounds beautiful!

Neil

[ArchivalAudio]

neil,
well
as long as the wave forms are truely lined up from start to end, then the delay should be "time aligned" correctly.
as for the delay filter, you'd need to figure out the speed of sound and distance
by using a fomula- of which math is not my strong subject, perhaps sone one else could help, may be in the computer recording thread area.  ok
I found this

Sound travels at different speeds in different physical media. For air, the typical speed is 350 m/s (1100 ft/s).

and  this

Code: [Select]

Speed of sound.
In air, approximately 1130 feet per second at 20 degrees Centigrade. [3]  here:http://www.keithyates.com/glossary.htm

also see:
http://en.wikipedia.org/wiki/Speed_of_sound

where you will finsd some formulas

for those savvy with the fomulas could figure out the millisecond delay for 45 feet- but not me.

peace
-- Ian

[Neilyboy]

I read somewhere that it is .010 per 10 feet.. or something like that. so I was going to try running a delay of .045 or something like that... I have no idea what im doing haha. If anyone wants to take a shot at mixing this thing let me know and ill get the stuff to ya.. otherwise im going to keep playing around to figure it out.
I would love to learn but am having trouble finding any tutorials on how to figure out how much to stretch one source to match up with the other..

Neil

[Neilyboy]

I think I may have just figured it out! I have to take the mix to a buddy's house over lunch break here but I think it sounds pretty good through my zune earbuds haha

Neil

[chris319]

Even if you get the waveforms lined up, your mix will consist partly of the lead vocalist singing at close range into his mic (I presume) and the distant, echo-ey pickup of your room mics. Just something to think about.

[chris319]

you'll need to physically move the  Soundboard feed  forward in time

You need to move the board feed later in time. The room mics are more distant from the source so the board feed must be later in time to match the delay to the room mics.

phasing usually refers to when sound waves line up on th e opposite -= causing cancellation, which is not really what would be happening if the mics were 45' from stage, you'd be hearing one source first (the soundboard) and then you'd hear the mics just a few milliseconds after it causing a boomy echo like sound.

make sense?

No, it doesn't make sense. Two mics picking up the same source at different distances are going to have different times of arrival for the sound they are picking up. This causes a difference in phase regardless of the distance. Phasing is the difference in the times of arrival no matter the distance. This can cause summing and cancellation at different frequencies.

[raymonda]

That is the beast you work with when using a 2 channel board mix and 2 channel ambient mics. Often, however, the vocals are fairly dominate in 2 channel board mixes done in indoor, small venues. Usually the only thing the soundman really has to reinforce in the house is the vocals. So, you can often get a decent mix.

Play with it to your liking until it sounds good to your ears.

[ArchivalAudio]

you'll need to physically move the  Soundboard feed  forward in time

You need to move the board feed later in time. The room mics are more distant from the source so the board feed must be later in time to match the delay to the room mics.

^^^ yep that's what I said- to the right is later (or forward) in time  -- exactly.. depending on how you look at time and the terms forward or later -
if it is 8:00 am then 8:01 am is later in time  - it is also at the same time moved forward in time

and as far as Phase I think we are both right
see definitions here:
http://www.recordingeq.com/glossary/glospt.htm#sectP

Phase - A measurement (expressed in degrees) of the time difference between two similar waveforms.

Phase Addition - The energy of one waveform increasing the energy of another waveform because the two waveforms have similar phase relationships.

Phase Cancellation - The energy of one waveform decreasing the energy of another waveform because of phase relationships at or close to 180 degrees.

Phase Distortion - A change in the sound because of a phase shift in the signal.

Phase Distortion Synthesis - A method of altering a wave shape to add harmonics by a phase shift while a cycle is being formed.

Phase Linear- The quality of not having phase shift.

Phase Lock - 1) In the control of tape machines, a method of keeping machines synced together by sensing phase differences in the playback of pilot tunes by the two machines and adjustment of speed to eliminate the phase difference. 2) In synthesizers, the control of one tone generator so that it begins its waveform in phase with the signal from another tone generator.

Phase Reversal - A change in a circuit to get the waveform to shift by 180 degrees.

Phase Shift - A delay introduced into an audio signal measured in degrees delayed. 

Phase Sync – 1) A term with the same meaning as the term Phase Lock. 2) A method of keeping machines synced together by sensing phase differences in the playback of pilot tones by the two machines and adjustment of speed to eliminate the phase difference.

Phasing - An effects sound created by variable phase shift of an audio signal mixed with the direct signal.

and here:
http://www.rane.com/par-p.html

phase Audio signals are complex AC (alternating current) periodic phenomena expressed mathematically as phasors, or vectors. Phase refers to a particular value of t (time) for any periodic function, i.e. it is the relationship between a reference point and the fractional part of the period through which the signal has advanced relative to an arbitrary origin. [The origin is usually taken at the last previous passage through zero from the negative to the positive direction -- IEEE.] See Georgia State University's great website HyperPhysics for more detail.

phase cancellation When two signals have the same exact time relationship to each other, they are said to be "in-phase;" if they do not, they are said to be "out-of-phase." (Compare with polarity) If two out-of-phase signals add together, since this is vector arithmetic (see phasor), they will, in fact, subtract from one another. This is called phase cancellation. Another type of phase cancellation occurs when water waves interact. One wave's energy becomes stronger when two waves collide in-phase (summing) and becomes weaker when they collide out-of-phase (cancelling).

phase delay A phase-shifted sine wave appears displaced in time from the input waveform. This displacement is called phase delay and is usually constant for all frequencies of interest. Used as another name for group delay; however there are instances where they are not the same, for example systems exhibiting ripple in their phase vs. frequency characteristics.

phase lag and phase lead Phase shift caused by reactive elements (capacitors and inductors) that either subtracts (lag) or adds (lead) degrees of shift. See the RaneNote Linkwitz-Riley Crossovers: A Primer.

that's why a long time ago -about 18- 19 years ago in my experience of recording - and running matrix, recordings - I found mics on stage are the way to go,.  run them thru the snake to the FOH mix position, and you are golden, or run the FOH mix back to the stage, though this can also cause more of a wire run - thus causing more delay. the other way all the stage sound is traveling through the wires the same distance and relatively the same speed.

peace
-- Ian

[Neilyboy]

I will have some samples posted soon but I think I did a good job on getting the show sync'd and I made 8 different mix's yesterday (dropping my aud pull by 1 db each time, as it was a bit louder than the board feed). I ended up liking my ~65/35 mix the best. I listened to it in two vehicles (work vehicle and mine) as well as two home stereo systems (one at my buddies place after work and then on my own). Every time I end up picking the same one as my favorite.. So I think I have it mixed pretty well. I will have to get it tracked and up on the archive here soon. Thanks for all the tips!

Neil

[rokpunk]

I hate to be the naysayer....but I'm a dealer for CAD/Astatic and have still yet to hear a mic by that company worth anything more than change I can find in my couch. Crappy quality, crappy sound. Cheap, yes. If that's what you are looking for, you have found it with the CAD's.

[illconditioned]

Thanks for the info about the CAD.  I guess this is what we suspected.

Has anyone tried the AKG Perception 150/170 small condensor yet?  --> may be similar, but with better quality control (I hope).

How about the Behringer B5 (not the C4), the one with omni and card caps. --> made by 797 Beijing, may be comparable to Studio Projects C4, which I like.  Something like $100 each new.

These both seem like good budget condensors.  Either that, or scoring a pair of Studio Projects C4 here for $200 used.

  Richard

[Neilyboy]

http://www.archive.org/details/bt2009-10-16.cad.e70.mtx

have a listen.. It sounds ok to my ears..

Neil