Testing an AT3035 thru VTB-1 Studio Projects Preamp,
directly to a Pro Tools HD rig, send signal to headphones mix.
Here is some pictures to shown where mic placement is, I am
using same room for tracking and mixing.
All the room has been treat with 120mm bass traps and 50 mm early reflections panels.
But because the vocal spot is in a corner with a ceiling slope,
I was thinking of adding some 50mm Auralex pyramid foam on the spots indicating by the red arrows:
1.Here you can see the angle of the ceiling, the distance height between
the mic and the ceiling is 50 cm. So I´m almost sure that is better to fix early reflections there.
You can see also one of the 16 blue 50 mm RockWool panels that I´ve made, they are great!
3.Here you can see the bass trap on the corner, and the other two
spots I want to put the pyramid foam, the distance from the mic to the
left wall (when the singer is in front of the mic), is 56 cm.
The other wall on the back of the singer is at 80 cm from mic.
Is there any way you can space at least half of your absorbers off the walls by at least 75mm, preferably 100mm? It looks to me like you have a combination of things going - some comb filtering, and not enough mid absorption but too much high absorption. This one change may fix it all, if not then some sort of absorber between the mic and the wall in front of the singer.
If possible, either double the foam thickness or replace it with mineral wool of around 48 kG/m^3, it will do more for you... Steve
Is there any way you can space at least half of your absorbers off the walls by at least 75mm, preferably 100mm? It looks to me like you have a combination of things going - some comb filtering, and not enough mid absorption but too much high absorption. This one change may fix it all, if not then some sort of absorber between the mic and the wall in front of the singer.
If possible, either double the foam thickness or replace it with mineral wool of around 48 kG/m^3, it will do more for you... Steve
Hi Steve,
Thanks for your reply!
Well, all the mid/high absorbers are 50mm thickness with 3.5 pcf (56 kg/m3) of density.
And they are 50mm away from the walls.
There´s 10 of them in the room and 7 Bass traps of 120mm with 4.4 pcf (70 kg/m3) of density.
When you say that there´s some comb filtering, and not enough mid absorption but too much high absorption
you are referring to the capture screen I´ve post uh?, so why dont I test the mic in the middle of the room and
see what the analyzer says...
After your reply, I really think the ceiling will need absorber in that spot
of the mic, but anyway I will test the middle of the room and see the response
By the way, what is exactly comb filtering and how can you figure out
that from a frequency capture?
Thanks for all the help!
:wink:
Your questions made me pay closer attention to your description - before, I thought from the pix that the singer was facing a glass at about 500mm - this can/will produce constructive and destructive echo, depending on frequency. This happens because at different frequencies the wavelength of the sound is different, so some frequencies are IN phase (original and reflection) while some are OUT of phase. Totally IN phase produces peaks, totally OUT of phase produces nulls, and frequencies that are somewhere in between will produce varying degrees of adding or cancelling of the sound.
Since I know that the ATM 3035 is a better mic than what your graph shows, and it's unlikely that ALL those peaks and dips are vocal chord related (I could be wrong) I jumped to the conclusion that comb filtering was happening - from my previous description, if you were to graph the frequency response of a mic in front of a hard surface, you would see a lot of peaks and dips in the response - a graph of these looks kind of like a comb (like you'd comb your hair with), this is where it got its name.
On closer reading, though, (mainly seeing that your graph is from a SINGER and not a test tone) I could be 'way off base here - now, I have to ask: are you asking this question because the recording sounds bad, or because the graph makes it LOOK like it should sound bad, or both? (you never did say how it SOUNDS - and that's the bottom line)... Steve
No, the recording voice does not sound bad.
But I dont like the way the graph is showing the voice response!
I just wanna make sure that this is the finest spot in the room
to recording vocals, so it came the idea of capture with PAZ analyzer
too see how it looks.
So, should I procedure with another test?
Using Pink Noise or just record a vocal with the mic maybe just turn it around,
so that the vocalist is singing into the center of the room, and not to the front ?
And there´s no glass, just the ceiling slope is 50cm height of the mic and
when you are singing the voice reflects there, so I wonder if I could deaden more all that corner
with the auralex foam in the red spots you see in the picture.
If this would help also to absorb more noise from the room (traffic, computers, etc...), great!
Remember is the same room for tracking and mixing.
Vocals are most voice-overs, narrator and some songs...
I do most instrumental music, as film composer.
So, am I on the right track?
You're on the right track with more absorption, since that will cut down on the reflections that cause uneven frequency response (comb filter effect) but I doubt you'll see much difference in room noise from doing that - things I would look at are
Reverse the direction the singer looks, so the corner is behind them
Make sure the music stand does NOT reflect between the rear of the mic and the singer's mouth - pick a different angle, move a light or the singer if necessary to eliminate light glare off the stand - microphones are NOT immune to rear pickup, especially at close distance; so you shouldn't have reflective surfaces returning echoes to the rear of the mic.
Don't worry about wierd looking waveforms from a human singer - if they produced only smooth frequency response sine waves, they'd be called a FLUTE.
The end goal is a good sound - so the most important thing you can do is EXPERIMENT. There's going to be some things about your space that either you don't think to mention, the pix don't show, or I don't catch, that can change the way your sound records - so make test recordings of the same singer with one thing changed per test, and compare them - the one that sounds the best, IS the best... Steve