Solved - thanks all! Microphone sound shielding

[boojum]

Folks, geeks, gurus and nerds -

I have a SONY ECM-MS957 which works alright but I get sound from behind it too much. Is it OK to place a sheet of sound absorbent material behind the mic to make sure all I pick up if from the front? Seems like a good idea to me, but I know nothing. Lots of ideas seem good to me.

I searched the forum for this and found nothing but I suspect that someone out there knows about this or has tried it.

Recorded a bar band last night and may upload the to etree, with their permission. Will record another bar band tonight and possibly upload that one, too. So far the sound has been thin because of overly bright rooms. This one may have better acoustics tonight. Eddy Merxx used to say if you want to get good at riding a bicycle, ride a bicycle a lot. Eddie got good, real good. Practice, iterations make the difference. I have hope of getting the hang of this fun geek hobby.

Edited January 30, 2007 by boojum

[A440]

The ECM-MS957 is already a directional microphone with two adjustable pickup angles: 90 degrees or 120 degrees.

http://www.epinions.com/pr-Microphones_Son...lay_~full_specs

You might try switching it to the narrower angle.

Also tell the people behind you to shut the &$#$ up.

That mic may also sound overly bright (unlike the people talking behind you) because its bass response only goes down to 50 Hz and is losing the lowest 1 1/2 octaves of bass, from 20-50 Hz. Human hearing is 20-20,000 Hz.

Edited January 23, 2007 by A440

[The Low Volta]

Eddy Merxx used to say if you want to get good at riding a bicycle, ride a bicycle a lot. Eddie got good, real good. Practice, iterations make the difference.

Eddy is a fellow Belgian... and he also cheated a bit (performance enhancing drugs)

I guess I have to support A440's statement about the mic. I have heard quite a few Sony mics (most of my collegues use them for work and I get to try them out for different stuff ) and all the ones I've tried share that same thinnish sound and are much better suited for human voice than for anything else

[boojum]

The ECM-MS957 is already a directional microphone with two adjustable pickup angles: 90 degrees or 120 degrees.

http://www.epinions.com/pr-Microphones_Son...lay_~full_specs

You might try switching it to the narrower angle.

Also tell the people behind you to shut the &$#$ up.

That mic may also sound overly bright (unlike the people talking behind you) because its bass response only goes down to 50 Hz and is losing the lowest 1 1/2 octaves of bass, from 20-50 Hz. Human hearing is 20-20,000 Hz.

I was at the 90 degree angle. Cement floors and wooden walls do not help any. No warm sound there at all. I an tweak it a bit but I do not like doing that. Oh, well, this is not my big deal with Telarc or MoFi so I guess I can tweak it a bit. 20 to 20KHz fades pretty rapidly to a narrower range. I cannot hear the high-pitched sounds I once did.

Eddy is a fellow Belgian... and he also cheated a bit (performance enhancing drugs)

Eddie rules! I understand he has put on a few kilos since he stopped spinning the cranks. He is still training on saucisson and biere. Allez-y Eddie!

[King Ghidora]

The ECM-MS957 is a M/S design mic with the same angle adjustments that the ECM-MS907 which is also a M/S design. I'm really surprised that you are getting noise from behind the mic because my MS907 is excellent at rejecting rear noise. You basically can't hear a thing that comes from behind it. It seems strange that a Sony mic with a very similar design has such different characteristics.

You should get good results with voice applications with this mic too because of the M/S design. Essentially there is a mono channel for the center plus the side capsules that capture the stereo information. Most single point stereo mics aren't that good for voice but a M/S is the exception. I get excellent stereo imaging with my mic too.

As for putting sound dampening material behind the mic sure that will work. But you can't just attach it to the back of your mic. You would have to make a shield of some sort that extended out from the mic a good bit. It might be good for recording where you won't be mobile but it would probably be too much to take on the road with you.

I think pretty much all bike racers use some sort of help or at least it sure looks that way. Back in the days before testing I'm guessing there were all sorts of helpers. Even today just because they don't all get caught I'm not so sure they don't all get help. Maybe they should just let them all get any help they want. If they want to make themselves into test subjects that's their stupidity I guess. It doesn't seem possible to stop them from doing it anyway. BTW I rode 3500 miles one year. Now I would be lucky to ride 3500 feet. So maybe there's more to that axiom of Eddy's.

[The Low Volta]

Eddie rules! I understand he has put on a few kilos since he stopped spinning the cranks. He is still training on saucisson and biere. Allez-y Eddie!

a bit off topic... but:

eddy before:

eddy after (he's on the left):

but to be fair, nowadays he has lost some weight again:

[boojum]

a bit off topic... but:

but to be fair, nowadays he has lost some weight again:

Eddie will always be a hero to me because that man rode to win no matter what. Injuries, like a face fracture, made no difference to him. He just spun those cranks. I understand that blood was running down his legs after he finished the flying hour he did in Mexico City. A hugely motivated guy. And he is Belgian. The world knows that more than lace and beer come from where you are. A larger than life man. I am happy to see he is smaller than a beer keg now. Allez-y Eddie!

Edited January 24, 2007 by boojum

[boojum]

The ECM-MS957 is already a directional microphone with two adjustable pickup angles: 90 degrees or 120 degrees.

http://www.epinions.com/pr-Microphones_Son...lay_~full_specs

You might try switching it to the narrower angle.

Also tell the people behind you to shut the &$#$ up.

That mic may also sound overly bright (unlike the people talking behind you) because its bass response only goes down to 50 Hz and is losing the lowest 1 1/2 octaves of bass, from 20-50 Hz. Human hearing is 20-20,000 Hz.

50Hz is a pedal note on an organ. It can shake the whole building. That is pretty low and rapidly approaching sub-sonic.

Hearing deteriorates rapidly, especially if you favor rock "concerts." I doubt many in their late 20's can hear anything like that range. 20 - 50 Hz is pretty much sub-sonic and above 16.5 KHz does not exist on FM because of the stereo multiplex channel at ~ 19 KHz, I think and the space alloted below it for protection and other reasons. I think that 20 - 20KHz is the best and not common. YMMV

Edited January 30, 2007 by boojum

[King Ghidora]

I disagree that the 20 hz to 50 hz range is out of the normal hearing range for adults. I'm 50 years old and I've been to way too many rock concerts (most of which were back in the 1970's when no one cared a hoot about how loud it was except that it had to be very loud). And I have a set of test tones that includes sounds all the way down to 20 hz. I can hear 25 hz perfectly well and I can hear 20 hz but it's starting to get out of my ability to hear it. I might even be able to hear some sound from a 15 hz source but I don't have a test tone that goes that low. Some people can hear sounds in that range though.

Now if you want to talk about the upper ranges almost no adults over 30 can hear anything above 14 khz even if they've never been to a rock concert. I'm lucky to hear anything over 12-13 khz.

Also I think the lower ranges are very important to music today because the source for most of what we record includes sound down to the 30 hz level. Back before the advent of Kicker truck speakers almost no stereo systems could even play those sounds but they caught on fast with the hip hop generation and they spread to other genres too. Now if you want your recording to sound like the original it needs to be able to record down to at least 30 hz IMO. That's one of the main reasons I moved up from my Sony mic. I liked a lot of things about it but it was shy on bass response so I got a better mic and I'm glad I did.

[A440]

I disagree that the 20 hz to 50 hz range is out of the normal hearing range for adults.

I'm with KG on this. The bottom A on a piano is 27.5 Hz, and I can hear that perfectly well as a tone, not a rumble. 50 Hz is probably around a G above that, and there's nothing subsonic about it. Organ pedals use various stops--16', 8'. etc.--and if it's a 16-foot stop, it's sounding an octave lower than the written note: half the frequency. So maybe your rumored 50 Hz organ pedal is really 25, which would be low but still not inaudible.

[From Wikipedia on "organ stop":

Registration usually begins with an 8' on the manual and a 16' on the pedal; the pedal thus normally sounds an octave lower than written pitch, providing the "full-bodied" sound typical of the organ. Halving the number raises the pitch by an octave; in growing a registration it is usual to draw next the 4', 2', etc. on the manual and the 8', 4', etc. on the pedal.]

Loud sounds destroy the high frequencies first, not the lows. So does age. But all those folks complaining about bad mp3 playback on the first RH* units knew they weren't hearing something way up there.

[greenmachine]

A natural instrument emits not only the fundamental (lowest frequency), but also a number of harmonics, which can mask the fundamental in some cases and make testing difficult. A pure sine waveform (no harmonics) would be best suited for testing the low frequency abilities of your hearing and/or playback equipment. On a piano (particularly in the lower registers), the fundamental is relatively weak compared to its harmonics. An organ can be adjusted to sound bright (strong harmonics) or dull (weak harmonics, strong fundamental, closer to a pure sine waveform).

Two interesting links about the topic:

http://en.wikipedia.org/wiki/Harmonic_series_(music)

http://www.phys.unsw.edu.au/jw/basics.html