Stereo drums, M/S etc

[Aled Hughes]

Hi,
Having recently found a drum sound I'm extremely happy with (highly damped kit, lots of acoustic screens and an LDC placed between rack tom and snare looking across the snare, supplemented with a close kick drum mix), I'm starting to want it in stereo.
The drummer plays very lightly, and the kit is quite compact with the cymbals set very low. As such ghe single mic picks a nice balance of everything, and with a decent mic the 'spill' is very nice and at just the level (AKG 414 B-XLS was great. Studio Projects B1 not quite as nice but workable. Cardioid seems best.)

Seeing as I have Mono sound that I'm perfectly happy with, I though about adding a side mic. Would the fact that the mid-side array would be placed in the middle of the kit be a problem? I.e it would be picking sound from 360 degrees (the rack tom sound at the moment is really just the spill into the back end of a cardioid mic, but it works). I'm not fussed about perfect stereo with, just some movement and spread on fills and cymbal work.

On some songs, a Blumlein array of ribbons looking through the kick and snare a few feet in front of the kit has worked wonders, but this obviously brings a completely different sound, and one that's not always appropriate. Same goes for a Glyn Johns-style of omni SDCs I tried - great lively sound, but often I just want the sound of that single mic placement, but in stereo!

The size of a mid-side array in that position could be a problem, but if an SDC could get.similar results to the LDC, it might be ok. Should that fail, I'm thinking a similar approach to the snare, but with another couple of LDCs - one placed close to the floor tom underneath the ride and another somewhere on the other side may work, though phase could be a bugger.

Any more suggestions? I don't have time to try anything out for a while hence my posting here. The M/S thing makes most sense in my head as I already have a Mid mic sound I'm chuffed with, but it.depend on whether the acceptance angle thing will screw things up or not.

Many thanks,
Aled

[Sam Inglis]

I've used a stereo ribbon mic aiming towards the snare from that sort of direction, with decent results. However, with both M/S and Blumlein you have to make sure the mic is far enough back that the entire kit fits within the acceptance angle of the array. If your Mid mic is literally over the top of the kick drum that won't happen unless you set it to omni.

[Aled Hughes]

Many thanks Sam. With the Blumlein array I always set it so it's as close as possible but always.looking a few inches past each side of the kit, so that's never been a problem.

What would actually happen with a mid-side array with cardioid mid in that position? How would anything not in the acceptance angle (i.e most of the kit I think!) be placed in the stereo image?
I guess it's always going to be a trade off between stereo width and room sound, in which case perhaps tom close mics would be best, though that would mean having the cymbals in mono. Quite severe HPF on that Blumlein array out front perhaps? Though when I tried things out quickly there didn't seem to much difference in the basic sound between different patterns on the main.mic, so the omni mid mice could be ideal.

[Sam Inglis]

What would actually happen with a mid-side array with cardioid mid in that position? How would anything not in the acceptance angle (i.e most of the kit I think!) be placed in the stereo image?

Unpredictably, I should think... but by all means try it! There are plenty of stereo techniques that shouldn't work but somehow do on drum kits (spaced cardioid overheads, Glyn Johns miking, etc) so you might like it. And of course you have the mono reduction issue covered.

I guess it's always going to be a trade off between stereo width and room sound, in which case perhaps tom close mics would be best, though that would mean having the cymbals in mono. Quite severe HPF on that Blumlein array out front perhaps? Though when I tried things out quickly there didn't seem to much difference in the basic sound between different patterns on the main.mic, so the omni mid mice could be ideal.

It sounds as though the position you've already chosen pretty much is a close mic, so not sure I'd want to be tangling with close mics on the toms too, that could get phasey.

You might find another apparently random position that works for a second mic, with enough trial and error!

[Hugh Robjohns]

What would actually happen with a mid-side array with cardioid mid in that position? How would anything not in the acceptance angle (i.e most of the kit I think!) be placed in the stereo image?

Anything outside the acceptance angle is generally just portrayed as hard left or right.

I think your only option here is to try it, with different Mid patterns and Mid-Side balances, so see if you can find something you like, and which gives an impression of width without upsetting your balance too much.

No Side contribution leaves you just with the mono mid mic, obviously, and introducing more Side will open the image out, adding emphasis to the toms, cymbals and hi-hat.

It may be that a better idea is to rig a conventional stereo pair, and use that to provide some width to the cymbals and toms, controlling how they affect the balance in part by high-pass filtering them (to minimise their impact on the kick/snare balance). But that might also bringn in more unwanted room sound...

In which case you're really only left with close miking the toms and panning them, and the same with close but spaced overheads, HP-filtered for the cymbals.

H

[Aled Hughes]

Many thanks to you both.

Sam, indeed the single mic really just a snare close mic with pleasing spill. The problem with just one other mic is that it would just lean the kit off in one direction, as the current mic would need to centered due to it providing most of the snare sound.

I think messing with the M/S would be best for now then - the hard panning outside the acceptance angle could well work perhaps. Mix selection and size is the main problem here - there doesn't seem to be many SDC fig 8s around, and the Sennheiser MKH(?) stuff is out of budget. LD side and SD mid may work, but I'm thinking some of what I like about the sound comes from the large diaphragm (half the diaphragm tends to be looking at the snare shell and the other half looking across the head of the drum)

A ribbon mic laid horizontal could work (I take it that a fig 8 mic can be rotated freely while 'hinged' between the two pickup spheres, if you get what I mean?)

Also, could the less than perfect HF omni response of multi-pattern LDCs screw thing up with the cymbals were I to use one as a mid mic?

[Studio Support Gnome]

aside from many other things…. i should tell you that most ribbon mics should be used (and stored) such that the ribbon is held vertically….. not laid flat…

otherwise the ribbon deforms over time due to gravity….. it "sags" in the downwards direction relative to it's position…. stetting the ribbon slightly and changing the way it performs as microphone. …… (and this does not take very much time) and the mic's performance is noticeably changed. and not for the better……

[Aled Hughes]

Ah yes, that's something else as well. Although the way I figure the ribbon would still be perpendicular to the floor, so wouldn't the magnets negate most of the effects of gravity? The ribbons would still be looking sideways, just that the long axis would be paralel to the floor. I always take care to store them vertically.

Another thing is that my ribbons are offset designs so wouldn't really be suitable for mid/side (though perhaps still worth trying in case it sounds pleasing anyway). This also means that the Blumlein pair isn't really so by definition, but nevermind!

[Sam Inglis]

aside from many other things…. i should tell you that most ribbon mics should be used (and stored) such that the ribbon is held vertically….. not laid flat…

otherwise the ribbon deforms over time due to gravity….. it "sags" in the downwards direction relative to it's position…. stetting the ribbon slightly and changing the way it performs as microphone. …… (and this does not take very much time) and the mic's performance is noticeably changed. and not for the better……

I'd be interested to know whether anyone has actually demonstrated this, or whether it's a myth. The mass of a ribbon is vanishingly small, and I'm not sure I understand how gravity would cause it to slowly stretch if left unused. I certainly can't imagine that using a ribbon mic horizontally for the duration of a recording session would be a problem.

I've bought a couple of ribbon mics that had clearly been stored on their sides for the best part of 50 years, and neither showed any sign of stretching.

Bob Crowley thinks it's a myth, at least regarding most ribbon mics:

http://microphonium.blogspot.co.uk/2008 ... -part.html

[Hugh Robjohns]

I'd be interested to know whether anyone has actually demonstrated this, or whether it's a myth.

Yes, and no, in that order.

The mass of a ribbon is vanishingly small, and I'm not sure I understand how gravity would cause it to slowly stretch if left unused.

It's not the material that stretches. It's because the ribbon is usually corrugated, and those corrugations can tend to flatten out under the small but finite weight of the ribbon itself. This problem is more significant with the longer ribbons, though. A lot of modern ribbons are much short than the vintage designs and are far less prone. It can also be caused because the ribbon tension has slipped over the years, through being knocked or just the screws working loose and the clamp easing the pressure -- although in that case vertical storage wont help, of course.

I certainly can't imagine that using a ribbon mic horizontally for the duration of a recording session would be a problem.

It's not. But I think it can be an issue when being stored for extended periods. And it's easy enough to store the mic with the ribbon vertical, so why wouldn't you?

I've bought a couple of ribbon mics that had clearly been stored on their sides for the best part of 50 years, and neither showed any sign of stretching.

Without an original to compare it with, how would you know? Sagging will, in theory, reduce the sensitivity, and particularly the LF sensitivity. But given that vintage ribbons generally have a very low output compared to more modern mics, and have more bass output than more modern mics, the average user is unlikely to notice a decline in original performance of either of these aspects.

Bob Crowley thinks it's a myth, at least regarding most ribbon mics

And conversely, Wes Dooley of AEA states that it is a very real problem... You pays yer money and takes your choice...

H

[Matt Houghton]

the ribbon is usually corrugated, and those corrugations can tend to flatten out under the small but finite weight of the ribbon itself.

Then, am I right to assume that laying the mic horizontally, but with the folds of the ribbon running vertically (as you can do with e round mic!) shouldn't cause a problem? (he asked, totally ignoring the "why wouldn't you?" question)

[Hugh Robjohns]

I would presume so, yes... And that would actually be better than having the ribbon entirely vertical, I think, too.

H

[Sam Inglis]

... which, if the theory is correct, would lead to all the corrugations bunching up at one end?

[Sam Inglis]

it's easy enough to store the mic with the ribbon vertical, so why wouldn't you?

I guess it is with mics that come in cases designed to be stood on end. A bit harder with something like an uncased, long stereo ribbon mic though.

Without an original to compare it with, how would you know? Sagging will, in theory, reduce the sensitivity, and particularly the LF sensitivity. But given that vintage ribbons generally have a very low output compared to more modern mics, and have more bass output than more modern mics, the average user is unlikely to notice a decline in original performance of either of these aspects.

In this case both were Bang & Olufsen BM5s, which use 'piston' corrugation and are thus presumably less prone to sagging?

These mics are particularly prone to low output because they use tiny magnets which lose their magnetism over time. When I bought my second one it sounded the same as my first and had about the same sensitivity. I sent the second one to Stewart at Xaudia, who replaced the ribbons and fitted new magnets, giving something like a 12dB improvement in sensitivity. We were both very surprised by how much difference this made to the actual sound of the mic. It actually became much *less* bass-heavy.

Bob Crowley thinks it's a myth, at least regarding most ribbon mics

And conversely, Wes Dooley of AEA states that it is a very real problem... You pays yer money and takes your choice...

That would make sense in light of what you said, since AEA recreate the old RCA designs with their long ribbons.

[Aled Hughes]

... All of which suggests that rigging the ribbon horizontal but with the corrugations running vertically should be fine?

Only thing then is aligning the capsules - that's 2" or so of diaphragm running horizontally that needs to be on the same plane as a condenser diaphragm. Not likely to be a problem in practice, or just align to the middle of the ribbon (which could cmpromise ease of placement) ?

[Aled Hughes]

Regarding the above - I've just though that the important dimension here if left/right relative to the kit, so it shouldn't pose much of a problem, right?

[Hugh Robjohns]

... which, if the theory is correct, would lead to all the corrugations bunching up at one end?

I dunno about all bunching at one end, but the top ones might well open out more than the others I suppose...

I have been shown over the years several ribbon mics with what were described as 'stretched ribbons'. Most were definitely the result of in-use damage rather than storage damage... but at least one was claimed to be the result of long term storage on its back.

H

[Hugh Robjohns]

I guess it is with mics that come in cases designed to be stood on end. A bit harder with something like an uncased, long stereo ribbon mic though.

Yes... but you wouldn't leave a ribbon uncased for long, would you, because of risk of air blast damage and metallic particles getting into the motor assembly. So you'd need to contrive a bespoke case of some kind, in which case (pardon the pun) you might as well comprise a vertical one.

In this case both were Bang & Olufsen BM5s, which use 'piston' corrugation and are thus presumably less prone to sagging?

Piston corrugation is where the top and bottom are corrugated, but the middle is flat -- instead of corrugating along the whole length. There are pros and cons associated with each technique. I would presume that with fewer corrugations in the total ribbon length, the percentage of stretch due to it's own weight will be even less than a 'standard' corrugated ribbon of the same length.

These mics are particularly prone to low output because they use tiny magnets which lose their magnetism over time.

All magnets do. But certainly the early magnets weren't very strong and weren't very permanent. Modern compositions are far better in both respects.

I sent the second one to Stewart at Xaudia, who replaced the ribbons and fitted new magnets, giving something like a 12dB improvement in sensitivity. We were both very surprised by how much difference this made to the actual sound of the mic. It actually became much *less* bass-heavy.

The ribbon tension plays an enormous role in the amount of bass output, with tiny variations having a profound effect.

That would make sense in light of what you said, since AEA recreate the old RCA designs with their long ribbons.

Indeed.

H

[Aled Hughes]

Having just bought a couple of multi-pattern LDCs (not specifically for this purpose) I'm looking forward to playing around with this (will also try a ribbon as the Mid mic out of interest)

Could anyone tell what difference in acceptancle angle would a figure 8 mid give instead of an omni?

Having further worked with the recorded tracks, I think fig8 or omni will be usefull as the rack tom could to with a little bit of help. Same goes for the floor tom, so I'm going to try a LDC off to the left of the kit as well, sort of a tom//ride mic. This will lean the kit off in one direction as mentioned previously, but this may not be too much of a problem and give the required movement.

[Hugh Robjohns]

Having just bought a couple of multi-pattern LDCs (not specifically for this purpose) I'm looking forward to playing around with this (will also try a ribbon as the Mid mic out of interest).

Be careful putting ribbons close to drum skins or anywhere that might be exposed to significant air blasts (from hats or cymbals or swishing sticks!).

Could anyone tell what difference in acceptancle angle would a figure 8 mid give instead of an omni?

I presume you mean as the Mid mic of an MS pair. The acceptance angle usually varies a bit depending on the ratio of Mid and Side mics, but notionally, MS with a fig-8 Mid mic gives two 90-degree arcs (front and rear), while an omni mid gives 360 degrees.

H