Sm57 & Sm7B (using them together)?

[Melodic Dreamer]

Does anyone or has anyone used them together on one cabinet? Just curious if I did use both of these together, what would be a few good choices in positioning them?
I just ordered the Sm7b, mainly for vocals, but also as a decent everything type of mic. I was wondering though, how the Sm57 would stack with the Sm7b when recording electric guitar.

[Ulysses]

We were just talking about this:

http://www.thegearpage.net/board/showthread.php?t=535024&page=2

They would sound pretty much the same as two SM57's. They are the "same" mic in different "packaging". The identical frequency patterns are dead on. Only the highs and lows vary a bit from the case and proximity due to location of the cartridge:

Sm7 and SM57 patterns:

http://i4.photobucket.com/albums/y127/swlabr/zSM57_vs_SM7_mmss3.gif

With screen off and mounted with diaphragms at equal distance they will yeild near identical results.

http://i4.photobucket.com/albums/y127/swlabr/zzzsm7v57.jpg

[mindwave_21]

Identical with the SM7 set flat or with the bass rolloff and presence boost?

[Ulysses]

Identical with the SM7 set flat or with the bass rolloff and presence boost?

I don't know if it says this in literature but seems the "boost" is not really a boost... it just brings the mic back to "flat". In tests with the boost added the frequencies are pretty much a dead match with the SM57. It appears from the (boost on) patterns above that the mic is flat with the "boost" on and filtered in the "off" position.

[mindwave_21]

They would sound pretty much the same as two SM57's. They are the "same" mic in different "packaging". The identical frequency patterns are dead on. Only the highs and lows vary a bit from the case and proximity due to location of the cartridge.

Looking at the frequency diagram, I find it odd that the bass response of the SM7 is approximately 10dB higher (twice as loud in the 30-70Hz region?) and also lower in the treble region. Proximity effect would explain the diminished highs, but the lows should also be below the curve of the SM57 with the capsule being further from the source, correct?

I own an SM7, but not an SM57, though I have access to an SM58. I'll have to listen to the differences with the capsule distance being the same, but from my limited experience using them through a PA they sounded drastically different. I feel that it's unfair to say that the SM7 and SM57 would sound exactly the same because the housing and the rest of the circuitry besides the capsule itself have a profound effect on the signal.

[Ulysses]

Looking at the frequency diagram, I find it odd that the bass response of the SM7 is approximately 10dB higher (twice as loud in the 30-70Hz region?) and also lower in the treble region. Proximity effect would explain the diminished highs, but the lows should also be below the curve of the SM57 with the capsule being further from the source, correct?

I own an SM7, but not an SM57, though I have access to an SM58. I'll have to listen to the differences with the capsule distance being the same, but from my limited experience using them through a PA they sounded drastically different. I feel that it's unfair to say that the SM7 and SM57 would sound exactly the same because the housing and the rest of the circuitry besides the capsule itself have a profound effect on the signal.

A 57 and 58 can also sound quite different and the only variable is the pop filter. Check the FFT below showing the SM57 and SM7 with sound source touching the windscreen on each. There's now a 3db difference now just from the different distances in diaphragms but more uniform in response. The in-line step up transformers in Beta, SM57/58 and SM7 are slightly different. There was an old mod that engineers used to do to open up both top and low end of a 57 by removing the step up and wiring the cartridge directly to the XLR. This would increase the relative top and bottom end but reduce overall output by 6 db. Not a big problem if you have super clean pre's with a ton of gain but pretty significant in in most situations. This along with the casing are probably responsible for the majority in audible differences between Shure dynamics. Mercenary is even selling a boutique step up transformer mod for $75!! which is absurd considering word was each SM57 costs Shure a total of $11 to put on a store shelf. With either the in-line step up out of the 57's circuit or the low cut "in" on the SM7 the low frequencies will pretty much line up. Many also attribute the SM7's low end tendencies to the larger proportions of the cavity the diaphram is housed in. Not sure why the top drops off the SM7 above 10K but having the diaphram inside that metal cage can't help.

Sm57 and Sm7 physically aligned (windscreen added to 57).
http://i4.photobucket.com/albums/y127/swlabr/sm7v57touch2.jpg

FFT:
http://i4.photobucket.com/albums/y127/swlabr/sm7touch_vs_sm57touch.gif

Tiny SM57 step up incased in glue:
http://i4.photobucket.com/albums/y127/swlabr/57stepup.jpg

[Melodic Dreamer]

hmm, now I'm wondering if I even need this mic. It seems a lot of people really like them on vocals.
Whats another mic that's good for vocals, but also can work with a sm57 on a guitar cabinet?

[Ulysses]

I still like to have both SM7 and 57. The SM7 is a great sounding broadcast style mic that does benefit from the design incorporating well designed pop filter screen and large body that slightly mutes highs and gives extra gepth to bass. Sure, you can rig a 57 to do something very similar because it's the same "voice'. But along with the solid adjustable mount it is more of a "pro" design and very convenient. If I were looking for a second mic to double for guitar and other utility purposes I would look for a different "voice" to give color to my available tone pallette. I quit using my SM-81's years ago because "peer pressure" from all the negative talk about "ice-pick-in-the-ear" etc. Instead of using my ears I figured they must be bad because all the talk. Affter using KM84's for a few years, I finally pulled them out of my mic drawer and was surprised at how wonderful they were (especially for a second guitar ambience mic) IF you used your ears and found the sweet spot. The most magical mic to use along with the SM of your choice is the Coles 4038 IMO. The Royer is awesome too but I much prefer the mid muscle of the Coles when mix time comes. Not a fan of the cheap ribbons although still may be a good choice for guitar. If you want a dynamic as your second mic the 441 is the best utility mic ever made IMO. It's a world class pro-studio dynamic, the "voice" is different than an SM, and it does "condenser" better than any condenser mic under a grand.