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Scott Dorsey Scott Dorsey is offline
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

Roy W. Rising wrote:
When I started in TV sound in '65, I was told the mic preamp input impedanc=
e should be "2K or greater" to avoid loading ribbon mics, which lose HF per=
formance when loaded.


And see, when I started in the seventies, I was told the opposite, that
ribbons wanted to see a lower impedance. Roy is correct, and Olson backs
him up, and what I was told was wrong, but apparently a lot of people
believed it at the time.

Dynamic mics generally "care" less about loading, wi=
th the exception of the SM57/58 as discussed here. EV co-founder Lou Burro=
ughs told me that as of the "Research Engineering" era, EV dynamics would n=
o longer use transformers for impedance selection.


If you want microphones that are efficient and have high output, you get
tight coupling and live with loading changing the response. If you can
make the magnetic circuit lossy, they won't be as sensitive to load.

One of the things about the SM-57 is that it uses a very low-Z winding with
a few big turns, going into a step-up transformer. The later EV dynamics used
higher impedance windings without the transformer, which was a win sonically
but might have made them less rugged.

The successor to the EV=
666 (with transformer) is the RE15. Lou said that inline attenuators' loa=
ding would not affect performance and that a true 150 ohm load would only l=
ower the level by 6dB. With all of the variables surrounding mic performan=
ce, I decided to step beyond the esoteric practice of "mic selection". Ins=
tead, I started using RE15s on "everything", in part because EQ on every in=
put was appearing. My other reason was that mixing TV orchestras amounted =
to mixing leakage. The RE15 is flat from all directions, hence "better" le=
akage. I have a matched pair for my desert island gig.


The RE15 is an unsung hero, alongside the Sennheiser 441. Both sound pretty
good when you're standing behind them. Try THAT with an SM-57.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."