i try to keep any kind of radio stuff as far away from the studio as possible... mobils, radios, wireless cans, bluetooth, wi-fi.... yet again... as far away as possible.

interfearence sucks, specially if you just spend more money then necessary on some wireless cans.

not the cheap domestic stuff
but
yes to Pro IEM radio
but usually
I am using EAR PHONES wired
less spill than with HEADPHONES

I do sense a change in the air with this stuff

People are getting very used to having EAR PHONES ... I don't mean the ones that sit just outside the ear
but the ones that go into the ear canal

You need to treat them with respect but once you ... get it
it is very impressive.
... and I didn't say it was easy to get it right.

Been there, baby! I was desperate- I was tired of tripping over a too-short headphone cable while working out some compositions in my home studio, running around with a Strat and over to the PC, the keys, etc. I saw an ad in a S---------r catalog for some Sennheiser wireless phones, and thought "That's the ticket!" I figured that if these puppies worked OK at home, I would try them in my "real" studio. WHAT WAS I THINKING?!?!?
I got them, and at first they were OK. I own LOTS of phones, and I like the Sennheiser 280Pro a lot. These were NO 280s! They sounded OK, but were a lot heavier on my head, which made me kind of "teeter" when I'd get up after sitting around with them on. The internal battery-I've taken dumps that lasted longer! Then there was the infernal drop-out and fizzy noises that would occur as I moved around the gear. And, yes, all of that RFI has to go somewhere, and it was usually between me and the transmitter. 2 nights later, they were in the "junk drawer". Never,never again will I believe an ad! RIGHT......!

Some people think I'm sort of wired all the time. They're right! The wireless headphones are crap except for television intercom purposes. And certainly you don't want any RF (that's radiofrequency in techno babble) in or around any of your studio stuff. This also includes any live televisions with the ballgame on, even with the sound down, they leave a nasty 15,750 hertz spike in your recordings! Yup, even with the sound down on the TV. It gets into everything.

I don't even like those dedicated " rackmount headphone amplifiers". What are you supposed to do with that? Nobody in the studio can use them! A reasonable passive distributed headphone system is the key. Go to Radio Shaft. By a bunch of little aluminum/plastic gadget boxes like, 2" x 3". Get lots of zip cord (3 conductor AC lamp cord). Get a reasonable stereo 40 W per channel amplifier. Now put a pair of 8 ohm power resistors across each channel of the output of the 2 channel amplifier, to properly load the amplifier. It would be nice if they were at least 10 to 20 W. Then take 2 more and put them on the hot terminal of each channel, these could be just 5 W. The idea here is to properly load the amplifier and not deliver too much power for the headphones. The output of the amplifier then goes into one of the larger size gadget boxes, 4" x 4". You drill 8 quarter-inch holes for stereo headphones sockets. Wire this stereo feed to the 8 sockets. Remember, tip is left, ring is right, sleeve is ground.

Now with the smaller gadget boxes, put a 20 foot piece of 3 conductor AC electrical cord in the small gadget boxes, it's good if you can also strain relief the cord. Of course, put a 1/4" connector on the end of the cable.

THIS IS VERY IMPORTANT! Get yourself a regular double ganged, 1/4 to 1/2 W stereo volume control. Also get 2 50 ohm to 100 ohm 1/2 W resistors. You must put each one of these resistors, 1 on the incoming left Channel cable and the other on the right Channel cable. You then connect them to the center conductor of each Channel of the volume control. The common ground is then strapped across both ends of both volume controls. The headphones socket is then wired with the tip to the other side of the volume control and the ring to the last remaining conductor on the right channel of the volume control. The headphones common ground is then tied to the other side of the volume control, amplifier ground side.

You must be careful. You must add these resistors! Otherwise you could cause permanent hearing damage! This system has worked very well for me in many studios including the famed MEDIA SOUND NEW YORK CITY, that I installed in 1980. This is the same system I have always built and it is great! Of course not everybody gets their own mix this way. Everybody gets a common stereo mix. Now if you want to deliver 2 different mixes. You can install a switch on the headphone gadget box and wire it so you can select with a DP DT (that is double pole, double throw) switch that will allow you to feed one channel or the other channel to both ears of the headphones in mono.

For the system, I personally like the old Crown DC 30. They are indestructible! The old Dynacos always blow up! Stay away from those and probably the Haflers. You certainly don't need a high-powered amplifier of any kind. An old stereo receiver also works.

Alternatively, you could get a couple of those lousy dedicated " headphone amplifier" boxes and go ahead and use the Radio Shaft gadget box scheme without the added resistors. Just the volume control in the cord long enough to get to the amplifier box. Just remember almost any taper, audio/linear volume control from 1000 to 10,000 ohm will work. It does not have to be one of those " 8 ohm speaker volume controls". They are lousy and proper impedance loading here is not a factor. I mean you can use one but they are generally wire wound and they get intermittent and noisy quickly. The cheap low powered carbon type work much better and last longer. Even if you have a 40 W amplifier, in all probability, you will never burn up the 1/4 to 1/2 volume controls before you cause hearing damage. Believe it or not, 1 watt of power into a headphone will generally below your head off! So beware!

Ms. Remy Ann David

RemyRAD wrote: ... A reasonable passive distributed headphone system is the key.
... I personally like the old Crown DC 30. They are indestructible!
... Even if you have a 40 W amplifier, in all probability, you will never burn up the 1/4 to 1/2 volume controls before you cause hearing damage.

correct

http://voyager.celestial.com.au/~rosswood/diy/headphonedist/headdist.htm

we use the extra available reserves for headroom
not current or power headroom
but
Voltage Headroom

However those Rack Headphone Amps are great for EAR PHONES because the rms volts for ample volume is MUCH LESS than that required for Headphones and so you now have headroom again.