Control room window
 

I am in the midst of remodeling. A part of this will be a two room studio where one room will be treated for recording vocals and guitar, and there will be a sort of control room with a window between the two spaces.

Any advice on what sort of window to put in? A double pane picture window from Lowe’s or Home Depot would be inexpensive and easy, whereas the few proper control windows I see online are between 2 and 3k.

Is this something a local fabricator can do? How much difference does it make? What do you guys recommend?

You can case the window opening yourself, if you are good with wood. At that point you might want to seek out a local glass shop. You want to mount the two at different angles with the lower portion set in deeper in the casing than the top to prevent internal standing waves and to prevent light reflections. It would be good to order one sheet at least as acoustic glass, which will be thicker than regular architectural glass for added stiffness. You'll use toe molding to case the glass on both sides. You can stand the lower lip of the window on a rubber gasket and then seal it with non-hardening caulk before adding the outside frame of toe molding. Be sure to add the width of the bottom gasket and the effect of the angle when you order the glass. Here is a detail on the three-pane studio window between the control room and studio here where I work:
Bob

I also understand that sandwiched layered glass (with a layer of plastic between two sheets of glass like they do in car windows) is best. That it is far less resonant than a simple glass layer.

The panels in our studio window are 3/8", 1/2", and 3/8" and are Amerada Acousta-Pane 36 Sound-Rated glass. More on the studio, HERE.

Bob

This link will provide an idea of how various wall/glass configurations will lower sound transmission between rooms: https://www.muzines.co.uk/articles/b...om-window/2884

The author suggests hardwood framing for wall(s) due to it being kiln dried. However, KD softwood is fine, and being KD only applies when building double-walls..., in order to keep moisture from being locked between the two spaces and causing fogging on the inside of the spaced glass surfaces.

If only constructing a single wall between rooms there will be some sound isolation, and that may be fine for your purposes. Double-pane and laminated (heavier/thicker is desirable) offer better isolation than single pane.

Should you have simultaneous live mics in each room or are listening loudly on control room monitors while recording mics in the studio, separate double walls and two (or 3) glass panels with different thickness to each other (heavier weight/thicker is better) is necessary. Tilting one of those glass panes (bottom to top) helps reduce visual reflections between rooms.

There is much more to consider in the wall design should one choose to pursue good sound isolation, but that is dependent on what you are trying to achieve.

Have fun,

Lance

For DIY using two different thicknesses is recommended as each thickness has different frequency transparency. A few degrees tilt as mentioned is good for reducing standing waves and reflections.

Some dark fabric in between the two panes makes the void more invisible and chuck a whole bunch of silica gel under the fabric to prevent condensation.

Also, wrangle any bugs out before you seal it up. Amazing how many studios have dead cockroaches or beetles in the windows...

My former band mates (two who are excellent carpenters/woodworkers) mounted 2 full glass storm doors as our control room window, 4 inches apart. Bleed from drums, amps, etc., loud stuff, was minimal to the control room. Voice communication between the studio and control room required hand signals or a control room mic, there wasn't a prayer of hearing each other.

I miss our Solid State Logic SL4000 console.
https://www.in2guitar.com/myhistory/bobwom2.jpg

It had a talk back mode that kicked on the control room talk back mic and the studio listen mic (which was heavily compressed so you could hear people across the entire main room) the moment you hit STOP on the transport so you had two-way conversation immediately without even punching the talk back button. Innovation!

Bob

Sweet! We used an ancient, cheap mic with the old on/off switch on the side. Worked.