"Nearfield" monitors mounted in-wall

[bwilkinson]

Hi all,

As I have said in the electrical side, I am in the brainstorming part of creating a studio, and am looking at all the different options. I have no design started at this phase. Right now I am trying to determine the best bang-for-the-buck in the smallest useable space (the smaller the space I have to build, the lower the budget - but I still want a truly useable studio). This is purely a hobby for me - if I ever make enough between live sound reinforcement and recording to cover the costs of my buying gear addiction, I (and my wife) will be content.

However, this topic specifically is about mounting "nearfield" monitors in-wall. I was under the impression that nearfield monitors were designed to be in the six feet (2 meters-ish) range for most accurate reproduction. So, I was shocked to see a set of KRK Rokit 8 speakers mounted in-wall in a control room picture for "Scott's Studio"

http://johnlsayers.com/Studio/Pages/Scott_1.htm

Now I am really interested - as these are the monitors I have. (we can go into discussions about how scooped they are on another thread, but monitors that others have said were flatter responding were painful to my ears - the midrange was causing too much fatigue to my hearing - I am comfortable with these) Is the room in that design simply small enough that the monitors could be placed in-wall, or do the Rokits not disperse enough that extra distance is acceptable?

I have no method of trying it myself right now, as my speakers are currently three feet apart, in a tiny room. Trying to mix in here is about as useful as trying to drive a car with a blanket over all the glass.

I look forward to your opinions.

[Soundman2020]

Well, the way I understand it, "nearfiled" technically isn't a specific distance at all, but rather depends on the room and the speaker: The "near field", as far as I know, is that part of the room where you only get direct sound from the monitors with none of the resonant field from the room. Or at least, where the resonant field is sufficiently below the level of the direct field that it doesn't interfere with your perception. The "critical distance" (IIRC) is the distance at which the level of direct sound from the monitors is exactly equal to the level of the resonant field in the room. Inside a small concrete pipe, that might be just a few inches away, but in a great room that could be several meters away. So the way I see it is that your "near field" depends a lot on the room itself. So it's not a matter of room SIZE really, but rather a matter of room DESIGN.

So the critical distance is kind of the extreme cut-off point for what you can consider to be "near field". As long as you are closer to the speakers than that, and all that reaches your ears is direct clean sound from the speakers, then you are in the "near field". As soon as your ears are in an area where the resonant field in the room is fighting for your attention too, then you are no longer in the near field.

(At least, that's the way I understand it: I'm sure one of the real experts here will shoot me down in glorious technicolor flames if I'm wrong)

So you sure can flush-mount your speakers in your room... provided that you design the room for those speakers. (As time goes by, I'm becoming more and more convinced that the entire room SHOULD be designed around the speakers, and not speakers chosen once the room is finished. But that's just me, I think.)

Anyway, mounting speakers in the wall (usually called "flush mounting" or less correctly "soffit mounting") accomplishes something else too. It forces the speaker to radiate into half space, which does several good things for you: It tightens up the bass end a lot, improves your stereo image all around, totally eliminates comb filtering off the wall behind the speaker, and helps to establish an RFZ (reflection free zone) around your mix position much easier than if you were to mount the speakers on stands behind the desk, or even worse, rest them on the console bridge or the desk itself. However, flush mounting also increases bass levels by up to 6 dB (since the long wavelength sounds that normally "wrap around" behind the speaker are now prevented from doing so, and are projected directly back into the room, nicely focused and in-phase), so you need to have some kind of control on the speaker itself to roll off the bass response the same way, and get your curve flat again. Usually that's a switch or knob on the back of active speakers that are designed with flush-mounting in mind.

Personally, I think flush-mounting is a great idea for speakers, especially in small, well-designed rooms. Some others don't agree, and prefer to put their speakers on a stand, but I think that the pro's totally outweigh the cons.

HOWEVER! (You just KNEW there was going to be a "however" in here somewhere, didn't you? ) if you do plan to flush-mount your speakers, then you need to make sure that your speaker actually can be flush mounted (some can't), and you need to take great care to understand what you are doing, and to do it right, very carefully. It isn't just a matter of cutting a hole in the wall, poking the speaker in, and hoping it will work. It wont. In reality, when done correctly the surface around the speaker isn't even really the "wall" at all! It's just a large, flat, very dense (heavy) surface, known as an "infinite baffle", with the the speaker in the center, and the REAL wall is still there, hidden behind that "flush mount infinite baffle" thing. That's why it isn't called "inside-the-wall mounting", because you aren't really mounting it inside the wall. (Although it is still called "soffit mounting", even though you aren't mounting it in a soffit! Go figure....).

I'm not familiar with the speaker you mention, but chances are REALLY good (as in somewhere around 101%) that if John did it for one of his clients with that specific speaker, then it sure can be flush-mounted successfully. So I'd say go for it! Just use John's design for your mounting system, and figure out how to roll off the bass.



- Stuart -

[bwilkinson]

You know, my wife finds it really funny as I tell her about the things I learn here. Typically I am the stereotypical "egotistical" mechanical engineer, and seem to have the answers to everything. Now as I dive deeper into acoustics, I realize how little I truly know - even inside my own profession.

Thanks - I am sure I will have more questions as I progress. I really love the design ideas I can find here - it's a nerd's paradise!

[Pepsi]

I thought the difference between near-field and far-field speakers is to do with the angle of dispersion of the high frequencies.

[Soundman2020]

Nope. It's to do with the critical distance, the resonant field, the direct field, and your location in relation to them. Not related at all to high frequency dispersion.

[Pepsi]

Hi Stuart, by direct field and resonant field, do you mean direct sound from the speaker and reflected room sound?