Reproducing Sun Studio room reverb
-
jeromy
- Posts: 3
- Joined: Thu Nov 14, 2013 4:52 am
- Location: Minneapolis, MN
- Contact:
Reproducing Sun Studio room reverb
So humor a newbie here (and thanks for all you do guys) - I've been kicking around the idea of installing large reflective tiles in the performance area of my studio. I loved the reverb/compression that Sam Phillips got out of that old asbestos tile. Any thoughts on reproducing that? Ideally I'd want to install a few large panels on the ceiling/walls that I could easily cover if/when the need arose. NOTE: I run a vintage studio - all tubes and tape. I don't have a computer or Pro Tools and don't use plugins (not cause it's better, it's just the way I do things). I'm currently using a few modded Lexicon LXP-1's for my reverb purposes but would like to try this. Curious if anyone's done this or if they know where I could get a few LARGE reflective panels?
-
Soundman2020
- Site Admin
- Posts: 11938
- Joined: Thu Aug 21, 2008 10:17 am
- Location: Santiago, Chile
- Contact:
Re: Reproducing Sun Studio room reverb
Hi Jeromy. Please read the forum rules for posting (click here). You seem to be missing a couple of things! 
The reverb time of a room depends on the total room volume and the total amount of absorptive surface in the room vs. the total amount of reflective surface. A smart scientist called WC Sabine did experiments a long time ago and figured out the equations that define reverberation. It's all about mathematics and the laws of physics, not the type of reflective panel . If you want to duplicate the reverberant sound of someone else's room, you'd have to have a room that has roughly the same total volume, and roughly the same ratio of absorption to reflection. If your room is significantly larger (in terms of volume) then you'd need a higher ratio of absorption to reflection. And if your room is smaller, then you need lower ratio. The problem comes when your room is so much smaller that even with 100% reflective surfaces you still can't get to the same RT time. So the first thing you'd need to know is how big the room was whose reverb you want to duplicate, and how much absorption / reflection it had.
But that's just the overall reverb time of the room. There is also the factor of how each individual frequency range decays during that time: A "brighter" room has more absorption in the low frequencies so they decay faster, and less absorption in the highs so they stay around longer, while a "dull" room has more absorption in the highs, less in the lows. You can "shape" the sound of a room to a large extent by using different types of absorption / reflective surface that behave differently at different frequencies. For example, if you want a "dull" sounding reverb (boomy, muddy) then you'd use very thin, heavy (weight) absorption on many surfaces, such as carpet on the walls, to absorb highs but not lows. If you wanted a "twangy" reverb sound, then you'd use very thick, light weight absorption with a membrane over it, and in fewer places (eg, mostly corners) to absorb a lot of lows, not so much highs. Etc.
Then there's the issue of how you place those surfaces in the room: Having all of the absorption bunched up in one place is very different from having it spread around the room evenly.
Rooms can even have variable acoustics, where some panels can be rotated to expose either a highly reflective surface or a highly absorptive surface, somewhat like a gobo, but on a much larger scale.
Finally, there's the issue of speaker and mic location: If you have your mic close to your speaker, both out near the middle of the room then you'll get mostly direct "dry" sound with a bit of distant, ambient reverb, but if you have your speaker close to one wall and the mic far away, near the opposite wall, then you get mostly the "wet" ambient reverb sound with just a bit of distant direct sound. Or anywhere in between...
So it's nowhere near as simple as just throwing up a couple of panels of plywood in any old room: the art of building reverb chambers is an awful lot more complex than that. Unfortunately, it seems to have become something of a lost art these days, as not too many studios even try to incorporate real acoustic reverb chambers into their buildings any more: they take up a lot of space (read: construction cost, "dead space" expense, property taxes, low use, slow "return on investment", etc.). That does not please the bean counters. So most places just throw a few digital reverb boxes in a rack, and hope that some place in the middle of all the electronics is a sound something like what the producer wants.... Pity: There's still a lot to be said for "real" acoustic reverb, as opposed to statistical numeric models of impulse responses and DSP chips crunching numbers to "re-create" the sound...
- Stuart -
The reverb time of a room depends on the total room volume and the total amount of absorptive surface in the room vs. the total amount of reflective surface. A smart scientist called WC Sabine did experiments a long time ago and figured out the equations that define reverberation. It's all about mathematics and the laws of physics, not the type of reflective panel . If you want to duplicate the reverberant sound of someone else's room, you'd have to have a room that has roughly the same total volume, and roughly the same ratio of absorption to reflection. If your room is significantly larger (in terms of volume) then you'd need a higher ratio of absorption to reflection. And if your room is smaller, then you need lower ratio. The problem comes when your room is so much smaller that even with 100% reflective surfaces you still can't get to the same RT time. So the first thing you'd need to know is how big the room was whose reverb you want to duplicate, and how much absorption / reflection it had.
But that's just the overall reverb time of the room. There is also the factor of how each individual frequency range decays during that time: A "brighter" room has more absorption in the low frequencies so they decay faster, and less absorption in the highs so they stay around longer, while a "dull" room has more absorption in the highs, less in the lows. You can "shape" the sound of a room to a large extent by using different types of absorption / reflective surface that behave differently at different frequencies. For example, if you want a "dull" sounding reverb (boomy, muddy) then you'd use very thin, heavy (weight) absorption on many surfaces, such as carpet on the walls, to absorb highs but not lows. If you wanted a "twangy" reverb sound, then you'd use very thick, light weight absorption with a membrane over it, and in fewer places (eg, mostly corners) to absorb a lot of lows, not so much highs. Etc.
Then there's the issue of how you place those surfaces in the room: Having all of the absorption bunched up in one place is very different from having it spread around the room evenly.
Rooms can even have variable acoustics, where some panels can be rotated to expose either a highly reflective surface or a highly absorptive surface, somewhat like a gobo, but on a much larger scale.
Finally, there's the issue of speaker and mic location: If you have your mic close to your speaker, both out near the middle of the room then you'll get mostly direct "dry" sound with a bit of distant, ambient reverb, but if you have your speaker close to one wall and the mic far away, near the opposite wall, then you get mostly the "wet" ambient reverb sound with just a bit of distant direct sound. Or anywhere in between...
So it's nowhere near as simple as just throwing up a couple of panels of plywood in any old room: the art of building reverb chambers is an awful lot more complex than that. Unfortunately, it seems to have become something of a lost art these days, as not too many studios even try to incorporate real acoustic reverb chambers into their buildings any more: they take up a lot of space (read: construction cost, "dead space" expense, property taxes, low use, slow "return on investment", etc.). That does not please the bean counters. So most places just throw a few digital reverb boxes in a rack, and hope that some place in the middle of all the electronics is a sound something like what the producer wants.... Pity: There's still a lot to be said for "real" acoustic reverb, as opposed to statistical numeric models of impulse responses and DSP chips crunching numbers to "re-create" the sound...
- Stuart -
-
jeromy
- Posts: 3
- Joined: Thu Nov 14, 2013 4:52 am
- Location: Minneapolis, MN
- Contact:
Re: Reproducing Sun Studio room reverb
Thanks so much Stuart. I've made some of the necessary updates, sorry I missed those. I should clarify, I wasn't actually looking to build an echo chamber but was interested in potentially giving the actual performance area some nice, natural reverberation much like Sam Phillips did with that old asbestos tile back in the day. I've attached some images of that room. Don't need a long tail by any means. I'm in the process of moving my studio so I don't have dimensions yet. Mostly just want to know if i'm crazy or if it's more trouble then it's worth
-
Soundman2020
- Site Admin
- Posts: 11938
- Joined: Thu Aug 21, 2008 10:17 am
- Location: Santiago, Chile
- Contact:
Re: Reproducing Sun Studio room reverb
You might be able to get a more lively sound just be adding acoustically reflective panels to the room, somewhat along the style of Gobos (except fully reflective, not "half-and-half"). For example, sheets of thick plywood or MDF on stands, or even on wheels so you can re-arrange them easily as needed.
Asbestos sheeting is out of the questions these days of course, with the EPA regulations, but fiber-cement sheeting is pretty close acoustically. However, it is also brittle, but attaching it to plywood and putting a frame around it to protect the edges should give you a similar effect.
- Stuart -
Asbestos sheeting is out of the questions these days of course, with the EPA regulations, but fiber-cement sheeting is pretty close acoustically. However, it is also brittle, but attaching it to plywood and putting a frame around it to protect the edges should give you a similar effect.
- Stuart -
-
jeromy
- Posts: 3
- Joined: Thu Nov 14, 2013 4:52 am
- Location: Minneapolis, MN
- Contact:
Re: Reproducing Sun Studio room reverb
Oh wow - great stuff Stuart! This is exactly what I was looking for. Thank you so much. I'm going to dig into this and will return with any questions I haveSoundman2020 wrote:You might be able to get a more lively sound just be adding acoustically reflective panels to the room, somewhat along the style of Gobos (except fully reflective, not "half-and-half"). For example, sheets of thick plywood or MDF on stands, or even on wheels so you can re-arrange them easily as needed.
Asbestos sheeting is out of the questions these days of course, with the EPA regulations, but fiber-cement sheeting is pretty close acoustically. However, it is also brittle, but attaching it to plywood and putting a frame around it to protect the edges should give you a similar effect.
- Stuart -