room acoustics, „equalizing“ a bright room

Seb77

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I work at a school that has a medium large music room I have used to record drums in for a while on weekends or in the holidays. Gradually learning to choose and place mics, adding more tracks to the recordings using close-micing, I notice there is still a certain bright ambience in the room I would like to darken a bit (this might also improve the room for ensembles, so it‘s not just my dummistic interest, but partly it is;)).

There is a large window front, pvc/vinyl floor, some kind of ceiling that might have some hidden absorbtion material,the walls are hard plastic and there is a large cabinet wall that has plastic covering as well, the typical white particle board covering. A large whiteboard opposite to that wall adds to the bright, reflective surfaces.

I like that there is some ambience, the reverb time is nice, but it is bright, cold in a way. If I could equalize it, I would reduce high mids and highs and add some mids and lower mids. To achieve this, intuitively I would add some raw wood surfaces, but I am not sure if I can pull this off at school, and if it would work as intended. I have read about absorbers for high frequencies; adding fabric covers to the cabinet doors would be rather easy, but I am not sure if this would make the room dead, I like the liveliness.
Has anyone modified a room this way?
 

Cauldronics

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I work at a school that has a medium large music room I have used to record drums in for a while on weekends or in the holidays. Gradually learning to choose and place mics, adding more tracks to the recordings using close-micing, I notice there is still a certain bright ambience in the room I would like to darken a bit (this might also improve the room for ensembles, so it‘s not just my dummistic interest, but partly it is;)).

There is a large window front, pvc/vinyl floor, some kind of ceiling that might have some hidden absorbtion material,the walls are hard plastic and there is a large cabinet wall that has plastic covering as well, the typical white particle board covering. A large whiteboard opposite to that wall adds to the bright, reflective surfaces.

I like that there is some ambience, the reverb time is nice, but it is bright, cold in a way. If I could equalize it, I would reduce high mids and highs and add some mids and lower mids. To achieve this, intuitively I would add some raw wood surfaces, but I am not sure if I can pull this off at school, and if it would work as intended. I have read about absorbers for high frequencies; adding fabric covers to the cabinet doors would be rather easy, but I am not sure if this would make the room dead, I like the liveliness.
Has anyone modified a room this way?
In your situation, I think the following will work well with panels that you can quickly setup and remove. If that's not practical or you have nowhere to store the panels, then maybe this won't work. The panels I'm referring to are 2'x4' and 2 to 4 inches thick, cloth (or burlap) covered, and made of either rockwool or Owens Corning 703 or 705 compressed fiberglass (2 inches difference in thickness between the two). You might already know, they can be readily bought premade or you can make your own. They will do a better job than any cloth covering or foam on the walls.

If you can get away with partially treating the room, try adding wideband absorber panels to about 1/3 of the surfaces that seem obviously reflective. That amount of coverage is considered a good general starting point and one that often does the job very well. The ceiling above the drums and walls on either side are the most immediate concerns. You can look at a standing mirror at different points along the walls and the areas where you can see the kit will generally produce more prominent audible reflections that will make their way back to the mics.

Leave about 3-5 feet of space between each panel; whichever sounds best and maintains the amount of liveliness you'd like to achieve. This well help to reduce the overly bright, cold reverberation that comes from farther away in the room while cleaning up the reflections near the source of your recording (drums). Win-win, since you already like the reverb time and there is no need to shorten it.

Note that you don't necessarily need to hang the panels, which avoids any minor wall damage (adding hooks to the walls). They can just be stood against the wall, even at a small angle to keep them upright, which actually improves their performance with an air gap between them and the wall.
 

Seb77

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Thanks everybody so far!

I tried closing the heavy curtains, hung blankets in the middle of the room, and both worked fine, but the sound became somewhat dull - and the room turned dark! I was thinking about ordering some divider panels, maybe our carpeter's department (vocational school) could even make some.

However, I think I should investigate diffusors since I'm not actually trying to deaden the room, just changing the colour of the ambience. I once tried opening all the cabinets, books/instruments inside - unsightly , but should break up the reflections. I also thought about open the doors halfway, to create as many diagonal surfaces as possible?

Any more insights on diffusors?

I'll set up my drums the next days (all the classes are taught from home at the moment), and leave everything the same except for these measures.

WHich leads to antoher question: in a large room, would you set up the drums in front of a wall (hard or soft surface, diffusor?) or rather in the middle of the room to avoid early reflections?
 

Cauldronics

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Rooms are tricky! Engineers will claim to have formulas but they don't always work.

The best approach, I think, is taking the bass drum and snare (the key components) around in the room and briefly playing them while listening for the sound you want. If you can find a good balance between the two, that location is a good choice to setup the kit, or if you're looking for a different sound and the bass drum is extra boomy in one spot, that could be another choice.

The middle of the room can be a spot where the reflections build up and you get a phasey, comb-filtered sound (not what you want). It depends on the room and how the reflective surfaces interact.
 

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Rooms are tricky! Engineers will claim to have formulas but they don't always work.

The best approach, I think, is taking the bass drum and snare (the key components) around in the room and briefly playing them while listening for the sound you want. If you can find a good balance between the two, that location is a good choice to setup the kit, or if you're looking for a different sound and the bass drum is extra boomy in one spot, that could be another choice.

The middle of the room can be a spot where the reflections build up and you get a phasey, comb-filtered sound (not what you want). It depends on the room and how the reflective surfaces interact.
Absolutely spot on! I have my drums in the living room. The room is about 30' X 24' with a slanted ceiling from 12 feet to 9.5 feet across the shorter side. Placement of the drums in that room is key for me to attain my desired sound. My brother plays his trumpet into the shortest corner and my other brother plays his flutes and saxophones into the tallest corner. My youngest brother plays his bass and keyboards wherever is convenient. Room placement of instrument overrides microphone placement in my case. I've had access to just about every microphone I could borrow or rent. From Audio-Technica to Sennheiser. What gives me what I want in my room are Audix D-Series on the toms, An Audix D-6 combined with a Rode NTG shotgun on the bass, Rode NT5s on the snare and hats and two Audix ADX-15s as my overheads. Sometimes I'll use Rode NT-1s for the overheads. Two Rode NTRs for room microphones top everything for the drums. Perfect!
 

Cauldronics

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Absolutely spot on! I have my drums in the living room. The room is about 30' X 24' with a slanted ceiling from 12 feet to 9.5 feet across the shorter side. Placement of the drums in that room is key for me to attain my desired sound. My brother plays his trumpet into the shortest corner and my other brother plays his flutes and saxophones into the tallest corner. My youngest brother plays his bass and keyboards wherever is convenient. Room placement of instrument overrides microphone placement in my case. I've had access to just about every microphone I could borrow or rent. From Audio-Technica to Sennheiser. What gives me what I want in my room are Audix D-Series on the toms, An Audix D-6 combined with a Rode NTG shotgun on the bass, Rode NT5s on the snare and hats and two Audix ADX-15s as my overheads. Sometimes I'll use Rode NT-1s for the overheads. Two Rode NTRs for room microphones top everything for the drums. Perfect!
I could be tempted to break the law for a room that big! In a room like that, I'd want gobos (free standing bass traps/absorbers) to limit how far the sound can travel and keep it out of the other instrument mics. That would be for recording, at least. For live, it changes quite a bit. Nothing new to you, but live, it's important to keep the sound and visual aspect open, which it can be for recording, but often not as much.

Nice choices of mics you have. Last night, I setup my recording rig in a two car garage with a triangular ceiling about like yours. The garage is much smaller, though.. maybe 20 x15. The pair of mics that really lived up to their (little known) reputation are the Line Audio CM4, which I had on overheads. They actually beat out my Neumann KM184s! The CM4 is smoother, not harsh, clearer in the mids and lows, and about 3x cheaper than the Neumann. They're made by a guy in Sweden who knows his stuff.

I need to dial in the bass drum and snare for recording a little more, but overall I'm getting good results in a room that theoretically shouldn't be great for recording.
 

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Lots of good advice here Seb. I'd recommend spending some time on a site like GIK Acoustics, they have great educational content:


They have a great team of designers who can help you find products that meet your needs should you decide to buy directly from them. With such a big room to work with, you hsould be able to dial it in without going overboard like one needs to in a small room. I think the idea of gobos that you can move and position around the instruments as needed and then store out of the way is a good plan.

If you decide to build yourself (great idea getting the kids in the vocational dept to do some work, its fairly easy) I would recommend the ECOSE boards. It's what GIK uses (you can buy from them) or here is the website. I thought the company actually came from your side of the world? Worth looking into for a local distributor, shipping can be a lot. Ive worked with store bought rockwool and these boards and the quality is just much better IMO with the ECOSE. It's also plant based/formaldehyde free, given you are in a school probably best to keep it as healthy as possible for all the young lungs (and yours):

 

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See the panels on the wall behind the kit? I have 7 of them in this room where I both practice and teach. They are filled with rockwool and there is 1” space behind them So they also absorb from behind so to speak. It works really well in this room. It kinda eq’d it quite a bit.

24A25146-5FCB-42E1-B3BB-51CDC46492D5.jpeg
 

Cauldronics

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See the panels on the wall behind the kit? I have 7 of them in this room where I both practice and teach. They are filled with rockwool and there is 1” space behind them So they also absorb from behind so to speak. It works really well in this room. It kinda eq’d it quite a bit.

View attachment 486382
I wish that kit didn't make me want to sell my car to get a Star maple. I won't, but I'm tempted!
 

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I could be tempted to break the law for a room that big! In a room like that, I'd want gobos (free standing bass traps/absorbers) to limit how far the sound can travel and keep it out of the other instrument mics. That would be for recording, at least. For live, it changes quite a bit. Nothing new to you, but live, it's important to keep the sound and visual aspect open, which it can be for recording, but often not as much.

Nice choices of mics you have. Last night, I setup my recording rig in a two car garage with a triangular ceiling about like yours. The garage is much smaller, though.. maybe 20 x15. The pair of mics that really lived up to their (little known) reputation are the Line Audio CM4, which I had on overheads. They actually beat out my Neumann KM184s! The CM4 is smoother, not harsh, clearer in the mids and lows, and about 3x cheaper than the Neumann. They're made by a guy in Sweden who knows his stuff.

I need to dial in the bass drum and snare for recording a little more, but overall I'm getting good results in a room that theoretically shouldn't be great for recording.
I use moving blankets clamped onto break-down wheeled garment racks as gobos that can be hung against the porch's wall when I'm done. I also have various density and differently weaved and patterned fabrics for fine-tuning. Some have tailored openings of various sizes and shapes that can be closed with Velcro for that extra touch of acoustical treatment. I almost never use any compression or EQ. I may suck as a drummer, but I'll admit that I've got great dynamic control even with the heaviest sticks or mallets. I also raid my photo & video location truck's c-stands and related grip-gear to build overheads and isolation booths. Building and striking a set only takes me a few minutes. I come from decades in the film industry mainly in audio capture and lighting. All my mikes run into a bank of Presonus Studio Channel Strips or into my Soundcraft 16MFXi mixer (when I want to use the on-board Lexicon effects) and then into a pair of Tascam SD-20 recorders. Four Furmans guarantee me the cleanest eletricity possible. The living room's power is completely separated from the rest of the house with it's own breaker box. A mighty simple and highly effective system for me. I went through experimenting with over 70 different microphones and tons of fabrics, insulation and foam densities to get what I wanted. If I wasn't recording in my living room more than likely I'd have a completely different recipe of audio gear. But for this room, pretty much hand- tailored perfection. Can't wait for the rest of my retirement remodeling to finish up. Keep getting set back from the CoVid!
 

Cauldronics

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I use moving blankets clamped onto break-down wheeled garment racks as gobos that can be hung against the porch's wall when I'm done. I also have various density and differently weaved and patterned fabrics for fine-tuning. Some have tailored openings of various sizes and shapes that can be closed with Velcro for that extra touch of acoustical treatment. I almost never use any compression or EQ. I may suck as a drummer, but I'll admit that I've got great dynamic control even with the heaviest sticks or mallets. I also raid my photo & video location truck's c-stands and related grip-gear to build overheads and isolation booths. Building and striking a set only takes me a few minutes. I come from decades in the film industry mainly in audio capture and lighting. All my mikes run into a bank of Presonus Studio Channel Strips or into my Soundcraft 16MFXi mixer (when I want to use the on-board Lexicon effects) and then into a pair of Tascam SD-20 recorders. Four Furmans guarantee me the cleanest eletricity possible. The living room's power is completely separated from the rest of the house with it's own breaker box. A mighty simple and highly effective system for me. I went through experimenting with over 70 different microphones and tons of fabrics, insulation and foam densities to get what I wanted. If I wasn't recording in my living room more than likely I'd have a completely different recipe of audio gear. But for this room, pretty much hand- tailored perfection. Can't wait for the rest of my retirement remodeling to finish up. Keep getting set back from the CoVid!
Your dedicated circuit for the recording gear is the way to go! I had a recording studio with Furman balanced power (not the same thing as a power conditioner) but eventually discovered the power draw for my speaker's amps made the speakers more sluggish and muddy than they'd be without the Furman (it was only 10 amps on a toroidal transformer... not ideal). I'm skeptical about power conditioners. They're usually just fancy power strips that have drawbar lights with no actual filtering built in. The balanced power I had was really good at lowering noise in preamps, outboard and mixers that don't have a need to cap-up again very quickly (speaker draw).

If I could've altered the building's electrical for a dedicated circuit, you bet I would have.

But I'm derailing the thread getting into another topic. Related in terms of recording, at least!
 

cruddola

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Your dedicated circuit for the recording gear is the way to go! I had a recording studio with Furman balanced power (not the same thing as a power conditioner) but eventually discovered the power draw for my speaker's amps made the speakers more sluggish and muddy than they'd be without the Furman (it was only 10 amps on a toroidal transformer... not ideal). I'm skeptical about power conditioners. They're usually just fancy power strips that have drawbar lights with no actual filtering built in. The balanced power I had was really good at lowering noise in preamps, outboard and mixers that don't have a need to cap-up again very quickly (speaker draw).

If I could've altered the building's electrical for a dedicated circuit, you bet I would have.

But I'm derailing the thread getting into another topic. Related in terms of recording, at least!
I have 4 Furman P1800-R conditioners. They're worth every penny. One is for just the various monitors and guitar amps. I'm a Yamaha and JBL guy. The second is just for the Video (Resolve-driven) and separate Audio computers ( there's two of each, all PC and no stinking proprietary-enslaving Apple!), Raid drives and the computer's monitor screens. I run Presonus Studio One (the cheapie's all I need). The third is for 8 of the 16 Channel Strips on the rack or the MXFi board. The fourth is for the Tascam recorders and the Tandberg recorder. All live off two totally separate 240 amp custom-built sine-wave systems just for the living room. Light switches and lamps are on two totally separate circuits feeding out of the rest of the house. Nothing beats clean electricity! Sucks that all is packed until the renovations are done! Even my drums are stashed.
 
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Cauldronics

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I have 4 Furman P1800-R conditioners. They're worth every penny. One is for just the various monitors and guitar amps. The second is just for the Video and separate Audio computer, Raid drives and the computer's monitor screens. I run Presonus Studio One (the cheapie's all I need). The third is for 8 of the 16 Channel Strips on the rack or the MXFi board. The fourth is for the Tascam recorders and the Tandberg recorder. All live off a totally separate 240 amp custom-built sine-wave system just for the living room. Light switches and lamps are on a totally separate circuit. Nothing beats clean electricity! Sucks that all is packed until the renovations are done! Even my drums are stashed.
Those are the "real' power conditioners. Not the ones everybody puts in their guitar rack. They should just get a rack mountable power strip. I have no real grasp of what it takes to build or install and 240 amp system, but that should do the trick! Isolation from other circuits is the key to clean audio. That's most of what I know about it.

Having the drums and electronics in prison for awhile didn't do anyone any good. The good news is everyone "should" be free to live safely again soon. People's lives are on hold. I had my drums locked away for 8 months before I could set them up and only got back into recording the other night.
 

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Those are the "real' power conditioners. Not the ones everybody puts in their guitar rack. They should just get a rack mountable power strip. I have no real grasp of what it takes to build or install and 240 amp system, but that should do the trick! Isolation from other circuits is the key to clean audio. That's most of what I know about it.

Having the drums and electronics in prison for awhile didn't do anyone any good. The good news is everyone "should" be free to live safely again soon. People's lives are on hold. I had my drums locked away for 8 months before I could set them up and only got back into recording the other night.
I bled the heck out of some of my 401K upon retirement back in June. Decided I was gonna re-hab the entire house, top to bottom. New roof and AC, plumbing, doors and windows. Electrical for my brother's welders and machining gear. It's just he and I in this dump! Might as well do the recording area right. 34 G's just for the juice! Now my stinking sisters wanna move in with her yacht-sized Yamaha piano that cost more than my house. They still owe me for a third of that Titanic! Hell No!
 

DamnSingerAlsoDrums

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I have a very bright room and the Beyer m160's I use as OH really do a great job at rejecting unflattering reflections and sweetening up the tone.
 

Seb77

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Based on the ideas from this thread, I tried setting up the drums more in the middle of the room, away from those hard surfaces, and it seems to have reduced the brightness. I also reduced the hard surfaces by opening the cabinet wall doors, and hung some blankets across the middle of the room, not around the drums, but dividing the room in half to reduce the reverb. Now I need to work on the lighting, there's a hum in the background.
I created a thread in the drum file corner with a soundfile: https://www.drumforum.org/threads/p...ple-toms-retrofitted-w-die-cast-hoops.182775/
 


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