[Russtafarian]

Some photos of the acoustic panels I built for a drum booth for my church auditorium.



Six pack of 4'x2'x2" 6 pcf mineral wool



5/8"x2 & 5/8" wood siding for panel frame


Mineral wool gets framed


Panel framed and ready for fabric


Fabric trimmed, tucked, and stapled


Completed panel


Completed drum booth with plexiglass front panels and absorptive rear panels


2'x2' panels line the base of the plexiglass for additional absorption.  Not shown are absorptive panels that fit on top of the plexiglass to form an 18" deep lid over the drum booth.

[eeejoy]

what you have not going to help

[Russtafarian]

Thanks for the encouragement.  Can you be more specific? 

Then I can tell you how much it actually has helped.

Russ

[Rob Babcock]

Very nice work, Russtafarian.  The look is clean and they look well constructed.

If you don't approve, eeejoy, please explain why.  Constructive criticism is always welcome here.  But keep it constructive if you want to post at AC.

[MaxCast]

Great work, Russ.
That six pack looks like a premade bass trap.  hmmmm.
What is the purpose of your drum booth?

[James Romeyn]

what you have not going to help

Just some lighthearted fun...maybe he means it won't solve world hunger?   

[Russtafarian]

My church just started meeting in a large (for us) 800 seat church auditorium with a 50 foot ceiling.  The acoustics were designed to accentuate the speech range so that someone talking in the front could be heard throughout the hall.  The sound of the hall is wonderful for traditional piano/organ/choir church music.  But… put a drum kit in there and all hell (figuratively speaking, of course) breaks loose. 

A drum kit puts out tremendous energy in the 800 to 8,000 Hz range with drum head whacks and cymbal crashes, which is the same range the hall’s acoustics are designed to emphasize.  Thus playing a drum kit would overload the room and make it very difficult to clearly project vocals and other instruments through the PA without reaching ear-splitting SPLs.

Simply putting a plexiglass shield in front of the drums would not be enough.  That would keep stage volume down, but would simply “chimney” the drum sound up into the reverberant field.  So I put together panels for behind the drums to absorb energy reflected back off the shield.  Not pictured is a 2 inch thick acoustic panel that attach to the top of the shield to form an 18 inch deep lid that blocks some of the energy coming off the front of the kit.

The result is that the shield and panels reduce the drum energy in the room by around 60 to 70%.  I can put some of that energy back into the room by mic’ing the drums.  This gives me the ability to balance the drums with the rest of the band while keeping the overall SPL at energetic but safe levels.

Russ

[MaxCast]

sweet, good work Russ.

[eclein]

Russ-any drummer would be happy to sit behind that sharp lookin unit!!

[santacore]

Nice work Russ, that looks real good!!

[James Romeyn]

My brother in law Gil Hernandez just played his conga set tonight at a live show in which I did the sound engineering.  It's a three drum set, the largest is called a "tomba", the smallest is the "conga" (middle is called a "kinto"; correct spelling unknown). 

I noticed the "tomba" has serious overhang/resonance, contrasting with the other two drums which sound really snappy and tight.  I look up at the ceiling over the stage, which is about 11' or so (taller ceiling over the audience floor, which is lower than the stage).  I estimate the stage/ceiling to have a bounce frequency of about 45 Hz... walk over to the grand piano and hit the notes around F1.  Low and behold, F1 and F#1 sustain noticeably longer than their neighboring notes.  Gil (whose band Cold Blood opened for Santana years ago) hits Mr. tomba, and its tuned to F1. 

Gil loosens the tuning screws about a 1/4 step and most of the problem is fixed.

Very interesting, as Arte Johnson used to say.

[Russtafarian]

That is very interesting, Jim.  I'll keep that in mind the next time I run into the bloated floor tom phenomenon.  It's quite common actually; now I know why.

Russ

[Russtafarian]

Russ-any drummer would be happy to sit behind that sharp lookin unit!! 

The drummers do like it because I put two floor monitors inside the shield pointed right at them.  They get everything in their mix, including the mic'ed drums.  So they get this big, clean, whompin' sound coming right back at them as they play.  They probably have the best sound in the house.

[Russell Dawkins]

A brilliant design.

I have been musing on something similar for a long time, as it is almost always the snare which upsets the balance in any venue smaller than 250 seats. Something like this is the only solution.

The difference between what you have built and my concept is that I designed a circular cutout in the front for the bass drum, so that it would function equivalent to an open baffle and a powerful 24" driver and not sap the power of the PA amp as putting a kick through the PA does. I also never thought of the absorption around the lower area. A great idea.

I have been in a few recording situations where I would have loved to have had this rig at my disposal, and I would have paid handsomely  to have acquired it! The rear absorption on the overhead absorption is also great.
I would like to see a photo of the overhead lid.

If people only knew ho much better drums would sound attenuated like this in smallish rooms, they would never put up with the rubbish sound balance they are otherwise subjected to.

I presume eeejoy will stay under his rock for a while longer - I would guess earth is not his native planet.

[ewarren]

I would be interested in seeing pictures of the whole set up with the 18" deep top. We might need to do something like that at my church.

Eric