Small Basement Studio - Home Working Place

Hi, this is my first post and i follow this forum several years now so i know a bit about acoustics and studio designs... i want to plan/build a nice little studio in my basement of my house... BECAUSE: i had a good studio until may 2011 because they raised the rent to an enormous amount so i moved out there... i was room in room, fully AC and window installed already between the 2 rooms... acoustics in the control room was mainly modular resonance and broadband absorbers from a german acousician... but its gone... and i dont want to use the module absorbers anymore because they deaden the room too much and do nothing below 80 hz... and this sucks :( the only thing i want to use further are 6 big diffractal diffusors i built myself out of mdf... my room dimensions are (sorry metrical only): 6m x 5.80m x 2.10m i know this is pure horror acoustically... :shock: but its the only basement i have... my main room resonance is 52 hz and several dips at 70 hz 140 hz and so on... another big problem are the 2 doors in the each rear corner of the room... and they cant be built over unfortunately... my mains are PMC IB1 powered with Bryston Amps, so i need good bass trapping in this room i think, right? :D i totally fell in love with the look / feel of slat resonator walls and soffit mounted speakers... is it possible to soffit the IB1? because u cant really shelve out the bass lift afterwards without parametrical eq in the monitoring chain right? ah and btw im a total sketchup noob but i tried to do a first design and played around a bit but i dont know if thats any useful... please guys help me !!!!!!!!! :yahoo: thanks in advance for any help :)

welcome! please update your profile to include your location information. could you also provide details on the desired isolation you need etc. if you already have the desired isolation and only need to treat the space, then soffit mounting (or as has been presented to the forum, in the wall mounting (IWM)) is an option for your monitors plus the slats etc. on the low ceiling though... consider a heavy solid backed cloud angled down in front up to the ceiling just behind your mix position. and use that space overhead for trapping as well as in the soffits.

Hi Glenn, thanks for the quick reply :) sorry for that location thingy, i though i did it... isolation needs are not that high because i got neighbors but the houses are decoupled with double brick and an air cavity in between... and isolation inhouse is not that important too because in our house everybody is still young and somehow affiliated to my work... :) so i just need to treat the room... i would love to build a soffit type front or mount them flush but isnt it dangerous for the +6 dB bass lift? because i really dont want to put an EQ in the chain... an with sold back cloud you mean absorbtive in the mid/high range but reflective below these frequencies? this cloud has to be at least 20 cm thick i think so when i am 1.80 m tall its getting small in there :? or did i get you wrong? did you have a look on my noobish skp file? :) is this any good or total crap? thanks

soffit mounting should be good and most modern monitors have the appropriate settings to roll off to compensate. since you're mostly seated at the console, have a cloud low over the front and angled up over the desk should not be an problem.

holy.... :D thanks glenn... u ´re the man!!!! would you mind to share the skp file with me? because of measurements and stuff... i really like it alot!!!!! cant wait to build that thing :-) thx again

try this. properly added side and front slats. added funky poly slat on back wall but could be angled or just absorption.

Hi Gullfo thanks fpr the file.... would it be possible to make the side slat walls a bit longer to have the naked wall behind the listening position covered a bit more? then of course the angle where the slat wall begins in the front gotta be adjusted right? or is the angle not that important? also i think i would go without soffit mounting... because what i´ve read so far in this forum it is just to complicated/expensive/hard to build for just having it in the basement for 1 year or so... what do you think? i just dont wanna build this massive thing for having EXPENSIVE Speakers with poor performance in the end... also i´d need phase linear EQ in the chain and that stuff is not in the budget right now :| or i´d have to tri-amp the speakers and turn down the bass in the crossover... but i think you know about prices of BRYSTON amplification so.... :cry: would your design change drastically without soffit mounting? or do recommend to try the soffit mount although all this difficulties? or is it not that difficult as i think? Thanks again Andi

it's not as difficult as you think and the benefits are excellent. on the wall behind the slats - some vertical absorbers will do it. if you make the treatment frames modular, you may be able to reuse in another space later.

awesome! by the way is the angle of the side slat resonator important to the functionality of the soffit front? and do you have some tips for me because of that low shelf filter? or should i just try my luck without EQ correction? :? Thanks Andi

Glenn? Help :cry: is it any possible to do that filtering low budget? Thanks

btw: here is a little topic about my diffusors i built while i got some spare time... viewtopic.php?f=3&t=16511&p=116099#p116099 Its in the acoustic forum Andi

sorry for the delay. i would go with 15 degrees on the side walls if possible or as low as 10 degrees if that extends the wall the way you want it. those diffusers look terrible, you need to ship the diffractals to me right away so i can test them :twisted:

ok cool... i can build you one... in case you could help me with my filter problem :twisted: i need a solution as long as i wait for ATC 110s Thanks

Glenn :?:

have you checked out the BSC filter Barefoot posted a number of years ago? it's in the speaker section. i believe Siegfreid Linkwitz has some designs on his site (and having helped invent the Linkwitz-Riley filters he may be the best source). http://www.linkwitzlab.com/filters.htm then if you need opamps http://www.mouser.com/Search/Refine.aspx?Keyword=opa627 if not, i recommend a proper cross-over unit in your rack as a means of adjust the LF cut off pending your new monitors. also DIYAudio has numerous circuit designs if that is the route to pursue.

Hi Glenn, i really really appreciate your help... your designs gave me new motivation to start this... thanks for that... :wink: i changed the sketchup a bit and added side absorbtion as well as angled the front wood baffle a bit (is this ok acoustically?) because i really am in the critical planning phase right now... do you recommend a certain soffit design? i wanted to go with johns shelf design but i dont know if i can get my speakers (or the whole mdf box) decoupled enough with that... they weigh 36 kg each... have to try thick sorbothane maybe... any special hints or tricks? and do you think my dominant room modes are being trapped enough with only porous absorbtion in the back of the room and the hangers in the soffit front? and can you determine which frequencies to absorb with hangers ? ( maybe distance to each other or varying angles....) ? because im really scared that the modes are not trapped enough in the end, because i can´t really treat the room corners... i know... so many questions... :mrgreen: please help me once again :P i wanted to attach the .skp but its 6 mb now... i dont know how to reduce file size.... so only 2 pics Thanks in advance Cheers Andi

anyone?

glenn do you think this is ok? Thanks Andi

Andi, your basic idea seems OK, but the speaker geometry doesn't: it looks like your listening position is in the exact middle of the room, which is bad. You could fix that by adjusting the angle of the soffits a bit, pointing them a bit further forward.

as well as angled the front wood baffle a bit (is this ok acoustically?)

well, you CAN do that, but it looks like you might be creating problems fr first reflections like that. Why do you need that piece tilted down?

and do you think my dominant room modes are being trapped enough with only porous absorbtion in the back of the room and the hangers in the soffit front?

No since that will only treat the 1,0,0 mode (and harmonics), and maybe some tangentials and obliques that happen to involve those walls. One of the best treatments for modal issues is bass trapping in the tri-corners, or in as many other corners as you can.

because i can´t really treat the room corners...

Why not? There are twelve corners in a rectangular room, and you seem to have access to several of them... :) - Stuart -

thanks for your reply stuart... i cant really treat the corners because there are doors in each corner and they have to stay usable... i really would like to place faaat hangers there but thats not happening unfortunately...

i cant really treat the corners because there are doors in each corner

You have doors in your ceiling and your floor? :shock: Like I said: there are TWELVE corners in a rectangular room (count them). Only four of those are vertical. All the rest are horizontal, and most of them are available to you. Think about it.... - Stuart -

Andi, your basic idea seems OK, but the speaker geometry doesn't: it looks like your listening position is in the exact middle of the room, which is bad. You could fix that by adjusting the angle of the soffits a bit, pointing them a bit further forward.

ok, how much is a "bit"? :?

Why do you need that piece tilted down?

i just thought it looks better :) but acoustics go first... any other suggestions?

No since that will only treat the 1,0,0 mode (and harmonics), and maybe some tangentials and obliques that happen to involve those walls. One of the best treatments for modal issues is bass trapping in the tri-corners, or in as many other corners as you can.

ok then i will built some chunk-style soffits on the side wall- ceiling and rearwall-floor and rearwall ceiling?

Why not? There are twelve corners in a rectangular room, and you seem to have access to several of them... :)

thanks for the math :lol:

ok now my reply is readable... i am not yet used to the quote function :)

ok, how much is a "bit"?

Theoretically, a good place for your listening position is 38% of room depth. In other words, 38% of the distance between the front wall and the back wall. That's where you want your EARS. So you aim the speakers such that the acoustic axes just touch your ears, and intersect a few inches behind your head, at an angle of somewhere between 60 and 90 degrees. But you don't need to go crazy trying to get your ears at exactly 38% of the room depth: it's just a rough guideline. What you DO want to do, is to make sure that your ears are not in the exact middle of the room: that's a bad place to be.

i just thought it looks better :) but acoustics go first... any other suggestions?

Well, you CAN tilt it, if you want, but you just need to make sure that it is not creating first order reflections. The concept of an RFZ design (like yours) is just that: no first order reflections without at least 15ms. So if you can't find an angle for that panel that eliminates reflections, then you could replace the hard panel with absorption: Put a piece of 703 there, with cloth stretched across a frame in front of it, for example.

ok then i will built some chunk-style soffits on the side wall- ceiling and rearwall-floor and rearwall ceiling?

Sounds like a plan! :) One easy thing you could do is to just tilt your entire rear wall forwards, and fill it with absorption (maybe wrapped in plastic, to keep the highs in the room). That would give you a lot of broadband bass trapping at the rear, and would look good, too! Or if you don't want to tilt the entire wall, then just tilt the top half: same effect. - Stuart -

What you DO want to do, is to make sure that your ears are not in the exact middle of the room: that's a bad place to be.

ok i´ll try to achieve that...

Put a piece of 703 there, with cloth stretched across a frame in front of it, for example.

so this middle part doesnt have to be reflective? ok cool so i´ll angle it the way it is in my model and make it absorbtive... ?

One easy thing you could do is to just tilt your entire rear wall forwards, and fill it with absorption (maybe wrapped in plastic, to keep the highs in the room). That would give you a lot of broadband bass trapping at the rear, and would look good, too! Or if you don't want to tilt the entire wall, then just tilt the top half: same effect.

i will put 4 or 5 big diffractals in the big frame of the rear wall so this is for letting the room a bit alive... but the thing with the angled rear wall is cool. i think i´ll combine the diffusors and rear soffit/wall... somehow.. :? btw do you know how to make sketchup files a bit smaller for uploading? mine is 6mb so far... BiG thanks Andi