Studio Construction 3 court Squash Centre

I have attathed poorly amended pic with brick piers beneath bearers coming off inside of wall with couple layers of escalator rubber - just to get an idea. Sorry about the 8-bit graphics... not my forte'

Pictures are fantastic! YOU DO NOT HAVE TO WORRY ABOUT VIBRATION THROUGH THE BEARERS! The only connecting path between the rooms is ground. What is the design for the HVAC system? This is the most likely flanking path. Andre

AVare wrote:

Pictures are fantastic! YOU DO NOT HAVE TO WORRY ABOUT VIBRATION THROUGH THE BEARERS! The only connecting path between the rooms is ground. What is the design for the HVAC system? This is the most likely flanking path. Andre

As much as I'd like to believe it - NOW is the time to do my reaserch and at the moment I'm getting 3 conflicting oppinions. One guy at Regupol http://www.regupol.com.au/ the rubber people, told me that escalator handrail rubber would be fine but the next guyat Regupol said that escalator handrail rubber was too hard and didnt have enough " deflection" & tha my 19 mm floor is not enough to stop sound travelling through the brick wall ( even beneath the floor ) and that I would have to build a floating floor ontop - at least the middle court ( control room ). According to him - floating the bearers would do nothing for me. * He may not have realised that I was to retain th " C" shape of the handrail to provide some " flex " or " deflection " ( see attatchment ). I'm thinking of just cutting around the perimiter of the floor so the floorboards are not touching the brick wall - and maybe NOT worry about raising the bearers onto rubber ?? It's ALOT of work raising those bearers - but NOW's the time to do it -- BEFORE I build the room within. I don't want to be repating mistakes. This sort of effort could be better spent in floating the middle court/room ( control room). Re: HVAC, I'll have 3 seperate industrial over rated ducted units ( 1 for each room ). Capacity: Cooling Btu/W 48000/14070 Heating Btu/W 52000/15400 Airflow m3/h 2880 Noise Indoor dB(A) 57 Outdoor dB(A) 78 http://www.domainair.com.au/browse.php? ... tegoryID=5 HVAC silencers and clever ducting & louvers for tuning should make the unit even quieter. Since it's over-rated, I won't need to run it at full throttle. On one end of the scale I have people telling me to leave floor as is - whilst others are telling me to go all out. All this effort on the floor while I'm punching a 2.2 x 2.4 m window either side kind of makes me wonder ??

Is there any reason why I couldn't build a baffle but still have my Main monitors on stands ?? ( see attatchment ) This way I still have the ' cool ' funny shape - it allows for fine tuning and fine movement AND I won't need to tear the wall down when I find the next set of monitors I don't need to upgrade to. What do you think??

Easy one first.

tonymite wrote:

Is there any reason why I couldn't build a baffle but still have my Main monitors on stands ??

Sound would travel from the speakers, and lows would also travel through the stands to the floor and room at a faster speed, muddying the lows. Standing tall, Andre

AVare wrote:

Easy one first.

tonymite wrote:

Is there any reason why I couldn't build a baffle but still have my Main monitors on stands ??

Sound would travel from the speakers, and lows would also travel through the stands to the floor and room at a faster speed, muddying the lows. Standing tall, Andre

Even with these? http://www.chinacones.co.uk/

tonymite wrote:

AVare wrote:

Easy one first.

tonymite wrote:

Is there any reason why I couldn't build a baffle but still have my Main monitors on stands ??

Sound would travel from the speakers, and lows would also travel through the stands to the floor and room at a faster speed, muddying the lows. Standing tall, Andre

Even with these?

Just pulled back for some data and saw your post. If "these" don't have any bass, then there will be no smearing. :D Have you looked at Barefoot's baffle design in the speaker section? It seems that might be what you are looking for. Still working on the other posts, Andre

As much as I'd like to believe it - NOW is the time to do my reaserch and at the moment I'm getting 3 conflicting oppinions.

Total agreement. On ALL parts of the design

One guy at Regupol the rubber people, told me that escalator handrail rubber would be fine but the next guyat Regupol said that escalator handrail rubber was too hard and didnt have enough " deflection" & tha my 19 mm floor is not enough to stop sound travelling through the brick wall ( even beneath the floor ) and that I would have to build a floating floor ontop - at least the middle court ( control room ). According to him - floating the bearers would do nothing for me. * He may not have realised that I was to retain th " C" shape of the handrail to provide some " flex " or " deflection ".

Thanks for the link. Proper floating of structural members can not be done on a whim basis. Several calculations are involved. Done wrong and it is disappointing best, worse most likely. Regupol is a underlayment company, not an engineering firm. The least concern is sound going through the: floor brick wall brick wall floor. The main route is: brick wall brick wall. Regardless of how little isolation the floors provide, the isolation is still controlled by two separate brick walls! I have attached a graph showing approximately how much isolation you can expect with double 90 mm thick walls. It is taken from NRC IR 586.

I'm thinking of just cutting around the perimiter of the floor so the floorboards are not touching the brick wall

Do it. It can not hurt.

It's ALOT of work raising those bearers - but NOW's the time to do it -- BEFORE I build the room within. I don't want to be repating mistakes. This sort of effort could be better spent in floating the middle court/room ( control room).

Consider this. Floating floors INCREASE sound transmission at the design frequency, and do nothing one octave above. The norm is therefor to design the resonance for two octaves below the lowest frequency where increased isolation is required. The frequency is determined by the equation: f=2.2(d^0.5) where: f=resonance frequency (Hz) d=deflection of spring (mm). At the calculated deflection, the spring still has to have enough resilience to still be a spring. Assuming improved isolation is desired down to 40 Hz, the design frequency is 10 Hz. The required deflection of the spring is 20 mm. Is any of the material you have considered for putting under the bearers so thick as to be still resilient after being compressed 20 mm? Is any of the material even 20 mm thick?

I could only get a 25 kN rating from escalator handrail manufacturers. Regupol QT4015 is rated at 0.5 N / mm 2 - Tensile Strength. I took samples at spring compression place and the REgupol QT4015 stopped compressing at 700kg / mm2 - whilst the escalator hand rail withstood at LEAST 1000 kg / mm2. The thing is - I retained the C shape with the escalator rubber and after approx 400 kg /mm2 of pressure it " deflected " ( ?? ) real suddenly but continued to handle more pressure. I think the escalator rubber idea is gone - too hit & miss. Regupol QT4015 seems like it'll do what it's suposed to.

AVare wrote:

At the calculated deflection, the spring still has to have enough resilience to still be a spring. Assuming improved isolation is desired down to 40 Hz, the design frequency is 10 Hz. The required deflection of the spring is 20 mm. Is any of the material you have considered for putting under the bearers so thick as to be still resilient after being compressed 20 mm? Is any of the material even 20 mm thick?

Doesn't stacking layers of this Regupol QT4015 give me my 20 mm + thickness ?

tonymite wrote:

AVare wrote:

At the calculated deflection, the spring still has to have enough resilience to still be a spring. Assuming improved isolation is desired down to 40 Hz, the design frequency is 10 Hz. The required deflection of the spring is 20 mm. Is any of the material you have considered for putting under the bearers so thick as to be still resilient after being compressed 20 mm? Is any of the material even 20 mm thick?

Doesn't stacking layers of this Regupol QT4015 give me my 20 mm + thickness ?

The 20 mm is the compression of the material, not the precompression thickness. Yes, thickness can be achieved by stacking the material. You mentioned testing. What was the deflection of the material? Andre

Thanks for the link on the HVAC units. The link has not worked for me yet. I will try again later. You have three units. How are they spread through the area? My biggest concern is flanking through the HVAC ducts. Secondary, as far as our writing right now is noise from the system. You write about the duct work already. Andre

AVare wrote:

tonymite wrote:

AVare wrote:

At the calculated deflection, the spring still has to have enough resilience to still be a spring. Assuming improved isolation is desired down to 40 Hz, the design frequency is 10 Hz. The required deflection of the spring is 20 mm. Is any of the material you have considered for putting under the bearers so thick as to be still resilient after being compressed 20 mm? Is any of the material even 20 mm thick?

Doesn't stacking layers of this Regupol QT4015 give me my 20 mm + thickness ?

The 20 mm is the compression of the material, not the precompression thickness. Yes, thickness can be achieved by stacking the material. You mentioned testing. What was the deflection of the material? Andre

I don't have deflection ratings just: I could only get a 25 kN rating from escalator handrail manufacturers. Regupol QT4015 is rated at 0.5 N / mm 2 - Tensile Strength. I took samples at spring compression place and the REgupol QT4015 stopped compressing at 700kg / mm2 - whilst the escalator hand rail withstood at LEAST 1000 kg / mm2. The thing is - I retained the C shape with the escalator rubber and after approx 400 kg /mm2 of pressure it " deflected " ( ?? ) real suddenly but continued to handle more pressure. also : ELONGATION at break si 20% ... is that it ?

Still waiting on deflection figures from ERegupol for QT4015 anaother option is Shearflex : http://www.embelton.com.au/anti2.htm again - I don't know figures. my bigest question now remains: Should I or Shouldn't I raise the barers onto rubber? AVare mentions I could make things worse - but now's the time to do it if I were to do so. I was always under the impression that it couldn't hurt - yet it still remains ALOTA work.. for mossibly minimal or even detremental return. Thanks for the link. Proper floating of structural members can not be done on a whim basis. Several calculations are involved. Done wrong and it is disappointing best, worse most likely. Regupol is a underlayment company, not an engineering firm. The least concern is sound going through the: floor brick wall brick wall floor. The main route is: brick wall brick wall. Regardless of how little isolation the floors provide, the isolation is still controlled by two separate brick walls! I have attached a graph showing approximately how much isolation you can expect with double 90 mm thick walls. It is taken from NRC IR 586. Pictures are fantastic! YOU DO NOT HAVE TO WORRY ABOUT VIBRATION THROUGH THE BEARERS! The only connecting path between the rooms is ground.

Attatched is PDF of Regupol specs. including deflection - Even though it looks as thoughI'm NOT going to touch it ( will not be raising bearers onto any rubber ). My issue now is the slight ' hollow ' sound I get when I stomp on the floor. The floor is sturdy as the floor joists are 450 mm apart on concrete stumps. The fact that it's raised approx 400 mm off the ground allows for a hollow type resonance - nothing major... but still there none the less. Will this pose any problems? Will this hollowness become part of my room sound? Will it be acentuated and transmited to the mic via the mic stands on the floor ? I don't think it''l be a problem other than drums. Could it even add to the drum sound - like make it sound bigger ?? A drum riser could also be the go - no ?

here's a response I just got from EHC Global re: Escalator Handrail Rubber : Unfortunatley deflection is not something we measure in the industry - my engineers have suggested though that a 1/2" thickness x 2" wide strip of rubber with a 70 shore hardness would be best for your application.

tonymite wrote:

Attatched is PDF of Regupol specs. including deflection - Even though it looks as thoughI'm NOT going to touch it ( will not be raising bearers onto any rubber ). My issue now is the slight ' hollow ' sound I get when I stomp on the floor. The floor is sturdy as the floor joists are 450 mm apart on concrete stumps. The fact that it's raised approx 400 mm off the ground allows for a hollow type resonance - nothing major... but still there none the less. Will this pose any problems? Will this hollowness become part of my room sound? Will it be acentuated and transmited to the mic via the mic stands on the floor ? I don't think it''l be a problem other than drums. Could it even add to the drum sound - like make it sound bigger ?? A drum riser could also be the go - no ?

I have been told to pack the sub-floor with insulation to minimise " bass-bleed " which will apparently only amplify the resonance. I thought about filling the subfloor with sand - maybe use a compressor as in sandblasting technique to push the sand through - but that's an awful lotta sand ( 300-400 mm ). I also thought of floatong a floor ontop of the existing floor and filling it with sand / insulation but I'm not sure a 50-100 mm layer of sand will be heavy enough to stop the entire floor from resonating. Any Comments ?

CASH FOR COMMENTS ?

Your description is vague as is your budget. Line the underneath of the floor with insulation and put another layer of top finish (plywood etc.) with Green Glue in between. Andre

Hey everybody - below are a couple e-mail discussions i had with Dr. Rodney Staples who taught Architectural Acoustics at RMIT ( Royal Melbourne Institute of Technology ). Any comments much appreciated. Thank you Toy for your vote of confidence, but as I said on the telephone, I am not qualified to provide building advice that is the province of a qualified and licensed building inspector or architect. I recommend that you seek the advice of ArchiCentre or the CSIRO division of building products, or a similar body that provides consulting services with access to licensed building inspectors who understand the building regulations. I hope the stumps have moisture barriers between the stump and the bearer? I would be extremely reluctant to put fibrous insulation under the floor. Firsly I don’t think it will have any significant acoustical impact, and more importantly it is likely to impede air flow and capture moisture causing the wooden floor to rot… not a good outcome at all. As well as reducing noise from the air-conditioning plant, you also need to reduce the rumble caused by turbulence in the air-flow. You do this by having low velocity flow – that is, large ducts. But this is the opposite of what you need for blocking plant noise. I really think here too you need to get specialist advice from air-conditioning practitioners with experience in low noise installations. I recommend that you seek assistance from properly qualified and licensed inspectors who are aware of the current building regulations as well as the acoustical properties of the materials and plant. Regards, Rod Hi Rodney, thanks for taking the time to have a look at my blog. In regards to the floor ( see attatchment ), since I only have approx 300 mm clearance ( reduces to 100 mm at bearer points - as floor joists deduct 100 mm and then the bearers deduct another 100 mm) and it's impossible to get under to fix any insulation - wheter it's batt or blanket form, I'm thinking of feeding ceiling type polyester insulation ( approx 250 mm thick and the length of the floor joists ) in between each joist - most likely by tying something around them and dragging them under - as an electrician would feed cable undernath. This would be to dampen the sub-floor cavity, as in a speaker cabinet and even if it's slightly loose/scattered it should be sufficiant at dampening - no ?? I could always add the additional layer of building grade compressed particle board, on a rubber sheet once the room is complete or near completion ( at this point I should have a clear indication of how bad the resonance really is ). The other issue I'd like to address is HVAC. Here's what I have in mind: Re: HVAC, I'll have 3 seperate industrial over rated ducted units ( 1 for each room ). Capacity: Cooling Btu/W 48000/14070 Heating Btu/W 52000/15400 Airflow m3/h 2880 Noise Indoor dB(A) 57 Outdoor dB(A) 78 http://www.domainair.com.au/browse.php? ... tegoryID=5 HVAC silencers and clever ducting & louvers for tuning should make the unit even quieter. Since it's over-rated, I won't need to run it at full throttle. Even though I can see you have a thorough understanding of what I am trying to achive, I would appreciate if at all possible ( I know you're a busy man ), If you could take the time to come by for a tour of the place as it's local ( Fawkner ) and you could pick up on something I have missed and save me alot of greif and money down the track. As I have mentioned before, I have no problem paying for advice, I just need it coming from a credible source. This floor ( and HVAC +/- ) issue is more or less the last thing/s stopping me from going full steam ahead. Best Regards, Tony Mitevski. Sorry for taking so long to reply Tony. My only excuse is that I have been very busy. I have read your blog and I like what you have so far done. It all seems quite reasonable to me, and the advice seems ok too. On the question of baffles, the speakers are mounted into a soffit and sealed, so the walls of the room become the extension of the main front surface. The only concern might be from reflections from an adjacent wall at some angle to the main surface into which the speakers are mounted. This is usually addressed by having a diffusing surface on the potentially offending walls (which can be very decorative as well) On the subject of your floors, they are a very large membrane absorber. At the moment the stumps fix the membrane at points around the surface, and just as putting a finger on a string to shorten it raises the vibration mode, so placing fingers (stumps) around the floor will alter the mode(s) of vibration. Mounting rubber on the stumps will decouple the floor from the ground (if that is a problem) but it will also soften the points of contact with the floor that raise it’s resonance frequency and multiplicity of vibration modes, making it more sensitive to low frequency resonance effects. I think the advice that you had from the rubber supplier that adding rubber would have no effect was reasonable. You have effectively eliminated the transmission problem by having a floor isolated from the walls, but it is not decoupled from the ground, so there will be a low frequency flanking path between studios (and into your neighbour’s house) through the ground. If outside rumbling of traffic and Low frequency transmission between rooms or buildings is not a concern then your construction seems adequate in that respect. To reduce the resonance of the floor, you need to make it more massive, An additional layer of building grade compressed particle board, on a rubber sheet, on top of the existing floor may be enough to damp the worst of the impact noise (foot falls etc.). You may also use this method to partially isolate areas from each other on the same floor structure. If you are going to increase the mass of the floor, you should probably get some advice from a qualified engineer about the effect this will have on floor loading capacity and on the number and spacing of stumps. How you treat your ceilings (and I’m not sure here whether you are talking about the control room or the studio spaces) depends on how you want the room to sound. If you want a live sound, then the option you suggest of particleboard and plaster is fine. On the other hand if you wand a non-reflecting surface then absorbers are in order: that is, plastic and cloth covered frames with insulation inside, or baffle diffusers if you want really low frequency absorption. Suspended hard surfaces are probably not appropriate, unless you want to use them at angles to the floor to aid diffusion in the space. In an acoustically sealed space air-conditioning becomes critically important, and is often overlooked as a flanking path between spaces. I hope you have directed your attention to the free flow of air in the spaces, and how transmission via these paths can be avoided. I would be interested in hearing how you go. Good luck with your project. I hope my brief comments help. Regards, Rod Hi, I'm not sure if I am writting to the person I'm thinking of - I'm hoping this is the Rod Staples that taught and wrote the book ' Architectrual Acoustics ' for the Sound Production course at RMIT which I did in 1996. I'm after some advice on floating a floor for a recording studio built in a Squash Center and am having conflicting oppinions from various experts and below are links to forum discussions relating to my project should you care to have a peek. http://www.johnlsayers.com/phpBB2/viewt ... highlight= The last remaining issue I have to resolve is the 'bass-bleed' issue where my timber floor is resonating ( amplifying bass further ) when I stomp my feet.. and frankly I don't see how packing insulation would do the trick and a floating floor has its own associated artifatcs no ?

Any objections as to why I shouldn't operate the above bathroom area as a Post-Production Room as the attatched diagram? Any comments appreciated. Thanks.

How 'bout this quick sketch to make it more symmetrical

Hi people, believe it or not... I'm still working on this thing and would just like to run it by you all for any suggestions. CONTROL ROOM #2/MEDIUM TRACKING ROOM will be leased long term (by a friend who will give me access to all of his analog synth's, guitars, amps, pedals, time based mix effects such as spring/plate reverbs, phasers, flangers, delays etc.. ) but only used half of the week and will double up as a medium sized tracking room. This way we don't double up on any equipment and it allows me to focus on my microphone collection etc... I may even be able to add natural light in the center (LARGE TRACKING ROOM) if not in all rooms. Also, do I really need high ceilings in ISO BOOTH at the cost of office space upstairs?? Any comments much appreciated. Thanks.

... must be perfect then 'aye ???

I have added hi-res PDF for your convenience. Thanks.