Owens Corning 705 and 707 and is king!

[T800]

Recently I got a chance to record in some world class recording facilities such as Cherry beach and Metalworks and i have confirmed that there was no chance that the panels built into the walls were owens corning 703... they felt much more rigid and dense.... [so i found out what they use] and I therefore just changed all my DIY panels to 707 and 705 in my own studio and let me just say that [in my opinion] this is the secret to that pro studio sound... the difference [to me] is outstanding.... i am finally starting to get that pro tight but smooth sound and tone that you also experience in theatres. And the bass traps also kill in those densities. My previous 703s actually resonated too much midbass.

If you are a DIY-er, make sure to track down 707 or 705... because you definetly get what you pay in terms of performance.

To me, 703 resonates too much low mids and midbass. The density has got to be [in my opinion] a good 6lb per cubic foot for the pro studio sound - but don't take my word for it.... go check out how dense the panels built into the walls are at a top class major recording facility. Have a nice feel.

[Zombie H]

were you recording an amp sim?

interesting tip on the owens corning tho

[johndykstra]

this should be fun.

[Glenn Kuras]

Not sure where to began but I will give it a go.

1)For thinner broad band bass traps I do agree that higher density works a bit better. Actually Ethan Winer did some tests on it and showed it, but as the panel became thicker it became less of a issue.
2)Million dollar studios use 703 (or lower for really thick or filled corner bass traps) with incredible results.

If you have some room tests before and after changing them please post them.

[DigitalMahem]

Every room is different and you might have to settle for a denser material in a small room where you might not have the wall depth to use enough 703. This is the fun of studio design, and it IS supposed to be an enjoyable experience! One thing for sure, this stage is critical.

[T800]

Originally Posted by Zombie H

were you recording an amp sim?

interesting tip on the owens corning tho

The wall treatment would not affect the recording since its a virtual amp. The treatment is only useful while recording the amp sim for less fatigue in the room. The treatment is only relevant to the monitoring of that take. If I would be recording a real amp then I would answer your inquiry which does not apply to apply to recording.

[T800]

Originally Posted by Glenn Kuras

1)For thinner broad band bass traps I do agree that higher density works a bit better. Actually Ethan Winer did some tests on it and showed it, but as the panel became thicker it became less of a issue.

Im not trying to say that the in house owens corning tests are definitive but they say .02 coefficient for 705 plain at 125 hz, and 703 plain says .11. I assume these are tests based on the spoken voice.

There are so many variances to tests... not like i know how to conduct one, but I am just referring to my listening experience and i find the room better to mix in with higher density materials.

2)Million dollar studios use 703 (or lower for really thick or filled corner bass traps) with incredible results.

This is the first time i have heard this. Please state which million dollar studio can attest to this. Especially your claim to "or lower" in reference to density. Because if you go lower you start to get into comparable densities to acoustic foam, which I heard is not a professional studio product at all, and I have never seen foam in any pictures of the world class recording facilities of the world.

If you have some room tests before and after changing them please post them.

There are so many variances to tests... not like i know how to conduct one, but I am just referring to my listening experience and i find the room better to mix in with higher density materials.

So perhaps I should have clarified that my experience is not the definitive yardstick for this matter...

[kasmira]

Originally Posted by T800

This is the first time i have heard this. Please state which million dollar studio can attest to this. Especially your claim to "or lower" in reference to density. Because if you go lower you start to get into comparable densities to acoustic foam, which I heard is not a professional studio product at all, and I have never seen foam in any pictures of the world class recording facilities of the world.

[avare]

Originally Posted by T800

This is the first time i have heard this. Please state which million dollar studio can attest to this.

Galaxy Studios. 4" of 703 like material with an 8" airgap behind.

Andre

[Zombie H]

wow so the 8" air gap is what really kills helps to kill off the low end bouncing all over the place?

sound hits the foam loses intensity - then hits the gap bounces into the wall and then gets passed back into the owens corning again?

[kasmira]

Originally Posted by Zombie H

wow so the 8" air gap is what really kills helps to kill off the low end bouncing all over the place?

sound hits the foam loses intensity - then hits the gap bounces into the wall and then gets passed back into the owens corning again?

Exactly! Most of the time when anyone is trying to absorb very low frequencies, air gaps definitely help. Its said that an air gap the same thickness as the panel can increase the bass absorption an entire octave below, though I've never tested it myself.

[avare]

Originally Posted by T800

Recently I got a chance to record in some world class recording facilities such as Cherry beach and Metalworks and i have confirmed that there was no chance that the panels built into the walls were owens corning 703... they felt much more rigid and dense.... [so i found out what they use] and I therefore just changed all my DIY panels to 707 and 705 in my own studio and let me just say that [in my opinion] this is the secret to that pro studio sound... the difference [to me] is outstanding.... i am finally starting to get that pro tight but smooth sound and tone that you also experience in theatres. And the bass traps also kill in those densities. My previous 703s actually resonated too much midbass.

If you are a DIY-er, make sure to track down 707 or 705... because you definetly get what you pay in terms of performance.

To me, 703 resonates too much low mids and midbass. The density has got to be [in my opinion] a good 6lb per cubic foot for the pro studio sound - but don't take my word for it.... go check out how dense the panels built into the walls are at a top class major recording facility. Have a nice feel.

703 is a tool in the acoustics treatment toolbox. It is correct for some applications and not for others. Its appropriateness depends on what is wanted and equations. It is not a one size fits all. Studio acoustics have much more happening than just what you see. What the material in the absorbers, assuming that they were absorbers to begin with, could be rigid 703 like material. Roxul makes 703 like materials that range from completely soft to completely rigid. The material you felt was firm to your touch. That does not mean it is 705, or any other specific material.

Andre

[T800]

Originally Posted by kasmira

FYI Foam sounds coffin-like and does not absorb much low end. At least Auralex, which claims a 1.9-2lb density, and yet is alot lighter and softer than Primacoustic who state 1.7-1.8lb density. Something not right on that one.

It is no wonder why Auralex is quite lower priced than Primacoustic. (i am not referring to convoluted, those are both companies lower grades).

[T800]

Originally Posted by avare

Galaxy Studios. 4" of 703 like material with an 8" airgap behind.

Andre

OC 703 is a flimsy board and definitely not industrial grade.

Who were the acoustical engineers and acousticians to guide the construction of Galaxy Studios?

Roxul makes 703 like materials that range from completely soft to completely rigid. The material you felt was firm to your touch. That does not mean it is 705, or any othere specific material.

The material was either 705 or 707. It was fibreglass insulation, not rockwool. I know what rockwool feels like. It punctures and wrecks easier.

Roxul has a huge range of products. The Roxul Equivalent in density would be Rockboard 60 and Rockboard 80. And RHT100 is up there too. Such boards are not available in Home Depot. But again, these are rockwool not fibreglass. They are not as rigid.

These serious densities sound ideal and have a most smooth quality to their absorption. I have also found that it seems more pleasant to mix, record or track in a room with these kinds of materials.

[DanDan]

Seems like high density can prevent a message getting through....;-)
DD

[johndykstra]

My wife and I went out to dinner last night. I had a porterhouse and she a grilled tilapia. Upon sharing bites as we typically do, I was astounded to find her tilapia much better than my steak. Based on this experience I can now say unequivocally that tilapia is better than porterhouse. Always.

[Rod Gervais]

Originally Posted by T800

I have also found that it seems more pleasant to mix, record or track in a room with these kinds of materials.

A statement like this only indicates your lack of knowledge on the subject....

Neither Power Station NE nor Avatar Studios NYC (formerly Power Station)- have materials anywhere near those densities included in the room treatments - yet they are world class studios (Tony Bongiovi was the acoustical designer for those studios).

I know that Eric Desart was one of the acoustical engineers involved with Galaxy Studios.

I design studios all over the world - and I never have used anything with greater density than 703.

I have been informed by the owners of Hit Productions that the engineers from both Abbey Road and Air Studios love my rooms.... so I must be doing something right.....

The sound of a room is much more than any single component - it is a combination of room geometry - volume, absorption, diffusion, and (when properly designed) should maximize the quality of sound with the minimal investment required.

This is (after all) in the vast majority of cases a business investment. Spending money just to spend it is nothing less than foolish.

To simply say that greater density is better indicates a total lack of knowledge about anything acoustic.

Rod

[amishsixstringe]

I am going to go put 4" of concrete on my walls in my control room, because it is WAY more dense than 707! Beat that hot shot!

Don't forget that density doesn't mean anything when ignoring the material. Auralex is made from foam. 70X is glass fiber. comparing their densities is like comparing steak to fish.

You don't think that just MAYBE that super expensive studio you were in probably would sound better than your room even if they used jello for broadband absorption, due to the geometry of the room?

Neil

[Rod Gervais]

Originally Posted by T800

FYI Foam sounds coffin-like and does not absorb much low end.

Foam doesn't "sound" anything........

No absorbent material "sounds"..........

[amishsixstringe]

Sure it does. I have a bass trap that plays ukulele all the time.

Neil

[johndykstra]

Originally Posted by T800

To me, 703 resonates too much low mids and midbass. The density has got to be [in my opinion] a good 6lb per cubic foot for the pro studio sound - but don't take my word for it.... go check out how dense the panels built into the walls are at a top class major recording facility. Have a nice feel.

Before this turns into a witch hunt....

OP, speaking for myself, and hopefully the rest of the repliers here... no disrespect intended. You've made an observation based on your experiences and that's great. However, acoustics is rarely as cut and dry as we would hope.

Echoing Rod's point above, "absorbent material does not have a sound". On the contrary absorbent material in any form allows, to varying degrees, some amount of the room's sound to remain. It's quite likely that your previous 703 panels were of an insufficient depth to effectively tackle the low mid modal region of your room. Upon replacing a too thin panel with a same depth panel but of greater gas flow resistance you likely witnessed an improvement. This is great news! What is not "good" is to assume a blanket statement such as your first post. When quasi-informed statements are presented as facts, those here in the know are left to explain why a myriad of internet myths are not accurate like bookcase diffusion, mattress absorption, good sounding vocal booths, and 38%.

Is 705/707 better than 703? Sometimes. But sometimes 703 is just right, and even other times something far fluffier than any of thee above is best.

[kasmira]

Originally Posted by DanDan

Seems like high density can prevent a message getting through....;-)
DD

zing!

[mikymike]

2" 703 is standard for broadband absorption. It's the number of layers and air gaps that determine how low the absorption will go. When we install our 9" QRD's, they are usually installed in back walls wth 6-8" of 703 surrounding the diffuser for broadband absorption.

[latestflavor]

Originally Posted by T800

To me, 703 resonates too much low mids and midbass. The density has got to be [in my opinion] a good 6lb per cubic foot for the pro studio sound - but don't take my word for it.... go check out how dense the panels built into the walls are at a top class major recording facility. Have a nice feel.

Wouldn't it be so nice if it was so easy?

There is nothing wrong with varying density in your absorbers, especially if it were multi-layered, but you seriously underestimate what it takes to make a pro room. (hint: they're not designed around velocity absorbers)

[Rod Gervais]

Originally Posted by johndykstra

Before this turns into a witch hunt....

OP, speaking for myself, and hopefully the rest of the repliers here... no disrespect intended. You've made an observation based on your experiences and that's great. However, acoustics is rarely as cut and dry as we would hope.

Echoing Rod's point above, "absorbent material does not have a sound". On the contrary absorbent material in any form allows, to varying degrees, some amount of the room's sound to remain. It's quite likely that your previous 703 panels were of an insufficient depth to effectively tackle the low mid modal region of your room. Upon replacing a too thin panel with a same depth panel but of greater gas flow resistance you likely witnessed an improvement. This is great news! What is not "good" is to assume a blanket statement such as your first post. When quasi-informed statements are presented as facts, those here in the know are left to explain why a myriad of internet myths are not accurate like bookcase diffusion, mattress absorption, good sounding vocal booths, and 38%.

Is 705/707 better than 703? Sometimes. But sometimes 703 is just right, and even other times something far fluffier than any of thee above is best.

+1..........

Great post John....... and I echo that no disrespect is intended, but what you present as fact is (in fact) not......

Rod

[avare]

Originally Posted by latestflavor

There is nothing wrong with varying density in your absorbers, especially if it were multi-layered, but you seriously underestimate what it takes to make a pro room. (hint: they're not designed around velocity absorbers)

There is no significant advantage to varying densities in an absorber. In all of the attempts of varying density I have seen here on Gearslutz, it decreases absorption, due to impedance mis-match.

Andre

[Rod Gervais]

Originally Posted by avare

There is no significant advantage to varying denisities in an absorber. In all of the attempts of varying density I have seen here on Gearslutz, it decreases absorption, due to impedance mis-match.

Andre

Andre,

I will often use a mixture of rigid insulation with fluffy insulation in very deep "traps" (think in terms of very large absorbers with 2' to 6' depths) with great results - there is a significant benefit in the cost to performance ratio with this approach.

This assumes (of course) that one has the real estate available to dedicate to this design.

However, I am in agreement that for treatments that are lacking in depth/volume there is no advantage whatsoever to layering different densities of rigid insulation, in fact I agree that it may be problematic unless it was really well thought out.

Doing this just for the sake of doing it makes little to no sense at all.

Respectfully,

Rod

[avare]

Originally Posted by Rod Gervais

I will often use a mixture of rigi d insulation with fluffy insulation in very deep "traps" (think in terms of very large absorbers with 2' to 6' depths) with great results - there is a significant benefit in the cost to performance ratio with this approach.

This assumes (of course) that one has the real estate available to dedicate to this design.

Agreed. The type of TRUE FULL RANGE ABSOBER that you are describing is one that a Gearslutz looking for direction on build would not use because of the real estate involved. If a Gearslutz person used such absorbers, they would almost certainly have the requisit acoustics knowledge, either personally, or through their studio designer. At the costs involved just with the real estate, it is almost that they have a professional working on the studio.

However, I am in agreement that for treatments that are lacking in depth/volume there is no advantage whatsoever to layering different densities of rigid insulation, in fact I agree that it may be problematic unless it was really well thought out.

Doing this just for the sake of doing it makes little to no sense at all.

+1.

Respectfully,

Rod

It is always a pleasure experiencing the dialogues with you.

Honoured,
Andre

[latestflavor]

Originally Posted by avare

There is no significant advantage to varying densities in an absorber. In all of the attempts of varying density I have seen here on Gearslutz, it decreases absorption, due to impedance mis-match.

Andre

you should wrote to cox and d'antonio and tell them their book is wrong.

[avare]

Originally Posted by latestflavor

you should wrote to cox and d'antonio and tell them their book is wrong.

A vague remark is not usefull. It might even be considered confrontational. Please reference what was is written, or at least the page number and edition. I have both first and second editions.

It is possible that you wrote your post before reading my qualification in my response to Rod, immediately above your post.

Andre