# TAKE a look, and...answer me



## irombeach (Sep 7, 2010)

Hi all.....
i try to understand something but, this field is very hard so i need your help.
i'm testing my room and the first question, may be obvious....but needs an answer!

Which is the goal of the treatments? is it to obtain a 'flatter' response curve?
If yes, please take a look to the enclosed picture.

what about the "A circle"?
red graph is without any treatment and cyan and yellow are two different kind of panels.
keeping in mind that my goal is to obtain a flatter curve, i think i'm getting worse because
i'm increasing the "null" (the opposite of peak....i don't know the correct word")
is it a correct idea?

i think that the "B circle" represents an improvement, am i wrong?


----------



## bpape (Sep 14, 2006)

Sorry- not seeing an A or B circle in the graph. While you did introduce some issues around 150Hz. you got rid of the nasty one around 60Hz in the red trace with whatever you did in the blue/green trace. The 150Hz will likely be much easier to deal with.

Bryan


----------



## irombeach (Sep 7, 2010)

sorry i did posting with the wrong picture.


red graph is the room without any kind of treatment


cyan : (front wall treatment)
1) one tube (40 cm diameter on the corner, 1mt hieght, density 100, thickness 4cm)
2) one big panel (width 60cm, height 2 meters, thickness 8cm rockwool, 2cm air) on the right of the speaker (outer)
3) one little panel (same thickness, 1 meter high)
2) one big panel in front of the column (do you remember the picture of my room?)



yellow : left wall treatment 

1) little panel near the column
2) big panel at the centre
3) little panael near the corner, 
4) one big tube on the corner (the same as before but 2 meters high)


----------



## bpape (Sep 14, 2006)

Evidently the tube is what's helping you though I'd be surprised if a single one actually did all of that around 60hz. Did you do all 3 of these measurements without moving the mic at all?

Bryan


----------



## irombeach (Sep 7, 2010)

ooops the attachment


----------



## bpape (Sep 14, 2006)

It's hard to tell what the reference level would be to say if A is better or worse for cyan. Yellow trace isn't doing anything really well and is hurting some other things. Cyan trace is going in the right direction in several places.


----------



## irombeach (Sep 7, 2010)

bpape said:


> Evidently the tube is what's helping you though I'd be surprised if a single one actually did all of that around 60hz. Did you do all 3 of these measurements without moving the mic at all?
> 
> Bryan


Yes the mic is always at initial position

but what about panels?


----------



## bpape (Sep 14, 2006)

Can't tell - too many thing changing at the same time to say what is doing what. 

My question was not if it was in the same place rather did you move it then move it back? Small changes in position can make large differences in response for an exercise like this.


----------



## irombeach (Sep 7, 2010)

no, no, mic always in the same position.
i've a tripod ( the object we use with cameras....) and the position is perfecly steady.


----------



## irombeach (Sep 7, 2010)

Talking about new issues introduced at 150Hz.......
is it a problem because we have "lost" that frequency?


----------



## bpape (Sep 14, 2006)

Most likely, there were 2 problem areas around 150Hz that were cancelling each other out. You've rid yourself of one of them so the other showed up. 

With all of the different changes between setups it's really hard to say what's doing what. Take a more stepped, scientific approach and start with a bare room. Add one thing at a time and see what each one does. That will give you a lot better feel for what's happening, where problem areas are, etc.

Bryan


----------



## irombeach (Sep 7, 2010)

ok Bryan i will follow your suggestion.

but ...can rew (impulse response graph?) tell me where problems are, instead of trying 10.000 places?

ale


----------



## bpape (Sep 14, 2006)

It can tell you when reflections occur in time but you have to figure where relates to those times. Also, just because you have a reflection doesn't mean it's bad. If, as I suspect, you have to places with cancelling reflections, and you rid yourself of one, the other one shows up.

If you want, just walk around the room and listen. See where bass builds up at the frequencies in question. This gives you a starting area anyway. 

Bryan


----------



## irombeach (Sep 7, 2010)

yes....it's an hard job!

i will start again with small changes....


i have undertood the problem related to canceling reflections....
you rid one.....two bornsaddle:


see you soon

and thanks a lot
alessandro:T


----------



## DanTheMan (Oct 12, 2009)

irombeach, don't forget to look at decay rate as well--csd/spectrogram.

Dan


----------

