John Sayers' Recording Studio Design Forum

Done some audio spectrum measurements today; but suspect that my approach is wrong.

The Audio Interface calibration file on REW is most probably distorted; I mention this in the REW forum with hopes of fixing the problem.

I have not been able to access the mute functionality on the M-Audio Fast Track pro; which might cause distortion due to "loop feed back".

If the calibration file is distorted my readings will be off.


I tested my room with the song of an artist that at this particular time-period was unknown outside local circuits; he used to often interrupt my conversations with my DJ friend and old production partner when I sat in his car about a decade ago when I was down in Miami.


I have a lot of respect for this artist; because of the fact that before he became "established" my friend used to play his records in a club that can in mild terms be described as an strictly "african american"
establishment.

(((I am pretty sure the Obama types would feel uncomfortable in this club; the cops where outside letting the people in; while the patrons smoked certain things ((lol)) that I believed no one should smoke if they want to maintain a good mental condition.
Certain substances should NOT (lol) be mixed and then smoked.))


He has been criticized by some for "becoming soft" because he has embraced pop music after making what one could label as graphically depictive music representing the social reality of certain social enviorments within the Miami-Dade County sphere.




I can't think of any thing more GANSTA (lol) then to go from hardcore rap to pop; especially when the fiscal benefits prove to be lucrative.

http://www.youtube.com/watch?v=bjgFH01k0gU


......

Song might not be everyone's cup of tea; but it sure entertains my incredibly small ego.



LOLOLO

Well; got to get the spectrum analyzing software to work properly now
(Cause Ya'll no that I'm doin all this work on my studio strictly fo loove baby!!!!!!)

On a positive note I tested the monitors with the broad band absorbers; what an incredible difference. !!!!!!



Sincerely,

Useg Diaz-Granados

An update on the audio interface loopback problem; it might have been as simple as to turn down the main volume on the actual interface.

Will test tomorrow in order to see what happens.




Sincerely,

Useg Diaz-Granados

Hope I solved the calibration issues .




Here is a reading of the room with the broad band absorbers.

I am going to make some measurements with a 0.1 mm sheet of plastic over the insulation to see how the results differ.


Sincerely,

Useg Diaz-Granados

Finished the test with the plastic over the absorbers insulation;


Problem areas (straight assumptions on my part) seem to be the peak at 147.8 Hz (121.9 db), the dip at 122.9 Hz (100.7 db), the peak at 112.8 Hz (110.4 db) and the sections in between 40 Hz to
74 Hz (db between 126 db to 110 db).


There was a major dip that was not there on the other test prior to placing the plastic around 53.81 Hz going from around 120 db to 112.15 db which is closer to what I (lol) assume to be the normalized curve around 110 db.


My plan now is to continue with the construction of the hangers behind the monitors, box for the outlets, flush mount construction and the saws; the bass traps and the corresponding center slot piece between them will probably be assembled last.

I can also add that even though it does not show up on the measurements; there was a BIG (lol) improvement on the" high end" register after the plastic was applied.





Sincerely,

Useg Diaz-Granados

An update;



Decided to start on the flush mount/bass hanger wood frame.

I attached some wood to the speaker stands in order to facilitate the placement of the 22mm MDF that will make up the baffle of the soffit
but have NOT (LOL) attached this construction to the frame as of now.

I made some adjustments and decided to make a section on the top part of the frame into a "super chunk" sort of absorber; I will fill this space up with loose insulation;
the will hangers will hang underneath.

The next step is to start on the 22 mm MDF flush mount box and the saw frames to see how they can be attached to the current frame; once that is done I will reinforce the frame to insure it is solid and place the hangers and isolation on the frame and the saws.

I will then re measure the rooms frequency response prior to placing the MDF and the saws into place.

Then I will make the bass traps and the corresponding slot resonator center piece frame and re measure the rooms frequency response and then finally fill the cavities with the MDF and the saw pieces (forgot that I have to make the electricity jack boxes somewhere within this process).


Hope to get some more work done during the week.




Sincerely,

Useg Diaz-Granados

hmmm ....

no 'top plate' on the front 2x4's. Also ... hard to tell at the floor level, but not seeing
a floor plate ?!?!?

Not sure if that would be an issue down the road ... but I'd be concerned with regards to stability AND secure mounting into the structure. Also ... lumber has a way of warping/ twisting.

Maybe one of the 'Carpenter Guys' will post on this.