Construction Diary - Stockholm/Sweden

An update; Thomman, the people I bought the M-Audio DSM 2 monitors from are transferring the money that I bought the monitors with back for the one that did not work. That process is going to take at least a couple of days. Meanwhile I decided to start varnishing the first layer of the wood frame for the broadband absorbers right now even though the time here in Sweden is 16:00. My game plan is to varnish the wood pieces then assemble the broad band absorbers and contrary to what I previously stated install them first after; I get the money from Thomann. Then I will finally conduct the frequency spectrum analysis of my room (before the broadband absorber installation) :wink: . Well, I got to go to work now. I will post pictures as soon as I am done. :? :o :shock: :| :evil: :mrgreen: Sincerely, Useg Diaz-Granados

An Update; It took a long time to localize the other M-Audio DSM2 Studiophile monitor. I am sold on digital monitoring. After a lot af searching I got one fromhttp://www.4sound.se/ for a reasonable price. I am getting back to sketch up mode in order to fine tune the flush mount construction, create a box for the electricity outlets, phone jack and the internet connection. Meanwhile I am using the line laser level in order to make accurate calculations so I can place the 1800mm x 1200 mm and 180mm thick broad band absorbers correctly. My sambo (a Swedish term used to categorize people living together without being married; I hope there are no tea party supporters here that would get offended;LOLOLO) is doing the varnishing and it is turning out amazing. :yahoo: :yahoo: :yahoo: :yahoo: :yahoo: :yahoo: I am also using the line laser level to place the flush mounts and the saws right. Sincerely, Useg Diaz-Granados

An update; Here are some picks of the wood pieces varnished. Sincerely, Useg Diaz-Granados

An Update; Started the frequency spectrum analyzation stage. After calibrating the sound card and the SPL meter (a Behringer ECM 8000) I proceeded to try to get a reading of the room. Not knowing what I am doing I decided to use the z weighting because it (as I understand it) gives the broadest/flat(est) frequency respons. I set the length of the sweeps to 1 minute and conducted a total of 4 sweeps which lasted 95.1 seconds. I will do my best to understand these readings in order to figure out how to approach the sound treatment stage most effectively. Sincerely, Useg Diaz-Granados

I am doing my best in trying to assess yesterdays readings. There seems to be some serious phasing issues. The Group Delay chart is not pretty (it is FAR ((LOL)) from the only chart that is not pretty). :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: Another recurring problem areas (as I with my limited understanding of how these factors impact the rooms frequency spectrum) seem to the spike that occurs from around 50 to about 90 Hz and the sharp spike beginning around 700 Hz and continuing all the way though the higher frequency spectrum. I assume that there is some kind of phase shift around 700 Hz up?????? :shock: :shock: :shock: :shock: :shock: :shock: The RT 60 chart confuses me. I know there are delay times on T20 and T30 from 90 Hz up of around 3 seconds which I have to neutralize but the EDT got me confused. It is VERY (LOL) high from 90 Hz on ( the entire spectrum!!!!!!) I wonder if the sharp spike beginning around 700 Hz and continuing all the way though the higher frequency spectrum might be caused by the window which i covered up with plywood causing a reflection behind the drywall, the back of my computer monitor or the metall strip going through the ceiling that was placed there to sustain the weight of the clouds?????? :cen: :cen: :cen: :cen: :cen: :cen: Well; the first thing I am going to do is to place the 180mm thick 1800mm by 1200 mm broad band absorbers in their respective walls and then take new measurements. Then I presume it would be smart to target the 50 to 90 Hz problem by making the bass traps so they can target these frequencies. Sincerely, Useg Diaz-Granados

Not knowing all of what I need to do in terms of properly measuring my rooms frequency response I am posting some threads that might be helpful. It seems that I need to redo the test since I measured the two (2) monitors in the same time and NOT (LOL) the right and left monitor separately. http://www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=17137&start=15&hilit=rew http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=16113&hilit=rew http://www.johnlsayers.com/phpBB2/viewtopic.php?f=10&t=17200&p=120907&hilit=REW#p120907 http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=17090&hilit=REW&start=15 http://www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=14333&start=90 http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=11542&p=101848&hilit=Carsten+d#p101848 Sincerely, Useg Diaz-Granados

Like the pros (in this particular field) in here most likely already figured out; the first test I made was done incorrectly. :| :| :| :| :| :| This time I conducted separate tests for the right and left monitor. :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: I will post the results tomorrow when I will continue to pursue my quest to better understand these particular variables that are a part of the studio creation equation. Sincerely, Useg Diaz-Granados

Here are the new results; Got my work cut out for me ...... :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: I don't get the RT 60 readings :?: :?: :?: :?: :?: :?: Even though I don't know what I am doing; something don't seem right; this part of the studio making process is giving me a headache ...... Sincerely, Useg Diaz-Granados

Finish the Sketchup frame; Only thing missing is the wood that the hangers are going to be attached to; the hole needed for the internet connection. The phone jack will be attached on the actual MDF (front plate). The yellow and green parts are a removable absorber; might be replaced with another slot resonator depending on what the new readings of the rooms frequency respons show. Now I am finally ready to start the final phase of this project. Sincerely, Useg Diaz-Granados

The REW software had bugs on the mac platform so I made a comment in their forum and got a respons from the owner. His explanation as I understand it has something to do with how the mac programmers messing up Java which forced him to spent a lot of his own resources to fix the problem. The dilema is that I have to make sure that the measurements I take are done properly; which might force me to use Voxengo span in order to compare the measurements with what I get with REW http://www.voxengo.com/product/span/. I've completed the assembly of the broadband absorbers and placed them on their respective walls which was a tedious exercise. Tomorrow is cleanup time. Hopefully I get some "audio spectrum analyzing" done. Here are some pics; of the progress thus far. Having been in many studios; I have to STATE (lol) that the way the room sound at this stage (without taking considerations to any spectrum charts) is way beyond what I've expected. One of the variables that makes me respect MR Sayers approach to building studios (as I with my very LIMITED((lol)) knowledge in this field) is that he trusts his ears. My presumption is that his production and mixing background has assisted him tremendously with regards to his work. In other words; I will trust my ears over the charts. I urge anybody benefiting from this forum to support this wonderful resource with their contribution(s). Sincerely, Useg Diaz-Granados

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. :blah: :blah: :blah: :blah: :blah: :blah: 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. :cry: :cry: :cry: :cry: :cry: :cry: 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 . :horse: :horse: :horse: :horse: :horse: :horse: 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. :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: Sincerely, Useg Diaz-Granados

An update; :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: 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. :lol: :lol: :lol: :lol: :lol: :lol: 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.