My desk is trapping to much of the low end

[F.A.D.]

Hello guys,

first of all thanks for all your great posts, I learned a lot from this but my problem does not seem to be covered from one of the previous posts (I used the search engine a lot).

To get a better impression of my room/studio I made a virtual panorama. You can click and move your mouse to look around. It is flash based so its not that fast on older machines.

Here is my room/studio:

http://www.orchidproductions.de/Pano...io/Studio.html

I´m having this monitor setup for a very long time and I am very pleased with it except for one thing: the low frequencies are traped under my desk (where the displays are). Most people use a lot of bass traps to reduce low frequencies and I´m having something like a natural bass trap. I can work very well with this setup but I wish I would have more low frequencies at my listening position. When I´m under my desk it sounds like I´m sitting in a subwoofer or something like that, very strange...
I wish there could be a way to get some of that low frequencies from under my desk to my listening position or that at least someone could tell me why the low frequencies are trapped under my desk.

Any help is appreciated.

Thank's in advance,

best regards from germany,

David

[SAC]

A thought...

The bass wavelengths are much longer than any encountered dimensions and will thus flow around any of the obstacles. And depending upon the exact separation from boundaries, you will also be experiencing some degree of LF SBIR gain.

I suspect that you are perhaps in a modal null if your bass if deficient.

You might want to use REW to take a waterfall measurement and an ETC to examine your early reflections in order to get a more complete and precise idea of what you are actually experiencing quantitatively and to gain a bit more insight into the particular contributing factors (modal behavior, SBIR, specular reflections) and go from there in order to move from speculation toa more specific analysis of exactly what is responsible for the real issues.

[DanDan]

David, that panorama is brilliant, how did you do that? You could get into measurements which will ultimately answer questions properly, but there is a learning curve. May I offer some immediate action. Use a signal generator, sine wave. SignalSuite is nice and smooth. Sweep slowly though the low frequency area. You will hear the room 'take off' when you hit an exact modal frequency. This can be very loud but note there will be nulls also, so move about, stand up etc. When you are happy that you have settled on a strong mod, now move your head/ears about the room, you many need a chair or ladder. Write down where the loud high pressure points are. From your description and your panorama I strongly suspect that you have a vertical mode between your semi vaulted ceiling and your floor. This would lead to boom under your desk AND at the apex of that ceiling. Plus a null, i.e. lack of bass where you are sitting. Check it out. If this is the case I would install a significant amount of Bass trapping on the ceiling, and/or in the wall floor corners under your desk. Bass traps diminish the amount of Bass bouncing up and down, which diminishes the depth of the null. Strangely Bass Traps will actually increase the Bass for you. Remember this is a guess, but the test will prove it or not. Your mode could also be between the back and front walls or the side walls. Sines and a little effort will find these just as surely as software.
To get more, more even, bass at your mix position, try moving those speakers back until they almost touch the wall. FuzzMeasure and REW are great for showing the results of such changes and lots more. FM is very easy to use.
DD

[criticaldistance]

i wanna know where you got a white juno106? looks freakin' awesome! did you mod it yourself?

[locutus]

+1 to what both SAC and DanDan said.

I can't make it out very well from the cool panorama, but I would guess the sidewall separation and the floor-ceiling dimensions are very close to each other.

You need to start measuring. Get the dimensional information of the room. Then start measuring the problem frequencies. Like DanDan said, a signal generator and your ears (or a simple sound level meter), will tell you the basics. REW will get you a lot more information to work with.

It seems apparent that you have strong room mode issues, especially being that you have little to no bass trapping. Any room of that size is guaranteed to need large amounts of bass trapping of some form. Remember, bass traps can actually increase the bass you hear. It seems counter-intuitive, but trapping bass can can actually increase the bass. You need to stop the cancellation at certain wavelengths.

With the room dimensions you can use a room mode calculator such as http://www.bobgolds.com/Mode/RoomModes.htm to figure out where the room where the primary room mode frequencies should be.

You have a lot of potential to get a lot more control of your room.

Nathan

[F.A.D.]

You guys rock !!!

So much information in such a short time, I´m really thankful. I will definitely try out all of your ideas.

concerning the off topic questions:

Panorama:
Made with a Canon EOS 5D MKII and a Tokina 10-17 fish eye-lens with shaved off sunshade. That is all mounted into a nodal ninja 3 MKII with RD-8 rotator. Stiched with PTgui. Flash Version was made with pano2vr. Hope that helps.

White Juno 106

Some more pictures of it:

http://www.orchidproductions.de/pictures/junowhite1.jpg

http://www.orchidproductions.de/pictures/junowhite2.jpg

I painted the knobs and sliders myself. The overlay is a special film with a rough surface that was custom made for me by customsynth.co.uk according to my concept.

The sidepanels are from massive walnut wood and also came from custumsynth.

Kind regards,

David