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How to Solve High-Frequency Suckout in Room?

After upgrading my system including speakers, I'm noticing with more upper frequency detail, that the right channel has some degree of missing high frequencies.  I've confirmed it is my room by swapping speakers, swapping cables for left / right, and of course the cables are all in phase.

My room is quite large, open concept, but my system is to one side of the open area.  Ceilings are vaulted and are 12ft at highest point. The speakers are not near any corners, due to a jut-out on the right side and the other end being completely open. However, there is a partial wall on my right side that has no treatment on it that extends up to 12ft, from the listening position.  This wall starts 3.5 feet in front of the right speaker (about 1.5 Ft to the right of the right speaker) and continues to behind the listening position. 

I've tried putting pillows against the right wall and thought it may have made the problem worse?  There is no wall on the left side, it is completely open.  Does this make sense that there is missing high frequency on the right side, where the wall is?  And, is there anything I can do to fix this?  I will attempt to draw the setup but I'm guessing the alignment will mess up when I post this! 

 

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nyev

Showing 7 responses by djones51

djones51
4,947 posts
 

I thought there had to be a load on the amp to measure this  with multimeter but I might be wrong.  

djones51
4,947 posts
 

Narrow directivity speaker like Dutch and Dutch 8c, Kii3,  would work better in that room.  Or a horn speaker maybe JBL 4367. 

djones51
4,947 posts
 

You could try extreme toe in where the speaker axis crosses about 3 feet in front of your listening position. You could also pull the speakers out into the room more, In live rooms where you aren't able to do a lot a treatments speakers with narrow dispersion would do better if you aren't married to those B&W. 

djones51
4,947 posts
 

When you're doing excessive toe you're doing, time intensity trading, like they talk about in video. You could give it a try as it will move the reflection to the side wall on the right. 

djones51
4,947 posts
 

Easy test without buying anything would be download and run a 1khz and/or 10khz test signal through one channel at a time and use a SPL meter on your phone. Make sure you don’t change the volume when switching. The right channel is the one you suspect so I would test the left first get up to 85db with your phone 1 meter from the center axis of the tweeter and mid. Then try the right channel 1 meter from center axis and see what db you get. It’s not a perfect test but it should show if there is a big variation. Should be able to  hear if there is a big variation. 

djones51
4,947 posts
 

Take it to the shop where they can put test equipment on it. If you had a multimeter you could run the 1khz test tone at 0db on the volume and see what the volts are on each side. 

djones51
4,947 posts
 

Play the  1 kHz test tone into  speakers don't play so loudly that it damages your speakers. Set your voltmeter for AC Volts. Measure the volts across the speaker terminals. Power is: E²/R where E = volts RMS and R is resistance of load. Both channels should be the same at the same volume setting, maybe slight variation. 

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