# Bass control disappointing after first round of room treatment



## rowan1 (Aug 11, 2021)

Hi Everyone! After 2 months of reading and building, I installed four 1.5' wide corner traps and two 2' wide corner traps. I also have two 6" deep x 4 feet panels at the back wall. I feel the bass is now more controlled in the 10ft x 10ft x 10ft room than before but its not tight or pleasing. I got an UMIK-1 and took REW measurements after installing the treatments with the sub and monitor levels balanced, sub cross over at 80hz & sub's high frequency filter also at 80hz.

Need your help to understand the next set of treatments that would improve the bass in this room. I could identify what looks like a 55 hz room mode and a 45 hz null. I am thinking of adding two 2' x 2' x 4' soffits to the ceiling. Is that the correct direction to go?


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## Da Wiz (May 8, 2019)

Nobody can help much with this unless you provide more information. The midrange and treble peaks indicate reflections you aren't controlling with smaller devices, often in corners (vertical wall corners or horizontal corners around the ceiling) and undamped first reflection points on side walls. There is a HUGE danger in overdamping the mids and highs. Your room tuning devices will have the LEAST effect in the bass, and the most effect on frequencies that are close to the wavelength of the thickness of the absorbent material you are using. The best tuning devices have reflective and absorptive properties. The reflective properties keep the mids and highs from getting over-damped. The absorption property helps control peaks and has small effects on bass. The biggest factor in bass response is the location of your bass sources (larger floor-standing speakers or subwoofer). You can move a subwoofer 1 inch and solve 3 problems while adding just 1 new problem (an example of what happens as you move and measure). 

I would suggest starting with 6-inch moves and when you find the best one, do a series of 3-inch moves to see if there's a better compromise at any of those positions. Also, you can measure each channel separately AND together to learn different things. These moves I refer to are moving the subwoofer or the largest speakers in the system. You cannot remove dips with EQ, so your focus when finding the best position for large speakers and subwoofer should be to find the fewest deep suckouts--the location where those deep dips are gone completely or are minimized will be the best position for the speakers. After that, manual EQ, manual parametric EQ, or room tuning software can manage response peaks... and once you have decided on best positions, you'll need to enable your room correction system, run it again with the new speaker positions, then re-measure to see if you're getting better results. You can't necessarily trust your first measurement of a room correction system. If you see something you don't like, re-measure with a microphone position that's as little as an inch different position than the first measurements. It can be time consuming to move-and-measure many positions, but you learn what your room is doing and can almost always come up with better end results. 

If you sit in your main seat and clap your hands... if you hear an echo, you have to treat side walls and corners around the ceiling. Keep messing with that until you cannot hear an echo after clapping your hands. You can walk around the room clapping every couple of seconds and will likely notice that you find some spot in the room that has very obvious echo and other spots where there's no or little echo. You want to get that no-or-little echo at your main seat at a minimum, but the more seats you encompass with very little echo, the better sound every listener will have. If there is echo between you and the speakers, it's not probably worth bothering with as long as you don't hear echo in your main seats. Good luck.


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## will95 (Jan 2, 2007)

Your starting problem is the dimensions of your room at 10' x 10' x 10'. A "cube" shaped room is not good for audio. There are several online room "mode" calculators available that will give you insight. One such site is www.bobgolds.com which provides calculation, along with some explanation and references for further review to understand your room audio challenges. You'll find a number of useful sites with a quick search. For example, taking a quick look at your SPL vs Freq graph shows a large peak at around 56 Hz. A room mode calculator shows this as a room resonance peak frequency for your room dimensions. Other peaks in your graph, will align with other room resonance frequencies. I'm sure there are some good YouTube videos that discuss the subject, but I have nothing specific to recommend at this time.


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## will95 (Jan 2, 2007)

The best room mode calculator that I've found is this one located at Harman International's website: HARMAN International: Room Modes Calculator by Dan Siefert and Alan Devantier. It's a downloadable spreadsheet.


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