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Help me tame my out of control bass

Hey all,

Hoping to get some advice on how to tame what appear to be some pretty bad room modes. See my system here:
https://systems.audiogon.com/systems/8800

I’m in a bit of a pickle for a few reasons. First, my NY apartment is on the small side and requires me to set up on the long wall with the listening position against the opposite wall. On top of that I upgraded to my dream speakers, Egglestonworks Kivas. They sound amazing but they’re big and have a lot of low end reach. The combination of these two factors leads to the waterfall you see in my system - a pretty massive bump in low end, particularly at 40-44hz and from 60-70hz.

There’s also a huge bump at 120hz, but I don’t understand how that one is possible. I think that might be a measurement or microphone error - I don’t hear that at all and it doesn’t go away even when I EQ 120hz out completely, but maybe it’s a resonance?

Things I’ve tried so far, each with modest success:
- Plugging the ports gave me about a -5db reduction in the trouble spots (all measurements are with the port blocked)
- I don’t have a ton of placement flexibility but moving them back from their original position gained me about a -3dB reduction in bass
- I added a pair of 5.5” thick GIK bass traps, but they didn’t do much that I’m seeing in the measurements. Maybe a -1-2dB reduction, tops. They honestly helped more with the mids and highs.
- Convolution curve in Roon - this works the best, but doesn’t solve the problem for home theater or vinyl

I’m pretty stumped as to what else I can do. I think that the amount of bass traps needed to fix this is more than my marriage can withstand. I’m considering the PSI AVAA active bass traps, but only if I can do a home trial of them first to see if they’ll actually help - I worry this 8-10dB bump I’m seeing will be too much for even a pair of those. I could get a DIRAC processor from miniDSP and that would at least then work for all digital sources. Vinyl is mostly not a problem since this is so low and most of my vinyl is rock and jazz.

Any other ideas? Rolling tubes that have less bass? Are there any less expensive EQs with digital in and out that I could use as an alternative to the DIRAC for home theater only?
hudsonhawk
59 responses Add your response
mijostyn's avatar
mijostyn
8,570 posts
 
@hudsonhawk, welcome to the world of impulse measurement. It is not just the troughs but the peaks also. By 20 Hz you have lost almost 25 dB.
Sonically troughs exaggerate the peaks! You are hearing 40 and 50 Hz more because 38 and 47 Hz are missing. You can not just cut the peaks. You have to boost the troughs also. I assume your listening position is forced up against the opposite wall which is going to make this worse. Take measurements elsewhere in the room. As you have noticed bass traps do not work. They are acting as diffusers of higher frequencies. I get castrated for this opinion all the time. They are a complete waste of money. Made the same mistake myself. Check out my system page and you will see this is the voice of experience talking. Many systems are worse than yours! You were headed in the right direction but forget about Dirac. Check out the DEQX Premate, the Anthem STR preamp and finally the Trinnov Amethyst. All of these units will totally fix your problem. If my TacT were to go down I would get the Amethyst. The Amethyst also has a built in phono section. All three units are much more comprehensive than a "mini DSP."  You have a nice system it deserves better. It will sound so much better you will wind up like me digitizing your turntable. You have a beautiful turntable. Nice choice, fully suspended, great tonearm. Please get it a dust cover!
fuzztone's avatar
fuzztone
5,631 posts
 
+1 oldhvymec
erik_squires
16,215 posts
 
Hi,
Just moved out of a very similar situation.

You have done a lot and are pretty much thinking the right way.  Remember that though a bass trap may only change your FR a little, it will help EQ work much better. 

Try miking your speakers like 1' away and see if your 120 Hz bump is still there.  If so, it may be a microphone artifact.

Personally I went overboard and used GIK soffit traps and have not really regretted it except for the space they take up.
oldhvymec
5,101 posts
 
I have a feeling the spike at 120 is a crossover issue, 60-70 is normally an 8 foot ceiling, 40-50 (and if you had 9 foot ceilings) is the room size. So reflection point over your head and in front of you. Pull the speakers out from the walls, if only for listening. The suck out is REAL important.
WHY?, you’ll enjoy the un bloated bass, because you’ll volume DOWN.

You filled in the missing parts, you’ll see, MC was right on. Take care of the suck out and the bass will clean up.. Bass traps at 12" to 48" in all 4 corners, Not higher, not lower.. Both front and rear walls, dead center, do something, Drapes, kill the returning waves a bit...

EQ the rest. I use full blown DSP for bass management, nothing else 300 hz and below. PEQ, GEQ, slopes, threshold, phase...everything..
Above 300 hz all passive with high quality parts..

The slow decay rates are because the room is WAY to lively.. That is also why you have all the combing (dips, and actual valleys..)

Ricochet biscuit, comes to mind..:-)

Regards
hudsonhawk OP
137 posts
 
Definitely aware of the back wall reinforcement, however the room isn’t big enough to allow moving the couch forward more than a few inches. I’m also aware that probably limits how much improvement I can realistically make here.

Don’t get me wrong, I’m worried about the suck outs as well - it’s funny, I generated a tone at 55hz after noticing that cavernous drop on the graph and confirmed it’s completely missing in the listening position, and reappears as soon as you move around the room. Room modes are funny things.

That said the humps are the more glaring problem since they have such long decay time they end up sounding super muddy and boomy.
russ69's avatar
russ69
3,520 posts
 
MC is right.
millercarbon's avatar
millercarbon
12,531 posts
 
Looks like pretty normal room response to me. Find me a room that does not have humps like that. Good luck! All that happened, you finally got some good speakers with good bass. Now you want to get rid of a lot of what is great about your speakers. Go figure.

Those humps are there in almost every room for the simple reason the room is smaller than the bass waves are long. So they all reinforce and cancel. Your real problem looking at your charts is not the humps but the suckouts. I notice you're not all that concerned with those. Not at all. Yet they are by far the bigger problem. Funny.

The other thing I notice, if that is where you are sitting, right next to the wall, well no wonder. Bass response is not just the speakers and where they are. It is equally the listener and where they are. Anywhere near a wall is going to be huge bass reinforcement. Move even a foot or two away from the wall and into the room, this alone will make a huge improvement.
hudsonhawk OP
137 posts
 
It is a calibrated mic (miniDSP uMik-1).

I just don’t have any other explanation for that spike at 120hz, which is present even when I EQ 120hz to zero. I’m at a complete loss what that could be.
fuzztone's avatar
fuzztone
5,631 posts
 
Mini-DSP. 
That’s what I:d do.
Sounds like your only option.

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