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
You are dealing with a number of immutable issues as things stand. The dimensions of your room and the actual output of your speakers. I think you can change your speakers, add mass to your room or add helmholtz resonators. If you are able to add mass with albums, books or other items this will help, although you most likely would need more mass than is practical. Helmholtz resonators are easy to build and the calculations are simple. You could dress these up a bit. You would need to get the dimensions of required resonators and target 2 or more frequencies. 5 years ago I would have steered you away from DSP, but now if you are willing to spend some money it might be a solution. I would imagine you would need to get well north of 1K for an adequate DSP solution but this really doesnt cure the fundamental problems. Too bad you live in an apartment or I could give you more suggestions. 
hudsonhawk OP113 posts02-23-2021 9:38pm@speakermaster Great question and a detail I forgot to mention is that i did decouple the speakers by adding Isoacoustics Gaia feet to the speakers. It didn’t make as big of a difference for the bass as I was hoping (although in retrospect I wish I’d measured before and after, I didn’t yet have the measurement mic) but it did improve the imaging significantly.


In terms of measurable differences, this is unlikely to make any difference. Their may be a slight slight difference, but the vast majority of the energy is coming out as sound, not vibration in the cabinet, especially something as solid as what you are using.

Add a couple of subs and position them so that your nulls hopefully becomes manageable. When you have a +/- 8 db bass freq range you can start to use dirac or similar. Paradigm sells a small and rather cheap ARC unit that works digitally. But if you use Roon comvolution filters they should do very well. Acourate software is fine for Roon. Roon also got PEQ filters for final manual adjustment to your liking. Remember good bass is not loud bass.
The 120 issue. I read Erik had said it may be AC. It that because 220-40 VAC. being on at the same time? Or some 220-40 VAC something being on? I’m not following, I’m a little foggy these days, the light is a little dimmer lets say..:-)

I don’t run anything at 220-40, except the AC and never when the stereo is on. Maybe that’s why I never see a serious spike like that.

I see it on the flame/graph, can you hear that? If it’s there you have to be able to hear it, right. Can the spike be so narrow you can’t hear it? I guess the answer is in the second graph, with no audible seen, proves you can’t hear it? I’m not understanding the bottom to top narrow line @ 120 (ish). I need the tech tofu!!!

Regards