Room Too Dead

@soix

That’s just mid bass and not what I’d consider “lows.”

Mid bass is usually what needs to be gotten after. What you call "lows" are very difficult to absorb.

I agree with your earlier statement that curtains and such are not going to absorb much bass or even midbass behind the plastic.

@erik_squires

Interesting what you said about too many TubeTraps causing mid-range suckout. This is not a situation that I’ve heard brought up before. Are we talking about midrange as below 600Hz? I’ve been told that a good goal for a home listening room is to shoot for an RT60 of about 0.3 seconds in the lower midrange and mid-bass, rising somewhat higher in the bass and upper treble. That sounds like a small amount of midrange suckout. From what I’ve seen of people’s rooms, it’s easy enough to get a rising RT60 in the bass, but getting it to also rise in the upper treble, that’s not something I’ve actually seen yet in a room measurement. My room is currently fairly flat around 0.3 seconds from about 400hz on up, which I consider to be a fairly fortunate result. Most of the time I see the RT60 falling in the treble, with the clarity conversely going up. It’s super easy to absorb the high frequencies. They also don’t tend to get dispersed from the speaker as well.

I’ve found a room can sound dead with one set of speakers and not another. The dead-ness I think is caused as much by the average frequency response of the reflections as anything, so a speaker that’s beamy in the midrange and widens quickly in the midbass can make a room sound murky. One that stays wider up to a higher frequency in the midrange can make the whole room sound more lively. I just bought several different waveguides to experiment with. EQing them all flat on axis, the overall effect in the room is strikingly different between them. A beamy tweeter needs to be matched to a well controlled, similarly beamy midbass, which is hard to do. Or you need to absorb a lot of midbass out of the room, and not the highs.

Hi @asctim  -

I really only got to hear this at a show in California where ASC was sponsoring the show.  Mamy rooms had tube trabs all over and what I noticed was terrible bass.  No matter the gear or the speakers, every system had 1 note that all the bass drums seemed to hit.  I don't know if anyone else has used the term "one note bass" but that's really a great description. 

Better sounding rooms lacked the tube traps but had more traditional, broad band absorbers liberally used.

@erik_squires

Well that’s exactly the opposite of what we would hope to achieve with liberal use of TubeTraps, and not a complaint I’ve heard before concerning TubeTraps. One note bass has been used a lot to describe bass where a particular room mode is dominating. Why a lot of TubeTraps would cause it rather than lessen it is something that requires some deep thought. Was that the 2019 California Audio Show? I was at that show and got to hear several rooms before and after we treated them with TubeTraps. Honestly, I was struggling to notice much of a significant difference. I was new at the time, unfamiliar with the listening spaces, and unfamiliar with the audio equipment, and tired. Most of the rooms we treated were large and I don’t think we were able to put enough treatment in them to get something highly noticeable to happen. The people that were running the rooms felt there was significant improvement, and chose the amount they wanted based somewhat on our own recommendations but also on their ears. Often they wanted even more but we only had so many to offer.

In my own experience, one note bass is mostly a speaker placement issue, but can also be addressed successfully with equalizing down peaks. I know some people are dead set against any kind of equalization, so if that’s out of the question, I think a distributed array of subs to break up the major modes is the only workable solution. Or, a very powerful and extensive array of bass absorbers.

Look up Dennis at Acoustic Fields. They have tons of videos on YouTube. You can buy their products or easily achieve the same effect DIY. You need to start with addressing the low end and some diffusers would help too.