Square rooms suck for subwoofers! (1 Viewer)

[Mike Up]

I previously drew a drawing of my room for another thread but it was an over generalization.

My right wall is completely taken by bookshelves and a giant doll house for my daughter along with shelves above that doll house. The rear corner is the only area open for a subwoofer. It produces over bloated bass with no low bass output at listening position, which is also only about 3' away.

The left wall is encompassed by a very large picture window along with a chair and end table. That rear corner is the same as the other, all bloated mid and upper bass with no low bass output at listening position. Also sub is right behind the chair so it's very loud at that listening position. Testing spots anywhere on that left wall, under the window, produces very weird results. Ultra low bass is good at listening position but mid and high bass are gone.

The rear wall has a sofa and chair with only those 2 corners open as I previously mentioned.

Front wall has no corners as right side of wall open to hallway in front and kitchen to the right side. On the left side of the wall is the foyer where living room door opens. The only spot I get good bass, ok, great bass, is behind the right front speaker.

The problem is I get a null right in front of the listening position so I have to push the sofa all the way to the rear wall. If I have the sofa pulled out, if you're really into a movie and sitting on the edge of your seat (sofa), your head is right in the null with no bass. With the subwoofer right behind the front speaker, all bass frequencies are in the null. With the subwoofer anywhere on the left wall, ultra low and low bass are not in the null, but mid and high bass are in the null and now the null area is larger swallowing up the listening position. The corners have no ultra low or low bass frequencies just over bloated mid and high bass.

Not really looking for advise as I've tried everything already, just tried again. REW and Mini dsp are more helpful with standing waves that add as the mini dsp can reduce those frequencies. Deep nulls are helped most by changing subwoofer or listening positions. Trying to diminish nulls with equalization and power output can just overdrive the subwoofer.

BTW, I tried dual subs with previous Klipsch R-120sw subs and results were terrible. Single sub in this room, works much better. Most likely because I don't have open areas to put dual subs, that would benefit a dual sub setup.

Just "venting", as I miss my days with better rectangular rooms.

 

[Wayne A. Pflughaupt]

I agree about square rooms, and even rectangular rooms. In both cases, the dead center of the room is a bass “hole,” and perceived bass levels increase as you move from that location towards any boundary. This is a problem that equalization can’t fix.

This is the primary reason I’m not a fan of dedicated rooms. I’ve had great luck in largish, open-concept living rooms getting reasonably consistent bass performance in multiple seating locations, except for those against a wall.

Regards,
Wayne A. Pflughaupt

 

[JohnRice]

I'm probably lucky with my HT, which is nearly square at roughly 20'x25'. In the past I've definitely had trouble getting good bass reproduction, but I also had no idea what the problem was. First, even though the room is nearly square, it also has several irregularities as well as a somewhat open side. So, there seems to be enough deviation from a normal, straight walled room to be able to produce good bass overall.

I have dual SVS SB16 Ultras, and their precise control turned out to be a benefit, since using REW it allowed me to analyze things and get their individual phase perfectly adjusted so they didn't conflict with each other, or the other speakers. I could go a step further and use a MiniDSP to further flatten the room response, but their internal DSP proved to be good enough for me. In my case, the theory of dual subs being able to complement each other was definitely real. The peaks and valleys of each individual sub genuinely produced a much flatter overall response when combined. I've had them for two years and while I fully expected to add a MiniDSP for the final degree of perfection, I've just never had the desire to go down that rabbit hole. I never feel anything is missing, so I just enjoy it.

 

[John Dirk]

I also have a square room with a few oddities such as an opening where a door would be and a large indented area where the stairs for the main level exist on the opposite side. With my previous SVS PB12 Plus/2 the bass had become unacceptable for music and boomy, even with movie soundtracks. My new dual SVS SB4000's made a huge difference although there is still that nasty null at around 70 Hz. It's something I see and hate on REW curves but, honestly, otherwise don't notice.

My brief time with the Anthem AVM70 did yield impressive results in this area so I know things could be better. Unfortunately there were too many other issues with that unit and I had to part with it. I guess my point is, there are ways to compensate for square rooms. It will be a main consideration whenever I do select my next Pre/Pro.

 

[Carlo_M]

A new friend from another audio forum invited me over to hear some bookshelves (he has at least a half dozen pairs ranging from sub-$1K pairs to $2.5K pairs). He takes his 2 channel music listening seriously, and has a devoted room to it. However that room about 12' x 12'. When I first saw the room I thought "oh boy this is a small, square room...the results are going to be interesting."

But he had two small subs in the front (can't remember the brand but they were probably like 8" or 10" sealed cubes) and also had bass traps in a couple of corners, and a combination of diffusers and absorbers strategically placed around the room. Talk about making lemonade. That was sonically one of the better experiences I've had, even the subs (which I can't imagine were super expensive) were paired up with his sub-$1K bookshelves. I didn't test every area in the room, but in his main listening position and a couple of off-axis positions the sound quality was uniformly high and no bass peaks/nodes that drew my attention.

But I bet he spent a good amount of time and effort into the type of acoustic treatment and placement. I'm actually in the process of setting up a music listening room and he's inspired me to think about how to treat that room.

 

[ManW_TheUncool]

Pretty sure part of the problem w/ a "square room" is kinda specific to HT application vs (most) dedicated/serious (typically stereo-only) music listening, especially for a single audiophile who doesn't (often) need to accommodate anyone else (for a single, relatively small sweet spot), and no video aspect to consider. That plus sub-bass isn't usually a big priority for music... certainly not nearly as much so as for HT application... which is likely largely why your new friend doesn't use big (and expensive) subs for that setup.

Traditionally, most (at least reasonably budget-minded) audiophiles even clearly choose to compromise most on the (lower) bass... and they actually still do.

I remember many such budget-minded audiophiles (still) raved about the Spica's back when I first got into the hobby. The then-famed, essentially entry level TC-50's in particular basically had no bass worth speaking of -- a quick google indicates they only went down to 60Hz presumably at -3db before rolling off big time... and also didn't go much above 17KHz (probably also at -3db), which was fairly common back then. Some did pair those TC-50's w/ "subwoofers" back then, but some were also happy enough to go w/out. IF they actually wanted/needed some bass back then, they were probably usually better off just moving upto the Angelus or some other brand instead... unlike now -- matching (well) w/ dedicated subs back then was definitely much harder to do... and most audiophiles simply shunned the idea...

Looking at the Angelus specs now, I see it too doesn't seem to go lower than my current ELAC UniFi 2.0 floorstanders (and only went upto ~17KHz at -3db much like its smaller sibling... unlike my UniFi 2.0 it seems or so ELAC claims anyway) -- they cost about the same in absolute dollars, but would really cost multiple times more in today's dollars.

Also, AFAIK, traditionally, (at least music-first) audiophiles typically don't mind dips and roll-offs nearly as much as elevated spikes/peaks (or lots of oscillation) in the FR curve -- a smooth curve, particularly around the core range for (mostly) acoustical music, is most important bookended by gentle roll-offs at the extremes... Most acoustical music won't really go quite that low (nor that high) anyway... and our ears aren't as good at noticing any issues at those extremes either, if we can even (still) hear some of them at all. We're probably (mostly) only bothered by distortions/aberrations that diverge from what we "know well" from lots of experience (and essentially, ear training)...

Plus typically, the focus w/ stereo-only music playback is on the imaging w/ just 2 speakers w/out the benefit of surrounds, so there are different emphases even above the bass frequencies, which don't generally matter in this regard.

_Man_

 

[Carlo_M]

Pretty sure part of the problem w/ a "square room" is kinda specific to HT application vs (most) dedicated/serious (typically stereo-only) music listening, especially for a single audiophile who doesn't (often) need to accommodate anyone else (for a single, relatively small sweet spot), and no video aspect to consider.

What Acoustic Treatment For A Square Room Do You Recommend? – Acoustic Fields

"Do you have any recommendations for acoustic treatment for a square room or is it always impossible no matter what the usage?"

www.acousticfields.com

Square rooms are harder to deal with acoustically regardless of whather it's for HT, 2 channel, etc. If you don't believe that blog I linked to above, my new friend will tell you how many hours (and much effort) he spent getting it to be musically optimal even for his one spot, let alone multiple spots.

 

[ManW_TheUncool]

What Acoustic Treatment For A Square Room Do You Recommend? – Acoustic Fields

"Do you have any recommendations for acoustic treatment for a square room or is it always impossible no matter what the usage?"

www.acousticfields.com

Square rooms are harder to deal with acoustically regardless of whather it's for HT, 2 channel, etc. If you don't believe that blog I linked to above, my new friend will tell you how many hours (and much effort) he spent getting it to be musically optimal even for his one spot, let alone multiple spots.

I took a quick look at that article, and it actually supports much of what I said, if one takes some care to read it.

It's quite clear the biggest issue is w/ bass as I pointed out (and usually mentioned by most/all)... and in your friend's case, his very small room size compounding the square room issue makes it a big problem (as pointed out by that article). That article writer would've likely recommended your friend just find another room instead (as he points out more than once)... although presumably, your friend's room is not actually a cube, which (as I previously suspected, but didn't mention since that's just not common/likely) would probably be the worst -- note the chart the article provides actually uses cube-like dimensions for the small square rooms, not just square dimensions w/ typically lower ceilings (than a cube).

Note also how there's less issue as you go to a larger (but still square) room... and also, what kinds of issues seem emphasized.

According to his chart, you should be fine w/ minimal EQ (and probably little-to-no treatments) in a 20x20 or larger square room -- and note the emphasis on bass treatment for the small, cube-like rooms.

Small rooms will generally be a problem due to increased problematic reflections of all kinds anyway regardless of whether it's square or rectangular... plus the necessary restriction on where you can place everything, including yourself as the listener, for best results. And smaller rooms mean shorter distances allowed for sound waves to travel, which also compounds the problem (probably particularly for the upper bass, which might not be an issue for most larger rooms).

And yes, HT setup for wider application, including difficult/complex movie soundtracks, does compound the relevant issues over stereo (for most music playback).

Moulton Laboratories :: Acoustical Measurements For The Rest of Us

Moulton Laboratories :: Taming the Big Wave

Any room/space big enough will make the exact shape not matter one iota... though of course, most of us won't have such a big enough dedicated space for music listening.

Anyway, typically, you should let your speakers have "breathing space" too (though again, most of us probably don't provide quite enough of that, if we're even aware)... and that pretty much rules out very small rooms, NVM whether they're square or not, but sure, very small, square room will be worse than very small, rectangular room.

Moulton in this article recommends 3-5ft behind the front speakers to the front wall and at least 3ft from the side walls, but not exactly the same distance from the front wall. Yep, that article mostly jives w/ what I've long been aware of from pretty standard audiophile MO, except he actually also recommends having speakers "mounted 'in' the front wall ('soffited')" as equally(?) good option, especially for a space that can't accommodate the in-room recommendation. However, that recommendation is probably *not* what most people actually do for in-wall speakers though -- he's actually espousing mounting normal, high quality, fully enclosed speakers, not typical in-wall variety, inside the walls... and probably still w/ the usual toe-in to boot, LOL, as notably illustrated in the big diagram.

_Man_

 

[ManW_TheUncool]

Audiophiles who are mostly only pursuing certain rather specific (stereo) music playback goals (like mostly only listening to jazz or chamber music or string orchestras or the like) can isolate/reduce/eliminate certain such issues, particularly when it comes to low bass. That's why I mentioned those Spica TC-50's earlier and how popular they were back in the day -- and there were plenty other (sometimes much more expensive) speakers/designs back then that provided little-to-no bass for similar reasons. And even today, your new audiophile friend chose bookshelf speakers probably partly for some of the same reasons... although (some of) those are probably far less issues today than back then.

But if you're trying to do HT w/ modern, action movie soundtracks, that will never cut it... so you can't just avoid those particular issues.

Still, your friend almost certainly isn't trying to replicate very low/deep bass w/ the (relatively inexpensive) small subs you noted anyhow (and of course, no surround sound complications... even though he's certainly fitting enough speakers into that small space ), and I'm sure that's intentional.

_Man_

 

[Carlo_M]

Actually turns out they aren't so inexpensive. He has a pair of Kef KF92s (I just asked him). He listens to all types of music, including bass-heavy tracks (though obviously none dig as deep as a good Christopher Nolan soundtrack).

 

[ManW_TheUncool]

Actually turns out they aren't so inexpensive. He has a pair of Kef KF92s (I just asked him). He listens to all types of music, including bass-heavy tracks (though obviously none dig as deep as a good Christopher Nolan soundtrack).

Makes sense. There does seem to be small-ish, audiophile-targeted, sealed subs designed more for music playback even these days I suppose.... and I wouldn't expect very serious audiophiles to skimp on a pair of subs, if they bother at all. Those being roughly similarly priced to a pair of his (better) bookshelves jives w/ what I'm aware of as one main school of thought on budgeting for such.

At one point a couple years ago when I was planning for a setup w/ some (mostly very old) used Thiels, I briefly looked (out of curiosity) at (used) subwoofers Thiel also made to mate w/ their, ahem, (quite hefty) "bookshelves/center channel" and smaller towers/floorstanders nearly 20(!) years ago. Even used (and certainly quite old by now), even the "cheapest", smallest of those subs, the SS1 -- a 10" model w/ 500W of power -- still seems to cost significantly more than my Hsu VTF-3 Mk5 today (w/ 15" driver and supposedly somewhat more power), if you can find a good one that is, LOL. Of course, it's quite possible the going rate is actually overvaluing that old sub nowadays, especially since servicing it nowadays will be difficult at best, but still...

Anyhoo, when you call your friend's speakers "bookshelves", I do wonder though. The old/used Thiel MCS1 I previously picked up to use for center channel and was also designed to be used like a "bookshelf", hehheh, certainly feels like it weighs a ton (at ~60lb) -- it definitely weighs notably more than each of my ELAC UniFi 2.0 towers. And then, they're meant to be used w/ hefty, dedicated stands designed specifically for them.

Some might also consider Vandersteen's 1 series (and maybe even the 2 series, which I've owned for a long time) to be sorta "bookshelves"-like I suppose... in large part because they're (again) designed to be used w/ dedicated stands -- some even filled those stands w/ lead shot, but mine just used sand fill, LOL. Don't ask me how many holes we've accidentally poked in the couple nice wood floors I've had them call home over 2-decade span, LOL. They were definitely hefty w/ those (sand-filled) stands attached... though nothing quite like a pair of old Thiel CS5i's, which of course could never be mistaken for "bookshelves" -- maybe a pair of monoliths from 2001: A Space Odyssey while they're cranking some Richard Strauss perhaps, LOL. But yeah, sadly, they can't fit (and be remotely usable) in my current space now...

_Man_