Never Put Subwoofers In Corners... Even with DSP and Multi-Sub Setups?

[Tangband]

You will be surprised of the audible differences experimenting with the hight when installing a subwoofer - the differences are as big as moving the subs L - R in the room.

My own experience in a room with 240 cm distance from floor to roof is that the bass quality will be best placing the subwoofer about 60 cm above the floor on a stable bench. This is the same optimal height as my main loudspeakers on loudspeakerstands. Coincidence ?

Here is more interesting videos from this guy:

 

[stevenswall]

He is right .
Not only this, but the fact is : The perceived pitch of bass notes will be clearer with two subwoofers in stereo mounted a bit above the floor - next to each speaker. You want to excite less room modes, not more.

This is one of the many reasons that a full register floorstander often sound better than small speakers with subwoofers in the corners or on the floor.

Edit: Genelec 8361 on stands sound better than 8351 with floorstanding subwoofers, partly because of this.

Seems like with modern DSP/room correction that room nodes and all peaks shouldn't be the concern, but rather getting rid of nulls since those can't be corrected.

I prefer the sound of the 8260 monitors I have when paired with a 7271 subwoofer that (totally irrelevant because of GLM from my understanding) is corner loaded.

If only I had a large enough dolly to move it around and up a couple of feet to test.

 

[Tangband]

Seems like with modern DSP/room correction that room nodes and all peaks shouldn't be the concern, but rather getting rid of nulls since those can't be corrected.

I prefer the sound of the 8260 monitors I have when paired with a 7271 subwoofer that (totally irrelevant because of GLM from my understanding) is corner loaded.

If only I had a large enough dolly to move it around and up a couple of feet to test.

GLM cant fix corner loading . Only make it less worse.

Every reflection or resonance in a room is like a bunch of bells ringing with different amplitudes. With a roomcorrection program such as GLM or Dirac , the amplitude of the ringing can be attenuated - but those bells are still there ringing, smearing the sound.

Acoustical treatment are usually much better than using room correction programes, but better still is correct installation of the speakers in the room, including the subwoofers, where experiments with the hight can bring benefits soundwise with real music.

 

[sigbergaudio]

So, more dB is only one profit with dual opposed?

It also reduces vibration in the cabinet to virtually zero. Great if you have wooden floors! Is there an audible difference beyond that? Perhaps if the single sub has a poorly damped cabinet. I think the main benefit is more SPL from one subwoofer, as opposed to needing two subwoofers for the same SPL.

 

[DRNNOO]

When I was writing dual opposed, I was thinking about subwoofers like Rythmik G25HP.
What about dual opposed vs subwoofer with 2 drivers like JTR Captivator R2?

Dual opposed like the Rhythmic sub cancel out vibrational energy
The Captivator? Theres nothing opposed about it... its just 2 woofers facing forward. You will still get a similar increase in efficiency by using 2 woofer in close proximity though.

 

[dasdoing]

The perceived pitch of bass notes will be clearer with two subwoofers in stereo mounted a bit above the floor - next to each speaker. You want to excite less room modes, not more.

I am in a small room, so my monitors are basicly in the corner. even after EQ the modes sounded terrible, and seamed to emerge (or "jump around") in the corners...hard to describe. A mono sweep at low frequencies would move left to right even below 80Hz. can't prove any of that. The number one reason I bought a sub was to move the bass "out of the corners". the (single) sub I am using is now dead center between the mains, and I never heard bass "in the corners" again.
I do believe that what I was hearing was overtones of the modes? or somehow an excited modes excites modes above? some day I'll try to find out what I was hearing

 

[ozzy9832001]

I am in a small room, so my monitors are basicly in the corner. even after EQ the modes sounded terrible, and seamed to emerge (or "jump around") in the corners...hard to describe. A mono sweep at low frequencies would move left to right even below 80Hz. can't prove any of that. The number one reason I bought a sub was to move the bass "out of the corners". the (single) sub I am using is now dead center between the mains, and I never heard bass "in the corners" again.
I do believe that what I was hearing was overtones of the modes? or somehow an excited modes excites modes above? some day I'll try to find out what I was hearing

I think I get the same thing you do. Like if you generate a specific tone it sounds like it's coming from the back corner? but if you turn your head it sounds correct.

This happens for me at from 130 -145. 135 being the most super obvious. I'm pretty sure it's the 8' ceiling causing mine. Probably the same for you. What I found that helped the situation was treatment in the back corners. Doesn't have to be bass traps. 4" panels across it worked well enough, but after I upgraded to 16" traps the issue went away. Prior to the traps, raising the subwoofer off the floor helped as well.

 

[DRNNOO]

cant fix corner loading . Only make it less worse

This makes no sense, EQ, can fix frequency response, and FR is first priority. EQ won't fix Group Delay and Decay issues. That is all. Corner loading gives the best bass response in a room and most FR issues are in the bass region. There are details on the most optimal corner loading but, non the less....

 

[Chromatischism]

Corner loading gives the best bass response in a room

It does not.

 

[RichB]

This makes no sense, EQ, can fix frequency response, and FR is first priority. EQ won't fix Group Delay and Decay issues. That is all. Corner loading gives the best bass response in a room and most FR issues are in the bass region. There are details on the most optimal corner loading but, non the less....

I am no expert, but if corner loading gives a consistent boost to bass such that it can be EQ'ed out, the it would be "free bass" as described by Dr. Floyd Toole.
Bass would then require less power and provide additional headroom.

- Rich

 

[DRNNOO]

fully I made a collage of the most important information from that study we discussed earlier...

Pink.... corner loaded, handsdown best response tested...

 

[Ron Texas]

I noticed a definite improvement in measured response when I moved my subs from near the center of the front wall to within 2.5 feet from the corners.

 

[Chromatischism]

I made a collage of the most important information from that study we discussed earlier...

Pink.... corner loaded, handsdown best response tested...

I have seen the same study many times, and have done my own testing in 3 different rooms.

Both are consistent. The best (note: flattest) response is achieved with mid-wall to 1/4 or 3/4 wall placement. You can see this in their Conclusions labeled "Best configurations are" (with the green background).

The only time corners are great is when you can do all corners and apply a lot of EQ. Corner-loading one or two subs usually gets bad results, whereas mid to 1/4 wall with one or two subs usually gets pretty good results.

 

[Purité Audio]

REW’s ‘room simulation’ can be useful given the constraint of its rectangular only format.
Keith

 

[DRNNOO]

Conclusions labeled "Best configurations are" (with the green background).

I can read, its my collage lol! I've been over the results, I'm not talking top three.... I am talking number one performer....

I have seen the same study many times

Well take a look at it now, there isn't a response better than

They didn't even include this positioning in the rest of the charts because there's no competition. Below is 11, which is a better performer than 10 and 12, If you think the 1/4 corner placement is 10 or 12 you are mistaken. 11 outperforms 10 and 12 and needs more than1 band of filtering, while they state 1/4 corner placement only needed one filter below 80hzZ

vs

The only time corners are great is when you can do all corners and apply a lot of EQ

This is untrue as well, If you just do one or 2 at 1/4 distance nearest wall span, you still will get a great FR... The major null from the nearest wall is cancelled in this position. I have one sub placed like this currently

"This configuration should result in cancellation of all odd order axial modes, and the cancellation of the first even order axial mode (where the subwoofers are at a null). This can be verified by looking at generalized standing wave plots like those on pages 17-21. Note that floor/ceiling axial modes would not be cancelled, however these modes are much less important. Floor/ceiling axial modes do not cause variation in frequency response over the seating are, assuming ear height does not vary.a virtually flat and uniform set of frequency responses could be achieved with 1 band of parametric equalization! Subwoofers (4) at 1/4 of room dimensions In this case, rule of thumb subwoofer placement worked well."

This is just one sub that is sorta kinda near 1/4 spacing on the width, can't do front to rear because the basement is 30 plus feet long lol. Looking at my phase I should be able to clean all of that up with eq and the resonant at ~58hz, I mean, it'll look better after EQ but this is pretty good if you ask me. The glitch near 60hz is predictable to the chart actually... once again, just one sub.

 

[Chromatischism]

Below is 11, which is a better performer than 10 and 12, If you think the 1/4 corner placement is 10 or 12 you are mistaken.

This is untrue as well, If you just do one or 2 at 1/4 distance nearest wall span, you still will get a great FR.

That is not corner loading. You said corner-loading gave the best results and I said my testing does not agree. You are looking at subs well out from the corners of the room. In addition, Welti shows you only get good results with corners when you do all 4. When you have 2 subs, the best results are mid-wall.

At any rate, good to see people looking at the research for pointers. I figured out these placements the hard way and spent a lot of time that I could have saved. Still, audio is a journey which we learn from as we go, so it's more than the destination.

 

[Trdat]

I have seen the same study many times, and have done my own testing in 3 different rooms.

Both are consistent. The best (note: flattest) response is achieved with mid-wall to 1/4 or 3/4 wall placement. You can see this in their Conclusions labeled "Best configurations are" (with the green background).

The only time corners are great is when you can do all corners and apply a lot of EQ. Corner-loading one or two subs usually gets bad results, whereas mid to 1/4 wall with one or two subs usually gets pretty good results.

I am confused how mid to 1/4 away from the wall proves better than corners when more SBIR will be presented? Closer to wall brings SBIR higher frequency then you use some absorbers to tame then EQ. Is there something else at play with mid to 1/4 away from the wall approach that goes against the norm of the abovementioned geneal consensus or is this method for people who don't use absorbers?

 

[Flaesh]

Sorry about the speaker instead of the subwoofer. Perhaps the optimization criteria in this case are somewhat peculiar. Somewhere in Malawi, note also the very high bass reflex tuning:

p. s.: Can someone identify this speaker?))

 

[Flaesh]

how mid to 1/4 away from the wall proves better than corners when more SBIR will be presented?

Normally at home SBIR (in the exact sense of the word) does not exist in the subwoofer range. 1/4 for subs on front wall and corner placed speakers - this is what I use. Crossed at ~80-90 Hz.

 

[Deleted member 48726]

Sorry about the speaker instead of the subwoofer. Perhaps the optimization criteria in this case are somewhat peculiar. Somewhere in Malawi, note also the very high bass reflex tuning:
View attachment 345437

Square passive radiator?
Reminds me of these-->