Seating height and bass

Hello churchgoer,

    Based on my experience, I believe you can improve your overall system performance significantly by treating it as two systems: a bass system and a mid/treble and imaging system. Good bass response is usually the hardest to get right in most rooms so I suggest attaining that goal first and then incorporate the much easier to attain good mid/treble and imaging response after.  
    Up front it's important for you to know you're going to need a minimum of 1 sub in your system. In general, 2 subs are going to perform about twice as well as a single sub and 4 subs, in a distributed bass array (DBA) system, are going to perform about twice as well as 2 subs. I'm assuming you're existing speakers on stands only have bass extension down to between 40-50 Hz and you're willing to spend $500 each for at least a single good quality 10-12" sub such as a HSU, SVS, REL or another good quality sub; I'm unable to state additional good quality sub brands mainly due to a lack of complete knowledge of subs currently available.  It's also very important to make sure the sub(s) you buy have variable controls for volume, crossover frequency and phase. A sub that includes an automatic room control feature with mic is acceptable but not necessary.

Procedure for attaining good in-room bass response:

1. Disconnect your main speakers and move them and their stands completely out of your room.
2. Hook up your sub and place it at your dedicated listening position. Set the volume control at halfway (12 o'clock), the crossover frequency control at 50 Hz and the phase control to in-phase ("0"). Play some music with good, solid and repetitive bass.

3 Beginning at the right front corner of your room, slowly begin walking in a counter-clockwise direction around the perimeter of your room. As you're doing this, carefully listen for the exact spot the bass sounds the best to you ( solid, detailed, dynamic and natural). Take your time, listen carefully and repeat if necessary to determine the exact spot the bass sounds best to you.
4. Once the optimum spot is determined, move the sub from your listening position to this exact spot. As I stated earlier, 2 subs will perform about twice as well as a single sub; the bass will be more effortless, more dynamic, smoother, faster and integrate better with your main speakers.  
    If you're satisfied with good in-room bass response at your listening position, you can continue on to the next step of attaining good midrange, treble and imaging performance at your listening position. If you'd prefer bass performance that'll sound about twice as good at your listening seat, however, then obtain another sub and follow step #5 first. You also have the option of beginning with a single sub and adding a second sub when you'd like.
     It's also important for you to realize that the horizontal banding in your room of areas with poor bass response, that you noticed when moving your chair forward and backward in relation to the front and rear walls, is completely normal and predictable in rooms based on the room's specific dimensions (length, width and ceiling height) and exact locations of bass producing speakers.  
     The procedure I'm describing will ensure your listening seat is not positioned in one of these poor bass response bands but will do nothing to improve the bass response in these bands.  The only method I'm currently aware of that will provide very good bass response perception throughout any given entire room is the use of a 4-sub distributed bass array (DBA) system, such as the Audio Kinesis Swarm or Debra 4-sub DBA complete kits that cost about $3K. It's also possible to build a custom DIY 4-sub DBA for perhaps less if desired.
     This is an extremely good bass solution that works in virtually any room and with any pair of main speakers but it may not fit everyone's room décor or budget.  I utilize an AK Debra 4-sub DBA system in my room with a pair of Magnepan 3.7i main speakers and consider the bass performance near state of the art.  
       However, utilizing 2 good quality subs are also capable of providing very good bass response at a single designated listening seat if they're both optimally positioned. Sorry for the digression, here's the remainder of my suggested procedure for utilizing 2 subs: 

5. Hook up your second sub and place it at your dedicated listening position. Set the volume control at halfway (12 o'clock), the crossover frequency control at 50 Hz and the phase control to in-phase ("0"). Play some music with good, solid and repetitive bass. 
6. Repeat the complete exact procedure detailed above that was used to optimally locate the first sub for the second sub. The only exception being that you begin searching, for the next exact spot the bass sounds best to you walking slowly counter-clockwise around the perimeter of your room, from the location of the first sub rather than from the right front corner of your room.
 
Procedure for attaining good in-room midrange, treble and imaging performance at your listening position:
 
1. Ensure that the distance from the floor to the middle of the tweeters on your speakers, positioned on their stands, equals the distance from the floor to the middle of your ears when you're seated at your listening position.  
     I want to mention at this point that I agree with Eric Squires when he stated that aligning your speaker tweeters with your ears height may only be a good starting point.  I think it would be best if you contacted your speakers manufacturer and asked them for their recommended alignment technique concerning exactly which drivers should be aligned with your ear height.    
     
 Failure to adequately height match the ears and speaker drivers will compromise imaging performance and may require the adjustment of the height of the speaker stands, the designated listening seat or both.
2. Midrange and treble frequency soundwaves are very short and much more directional in relation to bass frequency soundwaves which are much longer and have an omnidirectional radiating pattern.  

3. For better imaging, ensure that first soundwave reflections off of each sidewall are either absorbed or diffused with the proper placement of acoustic room treatments. Other soundwave reflections off of the front and rear walls as well as the floor and ceiling may also benefit by either diffusive or absorptive acoustic room treatments.

    Finally, I should point out that I just wrote a full book's worth of suggestions for you without even knowing the exact brand and model# of your main speakers.  Yes, my offered suggestions are probably best described as audio basics but you should probably at least contemplate this prior to evaluating my suggestion that you may also want to consider upgrading your couch and main speakers.

Best wishes,
   Tim

Dial in your room here
http://www.hunecke.de/en/calculators/loudspeakers.html

Ideally seating position should be for the most coherent sound, but almost nobody does that because most speakers are not coherent.

Buy/make stands that position your speakers at the correct height for the room and then adjust your seating height to match. In the 70's, I had my DQ-10s on cinder blocks. Much better bottom than the tiny feet. Very low WAF.

Lots of subs will give even, but not accurate or good bass.

If I remember correctly, most speakers want the tweeter to be positioned at ear height. That would be step number one.

That's a good starting point. This isn't always true. Some B&W's seem to measure much better at midrange axis, but only your own ears can tell you what you like. :)

When the speakers are unscrewed from the stand surface they are mechanically decoupled and resolution will suffer. Tom

@erik_squires  excellent. Makes total
sense. I’ll give that a try

@twoleftears  I did try this and it sounded off. These speakers actually screw to the stand and so when upside down seemed bass light. I’ll try it again though.

Or: move the couch back into position, and using the regular stands turn the speakers upside down.  See what that sounds like.  Might be horrible, but....

Or you can change the spectral balance yourself if you know how to do it and want to try. Commanility in all rooms are they have walls floors and ceilings. You can redirect and use some of this energy that travels these surfaces and redirect a portion to your advantage. Tom

OP:
Tweeters get darker off-axis. That is, they have the most HF output if you are listening to them directly, and as you go off axis the high frequencies roll off. See figure 6 (yeah, this is lateral, but horizontal should be similar):

https://www.stereophile.com/content/monitor-audio-silver-300-loudspeaker-measurements

As you go off axis, you get more mid (or mid-woofer) and less tweeter.

Ive got a 2-way that I designed to be flat on-axis, but I still like listening a little below the tweeter. Troels Gravesen has also reported similar findings.

Anyway, point is, off axis the speaker’s character changes, and it’s up to you to decide what you like more, but room modes won’t. That is, even if you tilt the speaker the room modes (if any) will remain the same, so this is a way to test if this is truly a room mode issue, or speaker tilt issue.


If truly a room mode issue, highly recommend the Soffit Traps from GIK Acoustics.

Best,

E

Play a favorite tune..climb a ladder and as you travel up and down the bass changes. At some step there will be a void. Once you hear that then what do you do with that energy and information. Tom

Pierre over at Mapleshade, who has exceptionally good hearing, sez sitting on the floor is usually best. Nobody seems to know why.

You can redirect the bass that travels the ceiling and redirect some of it to your listening chair. Tom

If I remember correctly, most speakers want the tweeter to be positioned at ear height.  That would be step number one. 

The old leather couch in my listening room is 32 1/2 years old.  We bought it when we got married.  When I bought new speakers 2 years ago I spent a lot of time finding the "right" spot.  The problem was I had to sit on a couple of pillows to get my head at the right height.  I clearly made a world of difference, not only in the bass, but everything. 

I bought some sofa risers on Amazon for 20 bucks or so that raised that old couch 4 inches.  I figure I saved at least $1500 or more by not having to buy a new sofa.
Try that first.  And good luck!

@erik_squires  tilt them back so they fire upwards? What should I be listening for? I think at one time I had them aimed slightly downward  thinking that would/could simulate being above tweeter height. 
I super serious as to what I sjould
expect with them pointed up.

It's hard to tell if you are actually hearing a bass issue, of if you are just discovering that your speaker's output is uneven.


Try tilting the speaker back. :)


Best,

E

Everybody has this problem, because every room has this problem, because sound waves interact with each other and with the room to reinforce or cancel and this happens in all three dimensions not only the two everyone talks about.

The most efficient/productive approach is to try a lot of different speaker/listener locations. Listen for the best balance of imaging and smooth frequency response. But do not put too much emphasis on really low bass, because this is as you are beginning to realize a problem that cannot be solved. Not with just two speakers, anyway.

So you get the ballpark locations first. Then dial it in with absolute precise symmetry for the best imaging.

Finally, add four subs. These can be just about anything. They can go just about anywhere. The key is four, and in different locations, as the only solution to the room mode problem is lots of different sources.

Do a search for Swarm or distributed bass array.