Is my room doomed? Pic

Enzo – Let’s see if we can diagnose before we perscribe; here is what I heard you say your problems were:

1) “I'm having a hard time getting it to sound anywhere as good as the dealer/distributor using very similar equipment (outside the preamp). Is it my room?”
2) “the soundstage height/depth is not what I know these speakers are capable of. The depth of the layers in the soundstage is also shallow” “But the huge soundstage width and depth And sense of ease at the dealers was not replicated.”
3) “I have no sidewalls”
4) “speakers are firing into floor to ceiling windows”
5) “room just kinda sounds dead and muffled” and “It just sounds veiled, with a soundstage that is between the speakers only”

Let’s take them one at a time:
Point 1) Above
• Identical equipment in different rooms will always sound different (unless they’re identical hotel rooms which’ll sound equally dreadful)
• Expecting your room to sound as good as the dealer’s isn’t realistic IF the dealer has a well acoustically treated room, and maybe using multiple bass sources and EQ to ensure near-perfect bass response, has good room dimensions, and side walls which you lack in the current configuration.
• Conclusion: yes it’s your room as you surmised.

Point 2) Above
• The depth of the layers in the soundstage is shallow because the soundstage depth is shallow so naturally everything is compressed. Soundstage depth needs distance between the front wall and the speakers – try 7 feet or so. Failing that put lots of broadband absorption centered on the front wall starting 2ft above the floor and extending to the ceiling. The absorption will significantly attenuate the reflections coming back towards you which will trick the brain into thinking the front boundary is farther away than it really is.
• Soundstage width is a function of side wall reflections at 1st reflection points that are less than 80ms and within the band of 500Hz-2KHz which add image broadening and hence your soundstage width you seek. Your absence of side walls isn’t helping matters. Dr Floyd Toole in his latest book debunks the popular notion that side wall 1st reflections are bad; they are bad IF you are a musician mastering his/her music or a reviewer trying to compare stereo components, but for all other purposes the side reflections are positive aspects of enjoying music by widening the apparent sound source width and reducing the Inter-Aural Cross Correlation coefficient.
• “Sense of ease” as you wrote may be interpreted that the balance of direct-to-indirect sound is off balance and you’re listening to too many of the latter, especially reflections off the glass windowed back wall in your current arrangement. The rear windowed wall is the perfect bass trap while it reflects higher frequencies so the sonic balance that you paid dearly for in those expensive speakers is being thrown off kilter at your ears.

Point 3) Above
• Side walls, as said above, provide much needed reflections for apparent source width and listener envelopment. Within Toole’s book listener’s highest preferences were when side wall reflections came at 60 degrees (if looking ahead at the speakers is 0degrees and over a shoulder is 90degrees).
• While it’s true that very stiff walls that keep most of the bass inside the room suffer terrible bass modes, the opposite is also problematic in that very thin walls (you’re your windows) won’t keep enough bass in the room which is the spatial domain of “listener envelopment”
• Reflections coming from the rear wall aren’t perceived as coming from the back wall but add a pleasant sense of envelopment

Point 4) Above
• Front and rear walls should have treatments that are broad enough individually or combined to cover as much of the freq spectrum as possible. If you only absorb the high or low frequencies then you’re also skewing the sonic imprint of the reflected sound (or indirect sound) that you also listen to thereby muddying or possibly veiling the sound.
• Bass trap absorption of the resistive type (i.e. fiberglass filled) must be a minimum of 4” thick and leave at minimum of 6”-7” air space behind it. Obviously the thicker the trap the better and the larger the air space distance the better affect absorption to lower levels. You want bass absorption to work from about 300-500Hz on down as low as it can go.
• From 300-500Hz on up you should consider diffusion or reflection. Absorption can be used if your room is overly reflective and bright sounding, otherwise reflection at 1st side wall points and diffusion in other areas will be beneficial by attenuating damaging reflections like flutter echoes between hard parallel surfaces which might be occurring between your front and back windowed walls in the current layout. Diffusion must be a minimum of 8” depth if of the QRD or Skyline type or 12” radius depth if of the hemi-cylindrical type so as to work down to 300Hz. Ideally you want the diffuser depth to be 50% of the 300Hz wavelength which equates to 22.5” but 8” will suffice at 300Hz but not nearly as effective as the longer lengths.

Point 5) Above
• Again “dead and muffled” could be due to a host of reasons not least of which is too much of the acoustical energy is being lost outside the primary listening position due to no side walls and the windowed back wall trapping all low frequencies.
• Soundstage between the speakers and presumably not extending to the outsides of the speakers is most likely due to the absence of side wall reflections.
Possible Solution:
• I’d recommend rotating your system and listening configuration 90degrees to use the windowed wall and wall with TV as the new side walls.
• (You can always mount your TV on an automatic stand attached to the ceiling that will drop down when in use or fold up parallel with the ceiling when not in use)
• Symmetry is usually pretty critical so if the windowed wall will always be the perfect bass trap then you’ll likely want some bass traps on the floor-wall corners on the TV wall to match.
• Side wall 1st reflections points can start off as bare and reflective as per Toole’s recommendations but if you find that the centre image is being pulled towards the TV wall because those reflections are stronger than those off the window (because they’re going through the window) then you could try absorption on the TV wall or both side walls. Thick drapes work best for absorption.
• The large deep space behind the speakers should act as absorption and thereby create a much deeper sense of soundstage depth than the current configuration
• With the new sitting position now equidistant between the tv wall and windowed wall you’ll also have what appears to be sufficient room behind the listening position for possible diffusion to be hung on the back wall of the new layout to attenuate reflections enough to help create envelopment
• You may need a pair of subwoofers to help boost the bass due to what’s being lost through the windowed wall.

Lastly, consider professional acoustical treatment consultation, OR get a damn fine headphone-based system ;)

". . .I'll have sidewalls but no front and back walls. Would that be a problem?"

The side wall lateral reflections are beneficial - particularly in stereo - since they can produce greater apparent source width and spaciouness, while the front/rear reflections can decrease these attributes since they come from the same direction as the direct sound and thereby increase the Interaural Cross Correlation Coefficient (IACC) which is a bad thing. So in short the situation of having side walls with no front/back wall is preferred over the opposite situation. Have you considered mounting some diffuser panels (DIY or store bought) on a moveable stand with wheels that can be moved to the side out of the way when not in use or put behind your listening chair for critical listening sessions? Just a thought.

"Why do thin windows act as an absorber of bass?"

Windows don't technically absorb bass unless they're loosely installed and their vibration back and forth acts like a diaphragmatic bass trap . . . As low frequencies have long wavelengths they don't "see" the window and easily pass through it; if they pass through it then they can't be reflected back into the room so therefore the windows function more like a bass trap/absorber. Higher frequencies with much shorter wavelengths will in fact "see" the window and reflect off of it. The biggest problem with the windows is that it's too good of a bass trap and allow too much bass energy to be drained out of the room while maintaining the higher freq energy and therefore acts like a high-pass filter throwing off the timbral balance which you hear. So diffuse or absorb in front of the windows to attenuate the higher frequencies.

I don't know your ceiling height but you could experiment with reflection, diffusion, or absorption at 1st reflection points there to see which you like best.

Good on 'ya for trying various things and noting the differences. Measuring the frequency response / SPL (dB) is also important for trying different things so you have a record of the sound for each setup variation.

You wrote: "the biggest issues are probably 1) soundstage height is a bit too low and 2) I still want more overall bloom in the soundstage (envelopment from up down left right)."

1) Sound stage height too low: Try sitting on the floor ;) Seriously, put a rug on the floor to kill flutter echo between floor and ceiling and see if that does anything for soundstage height. Otherwise, keep the wood floor bare and raise the front of the speakers (or lower the back of the speakers) with the thinking that just as side wall 1st reflections that aren't absorbed or diffused help with widening the apparent sound source and increase listener envelopement, so too should it work in the vertical domain. Raising the front of the speaker's will put more HF energy up to the speaker and subtly call your attention to the height. However, it's not likely to be as drastic a change as lateral reflections because we hear more effectively latteraly rather than vertically due to our ear positioning on our heads. Lastly, you could add white RPG Skylines (see my system or others that use it) to gauge if this impacts the height. Personally I didn't find it added much but that could be due to my speaker's vertical dispersion pattern, or lack thereof or the sheer angle that the 1st reflection is at given I sit near field.

2) Soundstage bloom and envelopment is a funtion of indirect sound resulting from reflections from bare or diffused surfaces, and mostly from side walls which you lack. Have you considered rotating your system 90 degrees like I mentioned previously? I know it's a lot of work - ugh.