Actually, I'd rather move walls than break windows so, in that spirit, some visualizations
The single flare horn on a single bass bin looks pretty innocuous. I'm planning on painting the inside of the horn to match the room walls for stealth effect. For scale, the Synergy is 28" wide and the center is 34" high.
I could add a secondary flare that extends to within a fraction of an inch of the walls to that:
If that passes the WAF filter, I'll be emboldened to add a 2nd pair of bass bins. Then my acoustic center won't shift as the sound goes below 200 Hz and I'll have 6 db more headroom at 20 Hz.
If that is too intimidating, I can remove the 2ndry flare:
No telling where I'll end up but I'm enjoying the journey.
The single flare horn on a single bass bin looks pretty innocuous. I'm planning on painting the inside of the horn to match the room walls for stealth effect. For scale, the Synergy is 28" wide and the center is 34" high.
I could add a secondary flare that extends to within a fraction of an inch of the walls to that:
If that passes the WAF filter, I'll be emboldened to add a 2nd pair of bass bins. Then my acoustic center won't shift as the sound goes below 200 Hz and I'll have 6 db more headroom at 20 Hz.
If that is too intimidating, I can remove the 2ndry flare:
No telling where I'll end up but I'm enjoying the journey.
The secondary flair does hurt the appearance (though it wouldn't be as much if it were wall color, too). The secondary flair is to avoid "waistbanding" in the coverage pattern down at the lower freq where the horn is about to give out, but if you crossover above that point, it wouldn't be needed. A 28" horn is pretty big so maybe you don't need to push it too low? After you get into the modal frequencies of the room, directivity doesn't mean much anymore.
How high can the woofers go?
How high can the woofers go?
Hi Bill:
Here are the H polars for my bass bins. Green is on axis; blue is about 22.5 degrees off axis. Yellow is 33 degrees and purple is 45 degrees. The null in the purple at 236 hz is no doubt due to the split horn path. The peak at 56 Hz is a length mode in the garage. Based on all my listening being in the first 22 degrees I could cross these as high as 275 Hz. That wouldn't avoid the waist banding but it would help incrementally with floor and ceiling bounce.
I can see the so called waistbanding or midband narrowing in the cursory polars of the conicals that I've done indoors. (too ugly to post) Over the window of 0 to 22 degrees off axis, there is near 6 db peak variation in the 400 hz to 1 khz range. My spot on the couch is something like 7 degrees off axis from one speaker and 19 degrees or so from the other. It looks like with careful EQ, I could get it to within +/- 2 db across the couch. That might be good enough, my relatively uneducated ears tell me so, but I'd like to do better, if I can.
I looked at Art Welter's SynTripp for an idea of what the 2ndry flare would do for me. According to his polars (in post #1), it would push the waistbanding lower where it would be less of a problem. But in his, it occurs outside the 0 to 22 degree window, where I don't listen directly. If I could repeat that result, I wouldn't need to consider adding a 2ndry flare.
Here are the H polars for my bass bins. Green is on axis; blue is about 22.5 degrees off axis. Yellow is 33 degrees and purple is 45 degrees. The null in the purple at 236 hz is no doubt due to the split horn path. The peak at 56 Hz is a length mode in the garage. Based on all my listening being in the first 22 degrees I could cross these as high as 275 Hz. That wouldn't avoid the waist banding but it would help incrementally with floor and ceiling bounce.
I can see the so called waistbanding or midband narrowing in the cursory polars of the conicals that I've done indoors. (too ugly to post) Over the window of 0 to 22 degrees off axis, there is near 6 db peak variation in the 400 hz to 1 khz range. My spot on the couch is something like 7 degrees off axis from one speaker and 19 degrees or so from the other. It looks like with careful EQ, I could get it to within +/- 2 db across the couch. That might be good enough, my relatively uneducated ears tell me so, but I'd like to do better, if I can.
I looked at Art Welter's SynTripp for an idea of what the 2ndry flare would do for me. According to his polars (in post #1), it would push the waistbanding lower where it would be less of a problem. But in his, it occurs outside the 0 to 22 degree window, where I don't listen directly. If I could repeat that result, I wouldn't need to consider adding a 2ndry flare.
H Polars graph for mids alone
I need to repeat this more accurately outside and with less smoothing. I'm glad I found them because they are better than I remembered.
Green is on axis. Yellow is an eyeballed 11 degrees off. Blue is 22 degrees off. The waistbanding is worst at about 550 Hz, showing +/- 2 db. Seems I could just take measurements for XO at 11 degrees off axis and be reasonably well off.
I need to repeat this more accurately outside and with less smoothing. I'm glad I found them because they are better than I remembered.
Green is on axis. Yellow is an eyeballed 11 degrees off. Blue is 22 degrees off. The waistbanding is worst at about 550 Hz, showing +/- 2 db. Seems I could just take measurements for XO at 11 degrees off axis and be reasonably well off.
One more thought on appearance.
Originally I was going for a classic Klipsh look. Thus the black side grills and a black grill on the synergy. I got away from that when I planned on stacking the BBs two high. If I want to go stealth, the black side grills also should go.
What I think I want to do is find a paint color that provides a little contrast with the walls but not too much. So far I've had trouble getting Sketchup to show it to me. What I did for the veneer was import a photo of my actual veneer and use it as paint.
Originally I was going for a classic Klipsh look. Thus the black side grills and a black grill on the synergy. I got away from that when I planned on stacking the BBs two high. If I want to go stealth, the black side grills also should go.
What I think I want to do is find a paint color that provides a little contrast with the walls but not too much. So far I've had trouble getting Sketchup to show it to me. What I did for the veneer was import a photo of my actual veneer and use it as paint.
But the listening position isn't usually the only concern when looking at polar pattern. Just because a wavefront doesn't reach directly from the horn to ear doesn't mean it doesn't matter (as I've probably pointed out too many times, point any speaker away from you in a room and notice how very little the sound level actually changes). The off-axis response that bounces around the room also matters. According to Danley, the response shape in the reflections can highlight the position of the speaker and make its location fail to 'disappear'. Don't know about that, but I do think that highly colored off-axis lobes are not a good thing at all.
But, then again, with your corner-located horns, there isn't much of anywhere in the room that is off-axis for a colored reflection to bounce off of.... you kind are sitting IN the horn!
I love where you're going with this... especially that second bass cabinet on top.
Hope you get the seal of approval from your wife.
Thanks! Approval will come. Right now she is more concerned about the impact of building (or lifting) the speakers on my health, than on how the speakers look... so I have to take it slow.
Contralateral reflection angles
It just occurred to me that the contra-lateral reflection - off the opposite side wall - is the one I need to be concerned about. A few minutes in Visio drawing tool, was sufficient to show that these too are less than 22 degrees off axis.
It just occurred to me that the contra-lateral reflection - off the opposite side wall - is the one I need to be concerned about. A few minutes in Visio drawing tool, was sufficient to show that these too are less than 22 degrees off axis.
On one hand these can be strong because the speaker placed in a corner toed in in front of the listening position tends to put them more on the axis of the speaker in the direction of the reflection you mention.
On the other hand it may be of less concern based on the longer timing (than the same side reflection), the reduced sound level due to this length, the ability of our ears to discern the difference due to it coming from the opposite side, and the fact that it is at least not a vertical reflection.
This is not enough to want to call off the deal. You can always use an absorbent panel if it makes enough difference.
On the other hand it may be of less concern based on the longer timing (than the same side reflection), the reduced sound level due to this length, the ability of our ears to discern the difference due to it coming from the opposite side, and the fact that it is at least not a vertical reflection.
This is not enough to want to call off the deal. You can always use an absorbent panel if it makes enough difference.
The context of my point was that these late arriving reflections would not be colored due to waist banding of the horn pattern and would therefore be benign, beneficial for envelopment. The same EQ that flattens that portion of the horn's pattern that is heard direct will also flatten that portion that arrives by the indicated reflections. The contralateral reflection rays are within a few degrees of being equally spaced on the other side of the horn axis.
Why do you say that? Schroeder limit is expected to be around 200 Hz but my abbreviated polars show the waistbanding occurring around 600 hz. Regardless of whether its modal or not there, I can definitely see floor and.or ceiling bounce artifacts there.
As you may have noticed I appear to have flip/flopped again on the 2ndry flare.
I've still got trying one on my to do list.
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