Hello Everyone,
As the title suggests, the curved ESLs I built and have been listening to for the past few years have run their course as far as my ears are concerned, it's time for an upgrade.
I want to build a set of segmented ESLs to replace them, and I have done a lot of homework, however things are scattered all over and I'd like to focus on my particular set of circumstances/restraints.
This set of panels will be in my basement HT, and I have a height restriction of around 60", but I'd also like to produce as much SPL as possible, few questions:
Do the same rules of thumb apply equally to segmented vs traditional panels regarding SPL for given panel width?
Does making a segmented panel too wide result in mid/high frequency clarity suffering? What about boomines?
What would the gains/losses be between say a 14.5" (old panel width) vs an 18"?
Enough questions for now, as purchasing parts/wire would hinge on these questions being fleshed out.
I plan on using the same type of wire Charlie M used for his latest segmented build, unless a different type would be preferable for a larger panel such as the one I plan on building.
Any and all help/comments/counter questions, greatly appreciated.
Cheers
As the title suggests, the curved ESLs I built and have been listening to for the past few years have run their course as far as my ears are concerned, it's time for an upgrade.
I want to build a set of segmented ESLs to replace them, and I have done a lot of homework, however things are scattered all over and I'd like to focus on my particular set of circumstances/restraints.
This set of panels will be in my basement HT, and I have a height restriction of around 60", but I'd also like to produce as much SPL as possible, few questions:
Do the same rules of thumb apply equally to segmented vs traditional panels regarding SPL for given panel width?
Does making a segmented panel too wide result in mid/high frequency clarity suffering? What about boomines?
What would the gains/losses be between say a 14.5" (old panel width) vs an 18"?
Enough questions for now, as purchasing parts/wire would hinge on these questions being fleshed out.
I plan on using the same type of wire Charlie M used for his latest segmented build, unless a different type would be preferable for a larger panel such as the one I plan on building.
Any and all help/comments/counter questions, greatly appreciated.
Cheers
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Hello Charlie, thanks for responding...
Definitely Hybrid ...meaning I just need the panels to be solid down to 200Hz.
I have a Transmission Line that will cover the lower octaves.
*edit* Unless, of course, you mean a hybrid ESL in and of itself, the answer is no.
Cheers
-Steve
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Segmented wire panels aren't as easy to build as the perf metal ones but there's a whole lot to like about them.
You won't have to worry about arcing, they're an easier load to drive, you'll love the smooth dispersion pattern, and they just look sexy.
Good luck with your project-- I'm sure Bolserst and Golfnut would chime in with answers to any technical questions and of course, I'm always here for immoral support
You won't have to worry about arcing, they're an easier load to drive, you'll love the smooth dispersion pattern, and they just look sexy.
Good luck with your project-- I'm sure Bolserst and Golfnut would chime in with answers to any technical questions and of course, I'm always here for immoral support
Hi,
Qo the same rules of thumb apply equally to segmented vs traditional panels regarding SPL for given panel width?
A: Yes, almost. What counts is the membrane area, the listening distance and membrane stroke.
Though the segmentation forms lowpass filters so that the part of the panel reproducing high freqencies reduces in active area, but leaving enough left so that it can easily cope with the possible SPLs at lower frequencies.
Almost all panels are restricted mechanically at the lower bandwidth limit.
Q: Does making a segmented panel too wide result in mid/high frequency clarity suffering?
A: No, it´s just that the imaging or staging may suffer.
The wider the panel, the larger the listening distance that staging develops.
Too close and its like sitting in a huge headphone.
Q: What about boomines?
A: That´s a matter of how close You drive the panel towards its base resonance.
Even fully notched out the resonance has a prolonged decay that might become audible.
Mechanical damping might may help.
Q: What would the gains/losses be between say a 14.5" (old panel width) vs an 18"?
A: Not much ... its rather a Q of how low You can crossover the panel.
The difference between 14.5" and 18" isn´t big anyway.
From experience I´d say You could xover 14.5" around 220Hz and the 18" around 200Hz.
Q: I plan on using the same type of wire Charlie M used for his latest segmented build, unless a different type would be preferable for a larger panel such as the one I plan on building.
A: look for H05VU PVC insulated wire.
jauu
Calvin
Q
o the same rules of thumb apply equally to segmented vs traditional panels regarding SPL for given panel width?A: Yes, almost. What counts is the membrane area, the listening distance and membrane stroke.
Though the segmentation forms lowpass filters so that the part of the panel reproducing high freqencies reduces in active area, but leaving enough left so that it can easily cope with the possible SPLs at lower frequencies.
Almost all panels are restricted mechanically at the lower bandwidth limit.
Q: Does making a segmented panel too wide result in mid/high frequency clarity suffering?
A: No, it´s just that the imaging or staging may suffer.
The wider the panel, the larger the listening distance that staging develops.
Too close and its like sitting in a huge headphone.
Q: What about boomines?
A: That´s a matter of how close You drive the panel towards its base resonance.
Even fully notched out the resonance has a prolonged decay that might become audible.
Mechanical damping might may help.
Q: What would the gains/losses be between say a 14.5" (old panel width) vs an 18"?
A: Not much ... its rather a Q of how low You can crossover the panel.
The difference between 14.5" and 18" isn´t big anyway.
From experience I´d say You could xover 14.5" around 220Hz and the 18" around 200Hz.
Q: I plan on using the same type of wire Charlie M used for his latest segmented build, unless a different type would be preferable for a larger panel such as the one I plan on building.
A: look for H05VU PVC insulated wire.
jauu
Calvin
Thanks WrineX, bengal, Calvin, Charlie. Your replies are greatly appreciated.
Well, with Calvin clearing up quite a few questions I had, I think I can start putting together a list of design criteria, and a list of general assumptions.
That being said, sometimes I get so wrapped up in this-or-that detail, I overlook something simple or obvious (just the way my screwy brain works I'm afraid
).
So if any of you see me about to make a mistake... Please stop me!
Special thanks to Charlie for e-mailing detailed plans for his stretching jig. I was able to zero in on certain elements of it and print them, scaling to my panel size is the next step, but at least I have a reference.
This will likely be a long process, as I still work about 50 hours a week, and need time to unwind between work and this project. I'm determined though..
Thanks again!
Cheers
-Steve
Well, with Calvin clearing up quite a few questions I had, I think I can start putting together a list of design criteria, and a list of general assumptions.
That being said, sometimes I get so wrapped up in this-or-that detail, I overlook something simple or obvious (just the way my screwy brain works I'm afraid
).So if any of you see me about to make a mistake... Please stop me!
Special thanks to Charlie for e-mailing detailed plans for his stretching jig. I was able to zero in on certain elements of it and print them, scaling to my panel size is the next step, but at least I have a reference.
This will likely be a long process, as I still work about 50 hours a week, and need time to unwind between work and this project. I'm determined though..
Thanks again!
Cheers
-Steve
Hi,
Just to expand on Calvin’s comments a bit…
But first let me clarify – make some assumptions
1. I assume the ‘traditional’ ESL you refer to is a square panel that does not extend from floor-to-ceiling. Depending on listening distance and dimensions, it may behave as a point source or line source. Because line sources and point sources have a different frequency response, the traditional ESL can only be equalised to have a flat frequency response at one listening distance.
2. Segmented ESLs are ideally floor-to-ceiling so they behave as a line source for all frequencies. The RC transmission line in that case gives the same, very nearly flat frequency response for all listening distances.
Now to the questions…
Q: Do the same rules of thumb apply equally to segmented vs traditional panels regarding SPL for given panel width?
A: Crudely, yes. The maximum SPL from any ESL is determined by its area and the lowest frequency to be reproduced. More precisely, for a segmented ESL, max SPL is determined by width and lowest frequency to be reproduced. As Calvin indicates, both limits assume that the stator-membrane spacing is sufficient to accommodate the membrane movement at low frequencies.
Q: Does making a segmented panel too wide result in mid/high frequency clarity suffering?
A: No. The traditional DIY ESL (rectangular panel) suffers very badly from a narrow listening position, perhaps as little as plus or minus 1 degree off-axis, which makes then extremely sensitive to setup and the head in a vice problem. If you move further off axis then you will also find phase reversals and zeros – places where some frequencies are not reproduced at all. Segmented ESLs expand the listening area to plus or minus 10 degrees or more, and completely eliminate the phase reversals and zeros.
Q: What about boominess?
A: In both cases, there will be a membrane resonance probably in the range from 40 Hz to 200 Hz depending on the area of the membrane sections and the membrane tension. Think of drum skin effects. If the segmented ESL is carefully designed, the resonance can be used to extend the ESL frequency response downwards about 2.5 octaves (in the same manner as bass reflex cabinets), but the resonance will need to be damped. Woven monofilament mesh such as screenprinting cloth is ideal and available cheaply off aliexpress with many different thread counts so that the damping can be tweaked. Usually it is glued close to the rear stator and over the whole panel. If you are planning a hybrid, then this is not so critical
Q: What would the gains/losses between say a 14.5" (old panel width) vs an 18"?
A: SPL max better or frequency response a bit lower, off axis response slightly narrower. Segmented designs work well up to about 500 mm wide.
Q: Which is easier to build.
A: not much difference for the stators. In either case, there is a type of conservation of agony principle – you can’t do easy AND cheap. The build is either a lot of work (wire stators) or pricey (PCBs). Actually, both are quite a bit of work and not cheap.
I would say that anything the traditional ESL does, a segmented panel does better. For example, segmented ESLs present a friendlier load to step up transformers, and can run easier at higher step-up ratios, but so do smaller ESLs and ESLs with a higher cutoff frequency. Making a good transformer for a large full range panel is a real challenge. Much easier with a hybrid – off the shelf transformers will do.
best wishes
Rod
Just to expand on Calvin’s comments a bit…
But first let me clarify – make some assumptions
1. I assume the ‘traditional’ ESL you refer to is a square panel that does not extend from floor-to-ceiling. Depending on listening distance and dimensions, it may behave as a point source or line source. Because line sources and point sources have a different frequency response, the traditional ESL can only be equalised to have a flat frequency response at one listening distance.
2. Segmented ESLs are ideally floor-to-ceiling so they behave as a line source for all frequencies. The RC transmission line in that case gives the same, very nearly flat frequency response for all listening distances.
Now to the questions…
Q: Do the same rules of thumb apply equally to segmented vs traditional panels regarding SPL for given panel width?
A: Crudely, yes. The maximum SPL from any ESL is determined by its area and the lowest frequency to be reproduced. More precisely, for a segmented ESL, max SPL is determined by width and lowest frequency to be reproduced. As Calvin indicates, both limits assume that the stator-membrane spacing is sufficient to accommodate the membrane movement at low frequencies.
Q: Does making a segmented panel too wide result in mid/high frequency clarity suffering?
A: No. The traditional DIY ESL (rectangular panel) suffers very badly from a narrow listening position, perhaps as little as plus or minus 1 degree off-axis, which makes then extremely sensitive to setup and the head in a vice problem. If you move further off axis then you will also find phase reversals and zeros – places where some frequencies are not reproduced at all. Segmented ESLs expand the listening area to plus or minus 10 degrees or more, and completely eliminate the phase reversals and zeros.
Q: What about boominess?
A: In both cases, there will be a membrane resonance probably in the range from 40 Hz to 200 Hz depending on the area of the membrane sections and the membrane tension. Think of drum skin effects. If the segmented ESL is carefully designed, the resonance can be used to extend the ESL frequency response downwards about 2.5 octaves (in the same manner as bass reflex cabinets), but the resonance will need to be damped. Woven monofilament mesh such as screenprinting cloth is ideal and available cheaply off aliexpress with many different thread counts so that the damping can be tweaked. Usually it is glued close to the rear stator and over the whole panel. If you are planning a hybrid, then this is not so critical
Q: What would the gains/losses between say a 14.5" (old panel width) vs an 18"?
A: SPL max better or frequency response a bit lower, off axis response slightly narrower. Segmented designs work well up to about 500 mm wide.
Q: Which is easier to build.
A: not much difference for the stators. In either case, there is a type of conservation of agony principle – you can’t do easy AND cheap. The build is either a lot of work (wire stators) or pricey (PCBs). Actually, both are quite a bit of work and not cheap.
I would say that anything the traditional ESL does, a segmented panel does better. For example, segmented ESLs present a friendlier load to step up transformers, and can run easier at higher step-up ratios, but so do smaller ESLs and ESLs with a higher cutoff frequency. Making a good transformer for a large full range panel is a real challenge. Much easier with a hybrid – off the shelf transformers will do.
best wishes
Rod
I see I'm a little late to the party and pretty much all your questions have been addressed.
But, I have a few of my own.
What is the floor-to-ceiling distance?
You mention a height restriction of around 60", is that because of the floor-to-ceiling distance?
If you want to maximum SPL for a given ESL size, you move the crossover frequency up as high as possible. If you do that, the best ESL to woofer matching is had with a line source of mid-woofers like Calvin does. Is this something you might consider? do you have the room? or do you want to stick with the T-line woofer you mentioned.
Hi Steve and Rod,
No worries on being late to the party, this is going to be a slow build anyway, I'm just grateful to have you folks with lots of experience and knowledge replying
Rod, thanks for expanding on Calvin's response, this is indeed going to be a hybrid panel, so I can use my existing bias supply and transformers, (and tweaks if needed).
The panel cannot extend from floor to ceiling because my basement has HVAC plus the main 8"x8" support beam running across (full length, L to R) the ceiling that would limit my height to around 6 feet, that's why I wanted to limit the panel itself to around 5 (60"). (more on that later)
Steve, I had not considered using a tower of mids, as my t-line seems to blend pretty well with the panel. BUT, You and Calvin both have mentioned this before, so if the benefits outweigh the cost/time, I may think about it.. put it that way.
From the floor to ceiling joists measures 7' on the nose, but like I said, the HVAC and that beam bring it to roughly 6' for line of sight/sound.
A question:
I'm assuming the panel should not be in the path of the obstructions, but could I make it a full 6'? Or does the sound travel upwards a bit on an angle? (I'm not sure/forgot about dispersion on the vertical plane)
SPL and x-over point decision: The reason I want the panel to cover down to around 200-220Hz, is simply that hearing is the most critical from around 300 (general conclusion) and want a little leeway for the x-over to roll off. That and I want the majority of sound to emanate from the ESL (within my constraints) due to the low THD etc. ..who wouldn't?
This is why I asked about a wider panel producing more SPL, and had not considered a mid-tower.
Now I guess I'm asking about height also producing more SPL, but big SPL is not the main goal or anything, maybe I should de-emphasize that. I hope worded that right (?)
As usual, correct me if I'm wrong/off track, thanks much..
Cheers
-Steve
No worries on being late to the party, this is going to be a slow build anyway, I'm just grateful to have you folks with lots of experience and knowledge replying
Rod, thanks for expanding on Calvin's response, this is indeed going to be a hybrid panel, so I can use my existing bias supply and transformers, (and tweaks if needed).
The panel cannot extend from floor to ceiling because my basement has HVAC plus the main 8"x8" support beam running across (full length, L to R) the ceiling that would limit my height to around 6 feet, that's why I wanted to limit the panel itself to around 5 (60"). (more on that later)
Steve, I had not considered using a tower of mids, as my t-line seems to blend pretty well with the panel. BUT, You and Calvin both have mentioned this before, so if the benefits outweigh the cost/time, I may think about it.. put it that way.
From the floor to ceiling joists measures 7' on the nose, but like I said, the HVAC and that beam bring it to roughly 6' for line of sight/sound.
A question:
I'm assuming the panel should not be in the path of the obstructions, but could I make it a full 6'? Or does the sound travel upwards a bit on an angle? (I'm not sure/forgot about dispersion on the vertical plane)
SPL and x-over point decision: The reason I want the panel to cover down to around 200-220Hz, is simply that hearing is the most critical from around 300 (general conclusion) and want a little leeway for the x-over to roll off. That and I want the majority of sound to emanate from the ESL (within my constraints) due to the low THD etc. ..who wouldn't?
This is why I asked about a wider panel producing more SPL, and had not considered a mid-tower.
Now I guess I'm asking about height also producing more SPL, but big SPL is not the main goal or anything, maybe I should de-emphasize that. I hope worded that right (?)
As usual, correct me if I'm wrong/off track, thanks much..
Cheers
-Steve
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Ran out of time on editing.
As far as the obstructions, I just don't want there to be any nasty reflection that could negatively affect the sound.
I'm assuming the mid tower was mentioned to be able to set ESL x-over higher, concurrently facilitating higher SPL along with such a setup.
But let's back up for a minute about SPL expectations.
I'd like to be able to achieve the SPL of a rock concert at my listening position when watching a concert DVD.
I'd also like a movie to be able to hit IMAX theater levels when watching a movie, or maybe a bit louder if the mood strikes.
(I was able to get to these levels with my flat and with my curved panels, but didn't have much headroom left, {I don't think/just a hunch})
What are we talking, dB wise, to achieve this?
Let's just start there and see where this goes...
As far as the obstructions, I just don't want there to be any nasty reflection that could negatively affect the sound.
I'm assuming the mid tower was mentioned to be able to set ESL x-over higher, concurrently facilitating higher SPL along with such a setup.
But let's back up for a minute about SPL expectations.
I'd like to be able to achieve the SPL of a rock concert at my listening position when watching a concert DVD.
I'd also like a movie to be able to hit IMAX theater levels when watching a movie, or maybe a bit louder if the mood strikes.
(I was able to get to these levels with my flat and with my curved panels, but didn't have much headroom left, {I don't think/just a hunch})
What are we talking, dB wise, to achieve this?
Let's just start there and see where this goes...
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Hi
As I may have mentioned earlier, the ideal line source is infinitely long and produces a cylindrical wavefront. (Conventional speakers mimic point sources - which produce a spherical wavefront.)
We mimic this behaviour with a finite linesource by exploiting reflections from the floor and ceiling. You could also think of the ESL producing a cylindrical wave that is not allowed to disperse in the vertical direction because it is trapped by the floor and ceiling.
So, ideally, the ESL should occupy the full height, and the floors and ceilings should be good acoustic mirrors.
In one of the other threads (DIY planar magnetic + open baffle woofer array around post # 172) there was a bit of discussion about the effects of a speaker that is not full height. Fair to say that its complicated, but the taller the better.
I also wonder about the obstructions on the ceiling that you describe. The effects are probably not significant, but you might find that it sounds slightly better facing the direction where the reflections are least obstructed.
Because (i) the source is a line rather than a point, and (ii) it has a dipole radiation pattern - not much out the sides, a lot of the potential problems with room reflections are reduced. My lounge is two rooms of different sizes with the wall removed - and has a terrible resonance with conventional speakers - disappears with ESLs. This may be a bi mitigating factor in your awkward space.
As I may have mentioned earlier, the ideal line source is infinitely long and produces a cylindrical wavefront. (Conventional speakers mimic point sources - which produce a spherical wavefront.)
We mimic this behaviour with a finite linesource by exploiting reflections from the floor and ceiling. You could also think of the ESL producing a cylindrical wave that is not allowed to disperse in the vertical direction because it is trapped by the floor and ceiling.
So, ideally, the ESL should occupy the full height, and the floors and ceilings should be good acoustic mirrors.
In one of the other threads (DIY planar magnetic + open baffle woofer array around post # 172) there was a bit of discussion about the effects of a speaker that is not full height. Fair to say that its complicated, but the taller the better.
I also wonder about the obstructions on the ceiling that you describe. The effects are probably not significant, but you might find that it sounds slightly better facing the direction where the reflections are least obstructed.
Because (i) the source is a line rather than a point, and (ii) it has a dipole radiation pattern - not much out the sides, a lot of the potential problems with room reflections are reduced. My lounge is two rooms of different sizes with the wall removed - and has a terrible resonance with conventional speakers - disappears with ESLs. This may be a bi mitigating factor in your awkward space.
Hmm, so it may not be a problem? Interesting.
However take a look at these pictures, two are my HT showing the floor and ceiling, plus the obstructions. The one doesn't show the beam, second one does.
Also, the ceiling pic is deceiving, the HVAC looks a lot lower than the beam that runs the length, but it's only 3 inches lower. (don't mind the mess or the speaker mismatch, theater under upheaval)
As far as moving ESLs, I cannot, as the posts that support the beam would be in the middle of the screen, this setup orientation is pretty much set in stone.
Just for fun, the 3rd pic is my new IB sub I'll be using once I mount it to the ceiling.
4 1200w-rms 18's driven with an iNuke DSP-6000, should be massive sounding (probably for movies only)
Cheers
-Steve
However take a look at these pictures, two are my HT showing the floor and ceiling, plus the obstructions. The one doesn't show the beam, second one does.
Also, the ceiling pic is deceiving, the HVAC looks a lot lower than the beam that runs the length, but it's only 3 inches lower. (don't mind the mess or the speaker mismatch, theater under upheaval)
As far as moving ESLs, I cannot, as the posts that support the beam would be in the middle of the screen, this setup orientation is pretty much set in stone.
Just for fun, the 3rd pic is my new IB sub I'll be using once I mount it to the ceiling.
4 1200w-rms 18's driven with an iNuke DSP-6000, should be massive sounding
(probably for movies only)Cheers
-Steve
Attachments
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LOL...Lazy Boy to the right, beer fridge to the left of pic.Hmmm, does not too bad at all. I did notice a couple of things conspicuous by their absence though - a lazy boy and a beer fridge
What? ..you think I'd really do without the essentials?
Meanwhile, back at the design table,
So you think I could benefit from a full, floor-to-ceiling ESL here, without any sonic concerns introduced by the obstructions?
Seems problematic from an inexperienced point of view, but what do I know?
Only thing I'm recalling is your post about needing different transformers for this type of setup, am I not recalling correctly?
-Steve
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HI - I assumed you were still talking about a hybrid.
The problems with transformers are with the full range ESL. Getting good voltage rating at 50 Hz + good step-up ratio + bandwidth ~20 kHz requires some care. If you take the heatoff by chasing 200 Hz bottom end instead of 50 Hz, then transformer is very much easier.
A line-source will reproduce good SPL down to f =c.r/h^2, where c is speed of sound, 340 m/s, r is listening distance, and h is height of speaker
To get to 200 Hz at 3 m listening distance requires a 2.2m high speaker, so reflections will still help the hybrid. No need to go all the way to ceiling, just a good fraction of the distance in a normal room I guess curtain height or a touch more is probably sufficient. The WAF gets rapidly worse, and they can be a pain in the butt to move about if they are too tall.
The problems with transformers are with the full range ESL. Getting good voltage rating at 50 Hz + good step-up ratio + bandwidth ~20 kHz requires some care. If you take the heatoff by chasing 200 Hz bottom end instead of 50 Hz, then transformer is very much easier.
A line-source will reproduce good SPL down to f =c.r/h^2, where c is speed of sound, 340 m/s, r is listening distance, and h is height of speaker
To get to 200 Hz at 3 m listening distance requires a 2.2m high speaker, so reflections will still help the hybrid. No need to go all the way to ceiling, just a good fraction of the distance in a normal room I guess curtain height or a touch more is probably sufficient. The WAF gets rapidly worse, and they can be a pain in the butt to move about if they are too tall.
Hi,
there are circumstances that apply to theory ... and only theory ... and there are circumstances that apply for praxis.
From my experience I'd say that the Q of panel height almost vanishes when a height of 1m is passed.
I'd rather concentrate on more practical aspects.
The higher and wider the panel builds the more difficult will it be to build precise.
A good and precise build will gain You more on SPLmax. and stable performance than the Q of 50" or 60" height.
Keep things practical and handy.
Just by perfecting the whole building process and improved application process of a new membrane coating the efficiency of my newest panels increased by almost 6dB (had been >90dB@4m already, at a bias of only 2.2-2.5kV)
Couldn't believe it at first, but measurements prooved the figures.
Actually the bass tower with its 8pcs of 6.5" long stroke drivers limits a tad earlier than the panel.
I'd suggest a panel slightly higher than the one to the left of Your pic and certainly not higher than the one on the right side.
I'd make it slightly shorter and fit a heavy base beneath that'd contain the electronics.
Provide for a as small as possible but very stiff mounting frame.
You'll need some means to prevent the top end of the panel/frame to move ... kind of stiffening beam from top to base plate ... or maybe even fixing to the ceiling.
Add a mid-bass tower -Dipole if possible- covering the range from ~200Hz down to 60-50Hz ... driver size 5"-7" ... capable of at least +-4mm linear stroke.
If Dipole tower -that guarantees for a seamless transition to the panel- but also as CB tower I wouldn't recommend a xover from mid-bass to panel higher than 250Hz, as comb filter effects will spoil the horizontal distribution.
Even at 200Hz the listeners off of the axis will recognize the effect .... going higher in xover frequency the effect becomes more and more obvious and disturbing.
If done right amplifiers delivering stable 100W will fully suffice to drive the panel as well as the bass.
jauu
Calvin
there are circumstances that apply to theory ... and only theory ... and there are circumstances that apply for praxis.
From my experience I'd say that the Q of panel height almost vanishes when a height of 1m is passed.
I'd rather concentrate on more practical aspects.
The higher and wider the panel builds the more difficult will it be to build precise.
A good and precise build will gain You more on SPLmax. and stable performance than the Q of 50" or 60" height.
Keep things practical and handy.
Just by perfecting the whole building process and improved application process of a new membrane coating the efficiency of my newest panels increased by almost 6dB (had been >90dB@4m already, at a bias of only 2.2-2.5kV)
Couldn't believe it at first, but measurements prooved the figures.
Actually the bass tower with its 8pcs of 6.5" long stroke drivers limits a tad earlier than the panel.
I'd suggest a panel slightly higher than the one to the left of Your pic and certainly not higher than the one on the right side.
I'd make it slightly shorter and fit a heavy base beneath that'd contain the electronics.
Provide for a as small as possible but very stiff mounting frame.
You'll need some means to prevent the top end of the panel/frame to move ... kind of stiffening beam from top to base plate ... or maybe even fixing to the ceiling.
Add a mid-bass tower -Dipole if possible- covering the range from ~200Hz down to 60-50Hz ... driver size 5"-7" ... capable of at least +-4mm linear stroke.
If Dipole tower -that guarantees for a seamless transition to the panel- but also as CB tower I wouldn't recommend a xover from mid-bass to panel higher than 250Hz, as comb filter effects will spoil the horizontal distribution.
Even at 200Hz the listeners off of the axis will recognize the effect .... going higher in xover frequency the effect becomes more and more obvious and disturbing.
If done right amplifiers delivering stable 100W will fully suffice to drive the panel as well as the bass.
jauu
Calvin
@ Rod: No no, I was just thinking/typing out loud, still going with hybrid for SPL and other reasons.. (many)
Calvin is right, no need to further complicate things when a simple design is far from perfected, not to mention construction issues that could arise from biting off more than I can chew...
Hopefully, by the end of the weekend, I'll have a solid plan.
If not I'll have more questions ...still mulling things over..
Thanks for your indulgence..
Calvin is right, no need to further complicate things when a simple design is far from perfected, not to mention construction issues that could arise from biting off more than I can chew...
Hopefully, by the end of the weekend, I'll have a solid plan.
If not I'll have more questions ...still mulling things over..
Thanks for your indulgence..
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