There are some hellaciously good PA compression drivers thatt get down to 300 or lower .
how about a synergy with an hf comp driver and a mf comp driver. More efficient,less holes? Thought 2 a crapload of piezo mid drivers, enougb to smooth theirselves out and get liw enough? Some make it to 800 on their own?
Random thoughts here. Yours?
how about a synergy with an hf comp driver and a mf comp driver. More efficient,less holes? Thought 2 a crapload of piezo mid drivers, enougb to smooth theirselves out and get liw enough? Some make it to 800 on their own?
Random thoughts here. Yours?
compression drivers give often a too thin sound below 500/700 Hz.
My thoughtswould be : if using a single driver at the apex to cover > 500/700 Hz, could it give a less hearable active or passive filter at here then 1200 Hz ?
Idem for the mid-woofs : is it possible to have an as good quality for the 700 Hz to 100/150 Hz (efficienty and low XO possible thanks the multiplication of the mid-woofs units) than a direct driver (2 ways synergy in home environment instead 3 Ways)
What could be the dreamed a°*b° radiation at the mouth for home environment ?
my basic two cents,
My thoughtswould be : if using a single driver at the apex to cover > 500/700 Hz, could it give a less hearable active or passive filter at here then 1200 Hz ?
Idem for the mid-woofs : is it possible to have an as good quality for the 700 Hz to 100/150 Hz (efficienty and low XO possible thanks the multiplication of the mid-woofs units) than a direct driver (2 ways synergy in home environment instead 3 Ways)
What could be the dreamed a°*b° radiation at the mouth for home environment ?
my basic two cents,
3-4 cone mids mounted on the horn are already more eff than the hf driver. When you add the coupling chamber to the mid CD I'm afraid the path-length thru the CD/chamber assembly will be too great. Also, I wonder if the compression would be too high with the additional bandpass chamber and the distortion would be higher thru the midrange? There's a plethora of data (much lately) that shows how well cheaper cone drivers work in the midrange. And big midrange compression drivers are big $$$.
Oh cone mid or full range drivers all the way. I am getting great sensitivity with even a single full range driver. The harmonic distortion of the cone drivers as recently shown by Weltersys and my own measurements indicate cleaner sound in the mids and even up to 10k vs a compression driver. I EQ'd the 2in Tang Band in the micro Trynergy to be flat up to 20kHz and HD is still not bad up high under 1% at domestic listening levels of 93dB.
Look at the 2" Be diaphragm compression drivers that don't need crossovers, or the dual ring compression driver (BMS 4592ND) that is good down to at least 300 Hz. This makes a lot more sense for a home version of a multiple entry horn than any that I've seen using additional cone-type drivers down to 300 Hz. Couple that with a good active digital crossover and bi-amping, using REW and a calibration microphone to set the crossover, delays and PEQs in-room (and getting acoustic treatments set up to handle early reflections), and you have a winning combination, I've found.
Also, I see a lot of efforts on trying to build a horn that is too small for a full range multiple entry horn + DR bass bins (which doesn't make any sense to me in terms of the audibility of the modulation distortion and higher order harmonics coming from the 5-10x greater displacement of DR cones as contrasted with the very clean sounding HF multiple entry horn).
I think that the right sized multiple entry horn for home use is on the order of a SH-96, of course without all the midrange drivers and perhaps half the number of woofers, in terms of the required mouth dimensions and coverage angles to do a credible full-range multiple entry horn (corner loaded) without DR bass bins...in a home environment. Fifty degrees of horizontal coverage just isn't enough, I've found: it needs to be more like 90 or 100 degrees.
YMMV.
Chris
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Imagine two mid-woofs ports face to face in a horn (ports looking each other on 2 of the opposite walls of the horn)
Imagine you need no more Sd & efficienty than one woofer unit for the low end
Imagine the horn is the loaded cavity of a band-pass woofer cabinet but this time, because above needs, you play the two mid-woof in push pull !
Have you the thir harmonic distorsion cancelation like in a Subwoof band-pass design like the Kef 104/2 ref for instance ?
In fact we can Imagine that for the 3 ways synergys and only for the sub-woof ports which are near the middle of the the inner horn ? (staying in normal push-push with the mid-woofs near the apex)
?
Imagine you need no more Sd & efficienty than one woofer unit for the low end
Imagine the horn is the loaded cavity of a band-pass woofer cabinet but this time, because above needs, you play the two mid-woof in push pull !
Have you the thir harmonic distorsion cancelation like in a Subwoof band-pass design like the Kef 104/2 ref for instance ?
In fact we can Imagine that for the 3 ways synergys and only for the sub-woof ports which are near the middle of the the inner horn ? (staying in normal push-push with the mid-woofs near the apex)
?
A push-pull don't cancel the first harmonic as there is an exit, here the mouth of the horn (at least the apex could be a problem maybe as the load of a band pass cabinet needs a calculation/simulation of its volume). ...the horn would be itself the third cavity of a symetrical load band-pass cabinet where the woofers radiate !
As the cone are seing at each others, you need to connect them in phase opposition to have a push pull (we don't want to see the magnet & motor of one of the woof in the middle of the horn and we can't because there is just two ports). This thinking doesn't work with 4 woofs I surmise (one woof by wall) but just with two ports seing at eacothers !
If I look at my Keff 104.2 ref, I swear there is a lot of bass ! But here the port is littlier than the load (the cavity where the push-pull woofers radiate).
The interrest according V. Dickason of a symetrical push pull load is a reduction of odds (not third as I writted above by error) harmonics and more linearity ?!
We keep half of the exursion of cone at equal spl than a unique driver so no changes in relation to the push-push of the known Synergy model. Sd stays x2 in push-pull.
Odd thinking exercice style, but I refer to the tittle of the thread
Maybe I don't understand the band-pass symetric load 3 cavity concept ? Does the main cavity needs a compression and so a calculated ports like a vented load to know the Fs of the enclosure???? In the Kef there seems just to be a big hole in the front pannel to let exit the sound, that's all... look this picture : Résultats Google Recherche d'images correspondant à http://hoone.com/kef1.jpg
But I assume here we don't talk about vented like load as we don't keep the rear radiation of the woofs but the front radiation...and cancelation of the second woofs.
I assume you could also make a standalone driver symertric load at the apex. the port will radiate at the apex, but here to targett what ??? A reduction of the electrical HP order ?
With the woofs, the goal can be also to use only a first order electrical filter as the band-pass is itself a second-order mechanical if I understood half of what I readed...
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The drivers still have to move in opposite directions to push air out. Push pull just means one is flipped so the back cone moves out while the front face of the other moves out. This cancels even order suspension and motor distortion due to hysteresis. The alignment is typically 6th order band pass for subs used in this configuration. The KEF 104 probably 4th order band pass.
Now, could it be possible to have a push pull of cone at the apex : e.g. : two drivers in axis but reversed (the magnets are seing each others in a little tunnel in the rear of the first driver which cone is seing the apex port.
The push pull effect would supress the return wave on the rear cone (bad sealed load interactions with the return of the rear wave at the bottom of the first cone).
The push-pull would supress more odd harmonics as well and give more linearity !
Two scanSpeak F10 or Vifa TC9 in push-pull at the apex of a horn instead a compression ?
Hey, hey...
, should be stupid as I never read Something like that ! But here we are in home environment and the compressions were made for powerfull outdoor or big space events !
The push pull effect would supress the return wave on the rear cone (bad sealed load interactions with the return of the rear wave at the bottom of the first cone).
The push-pull would supress more odd harmonics as well and give more linearity !
Two scanSpeak F10 or Vifa TC9 in push-pull at the apex of a horn instead a compression ?
Hey, hey...
, should be stupid as I never read Something like that ! But here we are in home environment and the compressions were made for powerfull outdoor or big space events !
You only need push pull to reduce distortion for cones that move a lot. For a 10F properly horn loaded, the movement is almost infintessimal (50 micrometers) for 100dB that the distortion is already low and hysteresis is not an issue. Putting the driver basket into the front horn would probably mess things up.
if the drivers are looking each others you go push-pull by reverting the phase of one of them ! You don't need neceraly to flip one of the two... if i understand well what you write (sorry my Vader English after the break of my helmet by papa Obiwan !)
Yes you're right for the 10 F, one may just try for the odd harmonic and linearisation behavior ???? It can be seen as more compliance (both of the air and surrounds !)
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I can imagine push pull woofers firing into a chamber, one of whose walls functions as a horn flare, porting the bass energy into the horn. The problem with that is that the (added) air mass due to making the chamber big enough to support dual opposed &/or push pull will reduce the upper frequency limit obtainable from the mids. You may well reduce the bass distortion but you will increase the CD's distortion by forcing the CD to play lower.
What you really need to do is the opposite - get the mids to play higher so a standard 1" CD like a BMS4550 or DEC250 or a DNA360 doesn't have to strain to reach below 1 Khz.
You don't need push/pull for cancellation of even order distortion products; you get a similar effect from the inherent acoustic low pass filtering of the mids and woofers bandpass chambers, if you design them correctly. In a 3-way synergy, mids and woofers each only play over a couple of octaves. The acoustic low pass effect should cut in just at or above each crossover frequency.
What you really need to do is the opposite - get the mids to play higher so a standard 1" CD like a BMS4550 or DEC250 or a DNA360 doesn't have to strain to reach below 1 Khz.
You don't need push/pull for cancellation of even order distortion products; you get a similar effect from the inherent acoustic low pass filtering of the mids and woofers bandpass chambers, if you design them correctly. In a 3-way synergy, mids and woofers each only play over a couple of octaves. The acoustic low pass effect should cut in just at or above each crossover frequency.
If you do this, you get net zero pressure generation and no sound. In fact, this is the basis of active sound cancellation. I know because in a push pull BP6 sub, or a push pull Z baffle, if one of the driver is polarity flipped so it moves in the same absolute direction as the other, you get no sound.
Ok, so the pull has to be made by the rear of the basket if they are connected in phase : in a push pull the drivers are looking at the same direction ?
But if they look at each others you need to connect in phase oposition between each others !
Is this better ? Do I mix push-pull which would be a physical orientation of the drivers with electrical phase opposition ? I refer to the chapter 2.18 of V. Dickason book but read it in french... not easy for me to swap from this to English ! Sorry for that !
(for me if one of the driver pull what ever the position of its cone : by the front or the bottom, I believed it could be called push-pull or push-vaccum if you prefer !)
But if they look at each others you need to connect in phase oposition between each others !
Is this better ? Do I mix push-pull which would be a physical orientation of the drivers with electrical phase opposition ? I refer to the chapter 2.18 of V. Dickason book but read it in french... not easy for me to swap from this to English ! Sorry for that !
(for me if one of the driver pull what ever the position of its cone : by the front or the bottom, I believed it could be called push-pull or push-vaccum if you prefer !)
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Would this work for mids injection?
Usually my ideas are thwarted by the laws of physics
After reading hundreds of posts I am slowly grasping the principles behind the Synergy.
Since a requirement is that the mids be within 1/4 wavelength to the apex, rather than try to crowd small drivers close to the throat like vacationers at a European beach in August
would this work?
One or more mids feeding into a chamber, to long tube (port) and into horn? I suspect that this would be too much the low-pass filter Is there a way to force enough pressure through a tube where it might work? Delay is taken care of by active EQ but can enough HF be put through a small port of several cm? Whole point of this is to allow higher crossover if we wanted, for the tweeter.
Let the anti-aircraft fire begin
Usually my ideas are thwarted by the laws of physics
After reading hundreds of posts I am slowly grasping the principles behind the Synergy.
Since a requirement is that the mids be within 1/4 wavelength to the apex, rather than try to crowd small drivers close to the throat like vacationers at a European beach in August
would this work?
One or more mids feeding into a chamber, to long tube (port) and into horn? I suspect that this would be too much the low-pass filter
Is there a way to force enough pressure through a tube where it might work? Delay is taken care of by active EQ but can enough HF be put through a small port of several cm? Whole point of this is to allow higher crossover if we wanted, for the tweeter.Let the anti-aircraft fire begin
One or more mids feeding into a chamber, to long tube (port) and into horn? I suspect that this would be too much the low-pass filter
Let the anti-aircraft fire begin
This would be the opposite:
J4 | Danley Sound Labs | Danley Sound Labs, Inc.
Did you get to that part of Danley's work yet?
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