Hi ! i am watching this most unique speaker The old Allison Six
i do not understand the rationale behind this design
I guess that the cross Hz between the woofer and the tweeter should be around 2kHz ?
for a good part of its range the woofer should be directional
I wonder what the designer tried to achieve
Can anyone explain me please this design ?
I would like to replicate it but with a wideband in place of the tweeter and lowering the cross frequency
What would be the best cut ? 500Hz ? less ?
i am lost but intrigued
i do not understand the rationale behind this design
I guess that the cross Hz between the woofer and the tweeter should be around 2kHz ?
for a good part of its range the woofer should be directional
I wonder what the designer tried to achieve
Can anyone explain me please this design ?
I would like to replicate it but with a wideband in place of the tweeter and lowering the cross frequency
What would be the best cut ? 500Hz ? less ?
i am lost but intrigued
Some info:
Type Two-way, bookshelf speaker
Tweeter one 1-inch (25 mm ) Convex Diaphragm
Woofer one 8-inch (203 mm)
Crossover Frequency 2 kHz
Crossover Network LC quarter-section. Air-core choke and polyester capacitor are used. Two-position control switch (accessible from front) supplied for selection of system acoustic power response, from nominally flat to gentle HF rolloff.
Impedance 4 Ω nominal, (3,5 Ω minimum in any balance control setting)
Efficiency better than 0,7% when placed with back against wall.
Minimum Amplifier Power 15 watts per channel to produce 97 dB sound pressure level in most domestic room environments; 30 watts per channel for 100 dB SPL
Power Handling Capability At least 15 watts continuous or average, at any frequency. At least 35 watts peak at resonance frequency. Over most of the frequency range, at least 350 watts for 0.1 second; 125 watts for 1 second; or 60 watts for 10 seconds.
System Resonance Frequency 59 Hz, nominal
Effective System Q 1.0. Power response -3 dB at 46,5 Hz; -6 dB at 39 Hz, when placed close to center of large wall. Low-frequency output increases when system is placed in typical positions with respect to side wall and floor or ceiling
Enclosure stabilized Radiation Loading sealed acoustic suspension design.
Internal Volume 14,1 litres (860 cubic inches)
Material particle Board veneered with walnut, oiled finish.
Dimensions 11.25"H x 11.25"W x 11.25"D
Weight 17 lbs. ea.
LINER NOTES
The Allison:Six is the smallest, and lowest priced addition to the Allison Acoustics speaker line. The half-cubic-foot Allison:Six is just large enough to enclose its 8-inch woofer, which faces upward and radiates frequencies up to 2,000 Hz. The dome tweeter, which faces forward, is identical to those used on all other Allison speakers, with a proprietary dome design that gives it exceptional dispersion. Like the other Allison models, the Six is meant to be installed against a wall, in which position the woofer .output is most uniform because there are no cancellations of its output from wall reflections within its frequency range.
Type Two-way, bookshelf speaker
Tweeter one 1-inch (25 mm ) Convex Diaphragm
Woofer one 8-inch (203 mm)
Crossover Frequency 2 kHz
Crossover Network LC quarter-section. Air-core choke and polyester capacitor are used. Two-position control switch (accessible from front) supplied for selection of system acoustic power response, from nominally flat to gentle HF rolloff.
Impedance 4 Ω nominal, (3,5 Ω minimum in any balance control setting)
Efficiency better than 0,7% when placed with back against wall.
Minimum Amplifier Power 15 watts per channel to produce 97 dB sound pressure level in most domestic room environments; 30 watts per channel for 100 dB SPL
Power Handling Capability At least 15 watts continuous or average, at any frequency. At least 35 watts peak at resonance frequency. Over most of the frequency range, at least 350 watts for 0.1 second; 125 watts for 1 second; or 60 watts for 10 seconds.
System Resonance Frequency 59 Hz, nominal
Effective System Q 1.0. Power response -3 dB at 46,5 Hz; -6 dB at 39 Hz, when placed close to center of large wall. Low-frequency output increases when system is placed in typical positions with respect to side wall and floor or ceiling
Enclosure stabilized Radiation Loading sealed acoustic suspension design.
Internal Volume 14,1 litres (860 cubic inches)
Material particle Board veneered with walnut, oiled finish.
Dimensions 11.25"H x 11.25"W x 11.25"D
Weight 17 lbs. ea.
LINER NOTES
The Allison:Six is the smallest, and lowest priced addition to the Allison Acoustics speaker line. The half-cubic-foot Allison:Six is just large enough to enclose its 8-inch woofer, which faces upward and radiates frequencies up to 2,000 Hz. The dome tweeter, which faces forward, is identical to those used on all other Allison speakers, with a proprietary dome design that gives it exceptional dispersion. Like the other Allison models, the Six is meant to be installed against a wall, in which position the woofer .output is most uniform because there are no cancellations of its output from wall reflections within its frequency range.
I lived in Natick MA less than a mile away from their plant on Tech Circle back in the mid 1980s. I was interested in audio at the time but never actually made it over there.
His designs were well respected in that time frame, but the speakers were a bit more expensive than the competition and had specific placement requirements which made them an impractical choice for many. Properly installed I recalled they sounded pretty good. They were higher quality than typical of mass market speakers of the time..
His designs were well respected in that time frame, but the speakers were a bit more expensive than the competition and had specific placement requirements which made them an impractical choice for many. Properly installed I recalled they sounded pretty good. They were higher quality than typical of mass market speakers of the time..
Hi thank you very much for your very helpful reply
I have the feeling that the woofer mounted this way could make the resonances control easier
The reaction forces should develop in the vertical direction instead of in the horizontal direction
When the woofer cone moves upward the stand will react
when the cone woofer moves downward the weight of the cabinet will react
But there could be issues due to such a high crossover frequency in the freq response
The woofer should be omnidirectional just up 200Hz more or less ? at 2Khz it should beam a lot towards the ceiling
Placing the woofer horizontally will make it work in an ideal position ?
I have the feeling that the woofer mounted this way could make the resonances control easier
The reaction forces should develop in the vertical direction instead of in the horizontal direction
When the woofer cone moves upward the stand will react
when the cone woofer moves downward the weight of the cabinet will react
But there could be issues due to such a high crossover frequency in the freq response
The woofer should be omnidirectional just up 200Hz more or less ? at 2Khz it should beam a lot towards the ceiling
Placing the woofer horizontally will make it work in an ideal position ?
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upward, downward, sideways
Full space it is all the same
The driver is 90 degrees off axis from the listening point.
Real world depending upward or downward.
Ceiling height or floor height, distance from the wall etc etc.
The room response is a different story.
And depends what the listening point is.
For your intentions, agree is better.
2 way.
Or WAW a Woofer assisted wideband.
Or low crossover point.
Will simplify the crossover. Easy to do also with side mounted woofer.
Same thing 90 degree off axis driver. Would roll off top end depending on listening point.
Usually sideways or downward any direction. Use full since we are removing high end
non directional.
For directional or high frequency
With " Sound Bars " that people hate so much.
It is easy to experiment if you want a 30 , 60 or 90 degree upward tilt.
To actually listen to the room response for high frequency.
Since standing or sitting, up close or at distance has big effect on vertical response.
And can be heard by just tilting your sound bar.
For crossing to a tweeter it only slightly improves vertical in the room
and your tilt would be no more than 20 or 30 degrees. Not 90 as shown
As mentioned 90 degree is more useful for bass crossover sideways or downward upward.
Dont matter because your rolling off high end, not directional below 300 or so Hz
Tilting upward for high end more useful for a specific listening position/ room position,
Since high frequency is directional.
Full space it is all the same
The driver is 90 degrees off axis from the listening point.
Real world depending upward or downward.
Ceiling height or floor height, distance from the wall etc etc.
The room response is a different story.
And depends what the listening point is.
For your intentions, agree is better.
2 way.
Or WAW a Woofer assisted wideband.
Or low crossover point.
Will simplify the crossover. Easy to do also with side mounted woofer.
Same thing 90 degree off axis driver. Would roll off top end depending on listening point.
Usually sideways or downward any direction. Use full since we are removing high end
non directional.
For directional or high frequency
With " Sound Bars " that people hate so much.
It is easy to experiment if you want a 30 , 60 or 90 degree upward tilt.
To actually listen to the room response for high frequency.
Since standing or sitting, up close or at distance has big effect on vertical response.
And can be heard by just tilting your sound bar.
For crossing to a tweeter it only slightly improves vertical in the room
and your tilt would be no more than 20 or 30 degrees. Not 90 as shown
As mentioned 90 degree is more useful for bass crossover sideways or downward upward.
Dont matter because your rolling off high end, not directional below 300 or so Hz
Tilting upward for high end more useful for a specific listening position/ room position,
Since high frequency is directional.
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Hi thanks a lot Yes something of the kind In particular what i find interesting is the horizontal woofer
its vibrations will develop along the vertical axis and i guess this would make them more controllable
when the cone pushes upward the stand will react
when the cone pushes downward the weight of the speaker will react
it is just to make the cabinet stiff and heavy i guess
this will tame the nasties resonances hopefully
i am studying the LXmini now Thanks again
Hi thank you very much I am studying your very valuable advice I will come back after some study
but for now i feel that this solution actually will make the placement in the listening room quite tricky
Now i have to leave for a Christmas lunch with relatives But today i will study your valuable reply better
The last thing i would like to do is to complicate things
In the end the my very goal is to avoid that the woofer vibrations reach the mid high section that will have its own cabinet
a two pieces speaker Head above a body
for now thank you very much
is it a Omni ?(not a Dodge Omni)
Nice!
Allison 6
https://cheshireaudio.blogspot.com/2015/01/our-favourite-classic-speakers-1.html
page 50
https://www.worldradiohistory.com/Archive-All-Audio/Archive-HiFI-Stereo/80s/HiFI-Stereo-Review-1981-06.pdf#search="allison 6"
https://www.allisonacoustics.org/cd-series/
====
related-Allison 7
John Cockroft- The Shortline TL Transmission Line p.18
https://www.worldradiohistory.com/Archive-All-Audio/Speaker-Buider/Speaker-Builder-1988-01.pdf
https://www.hifi-classic.net/review/allison-seven-512.html
====
also
RDL Acoustics / RA LABS
http://classicspeakerpages.net/libr...acoustics_ra_labs_broch_8.html#previous-photo
RDL ACOUSTICS S-1
https://audiokarma.org/forums/index...oy-allison-allison-acoustics-w-photos.307872/
=================
DIY Speakers with a Up Firing woofer
from PartsExpress Faital 6FE100
https://www.parts-express.com/FaitalPRO-6FE100-6-Professional-Woofer-8-Ohm-294-1150?quantity=1
Reviews
Rated 5 out of 5
Buy them - who needs cast baskets anyways?
Very impressed. I am using them in a LXmini clone driven by a Harman Kardon 120 wpc amp. Sealed - heavily stuffed. They are in a mass manufactured tower speaker that has had internal bracketing and drivers removed. 6" solid core pvc liquid nailed inside provides the perfect non resonant air space. Tight / clean sounding. They have no right sounding this good. Would highly recommend. Kick drum and low tom articulation to die for. Vocals render perfectly. Classical trance metal they take it and ask for more. Rarely does the subwoofer get powered up. My hats: FOH, broadcast engineer, monitor engineer, trumpet player, tinkerer
“Mid tweeter/woofer orientation.”
Glen M,Apr 10, 2019
Jabez Gough
https://paul-kemble.tripod.com/soundgc.html
http://www.novacon.com.br/audiocpap.htm
https://www.diyaudio.com/community/threads/is-the-gough-s-speaker-a-transmission-line.360742/
Nice!
Allison 6
https://cheshireaudio.blogspot.com/2015/01/our-favourite-classic-speakers-1.html
page 50
https://www.worldradiohistory.com/Archive-All-Audio/Archive-HiFI-Stereo/80s/HiFI-Stereo-Review-1981-06.pdf#search="allison 6"
https://www.allisonacoustics.org/cd-series/
====
related-Allison 7
John Cockroft- The Shortline TL Transmission Line p.18
https://www.worldradiohistory.com/Archive-All-Audio/Speaker-Buider/Speaker-Builder-1988-01.pdf
https://www.hifi-classic.net/review/allison-seven-512.html
====
also
RDL Acoustics / RA LABS
http://classicspeakerpages.net/libr...acoustics_ra_labs_broch_8.html#previous-photo
RDL ACOUSTICS S-1
https://audiokarma.org/forums/index...oy-allison-allison-acoustics-w-photos.307872/
=================
DIY Speakers with a Up Firing woofer
from PartsExpress Faital 6FE100
https://www.parts-express.com/FaitalPRO-6FE100-6-Professional-Woofer-8-Ohm-294-1150?quantity=1
Reviews
Rated 5 out of 5
Buy them - who needs cast baskets anyways?
Very impressed. I am using them in a LXmini clone driven by a Harman Kardon 120 wpc amp. Sealed - heavily stuffed. They are in a mass manufactured tower speaker that has had internal bracketing and drivers removed. 6" solid core pvc liquid nailed inside provides the perfect non resonant air space. Tight / clean sounding. They have no right sounding this good. Would highly recommend. Kick drum and low tom articulation to die for. Vocals render perfectly. Classical trance metal they take it and ask for more. Rarely does the subwoofer get powered up. My hats: FOH, broadcast engineer, monitor engineer, trumpet player, tinkerer
“Mid tweeter/woofer orientation.”
Glen M,Apr 10, 2019
Jabez Gough
https://paul-kemble.tripod.com/soundgc.html
http://www.novacon.com.br/audiocpap.htm
https://www.diyaudio.com/community/threads/is-the-gough-s-speaker-a-transmission-line.360742/
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from Burning Amp 2024
DIY Speaker NC-434 by Scott Hinson
looks like a mini Allison 6
https://www.diyaudio.com/community/attachments/nc-434-spec-sheet-v1-pdf.1361643/
https://www.diyaudio.com/community/attachments/nc-434-pdf.1367565/
DIY Speaker NC-434 by Scott Hinson
looks like a mini Allison 6
https://www.diyaudio.com/community/attachments/nc-434-spec-sheet-v1-pdf.1361643/
https://www.diyaudio.com/community/attachments/nc-434-pdf.1367565/
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Good morning to Everyone 🙂
first of all i thank you All sincerely for the very kind and valuable advice
Hi ! thank you very much for the very interesting advice
i think that some kind of equalization could solve easily the response issues
i have a feeling that the placement in the listening room could be critical
i think i will stick with a more conventional solution
in the end my only very problem is decoupling mechanically the woofer from the mid and high drivers
thanks a lot again
first of all i thank you All sincerely for the very kind and valuable advice
Hi ! thank you very much for the very interesting advice
i think that some kind of equalization could solve easily the response issues
i have a feeling that the placement in the listening room could be critical
i think i will stick with a more conventional solution
in the end my only very problem is decoupling mechanically the woofer from the mid and high drivers
thanks a lot again
Here's how to do that the old-fashioned way.
Attachments
hi thank you very much Nice speakers indeed
Do you think that this can provide benefits or the all issue of vibrations transfer from woofer to the baffle and then to midrange and tweeter is overrated ?
for sure the two box solution is more complicated and not very popular fwi can see around
maybe i am making a big issue out of nothing ?
Do you think that this can provide benefits or the all issue of vibrations transfer from woofer to the baffle and then to midrange and tweeter is overrated ?
for sure the two box solution is more complicated and not very popular fwi can see around
maybe i am making a big issue out of nothing ?
Here is science paper explaining it in a simple way:
https://jeeit.feit.ukim.edu.mk/index.php/jeeit/article/view/347/328