making a center channel speaker of Allison CD-9 speakers ? considerations please !

[quickjack]

So, is the model 8 ( If used alone ) set up w/ the crossover point in correct range ? ( apparently YES IF mounted against wall and does mounted under in front of TV screen 82" count as wall? LOL 

Yes , So what is the rule for a 10-in horizontal mounted woofer firing in a 45° angle ( Model CD-9) but with a speaker base that would turn that 45° to forward facing the audience?
ROY Allison SAID : 

Reflections from room surfaces can increase or decrease the power output of a woofer. Reflected energy increases the instantaneous density of the air in front of the woofer at very low frequencies. This provides an improved impedance match, and the efficiency of the woofer is thereby increased, along with the woofer's power output. At some higher frequency that depends on the distance or distances from the room surface or surfaces, the reflected energy goes out of phase with the woofer cone motion. That decreases the instantaneous density, and the woofer efficiency decreases. That's what causes the dip.

Now if the woofer is fairly close to one room surface and distant from others, in most home listening systems, power output in the range between 100 and 300Hz will drop about 1dB below what it would be without the nearby reflecting surface. At very low frequencies, there would be a 3dB increase in power output. That means, given maximum increase and maximum decrease, there's a total variation of 4dB. With the woofer equidistant from two intersecting surfaces, the dip is 3dB; factor in the maximum rise, in this case 6dB, and you have a 9dB variation. If it's equidistant from three surfaces that intersect at right angles, the dip would be a devastating 11dB and the maximum rise 9dB—a 20dB change over the bottom octaves. If the woofer is not on the line of symmetry, which is to say the same distance from all three surfaces, the dip is less severe but can still be significant. In home listening situations, I've found this reflected impedance typically causes variations from 5 to 12dB. If a tuner or receiver exhibited variations like this, it would be rejected out of hand.

Lander: You hold a patent relating to this boundary-effects phenomenon. What does it cover?

Allison: The design of cabinets that get the woofer very close to one or more adjacent room surfaces. That changes the frequency range of the dip, because the closer the woofer is to a surface or to the point where surfaces intersect, the higher in frequency the dip occurs. In the case of a three-way system, it's possible to position the woofer so the dip is above its operating range,

•  

Talking about using the model 9 here two of them horizontal.( modified ) 

thusly ! -maybe w/ added Allison 8' and 6' woofers ? 
mayhaps w/ push pull mounted extra woofers make 3,4,5 way design ?

Should be sweet ! modified DUAL horizontal situated CD -9 speakers for the C channel !

of the all Allison HT !

so far we have 7.1 ! AL130 L & R & rear AL115 side ,side front L & R

dual modded CD-9 laid horizontal for C channel ,( COMING SOON ! )

BTW it works ! ( we will minimize cone filtering by having t/mids together & orientated vertically ) note this guy did not mod his driver location! 

https://youtu.be/ZYhtSOBGUbw?si=Eq_Ha7KgnlCWGaDE

Two Center Channel Speakers - Yes Please!

YOUTUBE.COM

Two Center Channel Speakers - Yes Please!
hello y'all well looks like i may have found nice pair of model 9's to buy for my Center channel speakers !

Edited September 11 by quickjack
new info

[newandold]

I’ve been using a pair of Allison‘s in tandem in that sideways configuration for decades and it’s been very satisfactory for center channel duty.

 

The the speakers used are the later Allison NL 1440…… A very attractive system, with slightly smaller cabinet volume than the 115. When looking to acquire Allison’s back in the day, I managed to come up with six of them all together… The NL’s came from David Faulkner’s ill fated attempt and the other three were from eBay.