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The biggest Speaker cabinets I have ever seen !

Bracing progress...

...got some bracing done yesterday. Lotta lumber going into these cabs ! :D
 

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Different amount of port area between three 5" ports and four 4" ports. I was also tuning to 28hz, I don't recall what GW was tuning to. Lastly, the internal volume was ~28 cu ft for my calcs and larger when GW calculated. All will have an effect on the port length.
 
dnewma04 said:
Different amount of port area between three 5" ports and four 4" ports. I was also tuning to 28hz, I don't recall what GW was tuning to. Lastly, the internal volume was ~28 cu ft for my calcs and larger when GW calculated. All will have an effect on the port length.
Click to expand...

:D That's why I'm asking you guys 'bout this stuff. Thanks !
BTW 28Hz...I like it !

dnewma04 said:
Bracing looks good, any plans for cross bracing?
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Yessir,side to side and front to back !
 
OK,
4" ports added and tweeter moved to same position in relationship to woofer as the sentry 3. not sure if you plan on moving the mid-horn mounting face back like on the sentry (6.625") but i think the sides of the cabinet maybe a problem with the horn dispersment if you did.
 

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perchdog said:
OK,
4" ports added and tweeter moved to same position in relationship to woofer as the sentry 3. not sure if you plan on moving the mid-horn mounting face back like on the sentry (6.625") but i think the sides of the cabinet maybe a problem with the horn dispersment if you did.
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I think we are very close. Looks like the woofs can come up a little or mid horn down...or a little of both ?

At this point, I would like our AK technical experts to look it over and give their opinions.

I was planning on the horn extending out past the baffle,unless there is some inherent problem with that arrangement.:scratch2:
 
I'm by no means a tech expert. I am just not sure what the crossover frequency is going to be between the woofers and the mid, as that should determine the spacing. IIRC that mid horn is capable of being crossed over fairly low.:dunno:
 
Looking at the drawing, it looks like if you mount the horn from the front with the stock mounting flange, the woofs and mids will be lined up well enough.

If you can get ahold of an active crossover for a bit, you can play with the xover points until you find the ones you like and then build passives to match.
 
djnagle said:
Looking at the drawing, it looks like if you mount the horn from the front with the stock mounting flange, the woofs and mids will be lined up well enough.

If you can get a hold of an active crossover for a bit, you can play with the xover points until you find the ones you like and then build passives to match.
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:scratch2:
Well at least I should be able to finish the framing and bracing tomorrow. Backs after that.

budgetaudio6 said:
awesome thread. Cant wait to see and read of the results.
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Thanks, I pretty anxious myself.
I removed the baffle from the second cab today and started the bracing,so things are moving along.
 

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dnewma04 said:
Different amount of port area between three 5" ports and four 4" ports. I was also tuning to 28hz, I don't recall what GW was tuning to. Lastly, the internal volume was ~28 cu ft for my calcs and larger when GW calculated. All will have an effect on the port length.
Click to expand...

I was tuning for about 33.5 Hz. That was what seemed to give max LF output without causing a hump in the response.

Assuming 28 cubic feet effective volume- if you want to use 4- 4" vents, about 1.5" long each will give you 33Hz vent frequency. F3 of 33 Hz. I tried 28 Hz vent... but the f3 went up to around 45 Hz...

And yes... putting the vents beside the woofer is a good option.

Regards,
Gordon.
 
Stephen J said:
It'll play down to 500Hz recommended crossover point is 800Hz

http://archives.telex.com/archives/EV/Horns/EDS/SM120A EDS.pdf
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I'd definitely agree with a crossover point around 800 Hz. Should work fine. That's nearly an octave below the effective E-wave crossover point... which, given the stacked woofers, should give about the same vertical dispersion angle (twice the wavelength, twice the woofer stacked height).

And as for spacing- as TIGHTLY as they can be packed together is probably going to be the best, by far.

Regards,
Gordon.
 
No reason you can't put the vents on the back is there? Sonically that is. If they have to go tight against the wall, that is an issue. I've seen vents on the front, sides, backs, bottoms, and tops with good results regardless.
 
As long as the ports have room to move air, the location doesn't much matter. Putting them on the front does increase the chance of issues with them becoming more noticeable (port noise, midrange leaking out, and if real near a tweeter, I've heard of the port turbulance messing up the response of the tweeter.
 
A pair of 15" or 18" passive radiators on the back of each cabinet?

:D

Come to think of it, that's not a bad idea...

Regards,
Gordon.
 
GordonW said:
A pair of 15" or 18" passive radiators on the back of each cabinet?

:D

Come to think of it, that's not a bad idea...

Regards,
Gordon.
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Um ..OK if someone wants to donate a pair.....:lmao:
I still need to get the second pair of SP15's to you for re-coning...:yes:

BTW the walls are closing in with all the bracing,I think I've eaten up nearly 2 Cu ft per cab.
 
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djnagle said:
No reason you can't put the vents on the back is there? Sonically that is. If they have to go tight against the wall, that is an issue. I've seen vents on the front, sides, backs, bottoms, and tops with good results regardless.
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I like that idea ( on the back ), they wont be tight against the wall. Pretty much in the corners of the room. Toed in ?
 
The biggest speakers i´ve seen were chechoslovakian tesla akr-303 cinema speakers from 1960s. Boy they were huge. 200lbs each, 7ft tall, 32" wide. In my listening room they looked like radars or something. Sound came from the roof :) really scary :bat::bat: i sold them after a week...never again unless i live in a church :)
 

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