"do you think a standard DBR with K-coupler placed in front would pretty much work? - the upper vent might be shorter than with direct radiator arrangement due to the path and load of the coupler"
in the original paper about K-couplers the experiment was done using the K-coupler as a wave guide. X modeled the K15 as built in a wave guide form. In the XKi X modeled the K-coupler as a volume with an opening to the outside. Both showed the dips and spikes of the K-coupler. (thank you X
)
So i think the answer should be yes.
and thank you Freddi for that reminder. in the HAK the actual area of the front opening is smaller than the speaker itself(like 5.6in dia?) and this lowers the annoying spike at the top end of the bass shelf from 210Hz to 140+Hz
in the original paper about K-couplers the experiment was done using the K-coupler as a wave guide. X modeled the K15 as built in a wave guide form. In the XKi X modeled the K-coupler as a volume with an opening to the outside. Both showed the dips and spikes of the K-coupler. (thank you X
)So i think the answer should be yes.
and thank you Freddi for that reminder. in the HAK the actual area of the front opening is smaller than the speaker itself(like 5.6in dia?) and this lowers the annoying spike at the top end of the bass shelf from 210Hz to 140+Hz
here's a 1772 in the other high aspect K8 from a couple of years ago - what appears to be a peak might not be so severe as room modes may have been pulling in the plots. That ~210Hz spike did reduce when I blocked the very top 6 or so inches of the aperture's slot. Subjectively, it didn't seem to be obnoxious. I would say the old K12 with 1772 was about 2-5dB stronger in the 100-200Hz octave than the skinny coupler. Both cabinets are about the same bulk.
Freddi does your HAK8 use the larger vent(7.2in dia) if so using existing parameters it shows a u-shaped shelf starting at 70hz 103db dropping 10 db then rising to 180hz 104db. not too different from your measurement.
in proper dbr shelf will start at 40+hz 93db stop at 80hz and after dip will rise to170hz 104db
in dcaav shelf will start at 40hz 92db and rise to 170hz 104db similar shape as dbr but no dip at 80hz
are you still willing to try the experiment?
in proper dbr shelf will start at 40+hz 93db stop at 80hz and after dip will rise to170hz 104db
in dcaav shelf will start at 40hz 92db and rise to 170hz 104db similar shape as dbr but no dip at 80hz
are you still willing to try the experiment?
Freddi how are you keeping. I hope you are keeping active. I read its important to do so for at least 30 mins each day.
I modeled the HAK8 with the horizontal slot between the upper chamber and the front chamber and it showed the same u shaped shelf from 70Hz to 190Hz.
For the DCAAV version I modeled it as speaker chamber 28.6 lit
existing slot 3in by 12in by half in long between speaker and upper chamber
upper chamber of 19.6 lit
new divider (of pink foam insulation board 3/4 in thick)
3in dia hole in divider
23Lit top chamber
2in dia pipe 5cm long between top chamber and front chamber
front chamber 29.6 lit
front vent 7.3in dia(equivalent area) 0.75in thickness
will try to look for drawing program that uses ascii
May our Lord bless you and keep you
I modeled the HAK8 with the horizontal slot between the upper chamber and the front chamber and it showed the same u shaped shelf from 70Hz to 190Hz.
For the DCAAV version I modeled it as speaker chamber 28.6 lit
existing slot 3in by 12in by half in long between speaker and upper chamber
upper chamber of 19.6 lit
new divider (of pink foam insulation board 3/4 in thick)
3in dia hole in divider
23Lit top chamber
2in dia pipe 5cm long between top chamber and front chamber
front chamber 29.6 lit
front vent 7.3in dia(equivalent area) 0.75in thickness
will try to look for drawing program that uses ascii
May our Lord bless you and keep you
If you make a concept side view sketch in "Paint" with some notes then that should be enough. - am not that active
your sim and my measurements make me wonder about CN's HAK8 - take the drawing below scaled from 6.5 to 8 (~1.2 scale) - that should be ballpark for his HAK8 - (his tall K8 might be closer to 28-30 tall)
https://lh6.googleusercontent.com/-...ABVY/Kn9Ql6AVzrY/w1040-h796-no/HAK6.5.GCF.PNG
your sim and my measurements make me wonder about CN's HAK8 - take the drawing below scaled from 6.5 to 8 (~1.2 scale) - that should be ballpark for his HAK8 - (his tall K8 might be closer to 28-30 tall)
https://lh6.googleusercontent.com/-...ABVY/Kn9Ql6AVzrY/w1040-h796-no/HAK6.5.GCF.PNG
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Thank yo for the drawing Freddi. been struggling with libre draw and failed. glad you gathered enough info for the drawing but please remember the duct lengths when working on the unit. if do not have pvc duct maybe can just cut holes in your foamboard and stacklayers to the right length.
"what would have to move in this sketch to get the divider in the correct position ?"
dont understand. are you saying the back panel is not screwed to the battens so cannot be removed? if you are worried the back panel will not seal well with the new divider just glue an additional backpanel inside from the new divider to the top. if you are worried about the divider panel moving I used your idea of a dowel for the front panel and glue food skewers at the centroids to ensure my foamcore volumes stay more constant. hope that makes sense and is helpful
"what would have to move in this sketch to get the divider in the correct position ?"
dont understand. are you saying the back panel is not screwed to the battens so cannot be removed? if you are worried the back panel will not seal well with the new divider just glue an additional backpanel inside from the new divider to the top. if you are worried about the divider panel moving I used your idea of a dowel for the front panel and glue food skewers at the centroids to ensure my foamcore volumes stay more constant. hope that makes sense and is helpful
if you have Microsoft's "Paint", would you mark approximately where the divider should go? All you have to do is copy and paste (un der"Home" in Paint. There are drawing tools in fhe form of rectangles, ovals, etc. One of the shapes is a movable straight line
There's no problem with the back panel as held with drywall screws.
it could be interesting to see the response after the mod.
Thank you very much for your input.
here's how "Paint" will look and where to find the drawing tools
There's no problem with the back panel as held with drywall screws.
it could be interesting to see the response after the mod.
Thank you very much for your input.
here's how "Paint" will look and where to find the drawing tools
Freddi with the new volumes of 14.3L,20L and 19L the original HAK8 bass shelf has peaks at 90Hz and 210Hz.
we now require a top chamber of 11.4L. the volume from top to point of inflection is 8L. the shelf should be about 3inches below the kink.
the new vents are 3in diameter 0.75in long for the shelf and 2in diameter 4cm long for the vent between top chamber and front chamber
Thank you for lesson on how to use microsoft paint. unfortunately the windows section of my laptop died while updating from windows 7 to windows 10. I am now on a version of linux called mint debian
we now require a top chamber of 11.4L. the volume from top to point of inflection is 8L. the shelf should be about 3inches below the kink.
the new vents are 3in diameter 0.75in long for the shelf and 2in diameter 4cm long for the vent between top chamber and front chamber
Thank you for lesson on how to use microsoft paint. unfortunately the windows section of my laptop died while updating from windows 7 to windows 10. I am now on a version of linux called mint debian
thanks for the drawing Freddi. Looks good if not to scale when i measure from my computer screen. pls remember from claudio negros experiments if you were to make an error in position its better to make the top chamber smaller rather than bigger. but from measurement on the drawing its in the right place. please remember the partition should be 0.75 inch and the 2in dia duct 4cm long.
Have a good day and enjoy being active
its lots of fun to see K-experiments of the past works - here's a K15 based coupler with Diffusicone 8 University fullrange speaker - if the height includes the feet then it may be scaled - I bet the builder had a good time and back panel is attached like a bank vault door - lol.
a K12 even with the lossy slit vents and a good 10 will play drums better than some larger horn systems. My old B102 with qts ~0.23 sounds fine and makes powerful sounds with almost imperceptible cone movement. Performance with percussion was one thing that Julian Hirsch noticed in 1954. (Piano scored high too - fwiw, Julian seemed to favor Vilchur's Acoustic Research speaker over all others, and acoustic suspension did usher in an era of manageable sized cabinets, appropriate for the upcoming stereo revolution.
Pair Vintage Karlson Speaker Cabinets with University Diffusicone Eight 8-16 Ohm | eBay
a K12 even with the lossy slit vents and a good 10 will play drums better than some larger horn systems. My old B102 with qts ~0.23 sounds fine and makes powerful sounds with almost imperceptible cone movement. Performance with percussion was one thing that Julian Hirsch noticed in 1954. (Piano scored high too - fwiw, Julian seemed to favor Vilchur's Acoustic Research speaker over all others, and acoustic suspension did usher in an era of manageable sized cabinets, appropriate for the upcoming stereo revolution.
Pair Vintage Karlson Speaker Cabinets with University Diffusicone Eight 8-16 Ohm | eBay
don't know how much a flat response correlates - some of the nicest subjective quality came from vintage drivers but I've a Beyma 12cx which needs a good xover which seems promising in a K12.
for the little midbass K-family (K12 @ ~3.3CF - X15 @ ~4.5CF bulk), the Acoustic Control 115 makes a good graph with EV15L. I don't have an on-axis plot but you can see these plots with the mic laying on the ground and the coupler upright vs baffle perpendicular to the ground - both are below the central axis and look about identical at 1/24th octave. There's no damping material at all in that cabinet.
KK-Audio made a version with a fancier reflector (like BEC and presume Transylvania Power Company) and put a "rear shelf" in their - I think the shelf made the response look somewhat worse -that may not hurt things sonically.
If 115BK were scaled 1.2:1 then would be the same bulk as K15 plus have room for an 18" - tuning might be around 40-42.
the little sketch on the left of this 1/24th octave plot was for a "Westwood" bass cabinet
you can see on the insert picture that the baffle is ~perpendicular to the ground - not sure why I took that other than curiosity.
is there something beneficent about the taper of the 115BK which makes it smooth? - If so, can it scale a bit downwards and upwards ?
Here's the drawing I made from my Acoustic Control 115BK - its got a lot of vent area (~27 sq.in.), and tunes ~53Hz
Look at MMJ's constricted transflex fudge of 115BK
for the little midbass K-family (K12 @ ~3.3CF - X15 @ ~4.5CF bulk), the Acoustic Control 115 makes a good graph with EV15L. I don't have an on-axis plot but you can see these plots with the mic laying on the ground and the coupler upright vs baffle perpendicular to the ground - both are below the central axis and look about identical at 1/24th octave. There's no damping material at all in that cabinet.
KK-Audio made a version with a fancier reflector (like BEC and presume Transylvania Power Company) and put a "rear shelf" in their - I think the shelf made the response look somewhat worse -that may not hurt things sonically.
If 115BK were scaled 1.2:1 then would be the same bulk as K15 plus have room for an 18" - tuning might be around 40-42.
the little sketch on the left of this 1/24th octave plot was for a "Westwood" bass cabinet
you can see on the insert picture that the baffle is ~perpendicular to the ground - not sure why I took that other than curiosity.
is there something beneficent about the taper of the 115BK which makes it smooth? - If so, can it scale a bit downwards and upwards ?
Here's the drawing I made from my Acoustic Control 115BK - its got a lot of vent area (~27 sq.in.), and tunes ~53Hz
Look at MMJ's constricted transflex fudge of 115BK
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