The small circle after the number stands for degrees.
3.87° is the complementary angle (two angles whose sum is 90°) to 86.13°.
A saw would be set to 3.87 degrees to cut the 86.13 degree angle (90-86.13=3.87).
Supplementary angles are either of two angles whose sum is 180°, like 135° and 45°, the angle the saw would be set for the caster plate, bottom back and rear bottom cabinet pieces.
3.87° is the complementary angle (two angles whose sum is 90°) to 86.13°.
A saw would be set to 3.87 degrees to cut the 86.13 degree angle (90-86.13=3.87).
Supplementary angles are either of two angles whose sum is 180°, like 135° and 45°, the angle the saw would be set for the caster plate, bottom back and rear bottom cabinet pieces.
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gotcha, ( i needed to zoom in 300% so to spot the degrees circle )
SPOILER ALERT :
so i guess that if you miss that angle and make all 90 degrees you screw up the response of the design
and destroy the driver by over excursion mechanical failure
because of the improper loading of the compression chamber 😁
phun intendeed , i just gathered bits and pieces of sub theory that i have read over on this forum
SPOILER ALERT :
so i guess that if you miss that angle and make all 90 degrees you screw up the response of the design
and destroy the driver by over excursion mechanical failure
because of the improper loading of the compression chamber 😁
phun intendeed , i just gathered bits and pieces of sub theory that i have read over on this forum
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This TH is actually a bit oversized for one driver. Using two drivers in it MIGHT improve its passband response, but that should really be confirmed by adjusting the sim accordingly. The extra driver will of course have to be mounted right next to the first one, not where picture in maxolini's diagram.
Well, in a sim you get up to +6 dB if power is doubled, otherwise just +3 dB and the extra heat that may, may not (drastically) shorten their lifespan depending on how hard they're driven for how long.
ic, so then the narrow 15" width will need to be grown to acoomodate the dual side to side drivers and if that is the case then use one 15" or 18" or even 21" driver. but those plans were already visited here, what about a push pull config with dual Lab12 , can that be posible in a TH or you need a paraflex layout to make it happen, bass reflex is out of the equation, the db gain of horns is king vs bass reflex, but that leads me to this question , why big PA systems ( 20k+ people) use walls of double 18"s if they can use horns subs ? is cause the sound "timbre" or cause money is no constraint so they can have as many powersoft K30 amps full racks as they want and they do not give a s... about eficiency and sensitivity in subs, and not to say the hanging linear arrays, that will open a can of worms and i do not want to.
Danley Sound Labs uses a push pull configuration with 12" drivers in several TH designs, the DTS10, TH-212, TH-812 among them.
The design in this thread would take a fairly major re-design to work like the above.
I'd be concerned about uneven loading adding a second driver above the lower in this thread's design, the top driver so near the first corner expansion.
That said, worth a try and a comparison, the second hole could easily be covered if it didn't work out well.
The primary reason is more low frequency SPL output can be achieved in a given truck volume or space available for PA in a production from bass reflex designs.
Art
Brian,I tried a stab at simming what the PAL12's performance would look like with two drivers installed as suggested.
Someone please check this over...
Maxolini suggested the lower impedance LAB12C rather than the LAB12.
The Wizard Acoustical Response screen and the input parameter screen posted in #717 don't agree.
An L12 length of 21cm (8.27") is too short for the center of the area of 2x12" along the path, 51cm (20.07") is overly long- the top driver would extend past the first horn bend.
Art
Nice, hey but many guys over the AVSforum do not like that you show them your audio analysis/design skills lol, even they do not like to hear the truth about what is going on, looks like there is a cult for some brands and/or models and people get fanatic frenzy to the point of insult others who show superior IQ than them. I like here cause there is some nice people who know their stuff and they do not troll you with no reason, i mean unless you fook with them but otherwise it is a pretty nice community.
btw this was epic
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