posted
I tried asking a RF tech about an ABC box before, he didn't know what I was talking about and said if I was successful to tell them about it. Sounded clueless. So I don't think many of them really know about ABC boxes.
Posts: 3956 | From: State College, PA | Registered: Sep 2000
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posted
ill be trying one soon.... for 2 tempests... 13.2 cubes should do some justice
it will bw made oout of the box u see in my sig... only im gonna put the subs on top of the box instead of the back. with a total of i think it was 104 sq. inches of port for a little more sq then my old 150 sq. inches.
and im gonna tune it to 25hz and 48hz. should be NICE!
-------------------- eclipse cd5000 DD 9515 4.25 cu. ft box 83 sq inch port.
Say the total volume was 6 cu ft. The first box with the driver would be 4 cu ft and the smaller chamber is 2 cu ft. If you want a lower end tuning of 35 Hz with 3 4" ports, each would be 5" long. I recommend lining the inside walls of an ABC, it's up to you really.
Or you can build one 5 cu ft total. 3.33 cu ft for the big chamber and 1.66 for the small one. Use 5" ports since it's an SPL box, lower tuning is set at 40 Hz with 3 ports 7" long, 5" in diameter.
I don't know the thiele small specs so that's guesswork, but for any driver, the same volumes and ports will yield the same tuning.
Good luck
Posts: 768 | From: Ottawa, On, Canada | Registered: May 2000
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posted
Okay cool, at 6 cubes ported my sub sounded sloppy, i think 3cubes is good enough. So 2cuft and 1cuft suffice? or is that too small for ABC box?
-------------------- Why won't they just give that rabbit some damn cereal, sheesh. Posts: 900 | From: ARLINGTON, TX | Registered: Apr 2001
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posted
well, you cant go too small on these boxes.... it really depends on the subwoofers response to enclosure size, if the "peaks" in the frequency response are not great enough, the box may not function properly.....
it has to be a bit larger than the manufacturer may recommend (which is probly why they never do).... in order to achieve the high peaks in SPL, at the 2 tuned frequencies.
the larger you build it, the further the 2 tuned frequencies will be apart..... the smaller the box, the closer together they will be.... again, this is ALL dependent upon the size of enclosure the subwoofer opperates in, as some are smaller, or larger than others.
the bad part of separating the 2 tuned frequencies too much is, there will be little resistance on the cone in this reigon of things, between the tuned frequencies..... and it'll FLAP and SMACK like crazy.
if the box is too small for the sub, the too chambers will start to "blend" a little bit, which sound ALL messed up! more humming, or buzzing type sounds.
just some things i found out...
-Later
-------------------- - Wes Sowers - Discount Car Stereo L.L.C. Kent, Wa 98032 (206)824-5875
quote:Originally posted by MrFlamboyant: the bad part of separating the 2 tuned frequencies too much is, there will be little resistance on the cone in this reigon of things, between the tuned frequencies..... and it'll FLAP and SMACK like crazy.
if the box is too small for the sub, the too chambers will start to "blend" a little bit, which sound ALL messed up! more humming, or buzzing type sounds.
just some things i found out...
-Later
yes, MrFlamboyant is in fact correct! Which is why many people hate abc boxes cuz they are damn near impossible to get to sound good.
with my abc box at frequencies between the two tunes the sub makes a weird "twangy" sound like as if its in too small of an enclosure but im sure 6.6 cubes is PLENTY! for each sub.
it just has to do with the way i built my internal port. otherwise my box is..... LOUD and it sounds nice... but on those certain notes the only way to overcome iit is to either turn the vlume up or down to increase or decrease the amount of air flow in the box...
heres an example: if I was to play ghetto fabolous at 1/2 full volume it sounds punchy and messed up... however if i turn it 3/4 of the way up(or listening level) it sounds punchy then long and clear.... (the way it should be) u get it? it all has to do with air friction through that middle port. If u have too much or too little then weird things start happening!
hope this helps some people get a real world taste of an abc box. and how it works. and what MrFlamboyant said was just a shorter version... also very accurate... thanx MrFlamboyant
-------------------- eclipse cd5000 DD 9515 4.25 cu. ft box 83 sq inch port.
