Still need assistance designing a midbass cab

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i have fitted a behringer active XO into my rack. i will be running it this saturday in a reasonable sized resturant, ill be taking my two tops, and probably just one sub and will see how it goes.

then, next saturday i have the gig in the hall, so will be running all four subs. be good to get it up and see how it performs in that stage too. :)
 
Hi, I posted this in your other thread....personally, I think lack of time correction is your biggest issue:

A few suggestions:

- Your cheap compression drivers are probably falling apart in the midrange at high volumes. Consider an upgrade to something like a selenium D220ti

- In my limited experience with PA speakers, I find that they are not nearly inert in the cabinet as good hifi speakers, causing the sound to sort of fall apart at the higher volumes PA speaker are used at. Consider additional internal damping, bracing and stuffing to your mains.

- Are you running time correction on your mains to delay them to match up with the SS15's? Because the tapped horns have a baseline group delay at crossover that will cause funky cancellations in the midbass and a clear lack of attack. Try the system outside and physically move the subs ~4-6 feet in front of the mains, and don't use EQ. Also experiment with lower order crossover slopes, if you have the option, but this may not be effective considering the tapped horn.

It seems that kick bins are fairly popular with the UK sound system guys, but you have to consider these are used in massive, refined systems with multiple large subs and large mid-horns which do actually leave a small gap in the kick region when used together. The pair of delta-12's should have no problem keeping up with the ss15's above 120hz if implemented well.
 
IMO spend some time getting the most out of what you currently have before trying to design/build new boxes - a DSP LMS is the best place to start, along with a microphone/SPL meter and an afternoon in a big open space testing+tuning the rig.

Once you can identify the issues then you can rectify them... otherwise you'll probably end up chasing your tail and spend a lot of time/money in the process of trying to "fix" things without knowing what you actually needing to fix.

Also coincidentally I'm set on building 4x SS15 (with Delta 12LFA drivers as per thread discussion) and want to put BFM OT12s on top as well, 22" is the magic number!
 
After some good quality listening time over the past few weeks i have come to know what i want to hear, and what im not hearing.

first problem, which i believe will be rectified, is replacement tweeters. changing from chinese Weconic 1inch compression drivers, to Selenium D220ti comp drivers, i think i will pick up a good amount of clarity and much higher response, hopefully freshening up my sound stage.

second problem, is (IMO) still not quite enough "slap" to the sound. it has kick, and its solid, but i feel its a tad soft from 200-500hz area. i feel thats due to a single 12inch DR on either side trying to keep up with a pair of SS15.

heres my last pictured setup

20130104_185517.jpg


and heres what im thinking i need to replace the single 12s with>

dual12Tappedhorn_maybe.jpg


i think an extra pair of drivers, in a sort of tapped horn arrangement tuned around the 100-300hz mark, pending on the drivers natural roll off (i havent started looking at response graphs yet)

the current cabs, loaded with the Delta12a sound nice, theyre loud, and theyre clean, but just lack a little. especially knowing that im wanting another 4 SS15s in the near future. i feel that as they are, no way. but perhaps, horn loaded and double the cone area, could be quite capable at being a good blend.

any suggestions or opinions?
 
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Just try doubling the cone area.

A while ago I was amazed at the sheer volume and projection this tiny system managed:

An externally hosted image should be here but it was not working when we last tested it.


Its a pair of 6"ers a side, MTM, ported cabinet.

I suspect a D'Appolito arrangement or similar, which kept the vertical dispersion narrow.

Try disconnecting the tweeter in one of your cabs, stack them so its MTM and see what you think. Compare that to one midbass running, see if the extra output is sufficient.

If it is, go modular: keep your current tops, get another couple of 12"s, put them in their own cabinets and sit them on top of your current ones for the extra output when needed.

Chris
 
klampy
i suggested in an earlier post that you look at jbl 4560 style cabs for good reason, the mid slap i think your looking for is in horn loading your mid.
no front loaded or direct radiator is going to keep up to your long throw subs unless you have alot of them with 1.21 jigawatts of power but that would only apply in the near field!
 
and this is the Unity horn i have been reading about.

1371096992_e5330f931f_o.jpg


An externally hosted image should be here but it was not working when we last tested it.


but, im thinking that designing a tapped horn for midbass frequencies, ie:120-500hz will net me a bigger peak in that bandwidth than even a front loaded horn will give. am i correct in this thought train? or is the front loaded the way to go?
 
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