scoop style midbass horn.

[klampykixx]

Hi guys, im just thinking out loud here for a moment, but my first is a Q.

does a scoop play similarly to a tapped horn as far as function is concerned?

and second, can a scoop be made to play full range, and do it in a decent form?


im thinking about making a rear loaded horn, like a scoop, but with a shorter horn path to emphasise 80-200hz rage while keeping a DR type driver that will play up to 2.5khz.

thoughts?

 

[turk 182]

many a JBL 4520 loaded with E140's and a slant plate crossed in at 2.5k made up the primary two way disco systems of the early 70's(man i am old) not that i'm a fan of a 15 inch driver handling midrange but with proper eq'ing these systems delivered.

 

[klampykixx]

so basically if i rear load the drivers but still have them play their normal bandwidth (100-2.5k) will they end up sounding horrible, or just like an epic BR cab?

those JBLs look pretty gnarly

 

[turk 182]

not that i understand "an epic BR cab"is or what it represents but the 4520 or 4530(single 15 version) with the right(and by that i mean wider bandwidth driver) can yield excellent results well into the upper midrange but your original question was does a rear loaded horn behave like the tapped horn? i my opinion no(i'm stating opinion because while i am a knowledgeable individual i'm not an expert).
i might be wrong but in your post it seems like your thinking of using a rear loaded horn under a unity horn to what ...try and get better low mid definition punch, coverage, projection?
as an old dog eared PA guy i remember cobbling together festival pa's outta any and all boxes we could get our hands on, that meant a wide variety of different boxes to play with. i learned the hard way what combining different box designs designs could do. everything from creating massive nulls at frequencies and places you wouldn't expect to outright killing drivers in a combined "array"(translate to bric a brac of boxes)
a direct radiating rear horn loaded box with/vs a unity horn it think the sum of those two will leave wanting...(for better phase summing over distance)

 

[klampykixx]

..try and get better low mid definition punch, coverage, projection?

this^

basically what im looking for is the most efficient cab design that will net me what im looking for as far as better kick/punch arund the 80-150hz range, but will still act like a DR style cab into the upper frequencies (300-3000)

my current cabs are Bass reflex loaded with Eminence Delta12a drivers, theyre tuned to 80hz, so they play fairly flat from 80-16000 (two way) but flat do 80 isnt good enough to keep up with my subs as far as kickbass goes.

i designed some rear loaded horns but the cabs are going to get pretty bulky pretty quickly and i do need to be able to lift them by myself. heres a couple sims and a picture of what im on about.

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

and this is what i had in mind for a top cab.

12inch would reside in a sealed top section and fire down and forwards with a roughly meter long horn path.
the front firing drivers would be a pair of 6inch midwoofers. and the tweeter is a Selenium D220ti

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

cabs im otherwise considering (all running with the Delta12)
HD15
LaScala
Cubo12
JBL scoop mentioned above


and also, then considering going full normal DR style but line array instead.


my biggest problem, i need to choose something and go with it which is why im having such an issue deciding which way to go.

 

[klampykixx]

heres my sim in the Lascala cab.

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

note: "modded from current" was my idea of shifting the front baffle backwards into the box and fitting waveguid style panels onto the front of the driver for more directivity and attempting to enhance the bass response around the 100hz mark (even tho it boosts at 200 it would blend with the subs better if they were passed at 100-120hz @12db/oct

 

[turk 182]

let me see if i got this right your sub's are a folded horn your tops are also horn loaded and your dividing the frequency spectrum 4 or 5 ways?

p.s. your sketch reminds me of a Clair Bros M4

 

[klampykixx]

no, not quite.

my current set up is 4x SS15 Tapped horn subs.
and 2x 60L bass reflex 2way cabs. loaded with Delta12a and D220ti tweeters.

and i want more kick bass without resorting to more drivers as a first step.

 

[tinitus]

looks like you might need a forklifter to move it ?

my current cabs are Bass reflex loaded with Eminence Delta12a drivers, theyre tuned to 80hz, so they play fairly flat from 80-16000 (two way) but flat do 80 isnt good enough to keep up with my subs as far as kickbass goes.

how about a pair of 15" below the Delta12 ?

 

[klampykixx]

I think I wanna stick with 12s.

What I was actually thinking was to use my current 12s as a central kick bin and using two way 10/tweeters in a linearray setup
Thoughts?

 

[tinitus]

sorry I don't understand

I thought you just said the Delta's are better mids than woofs ?

but if using medio size woofers like 12" maybe consider SPL might suffer
and from what I understand SPL is exactly what you are lacking to keep up with your TH subs ?

or maybe look at PPSL designs ?

 

[klampykixx]

Theyre a good alrounder yes.
Im just thinkn outloud

 

[tinitus]

4x 12" per side, in a V-baffle ?

 

[turk 182]

ok i think i understand you've got tapped horn sub's and two 60 liter two-way boxes with eminence 12's and a selenium horn top that are essentially direct radiators.
horn loading your 12 is the way to go.
something like a jbl 4560 would do nicely or a unity horn perhaps.

 

[klampykixx]

Just had a bit of a read on the 4560. Its most efficient above 200hz by the looks of it so id still have a gap in the bass range at around 90-150hz which is the exact situation im in atm.

 

[wg_ski]

Unfortunately, efficiency takes space. I have two midbass designs I use which are flat to 80 and do 105dB/W, and both are almost as large an SS15. You could do 102dB in half the space, but it's still a big-ish box at around 5 cubic feet.

 

[klampykixx]

When I set up outdoors I still havent established a "best" way for positioning everything. If I run the subs central it leaves me with no choice but to run my tops on tripods. However running my subs two per side gives me enough height that I can run my tops on top and thats where I could certainly run a bigger, heavier top no problems.
If I cant pick a distinct sound benefit then maybe I should run them for optimal setup?

 

[klampykixx]

Sorta missed my own point just there,
If I run each side as a big stack id remove the issue of the mid cab having to be on a tripod.

 

[turk 182]

what crossover frequencies are you using?
i'm not sure but do the ss15's suck running up to 200 hz i've done heretic things like running Cerwin Vega B38's as high as 500 hz.
so i guess i'm trying to determine why you can't simply raise the upper limit on your sub's?

ps in vertically stacking two ss15 are you placing openings together,apart,same side?

 

[klampykixx]

I use a mini dsp for crossover duty. The problem is volume. I feel the subs run cooler and go louder when crossed no higher than 100hz.