Still need assistance designing a midbass cab

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi guys. i had my first proper gig on the weekend and have established that 4x SS15 subs are well and truly awesome, but my tops just cant seem to make the right amount of noise to keep up.

now, they sound great. theyre currently reflex cabs, tuned on Bassbox pro to 80hz, with a 100hz 12db/oct HPF. fitted with Eminence Delta12a drivers, and a compression horn 1inch throat.

so, what im thinking is giving them more directivity and fitting them into a horn cab.

heres what i had come up with at the time of typing this, i have since played with HR a little more and come up with a smoother hump around the 300-400hz by shortening the horn down from 400mm to 150mm.

KMBHvsSS15vsDelta12HRplot.jpg


i just feel from the weekend, that the deltas just arent enough on their own to give that full "kick" or "slap" that the SS15s dont seem to deliver.

on that note though, i didnt exactly play with the XO filter on the EQ either. so its possible that with a bit more tweaking on the active filter, that i could achieve more punch/kick from the SS15 subs.


here is the HR plot of my current reflex cabs, grey line, and the proposed horns, black line.

lengthening the horn spikes more, shortening it brings me a smoother response. i guess due to focusing i guess...

Deltareflexvshorn.jpg



i can see that HR has tapered off the response of the upper mids naturally occuring to the delta, will having the "horn" (read waveguide...) in front help to improve upper mids as well?? if so, im probably going to go ahead with this basic design.
 
Last edited:
thanks Xoc1, i did read that thread actually, as i did do a bit of searching around before posting.

my only constraint is that it fits on top of my SS15 sub. so limiting myself to 22inch (~600mm)

20120929_165111.jpg


additional to the existing tops to start with, and then replacing current ones if all goes well.
 
just realised something rather stupid.

i purchased a while back, plans to built an OT12 off the BFM site. the strange thing is, that the cabs i have drawn up are so similar to the BFM design... i had completely forgotten about that design... well. at least i know im on the right track then.

anyone else have any suggestions or help on this matter?

can anyone explain why the pioneer speaker shows so much more spl than the delta? is it the impedance? (or lack of?) or just a combination of factors?
 
I have been designing some bi-amped 2x12" + 1" horn cabs for my future PA system, so this thread definitely interests me. Do you have any more information on your current cabs? I see "reflex cabs, tuned on Bassbox pro to 80hz, with a 100hz 12db/oct HPF. fitted with Eminence Delta12a drivers, and a compression horn 1inch throat.", but not sure on how many cubes per cab. Also, 2 drivers per cab I assume?
 
Also, 2 drivers per cab I assume?

currently i have 1x delta12a and 1x 1" compression horn in each cab.

i still might get another pair of deltas, but at this point im thinking that the horn cab will be enough to bring my perceived output to the required level.

as i said before, they sound great, certainly not complaining about their sound. just feel theyre not quite loud enough. its litterally only just not loud enough.


but not sure on how many cubes per cab.


cabs are about 50L internal volume.
 
Last edited:
How miuch adjustment have you on your crossover settings?
100 Hz is quite low for a Delta 12a which has a fairly small Xmax.
As an experiment you could try stacking your existing 12" +1" cabs on top of each other - inverting the top cab to keep the HF as close together as possible. This will give you an idea how it would perform as a double 12 cab.
I tried this myself recently with a pair of my mid tops and it worked OK but I had to adjust the crossover frequency of the mids to the HF to below 2 KHz.
The other issue you have to address is your compression drivers and the crossover.
A horn loaded mid would require a better compression driver, as would a double 12" and compression driver cab.
Have you seen these mid top horn loaded plans for a double 12"
Speakerplans.com
Regards
Xoc1
 
i do like the look of the MT112. what i had in mind to build was much more simple than that tho... lol

had my system setup in a sporting hall tonight, and with a bit of EQ tweaking, and Sub LPF adjustment, it actually sounds reasonably clean and solid, without any real gaps in response. i didnt realise the sub LPF was set at 75hz. i lifted it tonight to about 120 and gained massive punch from the subs. normally i have the 35hz EQ slider minimised to -12db, but tonight i lifted it to 0 and must say, it sounded so much better. also, dropped the HPF filter from ~50hz to about 40hz on the EQ as well. (ive got a picture of the settings but cant upload right this minute, so ill have to do it later.)

as far as adjustment on the cabs XO, its passive, and i only recently tweaked it , i fitted a selectable 100uf cap on the input so i can select whether or not the cab plays full range. or is highpassed at approx 80-100hz (12db/oct) and yes, it makes a big difference to how much power they can take.

id be very interested in owning a second pair of Delta12's but havent got a spare $300 atm...

nothing will happen this side of november anyway, so it will stay as is for now. unless i find funds to build more cabs and slip the pioneer drivers in for interim. <which is the plan for the new cabs regardless, since i have them here sitting doing nothing.
 
Tops wont handle much more power as they are. They go loud but lack the real slap im looking for. Basically what im wanting to know before i commit to any horn design is wether the horn will emphasise the whole range of response or only boost what HR simulates.

If i was to add a high frequency hp filter to the delta i think it would start to sound a bit harsh up in the top end so im thinking the driver is as loud as it can get and stay clean. Im really just looking for a way to make it seem louder than what it is as a direct radiator in a reflex cab.
 
It's going to be hard to get 2 direct radiating 12's to fully keep up with 4 horn subs. Two Delta Pro 12's and a 2" CD per side (with plenty of power) does a reasonable job. A horn on the mid that's as short as the one you propose won't offer any boost in the 100-200 Hz range. To get boost down there it needs a 3 foot path length, and the resulting box is about half to 2/3 of an SS15.

The output of the tops may be sufficient if your mix is intentionally bass heavy. If the setup is just lacking "slap" or "punch", it is probably just a time alignment issue and it just takes tweaking to get it right. Playing pre-recorded dance music with the bass turned up you just don't need as much output from the tops as you do subs.
 
Hi klampykixx You will not get the full performance of your mid tops using a passive filter.
You need to filter before the mid top amplifier with an active crossover.
I have looked closely at the photo of your set up on the SS15 thread and am stiil not sure how you are setting the Low pass filter for your SS15 subs :confused:
 
this is my amp kit. this is how it was set up for the gig that the picture at post #3

20120929_174011.jpg



EQ has a sub out, thats what the EP4000 is connected to.

i need to get myself an active XO, i am well aware of this, so perhaps what you are saying is that i might be able to get just a little bit more sound out of the tops using an active XO?

could then get a little more bass out of the subs as i have the eq set all at 0 for everything regarded as bass as you would see in the picture.
 
Hi Klampy,

System looks great! I just spotted something though:

>"normally i have the 35hz EQ slider minimised to -12db, but tonight i lifted it to 0 and must say, it sounded so much better"

Was you using that as a low cut? Or do you have a high pass 35hz filter? Otherwise, your going to start blowing drivers.

Also, there is a great mid-cab horn plan in the Bass my Soldier thread.

cheers,
col.
 
Low cut is a seperate adjustable dial to the left side of the eq. I have hi cut and low cut and gain. Low cut is usually set between 35-45hz. And normally have the three lowest eq sliders all the way down for max cutoff.


On a different note, how would a lascala clone perform fitted with my delta compared to the current reflex cabs? And then also compared to the horn i simmed on HR?
 
as far as setup goes, the tops take the full range of sound that the EQ spits out.

the top cabs have a 100uf cap inline on the input side which filters out the lowest frequencies, but still makes quite a bit of bass. (i think maybe i could focus on making that cutoff steeper??)

the subs are amped off the subout on the EQ. so take everything below the adjustable cutoff on the back of the EQ.

so, basically for example, if i cut everything lower than 100hz on the EQ, it takes it from both the subs and the tops, which is why i dont boost the EQ in that range, i just turn the sub amp up a bit higher on its gain.

the more im thinking about this the more im leaning towards getting an active XO first. running the high freq output to the EQ and then my EPQ1200. and the sub out to my EP4000.

am i going the right direction on this? i figure i can do a proper HPF on the tops, and a proper LPF on the subs this way. its starting to sink in i think....
 
the subs are amped off the subout on the EQ. so take everything below the adjustable cutoff on the back of the EQ.

so, basically for example, if i cut everything lower than 100hz on the EQ, it takes it from both the subs and the tops, which is why i dont boost the EQ in that range, i just turn the sub amp up a bit higher on its gain.

the more im thinking about this the more im leaning towards getting an active XO first. running the high freq output to the EQ and then my EPQ1200. and the sub out to my EP4000.

am i going the right direction on this? i figure i can do a proper HPF on the tops, and a proper LPF on the subs this way. its starting to sink in i think....

That's the way I'd do it.

You could put the eq before the crossover, giving you control over eq in the low frequencies as well (useful for tuning into rooms etc).

Chris
 
Well at this point in time i can get an active xo cheaper than i can get wood to make new cabs so ill see about getting an active xo and if still not loud enough on the tops ill get a hold of another pair of deltas and do a dual 12 cab for each side.

So with that in mind would people build more direct radiating style cabs, or horns like the MT112 or OT12, or klipsch lascala copies?
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.