15" BPH Kick for Scoops

Modified HD15 Kick for Scoop Systems

Based on TDA Modified HD15









Modified Prototype for 18mm timber, & H600mm, to suit scoops when layed on side.

Width for this cab is 460mm.

Interested in builders prototyping this in MDF, for feedback on performance.

No spamming of this thread or irrelevant posts "please".

the dip at 125hz is a massive dip in terms of a kick cab, this area is were you need the kick to perform. regardless of what the rta says, this cab wont be able to play over 150hz. I would rather a peak at 125hz and eq out than have to add eq. The other down side is it only plays down to 60hz, making it not usable as a part of a small system. The other down side is this design is not very loud spl wise, making it very hard for this design to keep up with an 18" scoop..... play around with it in horn resp lev, at this point I would not even take this design to proto type stage build..... I no 4db down at 125hz don't seem to bad but its 8db down at 200hz on the rta also when simming in horn resp sim at 4pi in stacks of 4, this will give a better idea of how it will perform in a mono stack with scoops....

bee wrote: the dip at 125hz is a massive dip in terms of a kick cab, this area is were you need the kick to perform. regardless of what the rta says, this cab wont be able to play over 150hz. I would rather a peak at 125hz and eq out than have to add eq. The other down side is it only plays down to 60hz, making it not usable as a part of a small system. The other down side is this design is not very loud spl wise, making it very hard for this design to keep up with an 18" scoop..... play around with it in horn resp lev, at this point I would not even take this design to proto type stage build..... I no 4db down at 125hz don't seem to bad but its 8db down at 200hz on the rta also when simming in horn resp sim at 4pi in stacks of 4, this will give a better idea of how it will perform in a mono stack with scoops....

Many thanks for the input.

Any chance of providing the HR plot/data you used to arrive at the above conclusion?

Often on FSP, there are so many HR bods, so there maybe different methods to arrive at input data, which may alter resulting plot.

Seems strange, no negative feedback was voiced, when TDA modified plan was first posted years ago. I've highlighted this in thread on SP, to restart interest.

IMHO, the cab is sufficiently different to HD15, to at least prototype 1x cab and try with different drivers.

a plott tells only one half of the story, a plott can look good but, wont give us any indication in to tonality of the speaker. BHP cabs suffer from sounding honky if taken over x freq, but the plott can indicate a smooth response. Ive built, designed and listened to so many bhp designs in my quest to understand how and why they work, and more importantly how only a very few companies have managed to get there bhp designs to play higher....

Now that x\o points have been mentioned, I would like to add the following.
I see a lot of people asking how high certain bass or upper bass cabs will go. I always assume that it's because they don't think the mid will go down low enough. My view has always been that you should try and keep the voice out of the Bass Bins. Bearing in mind that the human voice goes down to 100hz, it's hard anyway. Firstly, try to keep the fundamentals coming from one source instead of splitting them between two cabs, and secondly try to keep the x/o point as low as possible when using a folded horn for upper bass.
So basically, when making your mid cabs, make sure they respond low enough. In my own upper bass cabs, I go out at 120hz.
One other thing to remember, with a cab that is used for "kick", just try to imagine what the speaker is trying to do when attempting to jump out of the box, and at the same time reproduce the delicate mid frequencies. Mid signals aren't helped by the velocity that occurs when hitting it hard. Just a thought.

tony.a.s.s. wrote: Now that x\o points have been mentioned, I would like to add the following.
I see a lot of people asking how high certain bass or upper bass cabs will go. I always assume that it's because they don't think the mid will go down low enough. My view has always been that you should try and keep the voice out of the Bass Bins. Bearing in mind that the human voice goes down to 100hz, it's hard anyway. Firstly, try to keep the fundamentals coming from one source instead of splitting them between two cabs, and secondly try to keep the x/o point as low as possible when using a folded horn for upper bass.
So basically, when making your mid cabs, make sure they respond low enough. In my own upper bass cabs, I go out at 120hz.
One other thing to remember, with a cab that is used for "kick", just try to imagine what the speaker is trying to do when attempting to jump out of the box, and at the same time reproduce the delicate mid frequencies. Mid signals aren't helped by the velocity that occurs when hitting it hard. Just a thought.

Many thanks for that boss..

For intended application, it's MT121s above, and even with sturdy 12", not sure if running below 160hz is a good idea.

Many Reggae dudes are talking about enlarging MT121 chamber slightly to improve 130-160hz response, but seems bit drastic to me.

But have heard about people playing MT122s down to 130hz, so guess MT121s in of multiples 2+ would be ok.

your best just extending the horn a bit on the mt lev, and increasing the mouth area....

I reworked the plan lev and got the sim looking like this....

light grey is original
dark gray updated version....

fane sovereign 15-500

light gray original lev rework 4pi stack of 6
dark gray bees rework of the rework 4pi stack of 6
same driver for both designs, based on fane sovereign 15-500.
cabinet size is the same for both versions.....
good from 70hz to 200hz

fane sovereign 15-500

light gray hd15 4pi stack of 6
dark gray bees rework of the rework 4pi stack of 6
same driver for both designs, fane sovereign 15-500.
cabinet size is the same for both versions.....
good from 70hz to 200hz

bee wrote: I reworked the plan lev and got the sim looking like this....

light grey is original
dark gray updated version....

you said u reworked the plan what's the dimension you used???