Variation of SMT-212

So here is the mid top without the 8inch or 1 inch horn mounts cut out and shown relative to my mini scoops. That's scoop number three half way completed.

I would cut the horn baffles but I'm waiting until I actually have the horn in my hands,, which may not happen as I've emailed every known supplier and can't find them second hand :(

sushi wrote: I think the SMT gonna look good! I saw a similar project on google images, black painted, with the midhigh and high section very lookalike the tms111.. What about delays on the bass? Considered that the 12 woofer and the hf driver are alligned (in my project) should i use a delay on subs, even if the hornpath of the midtops is not longer than 30 cm? I think i should do some maths and calculate the right delay

To answer your question I'd need to know what subs you're using. The tops may still need a few m/s delay even between the 12 and HF.. when I say need I mean could be done, whether it makes an audible difference is another matter all together. Typically you would be delaying the mid-tops to the subs. If you have reflex subs then maybe the other way around.


It will also depend on how many sub you have and their group delay. Which will depend on your chosen pass-band also.

I will measure and delay all three sections of the top using a mic. As for my scoops, well they never behave. Generally the phase on the scoops is flipped 180 degrees.

The only way is to measure and align, using horn path length doesn't always work.

you can use pink noise and polarity flip to do it by ear, but I'm not very good at that.. ravers ears, so I'm tone deaf.

#Nkdk
I will absolutely try them! I love the Kappa12A, they gave me some serious satisfaction for my first build, and Eminence still means good sound at good prices for me (i got Kappa15LFA and PSD2002 as well) I'm buying 18sound anyway cause i'm trying to sell the kappa12's with the midbass cabs i built for them, old school mid horns with two round panels beside the speaker, sound great but they are 84cm wide.. they really look enormous on my kicks and subs, would need a larger sub stack under them.. something i can't afford right now

#FractureClinic
I'm going to stack the SMT's on a pair of RCF ESW1018.. not a proper sub but since i'm mainly playing hardcore tekno, crossbreed neurofunk, i'm quite good with them. I just put a 40hz high pass (my plan is to build 2 more,but maybe one day i will build proper subs and use the ESW only for bass range) They are front loaded and have a large reflex port. Look like the miniscoop but have a slightly shorter reflex horn.
I have also HD15 kickbins that i'm gonna use in case the midtops are not doing well under 300hz, but they would need a delay set on subs because of the horn, plus a shorter delay set on midtops.. actually, i don't know the correct delay to set and neither i know how to calculate it for reflex horn cabs like mine. At least i have DSP on my amps so i could set different delays.

sushi wrote: Fracture_clinic wrote: Typically you would be delaying the mid-tops to the subs. If you have reflex subs then maybe the other way around. It will also depend on how many sub you have and their group delay. Which will depend on your chosen pass-band also. I would like to understand more about this point.. how do reflex cabs behave? Why should the midtops be delayed? Thank you, by the way.. this conversation really starts being inspiring.

Let's say you only have two ESW1018 per side and some horn loaded mid tops, like something with a long horn, not a 'pseudo' horn like the SMT 12 inch section (which is more like a wave guided reflex)..

Your subs are in front of the stage and your tops are up on the stage for some live music work.

You might find that the group delay on a pair of ESW1018s is for all practicality none existent.

So due to the mid-tops being horn loaded and set nice and high for projection, their sound takes a little longer to reach the listeners ears so you would need to delay the subs. The subs are also physically a little in front of the mid tops.



You mention you have HDs also, so let's thrown them into the mix.



So same set up as before, you have a stage with your ESW1018s on the gound infront of the stage, two per side. Only now you have a pair of HDS under each top up on the stage.


First things first you'd likely want to flip the polarity on the HDs if theyre not already reverse wired. (Don't reverse wire them, or any bin for that matter, do everything at your LMS if you can).


Now your mid tops are even higher (not by much so let's just say it doesnt make a difference). But what might be more important than delay now, is phase alignment at the crossover points. So in this situation that might be more important to you than delay. From what I gather phase and delay crossover, excuse the pun, somewhat.


I'm still very much on the learning curve so please don't take what I say as fact, mearly my attempt at taking some of the things I've learnt on here and trying to give back to the community.


What I would say is keep reading, there are long threads in the deep reaches of Speaker PLans with some awesome information.

nkdk wrote: #fracture I hope your planning to make vents fore the driver,its a very small chamber nkdk

Yeah I will do, to the original port spec too. Four 1 inch holes is practically the same as half of the SMT212's port volume.

But first I'm going to load it without any holes and measure it and then do a before and after, just because why not really.

sushi wrote: #Fracture_clinic Ok i understand the first part, it's quite basic.. But i think i have some doubts on reversing the polarity: what's the effect it does? Have the polarity anything in common with the phase? I don't know what a LMS is but i imagine you're talking about a sort of processor.. is it so?

Reversing the polarity has the same effect as wiring the red wire to the black terminal and the black wire to the red terminal. Yeah LMS/processor/active crossover ect.

The effect is the driver moves in the opposite direction when the signal is positive compared to a driver wired red to red black to black.

This is done (but not always needed) when the bins are loaded with backwards firing drivers, such as the HD or USB.

Adding to yoru previous question about reflex bins, they dont have long horn paths that affect the delay compared to big horns like labs ect.

Horns have other phenomena like natural high pass filtering and all kinds of other things. Their usable pass band is also more limited compared to reflex, typically. This means more complex systems with more crossover points, more places to be out of phase or time.