Beyma TPL 150 AMT - the ultimate driver whats the catch?

[steve 57]

Steve

I have some price options for your second pair if your interested.

I'll pm you , i'm very still very interested
cheers

[vinylnvalves]

Having now got a pair of these AMT's to play with - i am stumped by knocking up a simple crossover. I have looked at a couple of crossovers posted on the web and have been bloody confused by them. I throught the AMT would be the easy to design a crossover for as its a pure resistive load, but looking at this example http://www.tangenavdesign.com/DUKE%20Delefilter.pdf No matter which calculator i use for the 4.9 ohm resistance of the driver i cannot replicate this. ( The other end was going to be for a PR170M0 which is 10 ohms @ 1200hz)
Anyone got any better ideas than just using a simple LR crossover using 4.9 ohms top end and 10 ohms bottom end - what am i missing?

[AmDismal]

It would make sense to do your own second order LR to start with. That xo seems to be for a particular bass setup as well, so you need to start from scratch.

[vinylnvalves]

I wasn't going to copy the xover completely i was just confused on why i cannot understand it. I was equally confused others excepting this http://www.audiodesignguide.com/HiEff/HiEff2.html which seems close to a butterworth @ 1200hz in some examples. I will start simple and see how it goes.

[vinylnvalves]

I thought i would make some bigger horns than the constant direction ones Beyma supply. Does anyone have a spreadsheet etc, that will allow me to determine the profile for a rectangular le cleach horn, for these AMT's. The ones i have got all assume a round throat, whereas i want one with a 26mm x 120mm throat.

[steve 57]

I'm no expert, but didn't you get Scott's email when you where around at mine, theres a few on the wam have built his designs... he as as knowledgable any one I know.
Cheers...

[anubisgrau]

I thought i would make some bigger horns than the constant direction ones Beyma supply. Does anyone have a spreadsheet etc, that will allow me to determine the profile for a rectangular le cleach horn, for these AMT's. The ones i have got all assume a round throat, whereas i want one with a 26mm x 120mm throat.

what benefit you aim to achieve with a bigger horn compared to a factory WG?

[vinylnvalves]

Maybe stupidly i was (hopeing) assuming i could get better vertical dispersion, and maybe alittle more bottom end. I also know that you should not mix horn profiles, so keeping all my horns with a JMLC profile. I am also considering making a dipole horn and taking the back off the unit.

[anubisgrau]

Maybe stupidly i was (hopeing) assuming i could get better vertical dispersion, and maybe alittle more bottom end

i'm afraid this is pretty much defined by the nature of the driver, especially its dispersion pattern. have you find any evidence that someone achieved a better vertical dispersion in a bigger horn? i think it's impossible but maybe i'm wrong...

the same goes for low end, you may get it smoother there but i doubt any extension.