100db, AMT and 4x BETA-8 +sub

Status
Not open for further replies.
Hi StigErik,

Thanks a lot for responding and please kee up updated regarding eventual comparisons. I consider very much the TPL150H myself, and would be very interested in hearing more about your experiences with this unit. Thanks!

Best regards
Peter
 
I work with importers of AMTs & planar-magnetic drivers from Asia.

I have samples of the new larger Aurum Cantus AC AST 30100 & 30130 (like dipole AMTs) and expect a pair of the Beyma TPL150 soon to compare. AC just send us a 2nd. gen AST diaphragm for testing.

This AC AST is the mid-size model http://www.aurumcantus.com/aurumcantus-AeroStriction/aerostriction_30100.htm; the smaller model has lower SPL but smoother curve and extended VHF http://www.aurumcantus.com/aurumcantus-AeroStriction/aerostriction_2560.htm

Akip and other Asian (& German) factories make AMT style tweeters.
 
ears4hire58 said:
I work with importers of AMTs & planar-magnetic drivers from Asia.

I have samples of the new larger Aurum Cantus AC AST 30100 & 30130 (like dipole AMTs) and expect a pair of the Beyma TPL150 soon to compare. AC just send us a 2nd. gen AST diaphragm for testing.

This AC AST is the mid-size model http://www.aurumcantus.com/aurumcantus-AeroStriction/aerostriction_30100.htm; the smaller model has lower SPL but smoother curve and extended VHF http://www.aurumcantus.com/aurumcantus-AeroStriction/aerostriction_2560.htm

Akip and other Asian (& German) factories make AMT style tweeters.



Build quality - especially of the diaphragm - isn't comparable with Beyma and Mundorf - but hey if the sound is ok for the price - wellcome !

The diaphragm of the Aurum Cantus isn't equally folded - as can be seen in the close-up in the review of the AST 30100 - and also seems to touch the grid of the magnet structure occasionally.

Very much the same as with the ERGO headphones below -

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


Picture taken from the ERGO review at
http://www.head-fi.org/forums/f4/ergo-amt-review-56k-dont-even-try-193982/

Also the foil seems to be of standard design and not the yellowish high temperatuer films Beyma, ADAM and Mundorf use to get reliable high power resistance.

Michael
 
Hi

Just deleted a very long list of thoughts about this

I will only say, "back to basics"

ONE Beta-8A with a Hivi planar, RT2II or RT2H-A

OB baffle, cheap and simple
Dipole rolloff might help transistion to woofer

FaitalPro 18FH500, still my first choice
And I have a nice 180liter closed matrix box, made years ago but never used 😀

Beta-8 and Hivi are quite cheap, so those are just fore fun
Woofer cost a bit more, but those I will hold on to

Mind you, this would still be about 95db 🙂
 
tinitus said:
Hi

Just deleted a very long list of thoughts about this

I will only say, "back to basics"

ONE Beta-8A with a Hivi planar, RT2II or RT2H-A

OB baffle, cheap and simple
Dipole rolloff might help transistion to woofer

FaitalPro 18FH500, still my first choice
And I have a nice 180liter closed matrix box, made years ago but never used 😀

Beta-8 and Hivi are quite cheap, so those are just fore fun
Woofer cost a bit more, but those I will hold on to

Mind you, this would still be about 95db 🙂

Good choice, G. Pimm use 8A with HI-VI 8 planar (95dB) no need to attentuate at HI-VI end, result simpler x-over and achieve high spl close to 95dB.

Pls report the sound you get. I am still waiting for the arrival of 8As in Australia.


Cheers.
 
Back and it was great. Gary is running just 1 Beta 8 per side now - 200Hz to ~6KHz. Very sweet. Heavily modified DCX for crossover.

The bass is so strong and so clean that at times it gets the whole basement resonating. The bass wave travels the whole length of the house then comes back to shake the floor a large fraction of a second later. Most impressive! But it never, never obscurs the mids or fine details. Great power supplies and clean speakers allow this. The lights do dim on the big bass hits, tho....
 
panomaniac said:
Back and it was great. Gary is running just 1 Beta 8 per side now - 200Hz to ~6KHz. Very sweet. Heavily modified DCX for crossover.

The bass is so strong and so clean that at times it gets the whole basement resonating. The bass wave travels the whole length of the house then comes back to shake the floor a large fraction of a second later. Most impressive! But it never, never obscurs the mids or fine details. Great power supplies and clean speakers allow this. The lights do dim on the big bass hits, tho....

I have details the mid-range and highs, can you elaborate on the bass end, ie U-frame, dual woofer, what brand of woofer, etc?

thks.
 
Hi ttan

I guess you could call it an H frame. It's a box with no front or back. Dual 15s - the IB15 from Dayton.

You can see the woofers from the front, but they are placed at 40 degs. Sorry I didin't take any photos.

If you were to take the top off and look down into the box, you would see an inverted V shape. The drivers are mounted "stacked" one on each leg of the V - with the front of one woofer firing into the back of the other. So from the front you see 1 woofer front, 1 woofer rear.
So the cross of the H is not straight, but a V.

|V| (seen from top)

There is stuffing behind and a little in front, too.

Powered by a huge Crown amp.

Maybe Gary will post photos soon.
 
Hi, I am intrigued with Mr. Pimm's design, specially the mid-highs, Do you know ant what points and which slopes is he crossing the Beta to the planar driver? I have been thinking about a very similar project, but I had thought of the lil' Buddy 10" on OB. Do you know at what point he crosses the sub to the mids?
 
Beta to planar is ~6KHz, IIRC. Simple 1st order. A small coil kills the rise if the 8" which then blends into the planar tweeter.

Low to mid is at 200Hz. There is now a 200Hz hi-pass on the mids (DCX2496) that was not there before. Don't know the order, tho. 2nd?
Lots of EQ on the woofers. 18dB hi pass at 20Hz to control the subsonics. (it works)

For the price and the performance, the Beta-8 is a no brainer. Even if you want to go to an exotic driver later, the Beta-8 is a great starting place.
 
Status
Not open for further replies.