DIY a MantraSound Horn?

[ScottG]

I realize that the Dulcet Horn or even their linesource version are not fullrange drivers however neither is a Manger or most drivers under a 5 inch diameter.. and given the crossoverlessness of the horn/driver combo and the high eff... well you get the idea.

So then why do I bring this up now, specifically as a DIY effort?

The circular planars used for those horns look a L O T like the cheap planar capsuls from the east that have a fairly continuous highpass "slope" - seemingly perfect for a backhorn.

Specifically, they look a lot like the previously discontinued drivers from Apex Jr...

Note that I said "previously" - their back!

And at 5 bucks a pop playing with the idea of a backhorn for these cheapies may actually lead to sonic euforia (and/or build frustration and hell).

Well its just a thought..

The horn with the line source pic:

http://www.audio-consulting.ch/Dulcet.htm

The drivers:

http://www.apexjr.com/new.htm

Alas, I could not find the driver's measurement and spec.s on Planet 10's site.

(and no, I don't think they are the same drivers, I think MantraSounds drivers are slightly larger and they obviously have more holes in the magnets.)

 

[tade]

Which driver did you mean on that site? These horns look very very elegant. DIY worthy indeed!

 

[ScottG]

Which driver did you mean on that site? These horns look very very elegant. DIY worthy indeed!

The ones on the link I provided that start with:

"ribbon tweeters are back.."

Here is the link picture of the driver:

http://www.apexjr.com/images/Ribbon2.jpg

It could very well be that MantraSound's owner/designer started with these on a DIY basis and then started making his own with some higher quality magnets and then started drilling holes.

If I were attempting this (as if I had the time) then I would likely purchase the drivers and then start modeling with HornResponse as if the backhorn was a normal front horn.

 

[tade]

yes, i like those drivers, and 400hz, sounds doable. If i had any more space than my desktop to devote to speakers i would do it too! : )

can you remove the back of those drivers to give the rear wave access to the horn?

 

[tvi]

Here:
http://www.t-linespeakers.org/drivers/ribbon.html

 

[ScottG]

Here:
http://www.t-linespeakers.org/drivers/ribbon.html

Thanks tvi

The measurements will not of course take into consideration the modification needed for dipole operation - which should extend the response considerably. In this case the natural modification will be to simply find a drill bit that matches the diameter of the holes in the front magnet. Of course you will need to take apart the entire capsul before drilling.

 

[tade]

how about buy twice as many as needed, and use two of the drilled magnets per speaker.

 

[ScottG]

how about buy twice as many as needed, and use two of the drilled magnets per speaker.

yup, I had also thought of that soon after I posted. I'm not sure though it will work perfectly, but you would think that it would.

 

[tade]

if i only had the room!

 

[planet10]

Alas, I could not find the driver's measurement and spec.s on Planet 10's site.

http://www.t-linespeakers.org/drivers/ribbon.html

dave

 

[planet10]

The measurements will not of course take into consideration the modification needed for dipole operation - which should extend the response considerably.

how about buy twice as many as needed, and use two of the drilled magnets per speaker. [/B]

Already did that. Fairly easy to do. They did not measure any differently.

I have recently aquired some microMonitors from Akai that use this tweeter (and a PR on the back)

dave

 

[ScottG]

Already did that. Fairly easy to do. They did not measure any differently.

I have recently aquired some microMonitors from Akai that use this tweeter (and a PR on the back)

dave

That is very strange.. considering that the rear air-space originally is almost non-existant. It may be that the sd vs. excursion is so minute that no matter what you do you'll not achieve an extended freq. response.

 

[planet10]

That is very strange.. considering that the rear air-space originally is almost non-existant.

I was surprised too... but i trust the guy wih LEAP that did the measures.

dave

 

[GM]

Greets!

Ribbons are like compression drivers in that they have a very high Fs for their potential BW, thus the rear chamber can be quite small for the effective diaphragm area and still be ~an IB acoustically speaking, making them ideal for BLH loading.

So what's Fs?

GM

 

[planet10]

So what's Fs?

Kinda hard to tell...

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

I'll dig out the ones i have and do my own measures and see how they compare

dave

 

[ScottG]

Part Deux..

Looking over the BG Neo8 thread here I noticed member fcserei's contribution - in particular that his straight (though front loaded) horn in fact sounded better than the dipole version he worked with. (Also note the freq. response that was elevated from the horn which happens to "gell" rather well with the on-axis response of the driver.)

http://www.diyaudio.com/forums/showthread.php?s=&threadid=6228&perpage=10&pagenumber=1

I'm thinking that just two drivers per side would work rather well with a back-horn, perhaps with an Aurum Cantus G2si to fill in the highest freq.s. (i.e. vertically top to bottom:Neo8,Neo8,G2si 1st order cap with the driver inverted to adjust for polar tilt.)

Well, just something more to think about here..