Round tractrix horn for my B&C DE250

a007udio · 8th September 2007, 04:02 PM

I would like to make tractrix horn for my DE250. Can anyone help me?
I was trie to calculate horn with HornCalc but resaults are strange.
I will use DE250 from 1600Hz and up.

GM · 8th September 2007, 07:08 PM

Greets!

Haven't tried simming a Tractrix in Hornresp, but for a 1600 Hz XO I'd want the horn to have a cut-off at least an octave below it, or ~800 Hz:

throat dia. = 1"
axial length = 3.75"
mouth dia. = ~5.4"

........and since it's a Tractrix, preferably ~ 1.5 octaves IMO, or ~565 Hz:

throat dia. = 1"
axial length = 6.625"
mouth dia. = ~7.65"

Regardless, you can't accurately input a compression driver's specs AFAIK since it is itself a 4th order band-pass speaker, so there's no way to accurately sim the driver/horn combination.

GM

a007udio · 8th September 2007, 07:32 PM

Ok. Thanks.
I get similar results with HornCalc.
Would be anything wrong if i use horn with 350 hz cut-off.

GM · 8th September 2007, 07:36 PM

You're welcome!

Well, it will beam to a lower frequency and the center to center (ctc) spacing to the mid-bass will be larger, making the sonic blend even less coherent than the smaller, higher cut-off designs.

a007udio · 8th September 2007, 07:44 PM

So no easy way to do it.
And from where i could use my De250 with such (350hz) horn idealy?

Thanks for your help.

GM · 8th September 2007, 09:46 PM

You're welcome!

Good Q and without the driver's response in a plane wave tube (PWT) it's hard to say, at least for me since I have no experience with this driver. In theory the driver's compression (rear) chamber volume (Vb) will need to be increased to make best use of the horn's extra BW with the attendant reduction of acoustic efficiency since as is it's claimed to be designed for a 1600 Hz XO point, though for HIFI apps we can fudge this to a bit lower point and EQ it flat since we don't need a prosound's high SPL/protection requirements.

So lacking any other info, you can try it on a 350 Hz Tractrix with a > 990 Hz XO and EQ it ~flat in a HIFI app since the CC is tuned to a 1 kHz - up published BW and my SWAG is it will only handle ~30 W peak.

a007udio · 11th September 2007, 12:22 PM

I looks that i will buy a horn and not to made by my self.
Is there any good soruce of horns out there?

I was looking this one:

http://www.partsexpress.com/pe/showd...number=270-310

Any good?

Thanks.

Brett · 11th September 2007, 12:33 PM

Quote:

Originally posted by a007udio
I looks that i will buy a horn and not to made by my self.
Is there any good soruce of horns out there?

I was looking this one:

http://www.partsexpress.com/pe/showd...number=270-310

Any good?

It's not a trax, and has a threaded insert, so you'll need an adaptor for a bolt on driver. I don't like adaptors.

Other sources
http://www.stereo-lab.de/
http://cgi.ebay.com.au/Neu-STATE-OF-...QQcmdZViewItem
www.ddshorn.com - ENG 1-90 Pro

el`Ol · 11th September 2007, 02:25 PM

Here is the FR graph of a DE250 in a Supravox horn. Probably hard to beat.
http://www.supravox.fr/mesures/mespav1p1.htm

a007udio · 12th September 2007, 05:40 AM

I was looking links above. Nice horns, but prices are high.
Any cheaper alternative?
Any idea how low can i use my DE250?

8th September 2007, 04:02 PM	#1
a007udio diyAudio Member Join Date: Feb 2005 Location: earth	Round tractrix horn for my B&C DE250 I would like to make tractrix horn for my DE250. Can anyone help me? I was trie to calculate horn with HornCalc but resaults are strange. I will use DE250 from 1600Hz and up.

8th September 2007, 07:08 PM	#2
GM diyAudio Member Join Date: Jun 2003 Location: Chamblee, Ga.	Re: Round tractrix horn for my B&C DE250 Greets! Haven't tried simming a Tractrix in Hornresp, but for a 1600 Hz XO I'd want the horn to have a cut-off at least an octave below it, or ~800 Hz: throat dia. = 1" axial length = 3.75" mouth dia. = ~5.4" ........and since it's a Tractrix, preferably ~ 1.5 octaves IMO, or ~565 Hz: throat dia. = 1" axial length = 6.625" mouth dia. = ~7.65" Regardless, you can't accurately input a compression driver's specs AFAIK since it is itself a 4th order band-pass speaker, so there's no way to accurately sim the driver/horn combination. GM __________________ Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

8th September 2007, 07:36 PM	#4
GM diyAudio Member Join Date: Jun 2003 Location: Chamblee, Ga.	You're welcome! Well, it will beam to a lower frequency and the center to center (ctc) spacing to the mid-bass will be larger, making the sonic blend even less coherent than the smaller, higher cut-off designs. __________________ Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

8th September 2007, 09:46 PM	#6
GM diyAudio Member Join Date: Jun 2003 Location: Chamblee, Ga.	You're welcome! Good Q and without the driver's response in a plane wave tube (PWT) it's hard to say, at least for me since I have no experience with this driver. In theory the driver's compression (rear) chamber volume (Vb) will need to be increased to make best use of the horn's extra BW with the attendant reduction of acoustic efficiency since as is it's claimed to be designed for a 1600 Hz XO point, though for HIFI apps we can fudge this to a bit lower point and EQ it flat since we don't need a prosound's high SPL/protection requirements. So lacking any other info, you can try it on a 350 Hz Tractrix with a > 990 Hz XO and EQ it ~flat in a HIFI app since the CC is tuned to a 1 kHz - up published BW and my SWAG is it will only handle ~30 W peak. __________________ Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

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8th September 2007, 07:32 PM	#3
a007udio diyAudio Member Join Date: Feb 2005 Location: earth	Ok. Thanks. I get similar results with HornCalc. Would be anything wrong if i use horn with 350 hz cut-off.

8th September 2007, 07:44 PM	#5
a007udio diyAudio Member Join Date: Feb 2005 Location: earth	So no easy way to do it. And from where i could use my De250 with such (350hz) horn idealy? Thanks for your help.

11th September 2007, 12:22 PM	#7
a007udio diyAudio Member Join Date: Feb 2005 Location: earth	I looks that i will buy a horn and not to made by my self. Is there any good soruce of horns out there? I was looking this one: http://www.partsexpress.com/pe/showd...number=270-310 Any good? Thanks.

11th September 2007, 02:25 PM	#9
el`Ol diyAudio Member Join Date: May 2005 Location: Bavarian Forest	Here is the FR graph of a DE250 in a Supravox horn. Probably hard to beat. http://www.supravox.fr/mesures/mespav1p1.htm

12th September 2007, 05:40 AM	#10
a007udio diyAudio Member Join Date: Feb 2005 Location: earth	I was looking links above. Nice horns, but prices are high. Any cheaper alternative? Any idea how low can i use my DE250?

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