Horn Loudspeaker

[julian.weir]

Hi there. We have constructed a matching pair of horn loudspeakers as published in the Elektor Electronics magazine in May 1990 (pages 20-23). We have recently tested the speakers with a frequency analyser and found the low frequencies roll off at around 315 Hz, somewhat higher than expected and higher than the response indicated in Fig 2 of the article. Is anyone able to provide clarification of the following:

1. In Fig 2 of the article there are two response curves. Which one is the measured response of this unit? What is the other curve for? This figure isn’t referred to in the article.

2. Has there been any modifications or amendments to this design submitted or published that might answer our problem with lack of low frequency response?

Any suggestions or information would be very much appreciated.

 

[michiel]

Before i can say something i have some questions.

Can you post the response curves from the article?
What is the horn lenght, mouth/throat area and curve?
Wich driver do you use?

 

[julian.weir]

I have attached a jpeg pdf of the response curve (sorry had to keep quality low for file size limit on this web site).

Mouth/throat area less than 0.125 m^2.
Horn length unsure (can post construction diagram if desired)
Box volume of about 100 litres

The following woofer has been installed in the horn…

http://www.altronics.com.au/index.asp?area=item&id=C3060

I hope this is enough. Thanks.

 

[julian.weir]

Here is the construction diagram

 

[mike.e]

The second graph is impedence vs frequency,and the last is impulse response.

Perhaps the driver is entirelly illsuited to this horn. I wouldnt expect such a high cutoff. Are you sure the driver is sealed properly?

The horn is quite small,and seems to require corner loading.

 

[julian.weir]

Thanks. Will look into this.