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CNC Speaker Design
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Author:  chris1973 [ December 15th, 2017, 9:04 pm ]
Post subject:  Re: CNC Speaker Design

brombo wrote:
You might see if there is any software that can simulate your horn -

http://educypedia.karadimov.info/electr ... peaker.htm


Thanks Brombo!

So I prugged in as much information as I could understand into HORNRESP, but it was only minimumly informative.

The only thing it really told me is that the horn will fall off relatively steeply below 80 cycles, but may possibly reach above 1000. And that most of the acuostical impedance will occur between 100 and 200 cycles.

I was already in possession of this information though, just based on the length of the horn, and a little intuition.

What it didn't tell me, which Sashi eluded to, is the distortion that might be generated by the Driver/Throat Compression ratio, ( which I have now changed from 7:1 to about 3.5:1).

Author:  chris1973 [ December 15th, 2017, 9:11 pm ]
Post subject:  Re: CNC Speaker Design

On another note:

I modeled my 15" version of this horn on Hornresp, and It will make it down to almost to 50 cycles, which is perfectly acceptable to me, however the cone displacement graph for both horns shows an enormous amount of movement below 80Hz for the small horn, and 50 Hz for the big horn.

Is this in any way useable energy, or would I want to place a High Pass Filter on both, in practice, to increase my power handling?

Chris

Author:  Cogito [ December 15th, 2017, 10:20 pm ]
Post subject:  Re: CNC Speaker Design

chris1973 wrote:
brombo wrote:
You might see if there is any software that can simulate your horn -

http://educypedia.karadimov.info/electr ... peaker.htm


Thanks Brombo!

So I prugged in as much information as I could understand into HORNRESP, but it was only minimumly informative.

The only thing it really told me is that the horn will fall off relatively steeply below 80 cycles, but may possibly reach above 1000. And that most of the acuostical impedance will occur between 100 and 200 cycles.

I was already in possession of this information though, just based on the length of the horn, and a little intuition.

What it didn't tell me, which Sashi eluded to, is the distortion that might be generated by the Driver/Throat Compression ratio, ( which I have now changed from 7:1 to about 3.5:1).


The horn length is less than 50", it will not play freqs below 70Hz. What is the goal here in terms of frequency response?

The tapped horn sub I am planning to build is about 8' tall and goes down to 20Hz. Plan to cross it over at 80Hz.

Author:  chris1973 [ December 16th, 2017, 5:28 pm ]
Post subject:  Re: CNC Speaker Design

For the 10" horn to prove itself, it only needs to get to 70-80Hz, but it does need to extend over 1000Hz.

For the 15" horn, for which I haven't posted a design, if it gets to 50-60Hz, and makes it to 1000Hz, I think it's a success.

This is not a HiFi experiment. If I build any of these horns, I want to test them, and eventually place them in the hands of a local band.

Author:  Cogito [ August 19th, 2018, 10:52 am ]
Post subject:  Re: CNC Speaker Design

chris1973 wrote:
For the 10" horn to prove itself, it only needs to get to 70-80Hz, but it does need to extend over 1000Hz.

For the 15" horn, for which I haven't posted a design, if it gets to 50-60Hz, and makes it to 1000Hz, I think it's a success.

This is not a HiFi experiment. If I build any of these horns, I want to test them, and eventually place them in the hands of a local band.


Did you finish building the horn?

Author:  brombo [ August 19th, 2018, 11:02 am ]
Post subject:  Re: CNC Speaker Design

Since you are talking horns has anyone in the group done any work (analysis or build) on corner horns?

Author:  Cogito [ August 19th, 2018, 12:02 pm ]
Post subject:  Re: CNC Speaker Design

brombo wrote:
Since you are talking horns has anyone in the group done any work (analysis or build) on corner horns?


Not a traditional corner horn but I am going to try corner loading (eighth space) the 100Hz mid-bass horn and quarter space loading for every thing else.

https://www.trueaudio.com/st_spcs1.htm

Author:  chris1973 [ September 1st, 2018, 3:21 pm ]
Post subject:  Re: CNC Speaker Design

Did you finish building the horn?[/quote]


Hey Sashi,


No, I haven't. It's kind of been abandoned, but I did complete drawings for several different individual panels required to build two different sized versions (a 10", and a 15" driver).

Cost seems to be the primary obstruction. It's not necessarily the CNC part that is the problem, it's just that everybody I have talked to with the machine, wants to charge me $200/sheet, for the plywood itself.

Also, I don't really have an appropriate destination for it, or even a place to test it.

Another issue too: I'm not sure if maybe I just don't know what I'm doing, but I have been tooling around with HORNRESP for a little while, and i'm not really getting results I want. I have modeled several Tapped Horns, several Closed Back Horns, and several Transmission lines, but none of these designs have resulted in HORNRESP performance graphs that suggest they have any significant advantage over Infinite Baffle!


I also haven't posted anything in a while, and I'm not really watching any threads, because I'm a little bit confused!


I'm just trying to talk about things that are interesting to me, and I hoped they would be of interest to some other people too, but I'm really just making people mad!

I drew some pictures to explain the theoretics of Skin Effect, after I got some cool results with some Cardas wire experiments. It's simple stuff, and certainly no revelation for the engineers, but there might be people who view the site who have not seen this before.


I'm just not sure I want to post it.

Author:  Cogito [ September 2nd, 2018, 3:56 pm ]
Post subject:  Re: CNC Speaker Design

Quote:
I have modeled several Tapped Horns, several Closed Back Horns, and several Transmission lines, but none of these designs have resulted in HORNRESP performance graphs that suggest they have any significant advantage over Infinite Baffle!


If you are looking for better frequency response in horns, you will be disappointed. Typically horns are decade devices, even then too they start beaming on the higher end. In tapped horns, you will be lucky to get 2 octaves of usable bandwidth.

The reason to get horns is their sonic qualities; detailed, extremely dynamic and uncompressed sound which no other type of audio device can replicate.

Author:  brombo [ September 2nd, 2018, 4:48 pm ]
Post subject:  Re: CNC Speaker Design

You might consider an acoustic lens at the mouth of the horn to alleviate beaming. JBL used to do that.

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