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Building some horns


luckylou

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hello to all and may all be well hope all had a good thanksgiving , Well this is my point I'm at a point that i want to built some speakers and i come a cross a pair of Tractrix circular horns cf 350Hz for a 1" driver the spec on them are

Horn cut off frequency fc: 350 Hz or higher

Throat (diameter): 1" (25,40 mm)

Mouth (diameter): 13.5" (340mm)

Horn length: 13.8" (350mm)

Now I'm new to all this but I'm doing my research and finding out many things does any one have any suggestion on what would work well with this , also do i need to get tweeters and crossovers this is a project that has me where i seek all the best advice i can get and make the best of it all. .

I know i need tweeters and bottoms for them at the present moment nothing is in hand yet but I have come up with some plans to built .

By the way is there a way that i can use my 3.2 that I have and add these to them . I'm in a world of need of good advice .

So all you DYI guys out there your in put will help .

post-33284-13819427565508_thumb.jpg

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Good luck on your project. You will need to make several decisions ahead of time.

Is this a two-way or a three way system? What are your priorities regarding: low frequency extension, efficiency, cabinet size? Is this for music or home theater? How loud do you play the sound and do you have a large room or flexibility in how you locate the speakers, will you be adding a sub-woofer?

You probably need to prioritize this list before you start designing things. A good resource is the forum at DIYAudio. Just make sure you think through your questions and how best to ask them before you start posting. Depending on how much design you will be doing, you probably want to get a copy of the HORNRESP software.

In any case, this should be a fun project.

-Tom

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IMO you won't need tweeters if you use a compression driver capable of extended highs when properly EQed or "compensated" as they say. There are many such drivers around----Altec 802-902, GPA 902, JBL 2420-27, various B&C, Radian, 18Sound and BMS drivers among others.

You need to choose the type of overall system you want--whether you want direct radiating or horn loaded bass, whether you want to go 2-way or 3-way. Then having chosen a goal you have to figure out how to do it.

Your easiest was to go would be a 2-way with a good high efficiency-high output woofer (most likely a 15) in a vented box crossing over in the 500-1200hz range to a 1" compression driver on those horns you like. The crossover is the hard part but if you model your speaker on a known speaker like the Altec Nineteen or JBL 4430 you can copy the much publicized crossovers of those speakers and get in the ballpark. Or use an active crossover and active EQ.

What I would do would be to build 2-ways with 15" woofers in vented boxes. I'd use the Altec-GPA 416 woofer combined with the Altec-GPA 902 compression driver (GPA is the company that now makes the old "real" Altec gear, it's the same stuff but you can buy GPA new whereas Altec must be found used) or I'd use the JBL 2226 woofer with the JBL 2426 compression driver. There are other good combinations but I've experience with those.

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I think so check out his completed listings 180hz, 250hz, 350hz, 500hz. If they sound as good as they look :) He is great about answering questions.

Check out the big blue eliptical.

http://completed.shop.ebay.com/merchant/tsa-horns_W0QQLHQ5fCompleteZ1QQ_flnZ1QQ_trksidZp3911Q2ec0Q2em283

Sweeeeet!

That looks perfect for a K Horn bass bin. So, who is going to be first?
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Word on the street is that these horns have bad quality control and teh flare rate does nto match the mouth opening.  I am going to avoid them and build my own rectangle horns. 

Thanks that is very good to know. The stereo labs DJK suggests aren't much more and have a good rep.

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"but the claimed 400hz is not shown "

You seem to be confusing cut-off frequency with where it can be used.

An exponential horn may be reactance anulled to be useable to the 1/4W cut-off frequency, a tractrix may not.

A good rule-of-thumb for HF horns is to only use them above their 1/2W point, or about 565hz for the (advertised) 400hz horn. I was intending to use the 400hz version ( 2" throat) at 600hz with the CLS M200.

The (advertised) 250hz horn looks to be useable above 350hz or so (Klipschorn).

Another one to look at are the JABO, the 'B' versions are the best. Earlier versions require some damping.

http://cgi.ebay.com/Hoerner-Jabo-KH-50-B-Kugelwellenhoerner-fuer-Altec_W0QQitemZ220327076784QQcmdZViewItemQQptZDE_Lautsprecher_Martin?hash=item220327076784&_trksid=p3911.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

The KH-50 looks big enough to cross at 400hz (with the added length of an adaptor for a K55V) with a deeper old style 2" driver (JBL, EV-DH1A, etc). Shallow 'pancake' style drivers would need to be crossed a bit higher, say 500hz.

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"but the claimed 400hz is not shown "

You seem to be confusing cut-off frequency with where it can be used.

An exponential horn may be reactance anulled to be useable to the 1/4W cut-off frequency, a tractrix may not.

A good rule-of-thumb for HF horns is to only use them above their 1/2W point, or about 565hz for the (advertised) 400hz horn. I was intending to use the 400hz version ( 2" throat) at 600hz with the CLS M200.

The (advertised) 250hz horn looks to be useable above 350hz or so (Klipschorn).

Another one to look at are the JABO, the 'B' versions are the best. Earlier versions require some damping.

http://cgi.ebay.com/Hoerner-Jabo-KH-50-B-Kugelwellenhoerner-fuer-Altec_W0QQitemZ220327076784QQcmdZViewItemQQptZDE_Lautsprecher_Martin?hash=item220327076784&_trksid=p3911.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

The KH-50 looks big enough to cross at 400hz (with the added length of an adaptor for a K55V) with a deeper old style 2" driver (JBL, EV-DH1A, etc). Shallow 'pancake' style drivers would need to be crossed a bit higher, say 500hz.

Thanks for the info but in laymen's terms please. 1/4w and 1/2w - what is the "w" so that I can do the calcs? Is that an octave? How do you arrive at 565 hz for this 400 HZ horn?

I have asked this question a bunch of times and your is the best answer so far. I was told before that about 1/2 octave below the cutoff frequency is what I need, or 300 hz for a 400 hz cutoff (200 to 400 being the octave below the cutoff frequency).

It looks like I either need the 250 hz horn or need to build a 300 hz (or so) horn for the K Horn, for a 400 Hz cutoff, which is still the ragged lower edge for cutoff for most 1" drivers (I have JBL 2470's).

These are some great links. Any more that you know of?

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