12" Tapped Horns? |
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FlipC
Young Croc Joined: 25 October 2007 Status: Offline Points: 654 |
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Uh
if you are referring to what I was thinking about, then No it is not. Here's is a link:http://geocities.com/loudspeakerguru/Jeff_Bass_Bin.gif Turns out it wasn't a pic I had saved. |
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Sheggy
Old Croc Joined: 23 May 2008 Location: London Status: Offline Points: 1989 |
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I think I see what you're saying about steps in the BH760 DB. Do you think the steps would cause turbulence at the higher frequencies? I would keep it strictly sub.
I've sketched out ways to fold Walt's stepped horn but none of mine look too good: they seem to increase the overall size of the box. I should play with it more but I haven't had time yet to get into the modelling (one day tho). Speaking of increasing volume, what would be the effect on freq response and sensitivity of taking Walt's stepped horn and having a rear chamber. S |
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Deadbeat
Old Croc Joined: 12 March 2008 Location: Singularity Status: Offline Points: 3167 |
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What i meant was that steps would complicate assembly as the BH760 is effectively 'stepped' (turn your head around a bit and you'll see on the pic). TD's reasoning which is perfectly fine is that at LF, having a smooth horn path isn't so important with such large wavelengths compared to the imperfections. I agree. The only thing is that such irregularities may have you ending up with rogue air masses, but that's for another day. Besides, with such a low expansion, actual horn action isn't strictly there (the hot topic of the 'does the TH actually act as a BP in the low end' debate). The latest version of Hornresp actually allows for rear chambers on tapped horns (you can now model EV T18's and friends nicely). I'm not sure about their effect as I haven't played around with the new HR . But I have a pretty good idea of what to expect...ask someone who's used it (mobiele eenhied?). The tapped horn wizard makes modeling accessible to everyone. To be perfectly honest, it would be more fun just having a play on HR, finding something that works, and drawing it up that refolding the stepped horn. May I just ask, what kind of box are you exactly looking for? (use, etc) PS A nice little guide: |
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Away on extended leave.
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Sheggy
Old Croc Joined: 23 May 2008 Location: London Status: Offline Points: 1989 |
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I'm just looking for something more compact really. 12" tapped/stepped horns have a small footprint at the expense of height - I'm really trying to keep the characteristics of Walt's horn but improve it's portability. Oh, and also to keep the Ciare 12.00, which seems great for this.
I'll have to find the time to get to grips with Hornresp and get a feel for how a rear chamber would change things. A little more kick would be good for some styles of music. For me improved sensitivity would also be good because I (underpower) the Ciare 12 with a valve amp. Not that Walt's horn has poor sensitivity mind ... I only use the box for parties so this is just fun for me. If I can find the time I'll take on a new project in the summer and a folded TH might be the one. It would also give me the opportunity to use ply instead of MDF and put some handles on. Then someone can have the old stepped box if they want it. S Thanks for the link DB - looks like my next project |
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Volvotreter
New Member Joined: 08 February 2009 Status: Offline Points: 1 |
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What would you guys think of someting like this:
It uses the 12" which is said to be in the TH-Mini: With this predicted response: It's a pretty small box with the size of the TH-Mini. Erik |
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staiper
Registered User Joined: 26 February 2004 Location: Croatia Status: Offline Points: 545 |
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Welcome Volvotreter
I have thought that B&C 12PS100 is used in Danley TH-mini (only based on power ratings)?.. (I did not tried to simulate 12PS100 one so I do not know what it "say" ) However 12TBX100 in your simulation looks daaaamn god Edited by staiper - 08 February 2009 at 10:23pm |
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mobiele eenheid
Old Croc Joined: 15 August 2004 Location: Netherlands Status: Offline Points: 1568 |
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In case of the plot you posted which rolls of sharply at ~50 Hz, is flat above and around 105 dB/W/m. A chamber size X would result in a more gradual roll off at 43 Hz but at ~101 dB/W/m then gradually climb up towards 105 dB, which it reaches at 100+ Hz. Something like that.
You can design to get a flat response again but than you need to alter the horn length.
Best regards Johan
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MikeHunt79
Registered User Joined: 12 February 2009 Location: Bristol, UK Status: Offline Points: 352 |
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I built this 6ft 5" beast back in April:
I built it because I had the wood, driver and glue and wanted to see if tapped horns live up to the hype! In my opinion they do! Sounds nice, uses an Eminence 4012 driver which only has 6mm of xmax yet still gives a nice amount of output down to 30Hz despite the driver having a Fs of 45Hz. My only complaint is it runs out a xmax at 40Hz, but hornresp also predicts this so it didn't come as a huge suprise... Quick question, would it have be a good idea to put extra wood panels in the top corners at 45 degrees? Am I losing output by the sound bouncing back from the top panel? (I only thought about this after gluing the final panel on!) I hope to build another one which will go down to 40Hz, but have higher output... When I get the time and slightly better weather... PS: Hey Volvotreter, this is the same same the Cowan 30Hz horn over at DIYaudio, I've just used a different driver to him... I've found the Eminence 4012 does a pretty good job with a TH-mini type app too, a little less SPL but a little more extension... Looks like it could be used up to 300Hz with a little EQ? It doesn't beat the B&C for output as the Eminence has less xmax and also the box is larger but it's still not huge. Edited by MikeHunt79 - 20 February 2009 at 1:18am |
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I'm English, and as such I crave disappointment. I actively seek it out.
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Deadbeat
Old Croc Joined: 12 March 2008 Location: Singularity Status: Offline Points: 3167 |
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Sounds nice, uses an Eminence 4012 driver which only has 6mm of xmax yet still gives a nice amount of output down to 30Hz despite the driver having a Fs of 45Hz. My only complaint is it runs out a xmax at 40Hz, but hornresp also predicts this so it didn't come as a huge suprise...
Perfect Fs for the job Quick question, would it have be a good idea to put extra wood panels in the top corners at 45 degrees? Am I losing output by the sound bouncing back from the top panel? (I only thought about this after gluing the final panel on!) Don't know, standing waves? What's the depth of the thing?
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Away on extended leave.
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MikeHunt79
Registered User Joined: 12 February 2009 Location: Bristol, UK Status: Offline Points: 352 |
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Nice, it was more luck than judgement really, as an existing design for a different driver happens to be suitable for a driver I had to hand. It definitely sounds different to a normal folded horn tho, more reflexy (if that's even a word)... I guess this is because the driver is visible so you get to hear a few more harmonics that would be inaudible with a folded horn.
That's the one, standing waves. I often forget the names for these things! Would it be worth using extra wood in the corners to prevent destructive interference if I was to build another? Internal depth is around 400mm. A pic speaks a 1000 words so this should make things a little clearer, this is the box I built: This design was originally posted by William Cowan on the massive Tapped Horn thread on DIYaudio, all credit goes to him! Edited by MikeHunt79 - 21 February 2009 at 3:24am |
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I'm English, and as such I crave disappointment. I actively seek it out.
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_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
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djk
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MikeHunt79
Registered User Joined: 12 February 2009 Location: Bristol, UK Status: Offline Points: 352 |
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9.1mm xmax? I'm not using that driver tho, I'm using this one: http://www.eminence.com/proaudio_speaker_detail.asp?web_detail_link=DEFINIMAX4012HO&speaker_size=12&SUB_CAT_ID=1 6.2mm, but I think that's also pretty optimistic as this driver is known to be the same as the Magnum 12ho which had 4.8mm xmax in the datasheet. |
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I'm English, and as such I crave disappointment. I actively seek it out.
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