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B Mo
Registered User Joined: 20 May 2005 Location: Afghanistan Status: Offline Points: 4 |
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Posted: 20 May 2005 at 10:03pm |
Does anyone know what happens when you eliminate the baffle and front load the driver in the space currently reserved for the access panel in the HD 15 horn ?
Edited by B Mo |
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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er im not sure I understand what you mean do u mean mount the driver in the baffle from the other side making the access panel on the back wall?
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All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
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B Mo
Registered User Joined: 20 May 2005 Location: Afghanistan Status: Offline Points: 4 |
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I was thinking of eliminating the baffle altogether and mounting the speaker where the access panel is now... facing outward. I would aim the front of the speaker at the audience and use the horn-assist segment as a 4th order band pass filter... I think... I'm afraid I'm just not enough of a designer and mathematician to figure this one all the way out ! My original thought was that there are several affordable 15" coax units available that would reach awesome SPL's (with somewhat predictable pattern control) for very little investment - if the advantages of the 'short horn' could be assimilated into the design ? |
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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Is this what you mean ? If so where is the rear of the driver going except into the ground? Youd either have to extend the cabinet downwards to create some weird scoop thing which has been done before or i suppose if the cabinet was placed on the floor and raised up on some short 6 inch or so legs, the floor would help with boundary loading to increase the perceived mouth size and lower the cutoff Are you thinking of this for Hi fi or PA use? Stu |
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All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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here is what i mean about the scoop Stu |
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All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
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B Mo
Registered User Joined: 20 May 2005 Location: Afghanistan Status: Offline Points: 4 |
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Yes ! That's it ! You are a mighty and patient person for dealing with this beginner... thank you, DS ! I was thinking of simply flipping the whole box on its side in order to avoid the weird scoop thing. Since bass is supposed to be omnidirectional, I didn't think it would matter if the horn fired at a ninety degree angle to the speaker... ? I was hoping to use one or two pair of HD 15's per side for a small band PA. I read 'horm vs. reflex' in the FAQ section and I'm very familiar with the standard 218 bottom/215H top box config. However, in terms of SPL delivered in return for for size, weight and power requirements, the HD 15 seems to be unequaled. Edited by B Mo |
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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Mighty and patient i think not! Anyway I havnt a clue what the output of that thing would end up being but my concerns would be these:
Alternatively other cabs of similar size that have had pretty good responses are: Bill fitzmaurices tuba subs www.billfitzmaurice.com Staipers ES18BPH http://groups.msn.com/SpeakerBuildingpics/shoebox.msnw?actio n=ShowPhoto&PhotoID=19 They are very different beasts the tubas cost a small amount to download but i would go for a tuba 30 over a tuba 24 if you do as the recommended drivers are easier to get hold of if you live in the UK and of course you can get a higher maximum output. The tubas are a bit more fiddly to build than staipers plan but staipers plan is a bigger version of the HD15 essentially and as such has a bit more extension and a bit more grunt Stu |
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All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
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Timber_MG
Registered User Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
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To be fair he wanted to use co-ax drivers. To realize beneits of
horn-loading you need a large mouth and a stack of co-axes won't
exactly integrate nicely. Methinks it might be wiser to go multi-way or
if you are really keen just go bass-reflex (if you're lookign for that
small a cab)
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freddyi
Registered User Joined: 22 September 2004 Status: Offline Points: 936 |
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sounds like resulting scoop would be close to JBL C34 - might help to use slower flare - more like hyperbolic
C34 http://www.lansingheritage.org/html/jbl/plans/C34.htm |
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B Mo
Registered User Joined: 20 May 2005 Location: Afghanistan Status: Offline Points: 4 |
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Actually... I don't have the acumen or the computer resources to accurately determine the response of the resulting horn/band pass device. I would lose the bent wood altogether in favor of a piece of treadplate - simply bent to the spec required and routered into the sides of the plywood - to maximize the bass response of a specific speaker in the available enclosure. If I could lay hands on the math. With this in mind, how about a 12" coax in the same enclosure ? It's just that I love the 'horn sound' and the efficiency is irresistable to a guy who often has a single, 20 or 30 amp circuit to run the whole show on ! I think I'll take Stu's advice and build one for the sake of experimentation. If nothinkg else, I can just make the initial horn entrance larger and smaller by way of changing the mouth ratios and see what happens ! You guys are great. Thanks ! |
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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Lol it always amazes me how people come up with new ideas from existing things. If you are gonna build it coax drivers might be too deep for the cabinet so be careful. I dont really understand why you dont just go for an existing design which works but anyway. Btw you can run a whole band PA including backline off of 1 13amp socket no sweat. Just take the lights off a different circuit. Some say its playing with fire running guitar, bass, keys and PA off of one socket but sometimes one socket is all thats available. Stu |
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All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
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tb_mike
Old Croc Joined: 01 October 2004 Location: New Zealand Status: Offline Points: 2744 |
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I think part of the luck is,that the peaky nature of music prevents the fuses/breakers from tripping rather than constant load systems like 2.4kw heaters.
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