Bill Fitzmaurice - Omnitop 12s (built by Insomnia) |
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Timebomb
Old Croc Joined: 11 October 2004 Location: Lancaster Status: Offline Points: 2716 |
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I remember watching that episode of mythbusters and thinking that an
engineer sent from meyer should be a bit more objective in his
experements, his test blantntly didnt proove anything but reconed he
did. I seem to remember they had the same guy on to prove a ducks
quack does eco, took him about 5 trys, seemed like a qwack has no clear
impusces do dificult to distinguish between the source and the
reverberation.
How do the omnitops sound in the low mids stu? Im interested how tight the kick range is on these with it being a ported short horn with no real frount chamber rarther than a long horn, the DRs sound really nice in the kick range but you have to run them down to about 90Hz to get that nice kicky effect from them, unfortunatly this eats up headroom with most dance music so i cross them higher a lot of the time. |
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James Secker facebook.com/soundgearuk
James@soundgear.co.uk www.soundgear.co.uk |
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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This is true, just use a church organ pipe, easiest way. 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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Well I would expect the DRs to be better in this regard, the horn loading provides support to much lower down in the frequency range, the OT12 starts to lose its horn support below 200Hz, thats not to say its not still good in that range, but I dont think it would have as much clout as a DR300 down there. The reason I went for the OTs over the DRs is simply because proportionally the box is a lot more scaleable to the application. I dont always do gigs that would require a DR250/280 so I stuck it with the OTs. Much smaller boxes and a not unreasonable 104dB on paper down to 200Hz and 12dB rolloff below that, pretty reasonable for the box size. Its a ported horn but the port is really providing support at 60Hz, to help control excursion and keep the reflex portion of the box in operation to as low a frequency as possible. Its essentially the same as a 4560. 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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Steak'n'ale
Registered User Joined: 31 January 2008 Status: Offline Points: 165 |
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Righto. I've bought the plans. Just been trying to find some decent 12mm ply to no avail. Any ideas? I'm sure suppliers must be on here somewhere but I can't find any.
I'm just surprised the plans came in inches! When it comes to doing a metric/imperial conversion what tolerance should I use? nearest mm? 0.1mm? I'm slightly unsure how accurate my cuttings going to be. |
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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1/2" = 12mm
So long as all the bits fit together snugly thats all that matters, just stick to inches, draw the parts out and use lots of polyurethane adhesive. Where are you based? 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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Steak'n'ale
Registered User Joined: 31 January 2008 Status: Offline Points: 165 |
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Sheffield/Manchester. Whats this PU adhesive? When I used to build with Davey T we used PVA and it worked ok.
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toastyghost
The 10,000 Points Club Joined: 09 January 2007 Location: Manchester Status: Offline Points: 10920 |
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Steak'n'ale: PM soundsystemdan, he's halfways between Sheffield and Manc and has made Omnitops, so should be able to give you a few tips.
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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I used PVA and it worked fine, if you know you can build to tight tolerance thats fine, its only because a lot of woodworkers are noobs Bill recommends the PU adhesive which expands to fill any gaps and saves you lots of potential problems if you have an air leak in your joint that you dont put enough PVA in to fill. 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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Tony Insanity
Registered User Joined: 06 January 2008 Location: United Kingkong Status: Offline Points: 236 |
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I've just got some plans for the Omnitop 12 and initialy intend to build 4, if I like 'em I'll build another 4. Stu, you say you used the 'double element' type piezo, these: http://cpc.farnell.com/LS02368/audio-video-tv/product.us0?sku=unbranded-mpt-177
how did you wire them? did you use a resistor?
The spl on these is 99db, is that the efficiency of the ones you used?
I see some people have used these:
they are only 91db, not sure these would be as good?
I need to order the peizos and was going to get the doubles but do the singles have any advantages? Edited by Tony Insanity - 01 June 2008 at 9:28pm |
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.....you might also look for her companion, a large Chinese rabbit, who is easy to spot since he is only standing on his hind feet in the shade of a cinnamon tree...
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Disco Stu
Old Croc Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
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When I built mine melded array was not an option, but now it is THE only option in a lot of the plans so I would go with that.
Piezo sensitivity means nothing, bear in mind that the double element is just that 2x elements so its going to be 6dB louder anyway, also its not really about that you are using 12 1016 piezos in a melded array, 3x 1177 elements in series (which is 3 bank series parallel if you are using single tweeters) is enough to keep up with the woofer and give equivalent to 900W power handling. The benefit of the melded array is wider dispersion and lower frequency response which just helps to smooth the crossover point. 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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djscooby
Young Croc Joined: 15 March 2008 Location: United Kingdom Status: Offline Points: 1414 |
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Does anybody have the plans for the omnitop12s and omnitop15s please fancy havin them built for me
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Well my wife has kicked me out saying it's over due to my obsession with speakers don't know watt I'm gonna do with no ohm to go to
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Strange Daze
Old Croc Joined: 14 July 2006 Location: United Kingdom Status: Offline Points: 2861 |
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The donation is only a couple of quid on the site mate......support the designer and all that :) Toasty.....Dan's OmniTops are awesome. Such a SUPER light cabinet, even when loaded. I love them to pieces. By far the nicest sounding sub <£200 box you can make in my opinion. Edited by Strange Daze - 04 January 2010 at 4:42pm |
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