Speakerplans.com Homepage
Forum Home Forum Home > General > Feedback Forum
  New Posts New Posts RSS Feed - Bill Fitzmaurice - Omnitop 12s (built by Insomnia)
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Bill Fitzmaurice - Omnitop 12s (built by Insomnia)

 Post Reply Post Reply Page  <1 34567>
Author
Message
Timebomb View Drop Down
Old Croc
Old Croc
Avatar

Joined: 11 October 2004
Location: Lancaster
Status: Offline
Points: 2691
Post Options Post Options   Thanks (0) Thanks(0)   Quote Timebomb Quote  Post ReplyReply Direct Link To This Post Posted: 11 May 2008 at 12:26am
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.  
James Secker          facebook.com/soundgearuk
James@soundgear.co.uk               www.soundgear.co.uk
Back to Top
Disco Stu View Drop Down
Old Croc
Old Croc


Joined: 03 March 2005
Location: United Kingdom
Status: Offline
Points: 2475
Post Options Post Options   Thanks (0) Thanks(0)   Quote Disco Stu Quote  Post ReplyReply Direct Link To This Post Posted: 11 May 2008 at 12:48pm
Originally posted by norty303 norty303 wrote:

, you need to be hitting the resonant frequecy of the bowel, and that is in the 7-10hz range, something that they were a looooong way from in the tests.  Although they had a nice lot of Meyer cabs there, none of those were suited to producing such a low frequency with any sort of efficiency.
 


This is true, just use a church organ pipe, easiest way.

Stu
All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output

My acts:
www.myspace.com/thebowiexperience
www.myspace.com/scheisseelektronisches
Back to Top
Disco Stu View Drop Down
Old Croc
Old Croc


Joined: 03 March 2005
Location: United Kingdom
Status: Offline
Points: 2475
Post Options Post Options   Thanks (0) Thanks(0)   Quote Disco Stu Quote  Post ReplyReply Direct Link To This Post Posted: 11 May 2008 at 12:55pm
Originally posted by Timebomb Timebomb wrote:


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.  


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
All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output

My acts:
www.myspace.com/thebowiexperience
www.myspace.com/scheisseelektronisches
Back to Top
Steak'n'ale View Drop Down
Registered User
Registered User


Joined: 31 January 2008
Status: Offline
Points: 165
Post Options Post Options   Thanks (0) Thanks(0)   Quote Steak'n'ale Quote  Post ReplyReply Direct Link To This Post Posted: 11 May 2008 at 11:04pm
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.
Back to Top
Disco Stu View Drop Down
Old Croc
Old Croc


Joined: 03 March 2005
Location: United Kingdom
Status: Offline
Points: 2475
Post Options Post Options   Thanks (0) Thanks(0)   Quote Disco Stu Quote  Post ReplyReply Direct Link To This Post Posted: 12 May 2008 at 12:42am
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
All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output

My acts:
www.myspace.com/thebowiexperience
www.myspace.com/scheisseelektronisches
Back to Top
Steak'n'ale View Drop Down
Registered User
Registered User


Joined: 31 January 2008
Status: Offline
Points: 165
Post Options Post Options   Thanks (0) Thanks(0)   Quote Steak'n'ale Quote  Post ReplyReply Direct Link To This Post Posted: 12 May 2008 at 10:26am
Sheffield/Manchester. Whats this PU adhesive? When I used to build with Davey T we used PVA and it worked ok.
Back to Top
toastyghost View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 09 January 2007
Location: Manchester
Status: Offline
Points: 10292
Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 12 May 2008 at 12:48pm
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.
Back to Top
Disco Stu View Drop Down
Old Croc
Old Croc


Joined: 03 March 2005
Location: United Kingdom
Status: Offline
Points: 2475
Post Options Post Options   Thanks (0) Thanks(0)   Quote Disco Stu Quote  Post ReplyReply Direct Link To This Post Posted: 12 May 2008 at 6:46pm
Originally posted by Steak'n'ale Steak'n'ale wrote:

Sheffield/Manchester. Whats this PU adhesive? When I used to build with Davey T we used PVA and it worked ok.


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


All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output

My acts:
www.myspace.com/thebowiexperience
www.myspace.com/scheisseelektronisches
Back to Top
Tony Insanity View Drop Down
Registered User
Registered User


Joined: 06 January 2008
Location: United Kingkong
Status: Offline
Points: 236
Post Options Post Options   Thanks (0) Thanks(0)   Quote Tony Insanity Quote  Post ReplyReply Direct Link To This Post Posted: 01 June 2008 at 9:22pm

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
.....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...
Back to Top
Disco Stu View Drop Down
Old Croc
Old Croc


Joined: 03 March 2005
Location: United Kingdom
Status: Offline
Points: 2475
Post Options Post Options   Thanks (0) Thanks(0)   Quote Disco Stu Quote  Post ReplyReply Direct Link To This Post Posted: 01 June 2008 at 9:42pm
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
All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output

My acts:
www.myspace.com/thebowiexperience
www.myspace.com/scheisseelektronisches
Back to Top
djscooby View Drop Down
Young Croc
Young Croc
Avatar

Joined: 15 March 2008
Location: United Kingdom
Status: Offline
Points: 1399
Post Options Post Options   Thanks (0) Thanks(0)   Quote djscooby Quote  Post ReplyReply Direct Link To This Post Posted: 03 January 2010 at 11:44pm
Does anybody have the plans for the omnitop12s and omnitop15s please fancy havin them built for me
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
Back to Top
Strange Daze View Drop Down
Old Croc
Old Croc


Joined: 14 July 2006
Location: United Kingdom
Status: Offline
Points: 2861
Post Options Post Options   Thanks (0) Thanks(0)   Quote Strange Daze Quote  Post ReplyReply Direct Link To This Post Posted: 04 January 2010 at 4:41pm

Originally posted by djscooby djscooby wrote:

Does anybody have the plans for the omnitop12s and omnitop15s please fancy havin them built for me


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
Back to Top
 Post Reply Post Reply Page  <1 34567>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.094 seconds.