BFM Omni 10 build

[peted]

Afternoon Bass Chatters,
I'm the the midst of my first BFM Omni 10 build. I haven't bought any of the speaker parts or taken any photos yet as I'm not entirely convinced my 'engineering tolerances' will mean it all fits together properly.

I was planning on going with Blue Aran (http://www.bluearan.co.uk) for all my speakers, corners, paint, grill, etc. I can't find the exact piezo tweeters that Bill talks about in the build manual on the site. Can anybody point me in the direction of a stockist, or equivalent on the Blue Aran site?

Promise that I'll put pics up if it all fits together properly.

Cheers.

Edited July 15, 2008 by peted

[Dood]

You can buy Piezo tweeters from Maplin shops (or via maplin.co.uk) I used to have two in a bass cab many years ago.. Very simple to rig up and cheap as chips!

[Sugden]

Tweeters From CPC, theres where I got mine, and mostly everyone else does as well. Plus there in stock which is a bonus. Item numbers LS02367

and link:

[url="http://cpc.farnell.com/LS02367/audio-video-tv/product.us0?sku=unbranded-mpt-016&_requestid=380717"]HERE[/url]

[bremen]

[quote name='Sugden' post='211127' date='Jun 2 2008, 02:35 PM']Tweeters From CPC, theres where I got mine, and mostly everyone else does as well. Plus there in stock which is a bonus. Item numbers LS02367

and link:

[url="http://cpc.farnell.com/LS02367/audio-video-tv/product.us0?sku=unbranded-mpt-016&_requestid=380717"]HERE[/url][/quote]

I have no direct experience of this, so forgive me for repeating hearsay, but apparently the Motorola branded units are a lot better than the unbranded ones that Maplin, CPC etc. sell.

[url="http://www.audiokarma.org/forums/showthread.php?t=79659"]http://www.audiokarma.org/forums/showthread.php?t=79659[/url]

edit: Oh well, probably not much in it. Good luck.

Edited June 2, 2008 by bremen

[peted]

Thanks Peeps! I'll check out Maplins and CPC tonight. I'll also take a quick photo of my woodwork 'attempts' tonight so this thread is more be-fitting its place in the p0rn section. I tell you now... it isn't pretty.

[peted]

Well, I've taken the full plunge and ordered all the hardware and bits for my CAB. Here's the woodwork so far...
[attachment=9270:OMNI10_01.JPG]
[attachment=9271:OMNI10_02.JPG]

I have yet to do the 60 degree cuts on the horn fronts. I'm dredding them

[peted]

All the hardware turned up today from Blue Aran and CPC (thanks again Sugden for the recommendation). Weather outside is no good for more cutting, so i've just balanced some bits together for a photoshoot.
[attachment=9331:OMNI10_03.JPG]
[attachment=9332:OMNI10_04.JPG]

[thinman]

I used the CPC piezos in my Omni10 and they're fine.

However, invest in a tube of silicone (black's best if you can find it - try a builder's merchant) and seal the piezos up. Mine had three quite big gaps near each screw that holds the horn to the back part. Cover the seam and those holes with silicone and use a bit more to seal the piezos onto the baffle when you fit them. It's really important to make them airtight else you'll get all sorts of odd whistles.

Also, if you're putting handles on the sides, don't do what I did and put them mid-way between front and back - they're much better mounted at the balance point which is nearer the back - mine's not too comfortable to carry as it is.

[peted]

[quote name='thinman' post='212799' date='Jun 4 2008, 10:15 PM']I used the CPC piezos in my Omni10 and they're fine.

However, invest in a tube of silicone (black's best if you can find it - try a builder's merchant) and seal the piezos up. Mine had three quite big gaps near each screw that holds the horn to the back part. Cover the seam and those holes with silicone and use a bit more to seal the piezos onto the baffle when you fit them. It's really important to make them airtight else you'll get all sorts of odd whistles.

Also, if you're putting handles on the sides, don't do what I did and put them mid-way between front and back - they're much better mounted at the balance point which is nearer the back - mine's not too comfortable to carry as it is.[/quote]
I was already planning on squirting a bit of silicone sealant around the joints of the piezos, and toying with the idea of a silicone seal around the piezo/cab join itself. Thanks for the heads-up.

I haven't decided on handles yet. I'm equiping this with Eminence Deltalites so I'll see how heavy it is at the end of the build and have a think then.

[thinman]

[quote name='peted' post='213106' date='Jun 5 2008, 12:19 PM']I was already planning on squirting a bit of silicone sealant around the joints of the piezos, and toying with the idea of a silicone seal around the piezo/cab join itself. Thanks for the heads-up.

I haven't decided on handles yet. I'm equiping this with Eminence Deltalites so I'll see how heavy it is at the end of the build and have a think then.[/quote]
I've got those drivers and it still weighs enough that without handles it would be an awkwardly big box to grapple with. You definitely need something to grab hold of.

[TDM]

(Unintended thread hijack)

I've seen a lot of Omni 10 builds around here lately. Do you just buy the plans from BFM and source all of the speakers, plywood, tolex etc yourself and build it according to his dimensions?

How hard is it for someone with basic woodworking skills? It says "Construction Degree of Difficulty: 3" on his site, but I guess that doesn't really mean anything if you don't have anything to compare it to.

[david_l_perry]

[quote name='thedonutman' post='213513' date='Jun 5 2008, 10:10 PM'](Unintended thread hijack)

I've seen a lot of Omni 10 builds around here lately. Do you just buy the plans from BFM and source all of the speakers, plywood, tolex etc yourself and build it according to his dimensions?

How hard is it for someone with basic woodworking skills? It says "Construction Degree of Difficulty: 3" on his site, but I guess that doesn't really mean anything if you don't have anything to compare it to.[/quote]

I have built lots of Bills plans and used them for PA/Bass backline and they work very well.

You buy the plans from Bills site (order and pay him via paypal)
Bills instructions are fantastic, and are certainly not just a set of dimensioned plans. The omni 10 plans for example are about 34pages long, with complete photos of each and every step of construction as well as alternate model variations (omni10.5, omni 10 wide body crossfired piezo's). They walk you through each and every step of the plans bit by bit. Worth every penny.

You source all of the parts yourself, but none of them are hard to obtain. In fact the whole theory behind Bills plans is to utilise standard inexpensive components in a well designed cab, to get the most out of them. The only thing that was initially hard to source was the 'PL glue', but screwfix has it and other sources too (check Bills forum 'hints and tips section' for uk sources of parts)

I would say to build the Omni you need very basic skills. As long as you can use a jigsaw, and drill, you should be good to go. A Circular saw is a very worth while investment, but even a cheap one will make a difference (replace the standard rough blade with ones with more teeth for better cuts)

Omni 10 'wide body' :-


Omni 10 'wide body' next to a typical 2x10 (old peavey 210TX)


My Flock of DR280's


Titan 48's


DR280 bass stack


My latest Omni 15 Bass cab


And just to confirm the post responses again, CPC is the best source as listed. I did a considerable amount of testing of different sources of Piezos, and found not all cheap piezo's are the same (as was originally thought on Bills site)....The CPC unbranded came out on top of the cheap batches, and I would not suggest using anything else. WLE/Skytronic piezos are utter crap. 8 CPC piezos outstripped 12WLE piezos not just in SPL but [i]massively [/i]in freq response.

Dave

Edited June 6, 2008 by david_l_perry

[bremen]

[quote name='david_l_perry' post='213646' date='Jun 6 2008, 09:06 AM']And just to confirm the post responses again, CPC is the best source as listed. I did a considerable amount of testing of different sources of Piezos, and found not all cheap piezo's are the same (as was originally thought on Bills site)....The CPC unbranded came out on top of the cheap batches, and I would not suggest using anything else. WLE/Skytronic piezos are utter crap. 8 CPC piezos outstripped 12WLE piezos not just in SPL but [i]massively [/i]in freq response.

Dave[/quote]

cheers for that clarification.

Is there any way to be sure that the unbranded CPC units I get are the same as yours, ie any distinguishing markings?

[david_l_perry]

[quote name='bremen' post='213692' date='Jun 6 2008, 10:20 AM']cheers for that clarification.

Is there any way to be sure that the unbranded CPC units I get are the same as yours, ie any distinguishing markings?[/quote]

Indeed. The typical SKytronic ones and the ones I see on ebay a lot of have a ribbed outer line (for her pleasure...) around the horn

Here is the skytonic one:-


These are crap.....and should be burnt on site. To be fair they do work, just not as good as the CPC ones.

The CPC ones are just flat fronted. I always get mine form CPC and they have never varied at all. I will be getting some next week to make some melded arrays up for a guy on Bills forum and will post if they are any different than usual.

CPC piezo's:-



Dave

Edited June 6, 2008 by david_l_perry

[peted]

My father and I did some more work last Sunday. It's really taking shape now. Had some trouble putting it all together as some of the pieces were a little 'rough' with the measurements. Went together with a fair amount of pulling and tugging.
[attachment=9525:OMNI10_05.JPG]
[attachment=9526:OMNI10_06.JPG]

The hardware:
[attachment=9527:OMNI10_07.JPG]

[jamesf]

[quote name='david_l_perry' post='213646' date='Jun 6 2008, 09:06 AM']The only thing that was initially hard to source was the 'PL glue', but screwfix has it and other sources too (check Bills forum 'hints and tips section' for uk sources of parts)[/quote]

I got my PU adhesive from B&Q - it came in a caulking-gun cartridge, and one tube did an omni 10 and two omni 10.5's. It's called Evostik Resin - Polyurethane Wood Adhesive and is phenomenal stuff which expands in the gaps, and dries fully in 24 hours. I spent several days sand-papering it off my hands after the first session with it, it's seriously good stuff!! only about £9 as well.

[thinman]

[quote name='jamesf' post='217136' date='Jun 11 2008, 07:41 PM']I got my PU adhesive from B&Q - it came in a caulking-gun cartridge, and one tube did an omni 10 and two omni 10.5's. It's called Evostik Resin - Polyurethane Wood Adhesive and is phenomenal stuff which expands in the gaps, and dries fully in 24 hours. I spent several days sand-papering it off my hands after the first session with it, it's seriously good stuff!! only about £9 as well.[/quote]
If you're buying other stuff so as to offset the P&P try www.toolstation.com or www.screwfix.com for the polyurethane. It's about £4.50 from them. Stuff like drywall screws very cheap from them too.

[david_l_perry]

[quote name='jamesf' post='217136' date='Jun 11 2008, 07:41 PM']I got my PU adhesive from B&Q - it came in a caulking-gun cartridge, and one tube did an omni 10 and two omni 10.5's. It's called Evostik Resin - Polyurethane Wood Adhesive and is phenomenal stuff which expands in the gaps, and dries fully in 24 hours. I spent several days sand-papering it off my hands after the first session with it, it's seriously good stuff!! only about £9 as well.[/quote]

The stuff from screwfix cost £5.95
[url="http://www.screwfix.com/prods/30590/Sealants-Adhesives/Adhesives/Wood-Glues/Polyurethane-Adhesive/Joiners-Mate-Adhesive-310ml"]screwfix adhesive[/url]

[david_l_perry]

Forgot about this stuff. Its what I used on my last set of Titans / Omni's
Its cheaper than screwfix and performs better:-
[url="http://www.tool-net.co.uk/p-324986/everbuild-lumberjack-5-minute-wood-adhesive-gel-310ml.html"]lumberjack adhesive £3.20/tube[/url]

[peted]

OK. This weekend I've fitted the top and bottom horn flanges, cut out the woofer baffle, filled the screw holes, and given the whole thing a thorough sanding.

Another question: Where do people get their 4 Ohm 20 Watt wire-would resisters from? I tried to order one of [url="http://cpc.farnell.com/RE01658/components-spares/product.us0?sku=welwyn-wh10-3r3-ji&_requestid=435615"]these[/url] with the other gear from CPC but it was out of stock and hasn't been in stock since. Any ideas?

I'll post up more picks when the woodwork is pretty much finished. Thanks.

[david_l_perry]

[quote name='peted' post='229769' date='Jun 30 2008, 03:11 PM']OK. This weekend I've fitted the top and bottom horn flanges, cut out the woofer baffle, filled the screw holes, and given the whole thing a thorough sanding.

Another question: Where do people get their 4 Ohm 20 Watt wire-would resisters from? I tried to order one of [url="http://cpc.farnell.com/RE01658/components-spares/product.us0?sku=welwyn-wh10-3r3-ji&_requestid=435615"]these[/url] with the other gear from CPC but it was out of stock and hasn't been in stock since. Any ideas?

I'll post up more picks when the woodwork is pretty much finished. Thanks.[/quote]

I ended up using a 10w resistor on my Omni 10, Omni 15 and wedgehorn, no problems.
Contact John here for all your bits n bobs:-
[url="http://www.audio-components.co.uk/store/category.asp?CategoryID=2"]UK Audio components[/url]

[clauster]

Thanks for that link David, I'd been wondering where to source crossove components.

[KennysFord]

apologies for hijacking but the seems to be the best point to ask,
where does it tell you in the plans about the wiring,in particlar about things like resistors etc,i fancy a go at an Omni 10 but the electronic side of things is a bit daunting.
apologies again.

[Hamster]

[quote name='kennyrodg' post='230322' date='Jul 1 2008, 09:50 AM']apologies for hijacking but the seems to be the best point to ask,
where does it tell you in the plans about the wiring,in particlar about things like resistors etc,i fancy a go at an Omni 10 but the electronic side of things is a bit daunting.
apologies again. [/quote]

The plans have diagrams to show you how to wire the speakers / tweeters in series and/or parallel, and tell you where to put the resistor in the circuit.

Hamster

[peted]

[quote name='kennyrodg' post='230322' date='Jul 1 2008, 09:50 AM']apologies for hijacking but the seems to be the best point to ask,
where does it tell you in the plans about the wiring,in particlar about things like resistors etc,i fancy a go at an Omni 10 but the electronic side of things is a bit daunting.
apologies again. [/quote]
Page 18 explains about how to best wire the tweeters and mentions the use of the resister in series to prevent damage to cheap amplifiers.