BFM Omni 10 build

[peted]

I'm also hoping to pop to Homebase this week to pick up some weather-stripping to put around the baffle and back cover. My cab is going to be painted with black speaker cab 'tuff' paint.

[david_l_perry]

[quote name='kennyrodg' post='230322' date='Jul 1 2008, 09:50 AM']I fancy a go at an Omni 10 but the electronic side of things is a bit daunting.
apologies again. [/quote]

Good thing about the Omni10/10.5 is that there are no electrics to talk of, no crossover, no filter components...its simple connect the woofers and piezo's directly to the speaker input socket and off you go....Piezo's don't need a crossover.

Ok, you have the resistor but that just gets wired in line with the positive lead that feeds the piezo's. Wiring of the piezo's are all clearly marked up in the plans, and Bills forum is a great source of help and advice

Having said all that, the other designs of Bills that do need a crossover are fairly well detailed, taking the mystery away...

Dave

[KennysFord]

thanks for that guys.
i noticed the diagram for the tweeters but i missed the bit about the resistor.
i'll go take another look.

[peted]

[quote name='david_l_perry' post='230318' date='Jul 1 2008, 09:40 AM']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][/quote]
I'm building the 500 Watt Deltalite 2510 version. I'm paranoid that if I go with a resister that can handle less thermal wattage then I'm going to end up cooking it. I've ordered a 50watt 4R7 (I think that means 4.7 Ohm???) resistor to see how I get on.

[Hamster]

[quote name='peted' post='231283' date='Jul 2 2008, 01:14 PM']I'm building the 500 Watt Deltalite 2510 version. I'm paranoid that if I go with a resister that can handle less thermal wattage then I'm going to end up cooking it. I've ordered a 50watt 4R7 (I think that means 4.7 Ohm???) resistor to see how I get on.[/quote]

With the 500 watt version it's imperative to use a flux capacitor - [url="http://www.shopneo.co.uk/flux-capacitor-free-shipping--pr-16735.html"]http://www.shopneo.co.uk/flux-capacitor-fr...--pr-16735.html[/url] - in series with the 50 watt 4R7, or else the interrossiter won't differentiate at low frequencies.

Hamster

[peted]

[quote name='Hamster' post='231290' date='Jul 2 2008, 01:30 PM']With the 500 watt version it's imperative to use a flux capacitor - [url="http://www.shopneo.co.uk/flux-capacitor-free-shipping--pr-16735.html"]http://www.shopneo.co.uk/flux-capacitor-fr...--pr-16735.html[/url] - in series with the 50 watt 4R7, or else the interrossiter won't differentiate at low frequencies.

Hamster[/quote]
I certainly don't need any more confusing with all this electronics malarky! To think I even followed that link to check out the component I would need. Well done.

[alexclaber]

[quote name='peted' post='231283' date='Jul 2 2008, 01:14 PM']I'm building the 500 Watt Deltalite 2510 version. I'm paranoid that if I go with a resister that can handle less thermal wattage then I'm going to end up cooking it. I've ordered a 50watt 4R7 (I think that means 4.7 Ohm???) resistor to see how I get on.[/quote]

As the piezos are a predominantly capacitive load and have extremely high impedance below 8kHz (very little bass energy beyond there) the resistor has to handle very little power. I believe a 10W resistor should be fine.

Alex

[peted]

Did LOADS today due to the great weather. Best bit had to be the 6 layers of tuff-paint with light sanding between each.

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[thinman]

[quote name='peted' post='233291' date='Jul 5 2008, 07:59 PM']Did LOADS today due to the great weather. Best bit had to be the 6 layers of tuff-paint with light sanding between each.

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Pete,

I've built one of these and I'd recommend doubling the number of screws holding the baffle board in place. I assume you've got some weather strip in there too as air leaks around the baffle are apparently a common problem. If necessary make a couple of cutouts in the back brace so you get some screws inside there too.

I also found that after a few weeks it's worth opening the box up again and tightening them all again.

[peted]

[quote name='thinman' post='234625' date='Jul 7 2008, 11:44 PM']Pete,

I've built one of these and I'd recommend doubling the number of screws holding the baffle board in place. I assume you've got some weather strip in there too as air leaks around the baffle are apparently a common problem. If necessary make a couple of cutouts in the back brace so you get some screws inside there too.

I also found that after a few weeks it's worth opening the box up again and tightening them all again.[/quote]
Thanks thinman, I'll put some more screws in the baffle this weekend. I have put weather strip around the baffle and have had air leaks at the front of my mind through-out this build. The whole thing feels like it's built like a brick sh*t-house, but I'm sure a few hours of low frequencies will shake some bits loose

[peted]

This weekend I have so nearly completed the cab.

I've put some more screws into the baffle as-per recommendation from thinman. I've wired it all up - Did an initial test of the wiring with my Hartke amp and started to panic - the sound was only coming out of the piezos! Aaaaaargh!

I've found from Bill's plans, he tells you exactly how to wire the piezos, and exactly how to wire the speakers, but does not actually show how to wire the piezos and speakers to each other. Just a sentence along the line of "take a wire from the piezos to the woofer". Turned out that I had mistakenly wired the drivers/woofers in series with the piezos. After scouring www.billfitzmaurice.com I read a thread which seemed to imply that the piezo's were in fact supposed to go in parallel with the drivers/woofer. Gave it a whirl and all is now fine. Phew!

I've stuffed the cavities with old pillows and am about to put that cool egg-crate style foam around the interior.

I bought a nice Neutrik 2-pole Speak-On connector to go on the back. I now realise that it won't fit the 4-pole plug that i've got on the cable going from my Hartke. So for the test I had to hard-wire the cable to the speakers. I have a 4-pole Speak-On connector on order from Maplins now. Expense, expense, expense...

[peted]

This evening I am applying the final bits of paint as the weather is staying off.

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[mr.sibs]

looking good, can i ask in total how much you think it cost to build the cab? and how much does it weigh?

[peted]

I'll sit down and add up all the receipts when it's finished. I reckon it will be close to £300.

I'll also weigh it when it's finished. It's not light though (and cumbersome as I haven't put any handles on it yet!).

[thinman]

[quote name='peted' post='239727' date='Jul 15 2008, 07:14 AM']I'll sit down and add up all the receipts when it's finished. I reckon it will be close to £300.

I'll also weigh it when it's finished. It's not light though (and cumbersome as I haven't put any handles on it yet!).[/quote]
Sorry for jumping in here. I built one earlier this year and reckon it came to about £220 all in.
[url="http://basschat.co.uk/index.php?showtopic=15187"]Omni10 build[/url]

[peted]

Finished! Sounds rather good. Very responsive with masses of mid-range and treble, which I think is just the natural sound of my Hartke through a transparent cabinet. The low end became much thicker when I added the Aphex Bass Xciter. The volume and projection is just silly. I'm very happy and will be bringing it with me to the South East Bass Bash at the end of September. I'm not in a band at the moment, so I can't try it out in anger

[attachment=10877:OMNI10_09.JPG]
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Costs and weigh-in will happen in the next couple of days. I haven't put handles or protective corners on it yet.

[Subthumper]

Nice job, I'm seriously considering one of these myself. Which Hartke is it? I've been using a 3500 for about nine years and love it to bits but my old diy 1x15s are just abit too heavey and cumbersome even though they sound the biz. Was just wondering how well the cab handles the full output of the amp as the hatrke's do always seem to have plenty of headroom. Do the drivers fart out at all at high volume and low notes?
Cheers Just

[peted]

I'm afraid I won't be able to tell you how it handles the full volume of my 3500 as I'd have the neighbours complaining 2 towns across! Suffice to say I had the master volume at 3/10 today and it was too loud.

[gilmour]

Nice one, congratulations.

[quote name='peted' post='240483' date='Jul 15 2008, 11:30 PM']Finished! Sounds rather good. Very responsive with masses of mid-range and treble, which I think is just the natural sound of my Hartke through a transparent cabinet. The low end became much thicker when I added the Aphex Bass Xciter.[/quote]

You'll find that the Bass response improves over time as the Drivers 'Break In' I used to think all that stuff was a load of rubbish, but after a few gigs/rehearsals I really noticed an improvement in the bottom end. There are other methods that are quicker an more efficent at breaking in the drivers that don't involvoe just playing through it, check Bill's forum.

[phil_the_bassist]

[quote name='Hamster' post='231290' date='Jul 2 2008, 01:30 PM']With the 500 watt version it's imperative to use a flux capacitor -[/quote]


But then, if you're playin at 88mph with a 1.21 gigawatt amp, won't you travel back in time..?

[KennysFord]

[quote name='phil_the_bassist' post='240947' date='Jul 16 2008, 03:21 PM']But then, if you're playin at 88mph with a 1.21 gigawatt amp, won't you travel back in time..?

[/quote]

was soooooooooo tempted to write something along those lines,i fought it tho'

[peted]

Weight according to my bathroom scales is [b]23.3 kg[/b] or [b]51.4 lbs[/b]

Total cost to build ([i]not[/i] including tools, screws, glue, labour, sandpaper, filler - as these were already provided by my father): [b]£250~[/b]

I've got left overs from this build included in that cost though, so building a 2nd cab would be slightly cheaper now.

Edited July 16, 2008 by peted

[thinman]

[quote name='gilmour' post='240621' date='Jul 16 2008, 09:24 AM']Nice one, congratulations.



You'll find that the Bass response improves over time as the Drivers 'Break In' I used to think all that stuff was a load of rubbish, but after a few gigs/rehearsals I really noticed an improvement in the bottom end. There are other methods that are quicker an more efficent at breaking in the drivers that don't involvoe just playing through it, check Bill's forum.[/quote]
+1 to that. It takes a while to play the drivers in - I reckon a good 6 hours at reasonable volume as I didn't break mine in pre-install at all but it really improved appreciably.

I'm really, really pleased with mine.

[woodster909]

thanks for putting all this up pete

I'm now inspired to have ago myself!