BFM Omni 15 Tall Boy

[gilmour]

Finished

sounds awesome

will find time for a proper update when I've finished waking the neighbours!

[gilmour]

Whilst waiting for the PXB lamp to arrive I removed all of the speakers and added a grill at the end of the horn (basically where bill suggests pet screen)

Looks like this...
midrange

...and this...
woofer


Once the PXB lamp arrived I gave my mums fella (Larry) a call to ask if he'd mind helping me, he said sure.

Larry is a bit of an electronics wizard, when I arrived at his he was in the middle of building his own flight simulator, mum now has no spare room!

Whilst laying out the parts we realised, genius that I am, that I had some how ballsed up my order for crossover components and was missing a coil and capacitor. A quick call to John at Audio Components and all was sorted, he had the bits in stock and I went over there to collect them, also got to listen to his amazing hi fi again, mine sounds rubbish again now

When I got back from Johns (about an hour later) Larry had nearly built the entitre crossover (without taking any pics, sry) He'd also mounted them on a board attached to the rear bracing, he's mounted the board in such a way that it can be removed for maintainance and adding components (an LPad if I decide it's needed)

It looks like this...

exciting eh?

I stuck my hand in the cab and tried to take a pic of the crossover components, but it didn't come out so well...

this is just part of it but you can see the long awaited PXB lamp though - isn't it a beauty?

In Bills plans he says to mount the coils quite far from each other, however Larry had done all this whilst I was out and ensures me that provided the magnetic fields are in different dirrections it will be fine. I'm sure he's right he does electronics like this with his eyes closed.

Screwed the back in, couldn't get the screw cups in black (and was in no mood to spray paint them), but they look knda cool in zinc


FINISHED


Transporting the kit back to min I realised one of the things that I like the best about the cab...

look at that fits perfectly in me boot. This is the forst gig sized cab I have ever owned that I don;t need to fold the seats down for!
[b]
So how does it sound?[/b]

most people here usually say loud, and yes it is noticeably louder than either my 1x15 or 4 x10, but that wasn't my overall impression, in one word I'd say ... [b]PUNCHY [/b].... and not like many 4x10's with that kind of grunty sound but a much more clear and defined note that still doesn't distort. I've always used solid states and relied on cabs to give me that little bit of grunt, however since I've been playing this I've had the 'warm' button (basically a valve emulator) on my am permanently on. My signal is now so clear, such an accurate representation of my bass

The sound is really clear, all of my little mistakes it picks up - for example resting my thumb on the B string you can hear when I knock the string against the pickup.

The sound is really really HiFi and does come through as Bass, Middle, and Treble. When I turned up or down one of the controls on my bass the corresponding speaker got noticeably louder or quieter! I know it's designed to do this but it still blows me away, and spent ages with a stupid grin on my face doing exactly this.

The top end is crystal clear, and I did find myself backing off the treble a lot more than I normally would (perhaps I won't have to change strings so often now ) When you slap at volume my biggest piece of advice would be - don't sit dirrectly in fron the amp, the top end is truly eye popping

As I said above the midrange is really punchy, I'm amazed at the volue and clarity that single 8" speaker gives out.

The low end is (without any doubt) my favourie part of the cab, it is subby, yet crysal clear, deep bass that doesn't boom. When I was playing around with this Sally made me come and turn down as the shower was rattling. You do need the 8" alongside the woofer, as it really is kicking out sub and deep bass, but sounds beatiful.

Over all I'm well pleased, I haven't decided wether or not to add the LPad, I think I probably won;t bother as you can control the volume of it by backing of the treble, and it's not an unpleasant Quacky treble like on so many cabs with tweeters.

There is a little bit of hiss that comes out of the tweeter, It's only really audible when you are up close to it and directly in fornt of it, the minute you move to the side it dissapears. I don't know what causes this, but I'm not overly worried.

The other downside is that it is pretty big, and as you can see from the pic above I can't put castors on it or I'd have to fold a seat down in my car. That said it is considerably lighter than my Trace 4x10 and a comparable weight (maybe slightly lighter) than my Peavey 1x15. I can definatley live with the size

I've not gigged this weekend, so will try it in anger at Band Practice on Wednesday. My band is an 11 piece with drums, bass, guitar, keys, horns, 2 vocals, so hearing and cutting though can be a problem, we'll see...

Edited February 10, 2008 by gilmour

[Gwilym]

hi Gilmour - that's looking great - contgrats! How easy is it to move around, lift into the car etc? Do you know how much it weighs?

[gilmour]

[quote name='Gwilym' post='137852' date='Feb 10 2008, 10:35 PM']hi Gilmour - that's looking great - contgrats! How easy is it to move around, lift into the car etc? Do you know how much it weighs?[/quote]

Hi, it is pretty big, so it's not like the O10.5 that is really transportable.

It's about the same size as a 6x10 maybe slightly smaller, or one of those SWR 8x8 and massivley lighter than either of those. It's not to difficult to move around, it's is narrower than most commercial cabs so really is saving my knuckles going though doors etc.

As I said above it's probably lighter than my peavey, and considerably lighter than my trace elliot 4x10. I don't have any scales sorry. That said I certainly don't struggle to lift it, and think i'll be able to cope quite comfortably withou adding any castors too it. I may put a third handle on to it if I carry on loading it into the car as I have above, just to make lifintg it in and out a little easier, but if I was folding down the seats I wouldn't even be considering it. (I might have benefitted from mounting my handles 5 or 6 " lower)

Weight is saved by using a neo woofer, which weighs next to nothing, and 1/2" ply wood that is then cleverly braced (rather than 3/4" MDF used in most commercial cabs). It's certainly a lot lighter than comparable FUll range PA cabs too.

[alexclaber]

Nice work!

Alex

[eude]

Nice work [b]Gilmour[/b]!
That looks amazing!

I've been GASing for an [url="http://www.billfitzmaurice.com/Omni12.html"]Omni 12 Tall Boy[/url] for a while, and you're really not helping...

Glad it came together so well though, credit to your craftsmanship.

Cheers,
Eude

[gilmour]

[quote name='eude' post='137962' date='Feb 11 2008, 09:04 AM']Nice work [b]Gilmour[/b]!
That looks amazing!

I've been GASing for an [url="http://www.billfitzmaurice.com/Omni12.html"]Omni 12 Tall Boy[/url] for a while, and you're really not helping...

Glad it came together so well though, credit to your craftsmanship.[/quote]

Thanks Eude, have to give Larry some credit to, he took a fraction of the time that I would have done to do the electrics.

You should go for it, I've really enjoyed the process (and have already purchased the parts for and omni 10.5). I was tempted by the O12 as it would be more portable, but I'm gald I went with the O15 the bass tone to this thing is really sweet and deep

Edited February 11, 2008 by gilmour

[Mums fella]

Hello dude. Glad the cab's causing glee! That hissing is the sound of excited electrons rushing through your pre-amp. You can hear them now because you have a really efficient HF unit. - Larry

[Merton]

Gilmour, that looks great. You have really made me catch the BFM bug! Now trying to decide between an Omni 15 Fullrange or a Tallboy like yours... I have the 15" woofer already and I want to build something!! Don't hold yer breath tho, it won't happen til the summer, plus I have a P-bass projec tot play with at some point.

[chenzo_1]

what can i say about this...one word..........Jealous!!!!

Looks and sure it sounds amazing!!!


Very nice work!!

[gilmour]

[quote name='Mums fella' post='138765' date='Feb 12 2008, 11:50 AM']Hello dude. Glad the cab's causing glee! That hissing is the sound of excited electrons rushing through your pre-amp. You can hear them now because you have a really efficient HF unit. - Larry[/quote]
Hehe, forgot you were reading this, thanks Larry, but credit where it's due, if it weren't for you I'd still be making the crossover! like I say the hiss dissapears the minute you move slightly to either side or more than a couple of feet from the amp, I was just nit picking really

[quote name='chenzo_1' post='138917' date='Feb 12 2008, 03:22 PM']what can i say about this...one word..........Jealous!!!!

Looks and sure it sounds amazing!!!

Very nice work!![/quote]
Thanks Vince, when you;re around you should drop by and have a Blast, you can hear me use it in anger when we play up your way at the Yardbird, 26 April I think

[quote name='Merton' post='138784' date='Feb 12 2008, 12:26 PM']Gilmour, that looks great. You have really made me catch the BFM bug! Now trying to decide between an Omni 15 Fullrange or a Tallboy like yours... I have the 15" woofer already and I want to build something!! Don't hold yer breath tho, it won't happen til the summer, plus I have a P-bass projec tot play with at some point.[/quote]
Go for it, I've enjoyed this so much I've already ot the parts for my next build, I really don;t need another speaker cab, but it so enjoyable, and as Larry pointed out to me, making a cab is great because they always work, and always sound good

The Tallboy is fullrange, it's a different shape to take up less floorspace, and also to bring the drivers closer to your ear level, both pluses in my book, plus it fits perfectly into the boot of a chrysler PT cruiser !

Rob

Edited February 12, 2008 by gilmour

[gilmour]

[quote name='Mums fella' post='138765' date='Feb 12 2008, 11:50 AM']Hello dude. Glad the cab's causing glee! That hissing is the sound of excited electrons rushing through your pre-amp. You can hear them now because you have a really efficient HF unit. - Larry[/quote]
Just thinking about this, do you mean the pre amp on my bass, or in my amp? or both?

I was thinking it would be really interesting to see how this sounds with a passive bass, but all mine have active pre's and active pups. I might just ask you this question when I see you next, seems odd asking you on a forum, yet I continue to type...

Edited February 12, 2008 by gilmour

[Mums fella]

[quote name='gilmour' post='139151' date='Feb 12 2008, 10:44 PM']Just thinking about this, do you mean the pre amp on my bass, or in my amp? or both?

I was thinking it would be really interesting to see how this sounds with a passive bass, but all mine have active pre's and active pups. I might just ask you this question when I see you next, seems odd asking you on a forum, yet I continue to type...[/quote]

I didn't realise you had a preamp on your bass as well. Does the hissing go away when you disconnect your bass? If so then it may well be worth checking the bass preamp circuit to see if quieter versions of the semiconductors could be sourced.

With regard to the hissing effect dissapearing when you move out of the tweeters 'line of fire', the higher the frequency, the more directional it is. In fact I believe I'm right in saying that if half the frequency's wavelength is longer than the room you are in, you can't get its direction which is why you get multiple upper range speakers and only one bass unit in home entertainment systems.

Looking forward to hearing this thing full-throttle. Well done Rob, a really very pro looking unit which will certainly have your fellow bassists asking where they can get one. (I personally prefer the open front effect. It reminds me of those folded horn units we used to use).

Larry

[Bill Fitzmaurice]

[quote name='Mums fella' post='139319' date='Feb 13 2008, 05:04 AM']I didn't realise you had a preamp on your bass as well. Does the hissing go away when you disconnect your bass?
Larry[/quote]Some hiss is inevitable, but this is where having a LPad on the tweeter to reduce its sensitivity can help to fine tune the system for the best result. That's usually obtained by boosting the highs as early as possible in the signal chain, starting at the bass if it has on-board, and cutting them at the opposite end.

[gilmour]

There is some hiss whether I have the bass plugged in or not, like I say it's not really bad, and I appreciat that as this cab is much more sensitive I'll now hear these things.

I've got practice tonight so I'll see how it sounds then, if it bothers me then I guess I'll install the LPad, I've already got one, it was only £5ish I bought it when ordering some other bits.

Can't wait to crank this up full volume though

[gilmour]

Used this last night at band practice and ahd a chance to try it out at gig volume. Without doubt it's the best sounding cab I've ever used.

As all BFM builders will tell you it is noticeably louder, I had the volume at about two thirds of what it would normally be.

As I thought would probably be the case, the slight hiss on the tweeter really was no issue at all, once you're in that environment you can't hear it, there is so much ambient nosie from everything else, in fact I feel silly having even mentioned it.

The big advantage of this cab was that often I find you have the choice between either deep bass or clear mids and definition, often finding that if you want a really fat bass sound you loose clarity and definition with some of the more subtle parts of your playing. Often I found mysefl 'over EQing' to try and compensate for this and further muddying my sound.

With this you have both, the deep low notes were really fat and subby, yet when I filled, played dead notes etc these were not lost and sat just as clearly in the mix. I set my EQ fairly flat, with the treble backed off slightly, and the bass boosted a little, sweet tonal heaven:)

One other thing of note that I wasn't expecting was how much my pedals come to life with this, the effects were just so much more transparent and audible, a lot of the 'effect' seemed to come from the midrange speaker, with the 15' holding down the low end, meaning that (as is sometimes the case) you don;t loose the bass or volume when you switch on your effects. Especially my Envelope filter, If my band mates hadn't insisted I'd probably have left it turned on all night.

As I'd mentioned above the band is a big 11 piece group so can be tricky picking yourself out, but with this rig, mmmmm ...

..simply awesome

and I made it !

Edited February 14, 2008 by gilmour

[eude]

Nice work [b]Gilmour[/b],
glad to hear it worked out so well!

Eude

[alexclaber]

A great result!

Two questions - what does the finished beast weigh and what type of plywood did you use (and where did you get it)?

Alex

[Merton]

[quote name='alexclaber' post='140425' date='Feb 14 2008, 04:17 PM']A great result!

Two questions - what does the finished beast weigh and what type of plywood did you use (and where did you get it)?

Alex[/quote]
That's 3 questions

But good point, I'll take notes for my potential build

[gilmour]

Hi Alex (and Merton),

Unfortunatley I don't own any scales (I'll try to lay my hands on some 'cause a few people have asked), but I can tell you that it is massivley lighter than a comparble sized 6x10 (IMHO it smacks an Ampeg 6x10 in every imaginable way - sound, portability, volume, looks, weight - you can tell I don't really like those cabs). It's also lighter than my peavey 1x15, it's no strain at all to lift it, but I put the handles a little to high so it keeps hitting my shins! I think the crossover coils are one of the heaviest parts of the cab, they weigh more than the 15" (I see your using the same one in your build) but there's no way around that.

Woodwise I just used 12mm Birch Ply from B&Q (in Slough), it was the cheapest and easiest to source (£20ish for 4 x 8 sheet), however I have since found out that Arnold Laver near me (in Reading) has Baltic Birch for £30 a sheet, which is cheap. But would still have been £20 more (I needed 2 sheets) and they wouldn't deliver for a small order (despite only being 2 mins away) B&Q cut on site, so I could fit it in the car, but don't expect massivley accurate cuts.

As Bill says in the plans if you carpet there's no need to use Baltic Birch, but you should use it if you are going to paint. If you're wanting ultra lightweight probably best to carpet the cab rather than paint so that you can use a lighter wood (spruce ply maybe, I think this is what I'll use for my next build) the carpet doesn't cost much more than the paint, although some find the carpeting tricky I found it really straigtforward, and enjoyable.

Hope this helps, I'm really keen to see how your build(s) pans out.

[Bigwan]

[quote name='gilmour' post='140450' date='Feb 14 2008, 04:41 PM']I think this is what I'll use for my next build[/quote]

You still want more?! I hear it can be quite an addictive hobby this old cab building...

[Hamster]

Nice job

I have the plans to build a couple of Bill's designs - but woodwork is my achilles heel!

Hamster

[gilmour]

[quote name='Bigwan' post='140597' date='Feb 14 2008, 07:44 PM']You still want more?! I hear it can be quite an addictive hobby this old cab building...[/quote]
hehe - I really don't need anything more than this cab, I just fancy the portable O10.5 - think it will be handy for smaller gigs, and use with my upright. That's just an excuse, it is an addictice thng, and I'm hooked!

[quote name='Hamster' post='140717' date='Feb 14 2008, 11:27 PM']Nice job

I have the plans to build a couple of Bill's designs - but woodwork is my achilles heel!

Hamster[/quote]

Before this the only woodwork I'd done was putting up shelves and simple DIY, if you follow the plans there really aren't many ways to go wrong, worst comes to the worst you use a bit more wood up.

[DirkThrust]

[quote name='Bigwan' post='140597' date='Feb 14 2008, 07:44 PM']You still want more?! I hear it can be quite an addictive hobby this old cab building...[/quote]

It certainly is. After reading this thread I've got a bad case of BFM GAS. I'm thinking of making a sub for my Omni10.5s. That would make a monster rig.

[DirkThrust]

[quote name='gilmour' post='140720' date='Feb 14 2008, 11:33 PM']Before this the only woodwork I'd done was putting up shelves and simple DIY, if you follow the plans there really aren't many ways to go wrong, worst comes to the worst you use a bit more wood up.[/quote]

Same here. You pick it up as you go along and make plenty of mistakes. Fortunately mistakes with 1/2" ply are not too costly.