Omni 15 Tallboy - my first build

[Gregory East]

There is a set of demo youtube recordings done with a Zoom for the sounds. Links to good recordings in the YouTube section.

I bumped Chris Allen's epic. HiFi is an understatement.

[Rickyvt]

Dude that's a sweet-looking cab. I've had the same plans for two years or more and have never built it- raising kids and re-habing a historical house, and living on a shoe string makes the Count a dull boy! But I'm going to do it now asap. Been hefting heavy boxes and that's getting old. Your thread has re-inspired the notion!

If I may...
What head are you using with it?
How do you describe the sound? As in, 'peaky', or 'hi-fi', etc? Do you get speaker break-up, or any of that kind of thing at all?... or is it clean 'all the way up'?

Sharp work man.

Thanks, your lordship!
All I can say is, it's really hi-fi. In fact, I discovered a lot of problems with my bass/amp combination. I'm using the Hartke model 1400 140W amp which I pulled from the combo I was using and I thought there was a problem with crossover filters, bad wiring, phase plug or maybe just some screws that were loose, because I heard some rattle at certain frequencies. I reconnected the amp to the old combo and when listening very, very closely I hear the same rattle, which means it's not the cabinet, but the bass I'm using or the amp. I just never noticed it until I hooked up the TallBoy.
So I was allready planning on buying a new head for it, but I haven't decided yet (Trace Elliot and TC electronics seem to have some nice models), now I'm planning on buying another bass too

[Rickyvt]

Look what I got for Xmas

[Bas Gooiker]

Look what I got for Xmas

Nice!!! Is the sound rattle free now?
A case to match the cabinet and you'd have the sexiest bass combo in Belgium!!!

[Rickyvt]

Yeah the rattle is completely gone. It was a combination of an active bass and the combo-amp I was using that could not handle high input. I just never noticed it with the combo. This Hartke Kilo is great with the Tallboy. My bass is sounding better than ever!
I agree on a similar casing for this amp, but it has vent holes left, right and on top, so I'm afraid of heating problems...

EDIT The main culprit is my Boss GT 6B - some settings seem to produce the rattle.

[Fenderfan]

Yeah go the matching case for the amp! Make holes to suit the venting, maybe larger, and from the front it'd look just the same! No one would ever know - it'd look wicked up on a stage.

[Rickyvt]

Mmmmm... tempting. I might just do that! This friday it's my first rehearsel with this amp. I'll check its temperature afterwards. Maybe it's not getting all that hot anyway...

[Bruce Weldy]

Mmmmm... tempting. I might just do that! This friday it's my first rehearsel with this amp. I'll check its temperature afterwards. Maybe it's not getting all that hot anyway...

Since it has rack ears, it was designed to go in a rack. Just leave at least 1/2" airspace on the sides.....it should be fine. If you want to build it without airspace, then certainly put air vents in the sides.

[Gregory East]

Best if there is a natural convective pathway sympathetic to the venting and/or internal fan. Some fans draw from side and others from the rear, hot air rises, you're a sharp cookie, you'll figure it out.

[Rickyvt]

I allready have a design in mind. It will have to wait till next year though. Happy New Year!

[Rickyvt]

One more thing...
About the rattle. It seems that certain settings on the Boss GT6B bass effects processor tend to provoke this, but at higher volume, even without the GT6B I do have the same rattle. This showed during rehearsal last night. It seems to me that the mid driver is "overpowered" This always happens on the lower notes on the B-string. I guess with a normal 4-string bass I would never have noticed it. When I play a CD on my bass amp (and it does a really great job at this, and since the Hartke Kilo is a stereo amp, a second identical cab would be nice) I never notice the rattle.
There are two solutions imho :
Not using the mid driver and use the full range of the Woofer. Changes the sound of the cab though...
Turning up the compressor level on the Bass amp seems to help Since I had a small combo I never had any use for a compressor. On the combo I could switch on/off a compressor, but that never made much difference. Now it does (might seem stupid that I didn't think of it earlier ).

[Gregory East]

The rattle might be coming from your bass. Try another!

[Rickyvt]

Could be, but it's only when the volume goes up to a certain point that the mid driver starts to distort.
I played the cab with tweeter and woofer only (without it's crossover to get full range on the woofer) and the rattle was gone.

[Bill Fitzmaurice]

The low B shouldn't bother the mid driver, as it's not going to get anything lower than 400Hz no matter what the fundamental tone is. See what happens by pulling down the EQ in the 400-800Hz region. The see what happens when you pull the 30Hz slider all the way down. All that the 30Hz does is to eat up headroom and cause everything to vibrate, without adding useful content. If pulling the 30Hz all the way down makes is seem thin boost the 64Hz a little bit to compensate.

[Rickyvt]

Pulling the 30 Hz slider down makes a big difference and with a little compression added I'm playing rattle free. Strange though that a mid driver starts to distort with those low notes. I measured voltage with those notes and the mid driver hardly gets 1.2 volts. I should try another 5 string and see if the problem persists (without compression or EQ) but I only got one... but that might change