Joe's Omni 15 Tallboy

[jdmrivera]

Started on my Tallboy this weekend.

For anybody else near Denver Colorado, I found Baltic Birch at Consolidated hardwoods for a decent price. 1/2 inch 5x5 was $45 a sheet.

Here's the basic cab shell:

Baffle cut was made with a jigsaw (very slowly):

Baffle installed:

Everything is screwed and glued which helps assembly proceed without waiting for glue to dry. I'll most likely pull the screws when finished and fill with bondo before sanding everything.

When sitting on it's base there is a very minor wobble (bottom is not totally flat) I haven't decided if I should try to force it out using bar clamps or just make up for it when I install the feet. It's only about 1/8" off but it bugs me.

[jdmrivera]

One thing I forgot to mention. In my excitement to get the woofer mounted on the baffle I forgot to epoxy the hurricane nuts. Is that going to cause problems for me?

[ctmullins]

Love watching TallBoy builds, thinking of doing one myself soon...

One thing I forgot to mention. In my excitement to get the woofer mounted on the baffle I forgot to epoxy the hurricane nuts. Is that going to cause problems for me?

Don't know, but now's the time to go and fix it. Then you won't have to worry about it.

[CoronaOperator]

One thing I forgot to mention. In my excitement to get the woofer mounted on the baffle I forgot to epoxy the hurricane nuts. Is that going to cause problems for me?

The problem with hurricane nuts is when they spin and you have no access to the other side like in the titan/tuba builds. On the tallboy you always have access to the back side.

[jdmrivera]

Don't know, but now's the time to go and fix it. Then you won't have to worry about it.

Thanks. Does anybody have any neat tricks for getting them out and re-inserting without damaging the wood. I suppose I could insert a bolt and try to tap them out.

[Bruce Weldy]

Don't know, but now's the time to go and fix it. Then you won't have to worry about it.

Thanks. Does anybody have any neat tricks for getting them out and re-inserting without damaging the wood. I suppose I could insert a bolt and try to tap them out.

Don't even try. At this point, use 'em the way they are. As CO said, if you have to get to 'em at some point in the future, just take off the back.

[ctmullins]

Don't even try. At this point, use 'em the way they are. As CO said, if you have to get to 'em at some point in the future, just take off the back.

Well there ya go. Bad advice from me.

I would've inserted a bolt and tapped them out, but I trust Bruce to steer ya right. <- Texas smiley

[jdmrivera]

Noob alert
The drivers I have range from 45 watts RMS for the tweeter to 450 watts RMS for the woofer. Based on advice from Bill I'll likely never use more than 100 watts for this system but even at that level what prevents the tweeter from receiving those 100 watts? Is it crossover or amp magic? (I realize I should be talking volts but the speakers are all 8 ohms so I think the comparison is correct)

[Bill Fitzmaurice]

Power density is halved (-3dB) with each octave increase in frequency.

[jdmrivera]

Power density is halved (-3dB) with each octave increase in frequency.

Thanks Bill. I'm not sure what the relationship is from power density to watts or volts. I'm just trying to understand what it is that will keep me from frying my tweeter or midrange since the woofer handles more power. If there is a reference or link you can point me too that'd be great. I've looked up some info on power density and too much math for me.

[David Raehn]

Think of it this way:
It takes a lot more energy to make bass waves than treble waves.
If the crossover is doing its part, bass waves will not go to the tweeter.

[DJPhatman]

Noob alert
The drivers I have range from 45 watts RMS for the tweeter to 450 watts RMS for the woofer. Based on advice from Bill I'll likely never use more than 100 watts for this system but even at that level what prevents the tweeter from receiving those 100 watts? Is it crossover or amp magic? (I realize I should be talking volts but the speakers are all 8 ohms so I think the comparison is correct)

As long as you are using recommended drivers from the plan, and the crossover networks from the plan, then no worries. You will be able to hear all the drivers complain before you get close to the limits. The crossover allows only the bandpass frequencies through. Since the highs (tweeter) and mids (mid-woofer) take a lot less power than the lows (woofer) the correct power is distributed to the correct range.

[jdmrivera]

As long as you are using recommended drivers from the plan, and the crossover networks from the plan, then no worries. You will be able to hear all the drivers complain before you get close to the limits. The crossover allows only the bandpass frequencies through. Since the highs (tweeter) and mids (mid-woofer) take a lot less power than the lows (woofer) the correct power is distributed to the correct range.

OK - I'll quit worrying and keep building!

[jdmrivera]

Hopefully I'll start on the mid horn parts tonight. Any advice on cutting all those angles without losing any finger tips? Seems like table saw is most appropriate with correct setup but I could also try my bandsaw.

[Bruce Weldy]

Any advice on cutting all those angles without losing any finger tips? .

Keep your fingers away from the blade?