Wild Burro Betsy OB Build

[danvprod]

I'm not sure why that other pic is broken. I think the came out nice as well. I don't see why you couldn't use the Pergo floorboards -- or two pieces laminated with the faces out. I think the inside is just chipboard anyways...

And here is my parts list so far:

Drivers: Wild Burro Betsy-k - $110 + $20 shipping

Baffles (All from Lowe's) - $136.00:
3/4x12x48 Stain Grade Pine x4: 47.76
3/4x16x48 Stain Grade Pine x2: 25.94
48" Silver Piano Hinge x 4: 39.92
Qt Clear Shellac Zinsser: 13.78
Old t-shirt to apply Shellac was free
All hardware came with the hinges.

Total coats of Shellac was 3x on the front, 2x on the back, there is still about 25% of the quart left.

Total: $266.00

Still need:
Cat 6e cables -- going to make 12' cables based on @cervelorider's recommendations (thanks for all your help!), and most likely use the HRT streamer II ($147) as my dac:
http://www.amazon.com/HRT-Music-Stre...s=hrt+streamer

I think I have the cat6e around the house so I can just use that for now. May have a bit more expenses if I damp the rears of the baffles with some of the recycled cotton, plus I need hardware for the speakers.

[GM]

Originally Posted by danvprod

-- so I am going to try with a pair of BestyKs with some series resistance.

Which suggests a 25-ohm series resistor, but that seems a bit high to me...

This is a better choice IME than using a high Q driver unless a low XO point is used since in the driver's mass controlled BW it's better damped.

FWIW, based on published specs, only 5.7 ohms is required to raise Qts to the Betsy's, but I typically use a cheap 25 ohm pot [+ a series resistor if it's not enough] to dial in what's needed, then insert a non-inductive power resistor or RLC [aka BSC] filter.

GM

[cervelorider]

GM: He does need a low crossover point as he isn't using a woofer.

[GM]

I meant a low, low pass on a woofer OB. Regardless, he says he's using a SET amp, so needs a lower Qts driver for best overall performance.

GM

[cervelorider]

[QUOTE=GM;3305106]I meant a low, low pass on a woofer OB. Regardless, he says he's using a SET amp, so needs a lower Qts driver for best overall performance.

GM[/

"best overall performance" in theory is often times at odds with "most musically satisfying presentation" in real life listening evaluations.

[GM]

True from a purely technical POV and why my personal builds would fail to meet the rigid standards of today's 'design by computer sim' crowd, but we have no way to know how each person perceives sound since we all hear the same and yet not so much, so no choice but to fall back on any well proven theory when trying to help folks achieve a good starting point for them to find their own "best overall performance" that provides the "most musically satisfying presentation".

GM

[danvprod]

Originally Posted by cervelorider

"best overall performance" in theory is often times at odds with "most musically satisfying presentation" in real life listening evaluations.

Agree 100%

[nebojsa]

GM, this is the best paragraph I have ever read. This cuts off pages of useless arguing. I will frame it.

[cervelorider]

danvprod: Since you are just at your starting point, well proven theory suggests that a high quality solid state amplifier has much lower distortion and control over a driver. You have "no choice but to fall back on well proven theory to choose a starting point" Pay no attention to all the people that have raved about the Bottleheads or Decware Zens. "we have no way to know how each person perceives sound since we all hear the same and yet not so much."
By all means, choose the lowest distortion, best spec'ed amplifier out there. It will be a good starting point.

[Bob Richards]

It may well sound better with the "wing", since baffle step will be reduced acoustically because of that, but the rear radiation will have a small amount of "cavity effect", which will color the reflected sound a bit. It seems that the best way to reduce baffle step is with active EQ, or at least passive electronic EQ. OB's need to be at least 3 ft. away from any walls, to work properly, because of the psycho-acoustic effects of the delays involved. Putting it another way, less than about 6mS delay of the rear radiation doesn't have a good psycho-acoustic effect.