Melon Head's State of the "DUMB" Open Baffle Design - Page 19

norman bates · 10th August 2012, 01:32 AM

actually, it measures almost exactly as it should.

(speed of sound) divided by the distance front driver edge to back driver edge closest distance

1129 / (39.4" / 12") = dip = 375hz = where driver front wave is 180 degrees out of phase from the back.

There should be a peak an octave below that where driver front to back wave is 90 degrees out of phase thusly adding.

375hz / 2 = 187hz (yours is about 175hz, I'd call it good)

So sucess and performs as it should.

And how does it sound ?????????????

Norman

Melon Head · 10th August 2012, 02:24 AM

Maceo Parker, Roots and Groove, Track 6, Pass the Peas. There is a drum solo half way through the track, accept the drummer is in your room. It is like someone hitting you with a cricket bat.

Melon Head · 10th August 2012, 02:33 AM

I suppose I should also do it for the 10 Neodymium

norman bates · 10th August 2012, 03:32 AM

well done.

Melon Head · 09:43 AM

To critically assess the sound I need to rebuild the baffle out of Birch or Bamboo ply.
The Audio Nirvana drivers are without any doubt a level above Seas.

norman bates · 11:14 AM

Looking at the an10 plus the dual an15, once you get the 300hz hump and 1khz+ knocked down, that looks like a great project (but expensive). That's what most are looking for, a baffle about Jamo R909 sized, like the one you made. A few have made a similar full range plus 15's on 18" wide baffle (b200 with a pair of eminence alpha 15a drivers popular at audiocircle).

Ideally one can use different woofers rather than the pricy an15s for bass duty. Audio Nirvana states the an15 has a qts of .483 with 1mm xmax, 500hz downward, sensitivity looks to be 95db. The eminence delta 15a has qts .53 and 2.7mm Xmax and is 97db below 600hz 8ohm for $95. Or the eminence delta 15lfa has a qts .58 with 4.8mm xmax and 95db from 500hz down ($100). I'd look for something with a shorting ring, it help clean distortion up above 100hz, but they cost more also. Then again, eminence is pricey outside the US.

Norman

Melon Head · 10th August 2012, 11:18 AM

I haven't had a chance to use the B5 yet, because I have been busy doing measurements, but it should make things easy to dial in the right crossover point

norman bates · 10th August 2012, 12:01 PM

what's a b5 ?

Melon Head · 10th August 2012, 12:20 PM

FIRST WATT B5

Bigun · 10th August 2012, 01:21 PM

Quote:

Originally Posted by Melon Head

Yeah I will measure it against the wall.

This ain't much difference from having a box - with all those reflections from the wall so close.... ?

10th August 2012, 09:41 AM	#185
Melon Head Banned Join Date: Nov 2006	To critically assess the sound I need to rebuild the baffle out of Birch or Bamboo ply. The Audio Nirvana drivers are without any doubt a level above Seas. Last edited by Melon Head; 10th August 2012 at 09:43 AM.

10th August 2012, 10:59 AM	#186
norman bates diyAudio Member Join Date: Nov 2003 Location: iowa	Looking at the an10 plus the dual an15, once you get the 300hz hump and 1khz+ knocked down, that looks like a great project (but expensive). That's what most are looking for, a baffle about Jamo R909 sized, like the one you made. A few have made a similar full range plus 15's on 18" wide baffle (b200 with a pair of eminence alpha 15a drivers popular at audiocircle). Ideally one can use different woofers rather than the pricy an15s for bass duty. Audio Nirvana states the an15 has a qts of .483 with 1mm xmax, 500hz downward, sensitivity looks to be 95db. The eminence delta 15a has qts .53 and 2.7mm Xmax and is 97db below 600hz 8ohm for $95. Or the eminence delta 15lfa has a qts .58 with 4.8mm xmax and 95db from 500hz down ($100). I'd look for something with a shorting ring, it help clean distortion up above 100hz, but they cost more also. Then again, eminence is pricey outside the US. Norman Last edited by norman bates; 10th August 2012 at 11:14 AM.

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10th August 2012, 01:32 AM	#181
norman bates diyAudio Member Join Date: Nov 2003 Location: iowa	actually, it measures almost exactly as it should. (speed of sound) divided by the distance front driver edge to back driver edge closest distance 1129 / (39.4" / 12") = dip = 375hz = where driver front wave is 180 degrees out of phase from the back. There should be a peak an octave below that where driver front to back wave is 90 degrees out of phase thusly adding. 375hz / 2 = 187hz (yours is about 175hz, I'd call it good) So sucess and performs as it should. And how does it sound ????????????? Norman

10th August 2012, 02:24 AM	#182
Melon Head Banned Join Date: Nov 2006	Maceo Parker, Roots and Groove, Track 6, Pass the Peas. There is a drum solo half way through the track, accept the drummer is in your room. It is like someone hitting you with a cricket bat.

10th August 2012, 02:33 AM	#183
Melon Head Banned Join Date: Nov 2006	I suppose I should also do it for the 10 Neodymium

10th August 2012, 03:32 AM	#184
norman bates diyAudio Member Join Date: Nov 2003 Location: iowa	well done.

10th August 2012, 11:18 AM	#187
Melon Head Banned Join Date: Nov 2006	I haven't had a chance to use the B5 yet, because I have been busy doing measurements, but it should make things easy to dial in the right crossover point

10th August 2012, 12:01 PM	#188
norman bates diyAudio Member Join Date: Nov 2003 Location: iowa	what's a b5 ?

10th August 2012, 12:20 PM	#189
Melon Head Banned Join Date: Nov 2006	FIRST WATT B5