First time OB builder - Page 32

Beau · 4th December 2012, 12:34 AM

Nice, but you are going to have lobing issues with such a large mtm. Id suggest ditching one of the mids.

Silent Screamer · 4th December 2012, 12:39 AM

The one furtherest from the tweeter?

jerome69 · 4th December 2012, 03:04 AM

Yes or try 1 or 2 x 3/4" dome ? the crossover frequency will be high 5/6kHz
http://www.scan-speak.dk/datasheet/pdf/d2004-602000.pdf

Silent Screamer · 4th December 2012, 03:41 AM

Just paid $2000 for a pair of those tweeters, so replacing them is not an option. I could replace the two 8 ohm 12MUs (in series) with a single 4 ohm 12MU (I have both).

The area I am most concerned about is the area behind the tweeter, do you think it will allow the sound to travel unobstructed?

jerome69 · 4th December 2012, 04:03 AM

Sorry

The distance behind the tweeter must be longer than the largest dimension of the tweeter.
Here the diagonal is the largest dimension. I think it is the primary condition if you want to minimise the area behind effect/obstruction.

Keep your MTM

Silent Screamer · 4th December 2012, 04:27 AM

ok so your saying the distance between the two blue arrows must be greater than the diagonal of the tweeter face plate correct?

Beau · 4th December 2012, 04:55 AM

Single 4ohm, yep.

jerome69 · 4th December 2012, 05:04 AM

Quote:

Originally Posted by Silent Screamer

ok so your saying the distance between the two blue arrows must be greater than the diagonal of the tweeter face plate correct?

Yes Correct

Silent Screamer · 4th December 2012, 05:10 AM

Thanks guys will do a few refinements to the design based on your feedback.

Silent Screamer · 4th December 2012, 10:34 AM

Did a bit of tweaking...

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4th December 2012, 12:34 AM	#311
Beau diyAudio Member Join Date: Jul 2003	Nice, but you are going to have lobing issues with such a large mtm. Id suggest ditching one of the mids.

4th December 2012, 12:39 AM	#312
Silent Screamer diyAudio Member Join Date: Feb 2012 Location: Sydney	The one furtherest from the tweeter?

4th December 2012, 03:04 AM	#313
jerome69 diyAudio Member Join Date: Feb 2008 Location: Lyon	Yes or try 1 or 2 x 3/4" dome ? the crossover frequency will be high 5/6kHz http://www.scan-speak.dk/datasheet/pdf/d2004-602000.pdf

4th December 2012, 03:41 AM	#314
Silent Screamer diyAudio Member Join Date: Feb 2012 Location: Sydney	Just paid $2000 for a pair of those tweeters, so replacing them is not an option. I could replace the two 8 ohm 12MUs (in series) with a single 4 ohm 12MU (I have both). The area I am most concerned about is the area behind the tweeter, do you think it will allow the sound to travel unobstructed?

4th December 2012, 04:03 AM	#315
jerome69 diyAudio Member Join Date: Feb 2008 Location: Lyon	Sorry The distance behind the tweeter must be longer than the largest dimension of the tweeter. Here the diagonal is the largest dimension. I think it is the primary condition if you want to minimise the area behind effect/obstruction. Keep your MTM

4th December 2012, 04:55 AM	#317
Beau diyAudio Member Join Date: Jul 2003	Single 4ohm, yep.

4th December 2012, 05:10 AM	#319
Silent Screamer diyAudio Member Join Date: Feb 2012 Location: Sydney	Thanks guys will do a few refinements to the design based on your feedback.