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

[Melon Head]

do it as a jpeg
either way I am sure it looks good

 

[Jack Caldwell]

Another try.

Well, I've got this in-room graph, I'll post the other ones later when I figure out how. Ignore the low-freq noise below 30Hz, it's noise from the A/C unit. It was really hot here in July!

 

[Jack Caldwell]

OK, mebbe this'll work.

Here are more pix AND the outdoor Frequency graphs for my TimePulse Lambda system, at 1/12th octave resolution and good vertical resolution.

 

[Melon Head]

Almost finished.

 

[buzzforb]

Awesome. This is a huge favor.

 

[Melon Head]

Just need to glue the 2 pieces together, and I can do some measurements.
I went with 8.5" holes - about 1/3 of cone area

 

[buzzforb]

Icannot thank you enough. These are allideas i was interested in. I am going to evetually join you in your experiments. Awesome!

 

[Melon Head]

Getting closer

 

[norman bates]

whazzat ?

 

[buzzforb]

emerald physic cs2.3 clone

 

[norman bates]

ouch, the emerald ain't cheap !!!!!!!!!!!!

48db crossovers ?????

Full range drivers or 6db slopes please for me....................

I like the ideal of a time aligned coax, such as the Thiel scs4t (nice waterfall past 1khz) or maybe even the Vandersteen vlr

Thiel Audio SCS4T loudspeaker | Stereophile.com

Audio Research—Vandersteen—AudioQuest (Room 1) | Stereophile.com


Norman

 

[buzzforb]

Lets just see what he finds.

 

[Vix]

Would be interesting to try various shapes instead of a simple hole. imagine you carve some visually appealing form/object 😀. Then sell it expensively, because you just discovered the shape of the soun wave 😀. Just kidding. Nice work. Just go on 🙂

 

[Melon Head]

ouch, the emerald ain't cheap !!!!!!!!!!!!

48db crossovers ?????

Full range drivers or 6db slopes please for me...................

Norman

I don't think anyone here is interested in copying the crossover, it is more about whether the loading on the 15" drivers gives the speakers a higher output and hence better bass extension similar to Nelson's slot loaded open baffle.

 

[Jack Caldwell]

it is more about whether the loading on the 15" drivers gives the speakers a higher output and hence better bass extension

Your project is looking good! I think the smaller area will give it mass-loading, extending the frequency response but somewhat lowering the efficiency. With two woofers a la EmeraldPhysics, it's likely to work fairly well, but depending on the cavity formed by the woofer and hole size, can exhibit partial horn-load response with a significant peak in the mid-bass. If the peak is large use a tank network to knock it out. Should sound great!

 

[buzzforb]

What would happen if the chambers of the two woofers were made into a singular chamber with no division, but you still maintained dual ports? Would there be coupling of some sort?

 

[Melon Head]

I should be able to do some measurents tonight

 

[Jack Caldwell]

What would happen if the chambers of the two woofers were made into a singular chamber with no division, but you still maintained dual ports? Would there be coupling of some sort?

Yes. Since the woofers are already fairly close, there is already a fair amount of coupling. Putting them both in a single mass-loaded chamber would increase that, we'd have to model it to see by how much.

 

[Melon Head]

The Emotiva XDA-1 arrived, so at some point in time I will compare the Sabre ESS9018 in BDP-95 vs AKM in DEQ2496 vs AD1955 in XDA-1

 

[buzzforb]

Wow, thats a nice lineup. Have you looked at the output for the Emotiva? The word on the DEQ is that in can be very good, but both the inputs and outputs need altering. I bet you got a sweet music room.