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

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
The only way I can describe the Seas is that it is like listening to music through a thick blanket compared to the AN15 cast frame.
When I say that, I don't mean the Seas are bad, I mean the Audio Nirvana 15s are impressive speakers.
I like the PHY OB design though. I have more ideas to expand on what they have done.
I actually have a crap load of ideas and permutations to try now.

I think I would like to try the Seas with a phase plug. Hey Planet 10, if you have one, let me know.
 
in the phy video, bernard had his winged baffle almost directly against the wall. And the wings wern't much more than 45 degrees splayed.

8" on an open baffle, basically flat to 100hz (against a wall) IS AN ACCOMPLISHMENT !!!

Good job on the graphs. I've always said the open baffles need to be huge. I'm sick and tired of 18" wide baffles with a 200-300hz crossover point (that sounds wron to my ears). Rolling in so 15's from say under 100hz 6db pole used with a full rang 6db rolled is about the only option in my book, short of a real decent sized baffle.

I'd imagine the an15 on that baffle will be great.

Norman
 
Post 39 ……………………………. the graph of the big open baffle.

It works out according to my numbers.
Baffle is 6 feet high with 40cm (15.7”) wide center baffle with 50cm (19.7”) wings.
Centre of driver is 95cm (37.4”) above ground.

Since the wings are the shortest distance front to back, we will ignore the distance over the top.
Okay, given the driver is 8” wide, the driver’s edge is 3.85” to the edge of the front baffle.
Now fold the wings straight back (19.7”).
The approximate distance from back of driver edge to back of wing is 20”.
So the total distance from front speaker edge to back speaker edge is 43.62”.
Take 1129 / [43.62” / 12”] = 310hz (there should be a dip there, driver is 180 degrees out of phase).
Now divide the dip in 2 (driver front and back only 90 degrees out of phase, thusly adding) making the Feq hump @ 155hz.
Just like the graph, only I see a +3db hump instead of 6db, but I do see a definite knee there at 150hz.

If the wings were 24” deep (71cm), that should get you a hump around 130hz, then against a wall would go even deeper (like you've shown).
Using the an15, you lose the 3.85” of driver edge to wing, but if the wings were 71cm long (24”) it hump and roll around 140hz.
The mass corner on the an15 is lower, and at roughly 4 times the cone area, it should whoop up on the 8”.

Be sure to cover the hinge with duct tape on the back when / if an actual hinge is used with wood.

Norman
 
OK. Guess what I am going to do with this?
 

Attachments

  • 03082012274.jpg
    03082012274.jpg
    19.9 KB · Views: 509
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.