CHEAP, High Efficiency Open Baffle

[augerpro]

Rudolph thanks for the info! I figured higher density was more accurate but wasn't sure if there was any downsides. Also I will be offsetting to the inside. I'll route the baffles tonight and tomorrow I'll have to build some sort of stand to get it off the ground for measurements.

WillyD good PA drivers are pretty expensive I've found. But for $53 this WN8S isn't too bad. F3 adn F5 are kinda high, enough to audible once in awhile I would think. One thing I can say though is this driver sounds real good just hooked straight to my stereo when I was breaking it in. Unlike the Selenium. It had what I've heard called "cone cry" real bad. I don't know if that's the high frequency breakup or distortion so I wasn't sure if it would go away once it's part of an XO.

[WillyD]

WillyD good PA drivers are pretty expensive I've found. But for $53 this WN8S isn't too bad. F3 adn F5 are kinda high, enough to audible once in awhile I would think.

Well this wouldn't be a problem with them crossed over 250-300Hz LR4 right?

[augerpro]

As far as lowend distortion yes. I was referring to the F3 peak between 1-1.5k Hz and the F5 peak at 600-900 Hz due to the cone breakup starting at 3k.

[WillyD]

Ohh ok. What is the highest you'd cross it over on the top end (using LR4)?

[augerpro]

I don't know...1k if you wanted it done "right". I'm going to try 1.5k, although I may use a notch for better then LR4...not sure yet.

[augerpro]

I wonder if I should use a bigger diameter in Edge for the tweeter to approximate a waveguide?

[JonMarsh]

Pattern control and dispersion of any good waveguide will basically eclipse what the baffle is doing UNLESS you run it down below the frequency range the waveguide maintains pattern control, or the waveguide you select has poor pattern control in the lower range anyway- like the MCM. Then you're more likely to get some baffle effects, though less I believe than for a standard dome tweeter.

[augerpro]

Thanks Jon. I may have to build my own WG if no one is going to come out with anything usable.


Made some progress tonight:





Now I was debating whether to go with a flat baffle and some EQ, or a very short U frame. I decided to try some tapered sides. Starting at the top of the top woofer and increasing to about 6-8" at the floor. Here is an Edge sim for the baffle:




And here is a sim with a representation of the side wings which you won't see from the front:




For bass that sim would this approximate the response?

[Rudolf]

Brandon,
simulating those wings is only a small step on your way to get a realistic picture of bass response. You will need to do a "floor mirror" simulation in EDGE to really see what happens up to 1000 Hz.

BTW: Nice Yammi you´ve got there :T

[augerpro]

I'll give that a try Rudolph, thanks! So does the upper woofer which is centered 24" above the floor contribute to this mirror image? Or just the lowest one?

[augerpro]

What´s more important: To the short side you get a more even decrease with rising angle for different frequencies.

Rudolf

I just reread this. Could you explain exactly what you mean? I have an idea but I want to make sure I know what you're saying. Thanks.

Here are two sims of with folded back wings and floor image included. Because I'm not sure the upper woofer will couple with the floor which is "more" correct? The upper woofer is 22" from the floor so I wonder if it will couple well enough to get this mirror image? Also will the ever increasing depth of the wing make for a screwy response? How about integration with the mid? I did this because it seemed like sort of a good compromise between a flat baffle (good mid integration, poor bass with most baffle widths) and a U baffle (good bass, poor integration with mid over a certain frequency). FYI I did a lot of work to find a good XO point considering floor bounce issues, mid excursion, combing, etc. and came up with 350Hz as the best compromise for those factors.






Until I measure the actual baffle I'm not sure where F3 will fall. Best case is 90Hz as shown. I'm thinking this should mesh well enough the monopole sub with receiver's XO set around 60-80 Hz. I hope anyway...