Navydoc's QSC Econo WG build

[Navydoc]

After reading this thread (here and the other site) I decided to build a 3 cu ft econowave from the specs on PE Tech Talk Forum. The LF's will be covered using an Eminence Kappalite 3012LF Neo 12" Driver coupled with a B&C DE250-8 1" Polyimide Compression Driver in a QSC waveguide (PL-000446-GP).

While playing with UniBox, I plugged in the parameters from Exodus Audio's 15" passive radiator (EX-PR15) and the results for the low end look very good (not that I need it with the Maelstrom-X sub (Exodus Audio), but the lower I can x-over w/ my Onkyo 805 the better). I do not know much about speaker design, I am more of a copier of other peoples plans (thanks to you, penngray and zilch for the inspiration ;x( ). However, I have not seen a build of an econowave using a PR. The excursion will pass that of the driver at 450 watts, but I do not forsee that being a problem - but I could be wrong.

Is this a feasible plan of attack? Any feedback greatly appreciated. I will now stop crapping on your thread!!!!

Attached are the plots comparing sealed to PR.

Edit by moderator. This thread was split from Augerpro's "What's Cooking" thread

[Dennis H]

Navydoc, have you tried modeling a ported enclosure? It would save you the cost of the PRs. PRs are often used when there isn't room to fit a port but I don't think that would be a problem with your box and driver.

[Navydoc]

Navydoc, have you tried modeling a ported enclosure? It would save you the cost of the PRs. PRs are often used when there isn't room to fit a port but I don't think that would be a problem with your box and driver.

I tried to model a ported enclosure using the UniBox program and could not figure out how to change the parameters. It kept telling me I needed an ~7" port that was ~2" long. Gave up and modeled with a PR. One thing I would like to try is building a sloted port along the bottom of the enclosure like one often sees in subwoofer design (such as NeoDan's Easy Button design). But my lack of skill with modeling programs keeps intruding :M .

[augerpro]

You can change the port diameter. You might be looking at properties under "Standard Design" which are merely suggestion. Input the specs you want into the areas above and below to define your own enclosure. I would use something like a 4" Powerport and a .78 end correction.

[Dennis H]

I can't run Unibox with my ancient version of Excel but I plugged the 3012LF into WinISD. The plots are for a 3 cu.ft. box (net after you subtract the volume of the horn, drivers and braces) with a 4" diameter port tuned to 40 Hz (4" long port), 35 Hz (6.2" port) and 30 Hz (9.5" port). I kinda like the 35 Hz tune -- room gain should bring up the gentle droop.

[augerpro]

Dennis what end correction does Winisd use?

[augerpro]

Nah, I just couldn't remember how winisd handled it. if Navydoc does use a Precision Port, I think considering about half the depth of the flare as part of the port length was about right when I did mine.

[ThomasW]

Bump....

[---k---]

Bump....

That's a first I've seen that! I would have thought that would have violated the rules.

I've got nothing to add, but I'm interested to see how this turns out. I've tried to read up on the econwave threads, but I often find it hard to separate the fact from hype. I'm very confused by what their using for the crossovers and how optimized they are. I'm hoping to hear some good feedback on them after the DIY No Cal. meet.

[Dennis H]

I think this one may actually be pretty good. Lots of input from people who know a thing or two. Brandon was the one who first identified the QSC horn as performing well and the same for the Eminence Kappalite woofers. Zilch and friends built one with Earl Geddes's favorite B&C compression driver and took some measurements. Pete Schumacher designed a crossover with only 5 components (6 if you include a variable L-pad) -- and got amazingly flat simulated response. Zilch says it sounds better than the other Econowaves. That said, I haven't heard it but some pretty talented people contributed so I wouldn't write it off.

[Navydoc]

ThomasW, Thanks for making this its own thread.

I received the three QSC waveguides (PL-000446-GP) last week (planning a L/C/R build for home theater). Current plan is to tune the ~1.85 cu ft PE trapezoid cabinet (w/ baffle flush mouted not recessed) w/ a 4" port to either 44.5 Hz (per recommendation of the Bagby Software and Eminance) or 35 Hz.

Attaching SPL and cone excursion data for both, I thought that it was best to tune a vented cabinet below the drivers Fs (37.02) but clearly could be wrong. ops: Both tuning frequencies have good vent air velocity (less than 5 m/s at 80 Hz).

Unfortunately, the Navy has sent me to a year of education 7 hours from my house - so the build will not be very rapid.

Any feedback highly welcomed, as I view this an iterative process.

[Navydoc]

By the way, my plan is to mount the QSC waveguide in a 1.5" baffle coupled to a parts express trapezoid speaker enclosure to maximize space for internal bracing, and to make the speakers look interesting. The baffle edges will be rounded over (not yet sure of the size of the roundover bit - I do not have a router table and don't want to lose body parts in the process).

Note: The attachment incorrectly identifies the volume as 1.65 cu ft, but that is with a recessed baffle.

The woofer will be recessed 3/4" per Zilch's design on the PE website. I also plan on using the updated Schumacher XO design for high SPL.

It must be noted that w/o the work of Zilch, augerpro and penngray I would not be attempting this build project! I lack the engineering background to develop a such a project.