or Connect
New Posts  All Forums:

Posts by catapult

Quote: Originally Posted by Bill Fitzmaurice What you're saying is that the technique allows you to predict what might be accomplished but doesn't give you the means of knowing how to accomplish it. That takes it off table as a practical design tool, at least until someone does quantify damping material performance to the level required. Gerry Koonce is the reigning expert on that scene, maybe he'll do so at some point. I don't really see that...
Quote: Originally Posted by Bill Fitzmaurice That's fine if you know the thickness and resistivity index required of the stuffing to give a desired Qa, Ql and Qp, but as far as I can tell you don't. I don't think any of the sims are good enough to predict exactly how much stuffing you should use or where you should put it. Fiberglass, poly and cotton all behave differently and where you put the stuffing in the box makes a big difference. The...
Quote: Originally Posted by soho54 All I can see is that you have no idea how these simulators work, and that you have never done any real measurements of anything either. That sums it up nicely.
Quote: Originally Posted by villastrangiato Now if you could only find the impedance profile button, the split view (port vs. driver response) button, and the electrical power drawn button - we might actually see something worthwhile or illuminating - like a halving of acoustical power at 15hz and a doubling of current drawn at the same frequency - all making this application of stuffing one of the most useless procedures to correct the crap response of...
Quote: Originally Posted by Bill Fitzmaurice Where are you adjusting the stuffing thickness and density? I didn't know WinISD had that ability. I use HornResp or Akabak when modeling stuffing. In the Box tab in WinISD Pro, click the Advanced button and you can change Qa, Ql and Qp.
Measure more, BS less. Go away, troll.
The sim is of the driver plus the port, just like you would hear in real life. Measure more, BS less. Go away, troll.
Here's how stuffing can change the response of an admittedly poorly-tuned ported sub. Yellow is without, green is with. It's just one more arrow in the designer's quiver. I don't have the files anymore but, back in the day when Scottmoose was redesigning Joe D's Thor TL over at DIY (Short Thor, Fat Thor, etc.), I was able to match his response curves pretty well with a ported box of the same internal volume and adjusting port length, Qa and Qp until I got a good match.
Bill, have you played with using stuffing to adjust Qa (box absorption) and Qp (how much the stuffing blocks the port) in a ported box? I haven't fiddled with this stuff as much as you have but my experiments years ago led me do believe that a TL's response could be duplicated in a ported box by adjusting Qa and Qp with stuffing.Edit: the total amount of stuffing in the box affects Qa. The amount of stuffing between the driver and the port affects Qp.
Quote: Originally Posted by Bill Fitzmaurice Actually, they do. When properly designed and implemented they use high Qts drivers, which are generally less expensive than the low Qts that work best in VBs. Good point, Bill. But, in the big scheme of things, I'm not sure saving 10 bucks on the cost of the driver is worth the added complexity of building a TL enclosure.
New Posts  All Forums: