Sanity Check Please - W130 2x4 with ND140-PR

[3rutu5]

Sanity Check Please - W130 2x4 with ND140-PR

I was under the impression that you generally need double the SD for Passives or close to it, but not 1:1. Dont ask what yet but you may recall i have a pair of Visaton W130 2x4 woofers i'm looking to incorporate into a build and scaled up something and ran this scenario through WiniSD and got this.

an enclosure of 0.15cuft with 1x ND140-PR and 20grams of additional weight, it models F3 50hz and looks reasonable? So have to ask the question, am i doing something wrong?

[1100xxben]

What you actually need is double the Vd, not Sd. It is possible to achieve desired alignment/tuning without abiding by that rule of thumb. The reason you need double the Vd is because your passive will run out of excursion/linearity before the driver(s) will. In your sims, you need to apply signal and look at excursion of the transducer and the passive. You will likely find out that when your transducers hit their xmax, your passive will be WAY over its rated xmax.

[3rutu5]

What you actually need is double the Vd, not Sd. It is possible to achieve desired alignment/tuning without abiding by that rule of thumb. The reason you need double the Vd is because your passive will run out of excursion/linearity before the driver(s) will. In your sims, you need to apply signal and look at excursion of the transducer and the passive. You will likely find out that when your transducers hit their xmax, your passive will be WAY over its rated xmax.

ok, so what im hearing is, it might model ok the way i did it, BUT once i put a load onto the drivers i run the risk of the PR's themselves exceeding what they can take, which i assume would be in the way of some form of distortion.

[1100xxben]

ok, so what im hearing is, it might model ok the way i did it, BUT once i put a load onto the drivers i run the risk of the PR's themselves exceeding what they can take, which i assume would be in the way of some form of distortion.

Yes, what you have modeled is the normalized response, but that assumes all aspects of the design are operating in linearity. If your PR size is too small, then when you start driving it to its limit, it will add a little bit of distortion, but it will also cease to provide more output. It will kind of start operating like an EBS alignment at high volumes.