[Arthur S]

As I mentioned in a previous thread, the HSU VTF-3HO is available for pre-order at $100 off. With the Turbo the pre-order price is $899.

Here is the first picture of the Turbo:

Note: You have to scroll to the top of the page for the photo.

http://www.hsuresearch.com/forum/sho...4803#post14803

Note:

The ports reportedly look larger in the photo than in person.

HSU has posted specs on the VTF-3HO and it is -1db at 16Hz.

Wouldn't it be great if Ed Mullen got to test the '3HO + Turbo' sometime soon.

[Chris Quinn]

http://www.hsuresearch.com/forum/att...ntid=373&stc=1

Am I getting this right that the turbo only lets the HO play louder but not lower?

[James Edward]

What cup size are the ports?

[Peter Marcks]

Yes Chris, the turbocharger means louder and cleaner bass in the very low frequencies, not added extension versus maximum extension mode with port plug. In theory, we could extend the turbocharger ports all the way across the entire top surface of the base subwoofer to further extend frequency response, or plug a port on the turbocharger to further extend frequency response, but I'm not sure how practical this would be.

James, the ports are 4" internal diameter, with very large flares.

Sincerely,

[Dustin B]

Making ports longer is doing essentially the same thing as plugging a port, just without sacraficing half your port cross sectional area. When you reduce cross sectional area and keep the length the same the tuning frequency goes down, but you up the port air speed significantly limiting how loud you can go before port compression or chuffing sets in. If you keep the cross sectional area the same (and therfore the port air speed), you either have to increase the size of the box, or lengthen the port to lower the tuning frequency.

What Dr. Hsu appears to have done is figured out how to successfully market a concept a few DIYer who don't have to content with SAF have tried. Building a sub where you solve the problem of the necessary porting being too long to fit in the box by having part of it stick out of the box.

[Gregg Loewen]

looks way wild!!