New HSU VTF-3 H.O. Specs (1 Viewer)

[Craig Chase]

Curtis, To date, NOONE has approved the blind test. I wanted to offer Hsu Research the first chance at this possible test, then, had things progressed, others would have been afforded a spot, if they wanted to be involved.

For example, HAD Hsu Research said "Yep, we are in" ... and all the other companies looked at Hsu's products and declined to participate, that would speak volumes ... true ?

 

[Peter Marcks]

Ultimately, Dr. Hsu is THE final authority on what units we send out formally to reviewers. I imagine that he is too flooded right now to give it much thought.

 

[CurtisSC]

Thanks Craig....totally understood.

Since the new driver and amp are not even part of the prototype at the show, I would imagine Dr. Hsu will be busy fine tuning them for a bit.

 

[Craig Chase]

Hopefully we WILL see Keith Yates put an "HO" through the paces... it would be a LOT easier for me to read his report than to go through another microphone calibration, setting the subwoofer 100 feet from our house, and running the necessary wiring ... JUST so I could measure the same stuff Keith does.

I did it with the Maestro ... it takes HOURS ... Just reading about it from someone like Yates would be FAR preferable.

Peter ... The best part about a Keith Yates review is it would allow your new subwoofers to be compared EXACTLY in the same method that he used for the Way Down Deep test...

 

[Chris Quinn]

Were is a tubrocharger picture? Hasn't anyone found one yet?

 

[Chris Quinn]

Quoting an Ed Mullen post on another forum-

"6) The turbocharger unit was not on display. This device externally entends the port length by coupling to the rear ports and then making an upward U-bend so that it fires forward on top of the enclosure.

The turbocharger unit will have the same wood finish as the enclosure. In addition to lowering the tune point, adding port length will likely overdamp the alignment, so there will be a custom EQ switch setting for both tunes, similar to the existing VTF series." http://www.avsforum.com/avs-vb/showt...65#post4960065


So, is the turbocharger using sort of the same concept as a transmission line speaker does to get good bass out of smaller cabinets and drivers?

 

[Chris Quinn]

Another interesting snippet form Ed's post-

"4) The VTF2-HO uses a single wide flared 4" port - rear firing. The amp is digital BASH with 350 watts continuous."

Are the present Bash amps that Hsu uses digital?

 

[Jack Gilvey]

No, standard bass-reflex theory applies. The "turbocharger" is, as I mentioned above, a port extension. With a fixed box volume and tune point (in this case, we'll consider the 18Hz Fb) porting needs to get longer as cross-sectional area increases. The extension "re-tunes" the box while maintaining the original porting area. Actually doubling the output of a 1220HO across its bandwidth will be quite a tall order with only a single driver, less amp, and less Vb, but it certainly sounds like a winner.
The native 22Hz tune point using both 4" ports would likely be enough for just about anyone, should be quite impressive.

Certainly, it'll be intriguing to compare the 3HO to something like an SVS PB12 Plus/2 which, with one port plugged, has a 20Hz Fb using two 4" flared ports. One could consider it as having its "turbo" already built-in due to the greater box volume.

 

[Arthur S]

With regard to the amp in the 3HO, there appears to be a bit of confusion. The placard atop the 3HO at CES says 500 watts. A post over at AVS says 375 watts. I have left a message for Peter Marcks of HSU to clarify. I would find it hard to believe that Dr. Hsu would put a sign on the 3HO saying 500 watts and then turn right around and drop it to 375. I hope to have clarification in the next 36 hours.

 

[CurtisSC]

Arthur.....Ed is wrong with that information.

It will indeed have a 500 watt amp as the placard states and as I have confirmed with Dr. Hsu.



The units on display had the current VTF-3MK2 amp and driver.

 

[paul clipsel]

Glad to see Edward confirms the same info from Dr Hsu about the 13Hz tune that both my brother and Curtis reported. It must be under consideration.



PC

 

[Arthur S]

Thanks for the clarification Curtis, as well as the photo of the placard showing 500 watts. Peter Marcks has also responded to my query and confirmed 500 watts RMS.

Curtis, under your photo you say:

>>The units on display had the current VTF-3MKII amp and driver

 

[Jack Gilvey]

No one doubts that having only one port of the "turbo" active will result in a ~13Hz tune. As with any tuning decision, what has to be considered is the inevitable trade-off in headroom, not to mentioned the amp power required for an eq setting allowing 13Hz to be flat. It seems some are seeing the 13Hz tune as magically "free". It's not difficult to have a 13Hz tune, you just need a long port.
Even if it's not an option in final form, one could still block one of the turbo ports and not tell the Dr Hsu.

 

[CurtisSC]

Jack....I agree. Taking floorspace and cost into consideration will make it even more interesting.

 

[Edward J M]

Hi guys:

Yes, it was a typo that I acknowledged and corrected right away (I was sorting through lots of notes from CES). The VTF-3HO is 500 watts continuous, which makes sense considering the higher thermal power handling of the woofer.

The difference between 350/500 watts is only about 1.5 dB (assuming there is no thermal compression occuring), but regardless, it is definitely 500 watts continuous.

 

[paul clipsel]

For me the trade off is fine. The problem comes in that it is an overdamp design, so to flatten the response out will require Dr Hsu to put in a third eq setting on the plate amp. A single TN1220s output if flat to 13Hz is more than I could use so this config sounds ideal for my organ music.

PC

 

[Craig Chase]

Does anyone have information regarding the effect of the turbocharger on gas mileage ?

Usually a turbo knocks about 25% of the MPG vs. the normally aspirated model....

 

[CurtisSC]

Paul.....how much of that 13Hz - 18Hz will you be able to take before falling apart?

 

[CurtisSC]

LOL!!!

 

[Edward J M]

The 18 Hz tune with both ports open on the turbocharger would be ideal for pipe organ. The lowest note on even the 32 foot pipe organs is about 17 Hz - smack in the middle of the sweet spot for the enclosure tuning.

And remember, the enclosure tuning point does not mean the subwoofer can't play lower than that. With judicious use of EQ and a high pass filter, expect 1/5 octave deeper extension below the actual tuning point of the enclosure. Add in typical room gain, and you might even see a rising response to 15-16 Hz in-room.