system Q

[drumzy]

in sealed subs,

Q=.5 = critically damped, super tight, non boomy, music only usually.

Q= .7 = usual compromise beteen music and HT....nice bloom, fatness,

Q=>.8 boomier, not good for music, muddy still for HT, but really impresses some.



here's my questions. how does Q relate to ported designs? is there an overall system Q for a ported sub, or does the port have a different Q at it's operational frequencies as compared the the frequencies where the driver is responsible for bass output?

Can a linkwitz filter be applied to a ported system to give it a lower Q?

What is the system Q of the VT-3?

thanks

[Lwang]

All of Hsu's subs are overdamped design, meaning the Q is less than 0.5. This will cause a early slow rolloff, roughly at a little more than 1 octave above the tuning freq at a rate of 6dB/oct. This would create a more efficient subwoofer, but with the early rolloff.

Hsu's amplifiers are all bass-optimized for his sub, meaning that they have a higher Q in the same region (done via an integrator?). So when combined with their sub, it would create a critically aligned system.

So the final system is a musical sub that is more efficient @ 1 octave above tuning freq, and equal efficiency compared to a critically damped sub at rolloff.


Now you know when neophytes are awed by HT subs, the real reason is that they are loose and flabby.

[drumzy]

is it a moderen myth then, that a vented sub cannot have the transient response of a quality 0.5 Q sealed box?

what about group delay inherent with the port.....does that make this design subjectively sound any slower than a sealed box?

I guess where I'm really going with this, is that I've been lead to believe that for the most musical sub, I've heard that I should go with a desigh like a sealed adire or aci titan, and I've also seen the rel subs associated (I know they're ported) with music first systems. Most of the reviews I've read about the svs and hsu boast about room shaking spl on dvd's and the tightness for music is a bonus.



I really want the sub for music, where HT is just a bonus.

Are there any hsu users that have really high end fast monitors like soundlab, magnepan, quad merlin, wilson, proac...etc?

I am looking for the best and tighest non-tube sub for music for < $1000.

[Chris A H]

I've heard that I should go with a desigh like a sealed adire or aci titan,

Most DIY subwoofers designs are on a much simpler scale. The level of design, engineering and component integration is much more advanced in something like the Hsu subs.

Most of the reviews I've read about the svs and hsu boast about room shaking spl on dvd's and the tightness for music is a bonus

Of the reviews I read about both, most all call the Hsu the more "musical" of the two. That's why I selected Hsu.

[Lwang]

Group delay is a know issue with vented subs, but in general with Hsu subs that are tuned in the upper teens, group delay becomes a non-issue at freq in which the sealed subs comes into play.

I use my TN1220 subs to mate with my magnepan MG-IIIa. They mate quite well. The best way to integrate the maggies while preserving as much of its characteristics as possible is to cross over the sub at as low a freq as possible. Either run the sub via bass-augmentation, or by utilizing Hsu's better amp/electronic crossover and filter out the bass from the mains in which the sub will handle.

Dr. Hsu originally designed his subs to mate with his Quads, so they were always designed for musicality and integration to transparent speaker systems. His utilization of cylindrical enclosures were not done for the purpose of ease of manufacturing as those DIYers do, but for their inert sound characteristics. To mate a sub to a speaker system in which there is zero cabinet coloration, one either build their sub out of concrete/lead or do what Hsu discovered over a decade ago and go with tubes.

[drumzy]

"I use my TN1220 subs to mate with my magnepan MG-IIIa"

"Dr. Hsu originally designed his subs to mate with his Quads"

this speaks volumes to me! ...pretty much just the kind of description I was hoping for.

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At levels below system limits, ie between 90-100 db and 25-60 HZ, will the the vtf-3 sound close to the hsu cylinder subs with the external amps, in terms of lack of cabinet coloration and taughtness?