Power Sound Audio Triax Subwoofer Preview

[TLS Guy]

That's what you think. No surprise.

Like I said, overrated and hearsay.

The XLS1000 can output 1100 watts RMS bridged into 4 ohms. It will do just fine.

I am using an AT3002 amp (450 WPC/4 ohms/ 0.03% THD) for my dual Funk 18.0 subs, and AT6012 (90 WPC/4 ohms) for dual RBH SX-1010N subs (w/ Orion). The bass is fantastic and sounds like an earthquake/F5 tornado when playing War of the World BD.

So, yeah, just fine.

It's not as flat as you think. ALL sealed subs roll off at 12 db per octave well above driver Fs. That is just math and physics, not hearsay.

The reason sealed subs take so much power is that you have to Eq them at 12 db per octave just above the 3 db point minus room gain. You are just proving that bass is perceived mainly above the last octave, so you don't need to chase the 20 Hz stuff and below.

 

[Irvrobinson]

You are just proving that bass is perceived mainly above the last octave, so you don't need to chase the 20 Hz stuff and below.

When you say "last octave", which octave are you referring to? 10-20Hz?

 

[haraldo]

It's not as flat as you think. ALL sealed subs roll off at 12 db per octave well above driver Fs. That is just math and physics, not hearsay.

The reason sealed subs take so much power is that you have to Eq them at 12 db per octave just above the 3 db point minus room gain. You are just proving that bass is perceived mainly above the last octave, so you don't need to chase the 20 Hz stuff and below.

I guess it's not exactly like this.... In anechoic conditions you do have a 12dB / octave rolloff....
In a room, it depends on the room and position of sub, in practice the actual equalization depends on the room gain and the corner loading.... is this not true?

 

[TLS Guy]

When you say "last octave", which octave are you referring to? 10-20Hz?

Actually 20 to 40 Hz

 

[Irvrobinson]

Actually 20 to 40 Hz

Ah, then I really can't agree. Using the RTA display on the OmniMic II with 1/12th octave resolution shows a surprising amount of output in the 20-40Hz octave, especially on contemporary jazz CDs. Popular music CDs with synthesizers also do it, like for example those from Sarah McLachlan.

 

[AcuDefTechGuy]

You are just proving that bass is perceived mainly above the last octave, so you don't need to chase the 20 Hz stuff and below.

Who says I care about any frequencies below my hearing threshold ?

You were talking about an F3 of 60Hz w/ 1,100 watts RMS amp, which is ridiculous. 20Hz-100Hz is all I care about for bass.

 

[TLS Guy]

Ah, then I really can't agree. Using the RTA display on the OmniMic II with 1/12th octave resolution shows a surprising amount of output in the 20-40Hz octave, especially on contemporary jazz CDs. Popular music CDs with synthesizers also do it, like for example those from Sarah McLachlan.

The issue is an audio psycho perceptive issue. The ear rapidly looses sensitivity below 40 Hz and what people actually perceive as bass is above 40 Hz.

Most pipe organs only have 16 ft stops and yet they have a lot of bass. 32 ft stops which go to 16 Hz don't actually change the perception of bass as much as skilled voicing of the organ does.

 

[TLS Guy]

Who says I care about any frequencies below my hearing threshold ?

You were talking about an F3 of 60Hz w/ 1,100 watts RMS amp, which is ridiculous. 20Hz-100Hz is all I care about for bass.

That Triax sub is a very small box for those 3 woofers and the F3 point will be 60 Hz or higher without Eq. That is why it takes so much power. Whereas my lines which are efficient acoustic transformers can reach 20 Hz without the amps breaking a sweat or much cone travel of the drivers. Of course they take up much more real estate and that's the rub.

 

[ShaunH]

I find this argument really stupid. Your getting a excellent amp from speaker power and you want a passive version.

Here how about this.... a outboard amp from speaker power.....

Rack Mount Models - SpeakerPower

Vs the plate amps they also offer

SP1 Mono Models - SpeakerPower

Not to mention you might actually get less output from a cheap outboard amp.

 

[Irvrobinson]

The issue is an audio psycho perceptive issue. The ear rapidly looses sensitivity below 40 Hz and what people actually perceive as bass is above 40 Hz.

Most pipe organs only have 16 ft stops and yet they have a lot of bass. 32 ft stops which go to 16 Hz don't actually change the perception of bass as much as skilled voicing of the organ does.

I don't know much about tuning organs, but I do know that rolling off bass response below 40Hz has a significant and easily perceived effect on the music I mentioned earlier. Sub-40Hz bass pressurizes the room and you feel it, and feel isn't logarithmic like hearing is. IMO, once you get accustomed to strong and accurate reproduction in the 20-40Hz octave you are addicted, it is difficult to go back to missing it.

 

[Irvrobinson]

my lines which are efficient acoustic transformers can reach 20 Hz without the amps breaking a sweat or much cone travel of the drivers. Of course they take up much more real estate and that's the rub.

And a commercial version would probably cost a fortune too, due to high construction costs. I'm guessing those TL cabinets were way complex to build.

 

[haraldo]

So to find out how much equalization is needed in this case with a sealed sub, in this case. 2 Peerless XlS-12 subwoofers in a 65 liter cabinet, see the configuration here, with also PEQ curve shown, 6dB raised at 15 Hz

ANECHOIC RESPONSE
The anechoic response calculated by the Embla Audio program:
Look at GREEN CURVE!

CORNER LOADING
The response calculated by the Embla Audio program when SUB is corner loaded:
Look at GREEN AND RED CURVE!

I'm sure there are many many variables, not covered here and I'm not sure how good this program is and how well it represents what you get in real life but.....
We cannot mix anechoic behavior with what you get when you corner load a sub

I'm sure Powersound audio will post the relevant metrics on their website soon
At least I would be very in seeing similar theoretical and measured figures on the Triax!

 

[haraldo]

And a commercial version would probably cost a fortune too, due to high construction costs. I'm guessing those TL cabinets were way complex to build.

There are not actually very many TL based commercial subwoofers around, as far as I know it's really only UK based PMC, and they're really good as far as I read, never auditioned them....
Also Australian VAF do have something with some sort of tuned pipe.....
There's a lot of woodwork going in here so I reckon a lot of the price is shipping of the big big box.....

I read somewhere the amount of work going into TLS's speakers and subwoofers and this would definitely make them an expensive set of commercial speakers if it should ever come to this!

TLS's subs are the best for one very good reason, he rely on Norwegian Seas Excel drivers

 

[AcuDefTechGuy]

That Triax sub is a very small box for those 3 woofers.

Oh, I forgot about the 3 woofers.

The Funk 18.0 sealed sub only has a single 18" woofer and it does not require more than 400 WPC to blow the windows out of my room.

The Rythmik D15SE is also sealed and only requires a 450watts amp (built-in).

But I never had a sealed sub w/ 3 woofers.

 

[AcuDefTechGuy]

There are not actually very many TL based commercial subwoofers around

Maybe there's a good reason for that. People always think their designs are THE BEST.

But no way of PROVING that unless they're all measured by Audioholics.

I'm not taking anyone's own word that their designs are THE BEST.

 

[haraldo]

Maybe there's a good reason for that. People always think their designs are THE BEST.

But no way of PROVING that unless they're all measured by Audioholics.

I'm not taking anyone's own word that their designs are THE BEST.

Somehow I always been very happy with bass from good TL designs, I think it's the best enclosure for a sub too, would really like to audition the PMC subwoofers....

Don't think Power Sound or Funk will make TL's it's probably too big and too expensive to ship anywhere

 

[haraldo]

That Triax sub is a very small box for those 3 woofers and the F3 point will be 60 Hz or higher without Eq. That is why it takes so much power. Whereas my lines which are efficient acoustic transformers can reach 20 Hz without the amps breaking a sweat or much cone travel of the drivers. Of course they take up much more real estate and that's the rub.

Well another thing, if cabinet is too small for drivers, you will get a too high Q value at resonance and a too "boomy bass", that is nowhere close to what you get from a good TL design, yes

Richard Vandersteen closely advocates a Q = 0.5 on all his subs in order to have less ringing and best possible bass.....John Dunlavy advocated similarly Low-Q tuning in all his big big speakers (SC-V and SC-VI), and they were certainly not known for poor bass quality...... they easily reached sub 20Hz in-room extension without the need for any equalization.... but the size and weight

opinions please?

 

[fuzz092888]

Don't get me wrong, I love a good brute force subwoofer (i.e. the massive dual opposed I built), but on the other hand the Phil's with their ML-TL produce extremely satisfying bass and a surprising visceral experience. Not the same as the dual opposed, obviously, but amazing nonetheless. Now, I'd love to build or at least hear a TL subwoofer because the idea of being able to drive a sub to extreme SPL's off of a couple hundred watts is extremely appealing. Much more appealing than adding about 4000 more watts to the dual opposed for the same levels of performance.

 

[ahblaza]

My Man, the sub man

 

[TLS Guy]

And a commercial version would probably cost a fortune too, due to high construction costs. I'm guessing those TL cabinets were way complex to build.

You just can't imagine how hard it was. The techical drawings alone took me months. The build was three and a half months. However I just can't tell you how much pleasure they have given. It was worth it and then some.