CSS Trio8 music subwoofer implementation?

[Brisso57]

Can anyone share their experience with the CSS Trio8 driver as a music subwoofer?
What alignment?
What cabinet volume?
What lowest frequency is practically achievable?

(Here's a link to CSS's data: www.creativesound.ca/details.php?model=TRIO8)

Thanks

Doug

 

[Kravchenko_Audio]

This might interest you Doug

I'm almost ready to post the design. Give me about a week and it will be up with measurements.


http://www.diyaudio.com/forums/showthread.php?postid=1878760#post1878760

Mark

 

[planet10]

I have 4 here. Initial thots are to put them in a pair of push-push sealed with a bit of boost.

dave

 

[Brisso57]

I have 4 here. Initial thots are to put them in a pair of push-push sealed with a bit of boost.

dave

Sealed. OK.
What cabinet volume would that be?

I have a pair of really strong (& immaculate) retro-style sealed ply cabinets of approx 27L each. (The volume can be reduced by including filler blocks, of course.)
I was thinking of a solo sealed unit. If it worked well, I could make a second.

Doug

 

[Brisso57]

Re: This might interest you Doug

I'm almost ready to post the design. Give me about a week and it will be up with measurements.


http://www.diyaudio.com/forums/showthread.php?postid=1878760#post1878760

Mark

Mark,

I can wait a week.

Doug

 

[planet10]

Sealed. OK.
What cabinet volume would that be?

After posting that, i loaded up the T/S... to get to Bessel Q (~.58) took just over 50 litres. So with damping anything from 40-some to 70 litres for a pair of drivers would probably do.

50 litres also works ported -- tuned somewhere between 20 & 30 Hz. 20 hz port gets kinda long, 30 looks about right for a high aspect slot port -- i might see how that works too.

dave

 

[bjorno]

..What alignment? What cabinet volume? What lowest frequency is practically achievable?..

Hi,

A T-TQWT in about 40-60 L is possible with a FR stretched down towards 20 Hz. See the simulations: 1(3)-3(3).

b

1(3)

 

[bjorno]

2(3)

 

[bjorno]

3(3)

 

[bjorno]

Another larger T-TQWT variant :

b

1(1)

 

[Kravchenko_Audio]

Bjorno you know what you are doing!

That's a beautiful example of effiecient use of a driver and an enclosure.

Mark

 

[Brisso57]

After posting that, i loaded up the T/S... to get to Bessel Q (~.58) took just over 50 litres. So with damping anything from 40-some to 70 litres for a pair of drivers would probably do.

50 litres also works ported -- tuned somewhere between 20 & 30 Hz. 20 hz port gets kinda long, 30 looks about right for a high aspect slot port -- i might see how that works too.

dave

Thanks. How about as a single driver box?

Doug

 

[planet10]

How about as a single driver box?

divide by 2.

dave

 

[GM]

DIY variant of DSL's new HT tapped horn sub using dual TRIO8s: http://www.hometheatershack.com/forums/diy-subwoofers/16807-tapped-horn-build-th-spud.html

GM

 

[bjorno]

Hi all,

FYI: Some sub designs for use in homes seems to follow a motto I've found is valid : Up climbs the SPL but down goes the SQ . This if used as a single sub unit and not masked by other sub(s).

I have nothing against TH:s in general but from what I've experienced from studying designs here at DIYaudio:
Most shown TH designs must be amplitude equalized, often at an extra cost if not already provided built in by the sub amp.

Obviously its often necessary to signal delay the mains too, causing even more money to be added for the total implementation cost for this TH type.
That of course if not using an amplifier with built in user defined signal delay time capabilities.
Most aware users (IME,IMO) have the intention to integrate with expected good timing(phase) performance at the XO point.

b

Comparing GM reffered DIY-SPUD :

http://www.hometheatershack.com/forums/diy-subwoofers/16807-tapped-horn-build-th-spud.html

with my T-TQWT: 1(2)-2(2)

1(2)

 

[bjorno]

2(2)

 

[GM]

FYI: Some sub designs for use in homes seems to follow a motto I've found is valid : Up climbs the SPL but down goes the SQ .

I have nothing against TH:s in general............

Greets!

Too often true.

Well, as DSL's designs and 'geitmans' TH has proven, proper damping, XO point/slope plus room loading solves all but the time delay issues, so combined with the large size there's no 'free lunch' for the extra gain.

Still, as you know I agree that the T-TQWT (aka BP-TQWT) is a better choice overall for most consumer apps, with the even simpler tapped straight pipe fine for most music and HTs that otherwise would be OK with the restricted gain/Fb of a B0$3 or PC 'sub', though AV folks in general seem to prefer being able to see their big 'bada$$' sub driver(s) pumping away in simple sealed or vented cabs, so a 'tough sell' to those who would potentially benefit most.

GM

 

[fb]

GM, bjorno - do you have any guidelines for designing the T-TQWT? Fiddling in hornresp it seems a multitude of different path length and compression ratio combinations can fit a bandwidth.

 

[GM]

This is true since its net Vb is what sets the gain BW same as a BR. I use some old rule-of-thumb based on compression horn theory, but with the advent of MJK's excellent Classic TL Alignment Tables, you can easily design them. FWIW, I'm fond of 10:1 compression (taper) ratio, but for more slender one fold designs a lower one is perfectly acceptable.

http://www.quarter-wave.com/TLs/Alignment_Tables.pdf
http://www.quarter-wave.com/TLs/Alignment_Tables_Calculator_3_3_09.xls

GM

 

[fb]

Thanks GM. I've had a fiddle with the calculator/tables. I notice the alignments are designed to produce a quarter wave at driver Fs. And I'm not sure how to usefully translate the alignments to a tapped layout - using an L34 that will actually fit the driver in increases the ripple well past what's there when simulating it as a regular TL using hornresp's combined response option.


I'm over in the TD18H thread if this discussion's better suited there



Cheers,