XXLS Large vented Sub

[LageB]

Hei folks,

What does the commmunity here say about my brilliant idea to use a peerless element XXLS, designed for sealed applications, but, to use it in a large vented box instead.

The Box will be around 240L (yes, I have space, yes, I have wife's approval)

For the element in Question. Please refer peerless Homepage.
http://www.tymphany.com/products_Peerless.html

Element: Peeerless 12" XXLS 8Ohm No.830843
Box volume: 240L
Vent Dia: 10cm
Vent Length: 18cm
Frequency to be used: 40Hz and below

What I can understand, it would give practically flat response down to 20Hz. Would there be any drawbacks? How do you think?

Looking forward to hearing your valuable comments

LageB

[bogicp]

Hi LageB,

You can find more information about building XLS vented subwoofer at
http://www.tymphany.com/peerless/tech/appxls12b.htm

With that large box you probably get better results with two of 830867 SLS 15" subwoofers (Peerless) http://www.tymphany.com/peerless/data/830867.htm

I probably speculate only, because I don't check this.

But I think that XLS subwoofers are designed for small boxes.

best regards,

-boggy

[Svante]

Hej!

I think a box of 150 litres would do. Here is a simulation of such a box tuned to 20 Hz. With a port diameter of 100 mm, the length becomes 316 mm. I would not stop at 40 Hz, why not use it up to the standard 85 Hz?

The maximum output level is 100 dB down to ~25 Hz, and 94 dB at 20 Hz.

BTW, the 830843 is the 10", not the 12".

[Collo]

Keep an eye on cone excursion and for a single 100mm port use port flares.
If its a DVC driver, look at single coil (8ohm) and parallel coils (4ohm) opertation - the specs change!

[LageB]

Nämen, hej igen Svante ! Kul!


Thank you Svante for pointing out my mistake. My idea was actually to use the XXLS 12", so the Number is 830 845 and nothing else.

Nice graph you made for me there. Is that the 10" or 12" ?

Reason why I tentatively do not plan go higher with XXLS, is that my woofer is a Scan speak 10" (sealed) that do quite well down to 40Hz. Anyway, final XO will be decided later. I leave that issue open timebeing.

LageB

[Asdonk]

I use th xxls12 830845 woofer in the 62 ltr sealed enclosure with a BK electronics 200w mosfet plate amp, the filling off the enclosure makes it 10 % bigger as seen by the woofer
with test tones 25 hz is there with homecinema
in the near futere I have plannes to use a Behringer DSp1124
to give the bass response below 35 hz a little boost
at the moment the sub is doing fine and it has replaced a peerless xls10 with passive radiator just for the fact that it is better with music
my front speakers are the scanspeak ultimo with the ss 18w8531Goo woofer in 40 ltr and a -3db off 30 hz
http://img228.imageshack.us/img228/1...450x6006bg.jpg
http://img224.imageshack.us/img224/4...600x4505ql.jpg

[Notax]

Originally posted by LageB
Hei folks,


The Box will be around 240L (yes, I have space, yes, I have wife's approval)

Element: Peeerless 12" XXLS 8Ohm No.830843
Box volume: 240L
Vent Dia: 10cm
Vent Length: 18cm
Frequency to be used: 40Hz and below

What I can understand, it would give practically flat response down to 20Hz. Would there be any drawbacks? How do you think?

Looking forward to hearing your valuable comments

LageB

Its 10" woofer.
I calculate with TS parametrers but with my corections, because, with bigger Qts, best Vb is not that you got with standard simulations (many kinds od compresions and you got lower SPL at lowest frequencies then average).
With my corections, I got Vb=49,5 l and Fb=24,6 Hz.
Port at least 70 mm in diametar. For that diametar, lenght is 380 mm.

[LageB]

Ladies & Gentlemen, if any


Please kindly forget about XXLS 10". I am sorry I have the wrong Peerless No in my initial post.

My idea is XXLS 12" No.830 845 (not 830 843)

As far as I simulated i get (with 240L Box)

a) -3dB: 18Hz
b) 106db at 20Hz within linear cone excursion limit (25mm p-p)
with 80W input at 8Ohm, simulated by LspCAD.


Am I wrong? This should be pretty good subowoofer, shouldn't it?

LageB

[Notax]

Simulations can give different result than real is.
For high Qts with standard simulations we got large enclosure, but with eksperiments, better is smaller, and higher Fb. Its because of compresion. Cant use that results of simulations as relevant for BR for higher values of Qts.

Peerless recommand closed box. Here is link : http://www.tymphany.com/peerless/data/830845app.htm
And Asdonk use this woofer just like that.(up, post #6)

My calculation for BR. (with my corections of standard simulations)

Vb=80 L
Fb=22,5 Hz
Dp=90 mm
Lp=395 mm

[Asdonk]

I have ordered a second xxls12 no. 830847 for basreflex
it wil do 32 hz in a 58 ltr enclosure without any bassboost
first I will build the 58 ltr enclosure to do some tests and lateron a bigger enclusre like 95 ltr which will go down to 25 hz