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
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
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
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
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".
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".
An externally hosted image should be here but it was not working when we last tested it.
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!
If its a DVC driver, look at single coil (8ohm) and parallel coils (4ohm) opertation - the specs change!
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
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
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/img228/198/peerless001450x6006bg.jpg
http://img224.imageshack.us/img224/4503/peerless002600x4505ql.jpg
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/img228/198/peerless001450x6006bg.jpg
http://img224.imageshack.us/img224/4503/peerless002600x4505ql.jpg
LageB said: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.
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
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
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
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
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
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
I used WinISD to model the 830847 a while back using a 350w plate amp with boost @ 35hz.
The two 8ohm coils were in parallel and it was 70 litre / 26hz tune but needed a high pass filter to control excursion below 20hz.
Graphs and WinISD project file at:
http://www.users.bigpond.com/bcolliso/driver-P-830847.htm
The two 8ohm coils were in parallel and it was 70 litre / 26hz tune but needed a high pass filter to control excursion below 20hz.
Graphs and WinISD project file at:
http://www.users.bigpond.com/bcolliso/driver-P-830847.htm
Member
Joined 2003
I have also modelled the XXLS 830847 in a large enclosure. I did not account for bass boost on the amplifier though. On the PE, Solen, or Rythmik plate amps, you can remove the bass boost by simply replacing 2 resistors. I thought it would be better to have a flat frequency response from the amp.
You can see some graphs in this post. It has an F3 of 30Hz, and the cone reaches xmax at 300 watts input.
You can see some graphs in this post. It has an F3 of 30Hz, and the cone reaches xmax at 300 watts input.
LageB said:
Ok, so here is one for 830845, in a 240 litre box, tuned to 19.5 Hz. I have used two vents of 10 cm diameter, length 410 mm. This might seem long, but as you plan to filter out high frequencies, this will not be a problem. A single tube, on the other hand would overload at 20 Hz, reducing max output by about 8 dB to the red curve. The blue curve shows two ports, clearly the max output level at 20 Hz is higher. You can also see the pipe resonance in the port(s) using the longer ports at 300+ Hz. However this is not a problem if you use a filter. Make sure you use flares for the port, and possibly even add a small baffle to the inner ends of the ports.
An externally hosted image should be here but it was not working when we last tested it.
Disabled Account
Joined 2003
Hi Collo,
I checked out your site- did you have a chance to physically build subwoofer with the `847 in the 54L sealed enclosure and AA0501 amplifier?
What were you impressions?
I checked out your site- did you have a chance to physically build subwoofer with the `847 in the 54L sealed enclosure and AA0501 amplifier?
What were you impressions?
Hi tktran
I've only built with the Titanium 10 inch driver. All the other designs were done in response to emails from fellow Aussies wanting help designing subs with the other drivers.
I was looking at the Peerless gear because ultimately I want to build a single driver sub that will take 350w
I would expect that the sealed / 240w design would be OK for music with 106db @ 35hz. For home theatre, 97dB @ 25hz is a bit thin for my tastes...
Collo
I've only built with the Titanium 10 inch driver. All the other designs were done in response to emails from fellow Aussies wanting help designing subs with the other drivers.
I was looking at the Peerless gear because ultimately I want to build a single driver sub that will take 350w
I would expect that the sealed / 240w design would be OK for music with 106db @ 35hz. For home theatre, 97dB @ 25hz is a bit thin for my tastes...
Collo
Many thanks again Svante,
I really appreciate your help to simulate the 830845 . You must have spent some time elaborating different alignments to reach your solution.
Your graph shows almost flat response down to 20 Hz - It is very temptating to build this subwoofer. Regarding flared ports, there are a good thread in this forum which I will study from now on.
As you know, I did own simulations in LspCad, but came up with different length of Port (using 1 Port) however, I did not consider overloading etc.
How do you think? Based on your experience and opinion, would you personally recommend this subwoofer (your alignment). I think it looks stunning.
LageB
I really appreciate your help to simulate the 830845 . You must have spent some time elaborating different alignments to reach your solution.
Your graph shows almost flat response down to 20 Hz - It is very temptating to build this subwoofer. Regarding flared ports, there are a good thread in this forum which I will study from now on.
As you know, I did own simulations in LspCad, but came up with different length of Port (using 1 Port) however, I did not consider overloading etc.
How do you think? Based on your experience and opinion, would you personally recommend this subwoofer (your alignment). I think it looks stunning.
LageB
LageB,
The box you mentioned at the start is far too big!
XLS is commonly used in small boxes, however, despite it being designed with a small box in mind, a larger box has advantages. Where a fairly large box is acceptable, I consider a 90L box to have very good performance. This is bigger than most others will suggest, mainly because they don't allow for the impact of a rumble filter.
Try this in WinISD pro:
90L with 120mm vent tuned to 20 Hz and 350w input.
filters:
* highpass (rumble filter) 3rd order @ 20 Hz
* lowpass 3rd order @ 36 Hz
This should match sealed rolloff @ 40 Hz to cross to your SS speakers.
-3 db points are at 20 and 40 Hz in anechoic conditions
vent velocity is kept below ~ 18m/s with 350w input which should be ok with a decent flare
Keep in mind that if you don't use the rumble filter, the bass won't be right. Also if you design it without a rumble filter in mind, then add one, you will lose extension and it won't work as predicted.
Also with smaller boxes, it is harder to get a non-chuffing port. If you use a 50L box, it will be difficult! Even a 70L box means the vent will need to be quite long. If you can live with 240L, then I suggest 90L is a good size. You don't really gain much by going bigger (unless you want an EBS with 15 Hz extension), but you have to compromise to get it smaller.
The box you mentioned at the start is far too big!
XLS is commonly used in small boxes, however, despite it being designed with a small box in mind, a larger box has advantages. Where a fairly large box is acceptable, I consider a 90L box to have very good performance. This is bigger than most others will suggest, mainly because they don't allow for the impact of a rumble filter.
Try this in WinISD pro:
90L with 120mm vent tuned to 20 Hz and 350w input.
filters:
* highpass (rumble filter) 3rd order @ 20 Hz
* lowpass 3rd order @ 36 Hz
This should match sealed rolloff @ 40 Hz to cross to your SS speakers.
-3 db points are at 20 and 40 Hz in anechoic conditions
vent velocity is kept below ~ 18m/s with 350w input which should be ok with a decent flare
Keep in mind that if you don't use the rumble filter, the bass won't be right. Also if you design it without a rumble filter in mind, then add one, you will lose extension and it won't work as predicted.
Also with smaller boxes, it is harder to get a non-chuffing port. If you use a 50L box, it will be difficult! Even a 70L box means the vent will need to be quite long. If you can live with 240L, then I suggest 90L is a good size. You don't really gain much by going bigger (unless you want an EBS with 15 Hz extension), but you have to compromise to get it smaller.
paulspencer said:
Mostly I agree.
See my post #9 : http://www.diyaudio.com/forums/showthread.php?postid=738127#post738127
Thanks Paulspencer, Notax and others
It seems that the majority here recommends me NOT to go along the path of giant BR Box.
But, does not Svantes' simulation look good ?
And, Paulspencer - Is your simulation really for the XXLS 12" ?
LageB
It seems that the majority here recommends me NOT to go along the path of giant BR Box.
But, does not Svantes' simulation look good ?
And, Paulspencer - Is your simulation really for the XXLS 12" ?
LageB
For good reason - beyond a certain point there is no advantage. A box should be as big as is required to get the necessary F3 at reasonable efficiency. Sometimes a little bigger can help with getting a decent vent in. The larger a box is, the more efficient it will be at tuning. However, if the box is too big, you then need to shift tuning lower to avoid a peak at tuning. If you keep making the box bigger, and tuning lower there comes a point where you start to lose overall output as the excursion will increase above tuning and efficiency above tuning will drop. So there are compromises to be made.
It does make a 240L box look ok. Once you factor in filters, which are not shown in his chart, things will look different. If you put in a 2nd order lowpass, for example with an fc @ 40 Hz, you won't get a correct integration, as the -3db point won't be at 40 Hz!
IMO you should include the filters in the design of your sub. This is often neglected in design, and a sub is designed as if it will not have any filters, which is never the case.
I have not done any sims for the low Qts version of the XXLS. I see no reason to use it for a vented sub. It's early rolloff due to lower Q will most likely make it more difficult to get the response you want.
Actually, they were for the XLS 12" , however a quick sim shows me that it's not much different, you just need to put the lowpass @ 30 Hz. This is allowing for the XXLS driver intended for a vented box
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