Member
Joined 2003
Hello,
I am planning to build my first home subwoofer box (I have built car sub boxes before) in the next few months and I have a few questions before I begin. I have chosen to use the Peerless XXLS 830847 for this project, and am going to power it with a 360W@4ohm class AB plate amp. The reason I have chosen this driver is that I currently am listening to my music through a pair of bookshelf speakers which have both Peerless drivers and tweeters and I couldn't be more happy with them.
The Peerless application note for this driver recommends a 58 Litre box with the port tuned so that the -3dB point is 32.5Hz. From my own tests playing around in WinISD Pro, I have found that a 83 Litre box with the port tuned so that the -3dB point is 27Hz will produce a much better response. However, when I look at the cone excursion graph, this larger box design will cause the cone to move farther at less input power. Is there any chance that I can be reaching maximum excursion before I hit the RMS power (350W)? My other question is will this larger box cause my output to be lower volume than the smaller box? I would like to reach a happy medium between loud output and deep bass.
I understand that the XXLS series are very new drivers and not many of you (if any) have experience with it, but I am exited to hear your comments.
I am planning to build my first home subwoofer box (I have built car sub boxes before) in the next few months and I have a few questions before I begin. I have chosen to use the Peerless XXLS 830847 for this project, and am going to power it with a 360W@4ohm class AB plate amp. The reason I have chosen this driver is that I currently am listening to my music through a pair of bookshelf speakers which have both Peerless drivers and tweeters and I couldn't be more happy with them.
The Peerless application note for this driver recommends a 58 Litre box with the port tuned so that the -3dB point is 32.5Hz. From my own tests playing around in WinISD Pro, I have found that a 83 Litre box with the port tuned so that the -3dB point is 27Hz will produce a much better response. However, when I look at the cone excursion graph, this larger box design will cause the cone to move farther at less input power. Is there any chance that I can be reaching maximum excursion before I hit the RMS power (350W)? My other question is will this larger box cause my output to be lower volume than the smaller box? I would like to reach a happy medium between loud output and deep bass.
I understand that the XXLS series are very new drivers and not many of you (if any) have experience with it, but I am exited to hear your comments.
Member
Joined 2003
Well I entered Pe = 350W for the driver i wasn't sure if this value was supposed to be the RMS or the PEAK power rating. It tells me that it will reach xmax at about 250W for the box i designed, or 313W for peerless's recommended box.
Higher sensitivity for a larger box makes me a happy man
[Edit: I tried changing the Pe and it made no difference to the graph so I guess it doesn't matter for this]
Higher sensitivity for a larger box makes me a happy man
[Edit: I tried changing the Pe and it made no difference to the graph so I guess it doesn't matter for this]
Pe is the RMS rating of the driver, it's useful if you use the max SPL and max Power graphs.
So, check the excursion graph, it means that you shouldn't drive more than 250W RMS in your bigger box, but you'll have deeper bass.
Go into signal, and system imput power, enter 250W and see how much SPL you get, to see if it's loud enough for you.
Since you're going vented and tune around 27 Hz, maybe you shoud consider a rumble filter if you want to play alot of movies or bass really low at around 20 Hz or so, as you can see on the graphs, the curve climb very fast under the tuning point.
So, check the excursion graph, it means that you shouldn't drive more than 250W RMS in your bigger box, but you'll have deeper bass.
Go into signal, and system imput power, enter 250W and see how much SPL you get, to see if it's loud enough for you.
Since you're going vented and tune around 27 Hz, maybe you shoud consider a rumble filter if you want to play alot of movies or bass really low at around 20 Hz or so, as you can see on the graphs, the curve climb very fast under the tuning point.
Member
Joined 2003
Thank you for educating me on how to interpret the graphs in WinISD. I will check the SPL once I get home today, but I am certain now that it will be plenty loud enough. I had considered using a filter to limit the excursion at very low frequencies, but I don't think it will be nessisary. I can always add it in afterwards if I feel that I do need it.
Now all I have to do is wait for my income tax return to come in.
Now all I have to do is wait for my income tax return to come in
.
Member
Joined 2003
Member
Joined 2003
Picture Show
Before I get started here I thought I would share some pictures of what I have modelled. Because I want to do this right the first time, please let me know if anything looks hairy.
Vb = 80.33 Litres
Fb = 23.24 Hz
QL = 6.603
Before I get started here I thought I would share some pictures of what I have modelled. Because I want to do this right the first time, please let me know if anything looks hairy.
Vb = 80.33 Litres
Fb = 23.24 Hz
QL = 6.603
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Member
Joined 2003
Member
Joined 2003
I am in a dilemma here. Now that The Atlas drivers are available super cheap, I am contemplating whether I should choose the Atlas 12" over the XXLS. A quick plunk of some values into the modelling software shows me that the Atlas doesn't look as though it will be able to play quite as low bass, but it will play effortlessly because it has xmax to spare! I will play around with the numbers a little more tonight and see how good I can make things look. I had experemented with the low Qts values originally.
What I would like to know is your opinions of which driver you would choose. Again I am looking for deep, loud and distortion free bass that isn't crazy expensive. Which of these drivers do you think will produce less distortion?
If the Atlas is the driver of choice I am going to make my decision before the weekend so I can get one before they are all gone. Thank you for your opinions and help.
What I would like to know is your opinions of which driver you would choose. Again I am looking for deep, loud and distortion free bass that isn't crazy expensive. Which of these drivers do you think will produce less distortion?
If the Atlas is the driver of choice I am going to make my decision before the weekend so I can get one before they are all gone. Thank you for your opinions and help.
Member
Joined 2003
Ok so I have played with the numbers a bit and have modelled the Atlas to in fact look better than the XXLS. In fact I just used the exact same box as with the XXLS. Same port too! What are the odds? The driver plays about 2dB quieter at any given input level, but I can live with that.
I am curious though, that the cone displacement at full RMS input is never reaching any more than 11mm, so what really is the point of the extra xmax if it is never used.
The other thing I noticed is that Ascendant Audio lists that Vd is 1.73L, where BassBox tells me that for 18mm xmax Vd should equal 0.86L. I went with 0.86L for the modelling.
I guess the question now is which would you prefer sound quality wise? An XLS or an Atlas?
I am curious though, that the cone displacement at full RMS input is never reaching any more than 11mm, so what really is the point of the extra xmax if it is never used.
The other thing I noticed is that Ascendant Audio lists that Vd is 1.73L, where BassBox tells me that for 18mm xmax Vd should equal 0.86L. I went with 0.86L for the modelling.
I guess the question now is which would you prefer sound quality wise? An XLS or an Atlas?
I think the Atlas will be good in your application. I think the curve match room gain better.
Also, at the same powerlevel, you lose no more than 1 dB if I modeled correctly. It's also the same output under 30 Hz. Then, the Atlas subwoofer can take about 575 watts versus 225 watts in that box so you are now 3-4 dB louder across the whole range.
In theory, the Atlas should sound better. Linear BL curve, two times lower Le, higher Xmax...
In practice I don't know but the comments are very good, IMHO it's better.
Also, the XXLS is 164$, so you could consider two Atlas 12 for 200$ (isobaric, deeper bass, less distortion), two Atlas 15 for 210$ (isobaric, extreme deep bass, less distortion) or a single Avalanche 12 for 200$.
Also, at the same powerlevel, you lose no more than 1 dB if I modeled correctly. It's also the same output under 30 Hz. Then, the Atlas subwoofer can take about 575 watts versus 225 watts in that box so you are now 3-4 dB louder across the whole range.
In theory, the Atlas should sound better. Linear BL curve, two times lower Le, higher Xmax...
In practice I don't know but the comments are very good, IMHO it's better.
Also, the XXLS is 164$, so you could consider two Atlas 12 for 200$ (isobaric, deeper bass, less distortion), two Atlas 15 for 210$ (isobaric, extreme deep bass, less distortion) or a single Avalanche 12 for 200$.
You also want to know why you are at less than 13mm with 300W imput, it's because your box is not big enough hehe!
Try a 135 liters box tuned to 16 Hz, you're now at 18mm Xmax with 300W.
In your case, because you have 360W, I would go with 120 liters tuned to 18 Hz.
Vd at Ascendant Audio is listed peak to peak.
Usually software uses Vd peak value, not peak to peak value.
Alot of people use the peak to peak value because it's the amount of air the woofer will move in one stroke on one way.
Try a 135 liters box tuned to 16 Hz, you're now at 18mm Xmax with 300W.
In your case, because you have 360W, I would go with 120 liters tuned to 18 Hz.
Vd at Ascendant Audio is listed peak to peak.
Usually software uses Vd peak value, not peak to peak value.
Alot of people use the peak to peak value because it's the amount of air the woofer will move in one stroke on one way.
Member
Joined 2003
Thank you for your input. I really don't have the room to have any more than a 90L box, but I will look into the isobaric configuration with 2 Atlas 12's.
I had modelled the Atlas 12" tuned to 24Hz. I tried 19Hz as well because someone else on this forum was tuning there and it didn't make a very noticeable difference in the graphs.
I think I will order one (maybe 2) of these things when I get home from school today, and cancel my pre-order on the XXLS.
Thanks again.
I had modelled the Atlas 12" tuned to 24Hz. I tried 19Hz as well because someone else on this forum was tuning there and it didn't make a very noticeable difference in the graphs.
I think I will order one (maybe 2) of these things when I get home from school today, and cancel my pre-order on the XXLS.
Thanks again.
Isobaric is nice, but check in WinISD before to see if it's ok for you.
Since you will use only one 360W amplifier, you lose 6 dB.
Then, the sound quality is a bit better and the bass is deeper.
Check if you think it's worth it for you. If you plan to purchase another amplifier, then the loss would be only 3 dB.
Since you will use only one 360W amplifier, you lose 6 dB.
Then, the sound quality is a bit better and the bass is deeper.
Check if you think it's worth it for you. If you plan to purchase another amplifier, then the loss would be only 3 dB.
Member
Joined 2003
Member
Joined 2003
Well the sub box is built now. Not finished yet, but built. I managed 100L tuned to 20Hz. The speaker looks so small in such a large box.
The Sub-250R amp from Solen is just fantastic. I replaced the input coupling cap with a high quality poly cap, and I think I might change the 2 resistors that determine the bass boost so that the output is flat. I wanted to hear what it sounds like as is before I make that modifiation though. Highly recommended amp.
As far as the sub goes, it doesn't play crazy loud, but it does sound beautiful. Clean deep musical bass. Besides being flippin gigantic, this is exactly what I was looking for. Complements my bookshelf speakers wonderfully.
Thanks to all that helped me out on this project. I'll have a picture or two up in a few days, but I have to warn you that I am no master carpenter.
The Sub-250R amp from Solen is just fantastic. I replaced the input coupling cap with a high quality poly cap, and I think I might change the 2 resistors that determine the bass boost so that the output is flat. I wanted to hear what it sounds like as is before I make that modifiation though. Highly recommended amp.
As far as the sub goes, it doesn't play crazy loud, but it does sound beautiful. Clean deep musical bass. Besides being flippin gigantic, this is exactly what I was looking for. Complements my bookshelf speakers wonderfully.
Thanks to all that helped me out on this project. I'll have a picture or two up in a few days, but I have to warn you that I am no master carpenter.
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