Hi there,
It's been a while now since I first hooked up at this forum but I never had an active roll in it since I'm a newbie on DIY's!
I've just purchased an 830845 Peerless XXLS Sub-Driver for a sealed application.
I’m thinking on using a Qtc value of 0, 62 meaning that I will be obliged to go for an aprox. 100 liter box, since the main purpose of this subwoofer is to play in an audiophile stereo system and/or a 5.1 application to play mainly music concerts!
I would like to have any kind of input from this community that would help me to make the right decisions to achieve the best possible sub application with this driver.
I was also thinking on using a Rythmik Audio - A370-Special Edition (SE) and a Linkwitz Riley Transform for my application.
Since this is a non-servo setup (I would prefer if it would be a Servo application but I don't know how I could implement such a setup), I'm a little concerned with de max excursion of the drive and with the clipping of the amp. Any suggestions?
I really would like to know your opinions and suggestions for my little project.
Cheers,
TIFF
It's been a while now since I first hooked up at this forum but I never had an active roll in it since I'm a newbie on DIY's!
I've just purchased an 830845 Peerless XXLS Sub-Driver for a sealed application.
I’m thinking on using a Qtc value of 0, 62 meaning that I will be obliged to go for an aprox. 100 liter box, since the main purpose of this subwoofer is to play in an audiophile stereo system and/or a 5.1 application to play mainly music concerts!
I would like to have any kind of input from this community that would help me to make the right decisions to achieve the best possible sub application with this driver.
I was also thinking on using a Rythmik Audio - A370-Special Edition (SE) and a Linkwitz Riley Transform for my application.
Since this is a non-servo setup (I would prefer if it would be a Servo application but I don't know how I could implement such a setup), I'm a little concerned with de max excursion of the drive and with the clipping of the amp. Any suggestions?
I really would like to know your opinions and suggestions for my little project.
Cheers,
TIFF
Attachments
I am a relative noob as well.... so take my post as such. If your sub is a non-servo (which it is) you would not be able to convert it into one. I think this is what you asked. Anywhooo, here is a link to an article that may serve your purposes. BTW, great sub you got there. Critical Q Subwoofer
Remember this is for an Audiophile (stereo) and not HT subwoofer build. Personaly I think it would work well for a HT too.
Ron
Remember this is for an Audiophile (stereo) and not HT subwoofer build. Personaly I think it would work well for a HT too.
Ron
Renron said:
Thanks Renron...
I Already knew about this "Critical Q Subwoofer" Project and it's really interesting but I must be honest with you, I'm a little concerned with the excursion limit of the cone and that it might bottom out since for now It's not my intention to build another HT sub!
But how can I solve this problem... I'm really not in the mood of being always looking at the cone's displacement and if it's too big when I'm watching a movie.
Is it that critical? Maybe if I pointed the system Q to a 0, 6 or so would it be a good compromise between audiophile sub-frequencies and movie blasting sub-freq.?
What is your opinion on this sub (12" XXLS) comparing to Peeress’s XLS 12”?
One thing is for sure, I'm thinking on implementing the Linkwitz Transform to this baby to optimize its curve.
Any suggestions?
PS: I apologize for my bad writing in English. It's been quite a while since I've written anything in English. Left Canada some years now.
I used the 10" version, the 830843, but his will give you a few ideas ...
http://www.gattiweb.com/samson_design.html
http://www.gattiweb.com/samson_design.html
Hi there...
I would Like to know if anyone can help e with the LT circuit for this specific sub (Peerless 12" xxls - 830845) with th Ruthmik Audio A370 Plate amp?
I'm considering on purchasing rithmyk's plate amp and chaging it's RC values to achieve a better set for my sub.
I've made some plots and I've come up with a 110,6 L sealed box!
Is'nt it a box too big?
I would Like to know if anyone can help e with the LT circuit for this specific sub (Peerless 12" xxls - 830845) with th Ruthmik Audio A370 Plate amp?
I'm considering on purchasing rithmyk's plate amp and chaging it's RC values to achieve a better set for my sub.
I've made some plots and I've come up with a 110,6 L sealed box!
Is'nt it a box too big?
Hi,
I´d suggest a completely different style of cabinet--- a dipolar one.
The high Qts-Versions of the Peerless are quite well suited for this application and it has the advantage of lowering the Fs even more and featurung extremely small cabinet dimension.
Besides that, the sonical reproduction quality is very high. Dipoles don´t boom, but deliver some of the most precise, natural and ´fast´ Bass You can get.
One drawback is that You need a lot of diaphragm area and longthrow capability to gain serious SPLs. Just one driver will be enough for music that´s played well above normal conditions, but with 2 drivers You´ll have more than sufficient reserve even for Homecinema.
Example:
2x 830845
Cabinet: 36*36*36cm (14.2"*14.22*14.2" or ~48Liters)
Fs: ~15-16Hz.
SPLmax,1m: @20Hz @15Vrms: ~100dB
@30Hz @25Vrms: ~109dB
@40Hz @40Vrms: ~114dB
You further need a passive correction network, consisting of 2 coils and one Cap that linearizes the sub to ~ +-1dB between 26Hz and 160Hz (nearfield).
A active Subsonic-filter is recommended. A basslift shouldn´t be necessary in most rooms, but could be added for ´Fun-mode`
jauu
Calvin
I´d suggest a completely different style of cabinet--- a dipolar one.
The high Qts-Versions of the Peerless are quite well suited for this application and it has the advantage of lowering the Fs even more and featurung extremely small cabinet dimension.
Besides that, the sonical reproduction quality is very high. Dipoles don´t boom, but deliver some of the most precise, natural and ´fast´ Bass You can get.
One drawback is that You need a lot of diaphragm area and longthrow capability to gain serious SPLs. Just one driver will be enough for music that´s played well above normal conditions, but with 2 drivers You´ll have more than sufficient reserve even for Homecinema.
Example:
2x 830845
Cabinet: 36*36*36cm (14.2"*14.22*14.2" or ~48Liters)
Fs: ~15-16Hz.
SPLmax,1m: @20Hz @15Vrms: ~100dB
@30Hz @25Vrms: ~109dB
@40Hz @40Vrms: ~114dB
You further need a passive correction network, consisting of 2 coils and one Cap that linearizes the sub to ~ +-1dB between 26Hz and 160Hz (nearfield).
A active Subsonic-filter is recommended. A basslift shouldn´t be necessary in most rooms, but could be added for ´Fun-mode`
jauu
Calvin
Calvin: How did you reach your box size and other essentials such as box shape (form)? Are there software that handles dipole subs? Have you seen Linkwitz "Phoenix" (spelling?) dipole sub at http://www.linkwitzlab.com? (I hope the link is correct, my DNS server play tricks just now so I am unable to check)
Tiff_Needle said:
110 litres is too big if you are going to use a Linkwitz transform. That box size is good for this driver in a sealed box - will give the best response.
Strictly speaking, the driver is not the best choice for a LT, as the Fs is low. Part of the advantage of using an LT is to make the driver work below it's impedance peak. To make the impedance peak hapen at a higher frequency, you reduce the box size.
As far as the amp goes - it's ok, should give 300 watts at the~6 ohmsof this woofer. Depending on the amount of boost the LT provides, and the source material (music, HT) clipping shouldn't be a problem.
Hi,
the dimensions are a result of the simulation I use. Since this is the same as used for a commercial product, please understand, that I don´t disclose the script. I could provide You with figures though. The experience gained over the years showed, that this script gives very precise and practical results, as long as the parameters of the driver are correct.
SL´s Site is a marvellously valuable piece of work and a must read for everyone interested in dipole technology.
Still though I prefer a similar but (always) smaller style of cabinet, that looks more pleasing to my eyes and that has distinct acoustical differences.
First it is a symmetrical cabinet, which Subs after SLs design are more than often not (if 2 or n*2 drivers are used) and second does it lower the Fs of the drivers condsiderably and raises Qt a bit. We´re talking of 5 to 10Hz reduction (sometimes more), depending on the driver and the cabinet´s size.
This has the advantage that You can use drivers with an slightly elevated Fs because of a stiffer suspension or/and lower diaphragm weight. This way You can use a lot of excellent PA-Drivers in the 15"-18"-class with remarkable results. They benefit from their good weight/force-relationship, their huge diaphragm size and their good highpower behaviour. What they usually lack (for homehifi) are a few Hz in Freq-response. But that is provided for by the very small cabinet (keep in mind that the shipping cartonage of the drivers is usually a bit larger than the actual cabinet size of this small dipole-type!! And the sim-figures I provided are for a pair of XXLS, hence ~24L for one XXLS vs. 50-110L in CB and still a lower Fs!).
The result can be an outstanding precise and deep bass with ´speed´ like no other. Sonically I´ve the impression of the combination of the goods of a Horn-bass with the ease and deep-going bass of an TL. There is of course a penalty to pay and that is a reduced efficiency and maximum SPL and a bit more of effort with the compartement building. But to me its worth trying ;-)
I find it much more comforting to have the driver do what it naturally wants to do, than to brute force him to an ´unnatural´ behaviour. While a L-transformed CB works fine on paper, in practise there will be audible sonic penalties, too much for my taste, but it might be ok for anybody else.
jauu
Calvin
the dimensions are a result of the simulation I use. Since this is the same as used for a commercial product, please understand, that I don´t disclose the script. I could provide You with figures though. The experience gained over the years showed, that this script gives very precise and practical results, as long as the parameters of the driver are correct.
SL´s Site is a marvellously valuable piece of work and a must read for everyone interested in dipole technology.
Still though I prefer a similar but (always) smaller style of cabinet, that looks more pleasing to my eyes and that has distinct acoustical differences.
First it is a symmetrical cabinet, which Subs after SLs design are more than often not (if 2 or n*2 drivers are used) and second does it lower the Fs of the drivers condsiderably and raises Qt a bit. We´re talking of 5 to 10Hz reduction (sometimes more), depending on the driver and the cabinet´s size.
This has the advantage that You can use drivers with an slightly elevated Fs because of a stiffer suspension or/and lower diaphragm weight. This way You can use a lot of excellent PA-Drivers in the 15"-18"-class with remarkable results. They benefit from their good weight/force-relationship, their huge diaphragm size and their good highpower behaviour. What they usually lack (for homehifi) are a few Hz in Freq-response. But that is provided for by the very small cabinet (keep in mind that the shipping cartonage of the drivers is usually a bit larger than the actual cabinet size of this small dipole-type!! And the sim-figures I provided are for a pair of XXLS, hence ~24L for one XXLS vs. 50-110L in CB and still a lower Fs!).
The result can be an outstanding precise and deep bass with ´speed´ like no other. Sonically I´ve the impression of the combination of the goods of a Horn-bass with the ease and deep-going bass of an TL. There is of course a penalty to pay and that is a reduced efficiency and maximum SPL and a bit more of effort with the compartement building. But to me its worth trying ;-)
I find it much more comforting to have the driver do what it naturally wants to do, than to brute force him to an ´unnatural´ behaviour. While a L-transformed CB works fine on paper, in practise there will be audible sonic penalties, too much for my taste, but it might be ok for anybody else.
jauu
Calvin
RobWells said:
Hi.
This driver in the configuration outlined in my previous post will not come near max excursion. Xmax for it is 13mm +/-, so about 1 inch in total. If anything, I'd reduce the box size even further, to drive up Fs, and increase LT boost and amp power. OR, skip LT altogether, and allign for a passive radiator in a small box.
As I've said before, this driver is not the ideal choice for an LT, better a higher efficiency, higher Fs pro type driver with a large Xmax.
MJL21193 said:
I'm of the opposite opinion. I believe make the box as big as possible and use as little boost as possible. Gives you a bit more headroom before you run into power compression.
I believe the original post said the sub was to be used for 5.1 stuff too. For dvd material at reference a single 12 with 13mm xmax will struggle.
For example a 12" with 13mm xmax has a 1 way VD of approx 660cc's , which will do around 100dB at 20Hz. Dolby Digital needs around 115dB to do reference. That's without any bass redirection from the mains or surrounds. With all speakers set to small you'd need 121 / 122dB from the sub.
Cheers,
Rob.
Out of interest, what frequency did you have the 14dB boost at in your example above ?
RobWells said:
Hi Rob,
When I said smaller box, it was strictly in reference to the Fs of the driver which is very low to begin with (22 Hz). The best advantage to LT is to make the driver work below Fs, thereby giving the amp a steady impedance to drive, rather than a large peak. A better driver for LT would be one with a higher Fs, such as 40 Hz, and of course, a bigger cone would also be good.
Like I mentioned before, this driver would work well in a small box with a passive radiator (or two), and with enough power should be able to hit ~ 120 dB at 20 Hz. This would probably be the best use for the driver IMO.
The frequency I used in the Linkwitz transform spreadsheet to calculate gain was 20Hz.
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