hello guys, (and girls)
in between my exams so time for surfing. I have red the open baffle topics over and over.
i have got some questions about drivers.
i wanna make an complete open baffle,
the lows : open baffle sub
the rest : fullrange open baffle
for the fullrange open baffle, i think i would use an coral driver, but Frank, aka mr tube told me that the highs are not always there, so probably i'm gonna use an super tweeter; the woofer will be crossed over with linkwitz filter at ~100hz, then for 100 to 12000 (maybe 15000) the fullrange and then the tweeter comes in;
but now my two questions;
1) as a fullrange driver i have seen something new, (well for me personally cidada
if i can lay my hands on a coral, probably i'm gonna buy that; but what do you take the coral, or the cidada; and most of all : why ; or would you step to a smaller model like fostex 127 or something. (i have the feeling that an 8 inch drive would perfrom better) (take for example the saba's of telefunken full range)
2)the subs; i have seen that nuke searched the whole got d*** planet, at least in europe, for a decent driver. He came up with a few; now i have found some to.
the question is are we gonna use PA material; if so on ebay you can get an eminence beta 15 for less then 50 euro.
But what if you wanna use "home" woofers; i have looked at gradient, because they are cheap, the have an 12 inch driver for 40 euro, it has an FS 32, allright not that deep, but i don't need anything lower. and also 93db sensitivity which isn't exactly super high, but still, i don't play that loud. oh yeah here is the url
http://www.plus-elektronik.de/shop/index.htm?lautsprecher___zubehoer_home_-_hifi__programm_gradient_-_produkte_tieftoener.htm
but it is a light cone, and probably rather fast.
i know it isn't an xls 12 peerless with 40mm lineair excursion, no it's one with 4mm lineair excursion, but since it has more sensitivity and most of all more Qts i doesn't need to be driven so hard. personaly i think an home-woofer will sound better, but wil it be enough?
Well actually my question is: what do you guys think of it.
thanx a lot guys, now going back to Mr. Kant and his Grundlegung zur Metaphysik der sitten.
greetings
in between my exams so time for surfing. I have red the open baffle topics over and over.
i have got some questions about drivers.
i wanna make an complete open baffle,
the lows : open baffle sub
the rest : fullrange open baffle
for the fullrange open baffle, i think i would use an coral driver, but Frank, aka mr tube told me that the highs are not always there, so probably i'm gonna use an super tweeter; the woofer will be crossed over with linkwitz filter at ~100hz, then for 100 to 12000 (maybe 15000) the fullrange and then the tweeter comes in;
but now my two questions;
1) as a fullrange driver i have seen something new, (well for me personally cidada
if i can lay my hands on a coral, probably i'm gonna buy that; but what do you take the coral, or the cidada; and most of all : why ; or would you step to a smaller model like fostex 127 or something. (i have the feeling that an 8 inch drive would perfrom better) (take for example the saba's of telefunken full range)2)the subs; i have seen that nuke searched the whole got d*** planet, at least in europe, for a decent driver. He came up with a few; now i have found some to.
the question is are we gonna use PA material; if so on ebay you can get an eminence beta 15 for less then 50 euro.
But what if you wanna use "home" woofers; i have looked at gradient, because they are cheap, the have an 12 inch driver for 40 euro, it has an FS 32, allright not that deep, but i don't need anything lower. and also 93db sensitivity which isn't exactly super high, but still, i don't play that loud. oh yeah here is the url
http://www.plus-elektronik.de/shop/index.htm?lautsprecher___zubehoer_home_-_hifi__programm_gradient_-_produkte_tieftoener.htm
but it is a light cone, and probably rather fast.
i know it isn't an xls 12 peerless with 40mm lineair excursion, no it's one with 4mm lineair excursion, but since it has more sensitivity and most of all more Qts i doesn't need to be driven so hard. personaly i think an home-woofer will sound better, but wil it be enough?
Well actually my question is: what do you guys think of it.
thanx a lot guys, now going back to Mr. Kant and his Grundlegung zur Metaphysik der sitten.
greetings
There is one problem staring me in the face, the excursion capability of the fostex full range. There is a reason linkwitz chooses 8" drivers with large xmax in his dipoles, because you need it. Unless you can use "wings" or whatever to extend the dipole down to the xover of 100hz I think you will run into problems with max SPL. A larger cone reduces the excursion demand at lower frequencies so that will help somewhat.
The XLS has 25mm linear excusion.
The XLS has 25mm linear excusion.
yeah, that's a good explanation, it sounds very logical to me, i think the baffle will not be more then 50cm wide, but i can always put whings on it.
damn you'r right, i have to think again, because i wanted to put the fullrange ontop of the open baffle woofers, but since they will be at least 60cm high, the baffle wil be to small in hight also; so probably i will have to seperate everything
thanx for the info
damn you'r right, i have to think again, because i wanted to put the fullrange ontop of the open baffle woofers, but since they will be at least 60cm high, the baffle wil be to small in hight also; so probably i will have to seperate everything
thanx for the info
Without big excursion you are going to need multiple drivers for the low frequencies because dipole bass is even more about moving a lot of air. Even 4 of those 4mm xmax 12's per side isn't going to cut it. A single high excursion 15" per side like the dayton IB15 may not even be enough to keep up with a highly efficient full ranger depending on the volumes you are looking for.
I have been sketching a design for a low frequency dipole unit.
Starting point for my "design" is the Likkwitz PW1. I am also examining the Na0 design.
For anyone that hasn't seen the PW1, it’s an H baffle dipole with dual 12" Peerless XLT drivers and a D of 12 inches.
The drivers for the project are $150 or so each, for a total of $600. The challenge is to make other design choices that will work for us.
Doubling the D of the H enclosure to 24" would halve excursion requirements of the drivers. Choosing drivers with an F3 of 40 Hz
(And not compensating below that) would also halve your excursion requirements. This seems to indicate that "normal drivers" are possible candidates. The Na0 documentation indicates that the 24" U would halve the excursion requirement again, or allow for 1 woofer rather than 2. I may try both.
I was looking for something with a Qts of .5 to .8 so I could minimize compensation in the crossover.
I just saw that 15" Dayton IB. Looks perfect.
Let me know how your design works out.
Doug
Starting point for my "design" is the Likkwitz PW1. I am also examining the Na0 design.
For anyone that hasn't seen the PW1, it’s an H baffle dipole with dual 12" Peerless XLT drivers and a D of 12 inches.
The drivers for the project are $150 or so each, for a total of $600. The challenge is to make other design choices that will work for us.
Doubling the D of the H enclosure to 24" would halve excursion requirements of the drivers. Choosing drivers with an F3 of 40 Hz
(And not compensating below that) would also halve your excursion requirements. This seems to indicate that "normal drivers" are possible candidates. The Na0 documentation indicates that the 24" U would halve the excursion requirement again, or allow for 1 woofer rather than 2. I may try both.
I was looking for something with a Qts of .5 to .8 so I could minimize compensation in the crossover.
I just saw that 15" Dayton IB. Looks perfect.
Let me know how your design works out.
Doug
TC2+ 12"ers
Doug, you might want to check out the new TC Sounds TC2+ woofers---John Marsh is using them in the Arvo Part dipoles with great success and they're garnering rave reviews in the Madisound Forums, too. About 20mm xmax, aluminum cones and cost is also around $150 each from O Audio in Texas. I've got four I'm building 18x19.5x28 well-braced H-frames for right now and can't wait to get them up and running....
Doug, you might want to check out the new TC Sounds TC2+ woofers---John Marsh is using them in the Arvo Part dipoles with great success and they're garnering rave reviews in the Madisound Forums, too. About 20mm xmax, aluminum cones and cost is also around $150 each from O Audio in Texas. I've got four I'm building 18x19.5x28 well-braced H-frames for right now and can't wait to get them up and running....
I used 2 per side of 18" Studio Pro PW1808. Xmax 4.6 mmQTS .82.
Small wings on the baffles. The cone hardly move on heavy rock at ear splitting levels.I have never seen in practive why this "thing" about huge Xmax. In theory yes. In practive no. Why is this?There seems something going on with open baffle that is baffling.
Small wings on the baffles. The cone hardly move on heavy rock at ear splitting levels.I have never seen in practive why this "thing" about huge Xmax. In theory yes. In practive no. Why is this?There seems something going on with open baffle that is baffling.
I agree...
I put together a pair of simple H frame dipoles using a single hi-Q 12" driver for each, OK they soak up more power than the closed boxes they replaced, but unless you really want to annoy the neighbours (& lose your hearing) I think more than 2 drivers a side is a luxury....
Pete McK
I put together a pair of simple H frame dipoles using a single hi-Q 12" driver for each, OK they soak up more power than the closed boxes they replaced, but unless you really want to annoy the neighbours (& lose your hearing) I think more than 2 drivers a side is a luxury....
Pete McK
Peter,
The Fs of that driver is 24.5hz . The rock you are playing at "ear splitting levels" doesn't have low content. If you play something with content anywhere near resonance, the drivers will bottom out with relatively low power applied to them. It sounds like they are perfectly suited to your needs, just be careful of low frequency content. You also have the advantage of 4 18's which move alot of air with small excursions.
The Fs of that driver is 24.5hz . The rock you are playing at "ear splitting levels" doesn't have low content. If you play something with content anywhere near resonance, the drivers will bottom out with relatively low power applied to them. It sounds like they are perfectly suited to your needs, just be careful of low frequency content. You also have the advantage of 4 18's which move alot of air with small excursions.
Hi johninCR,
I do not listen to test tones for pleasure. 24 Hz is pretty low in my book. I have some EQ on the drivers, and playing say Dark Side of the Moon on an Allen Wright moded SACD player at very high levels, as I say, and others have confirmed, on an OB the cones do not move as the books tell us they should. Nothing like say my old Tannoy 15" in a reflex box. I know that this is comparing apples with pears, but I cannot see this fixation on Xmax when clearly it is not needed. There is more going on with OB's than is generally recognized
I do not listen to test tones for pleasure. 24 Hz is pretty low in my book. I have some EQ on the drivers, and playing say Dark Side of the Moon on an Allen Wright moded SACD player at very high levels, as I say, and others have confirmed, on an OB the cones do not move as the books tell us they should. Nothing like say my old Tannoy 15" in a reflex box. I know that this is comparing apples with pears, but I cannot see this fixation on Xmax when clearly it is not needed. There is more going on with OB's than is generally recognized
I have not been able to bottom my woofers yet, but I now have a much bigger amp and will try again, but what is the point. The thing is, cheap Pro woofers work great. Keep that QTS high and it works a treat. I used 4x15" low Q drivers once, years ago, and that was a waste of time. No bass , you would have to EQ them to death. But why bother when you can use the proper drivers.
FWIW I'm presently running Fostez 208ESigma, Arum Cantus ribbon XO at 4KHz in a plane baffle, and Altec 3182 18" woofers in H-baffles, XO at 125 Hz.
I think the Fostex is wonderful - open, detailed, dynamic.
With an Fs of 18 Hz and Xmax of 13 mm I haven't had the Altec woofers bottom out. I'm using a 15 Hz high-pass.
In the midst of going to a plane baffle for all three drivers. "Upgrading" the woofers to Adire Tumults (34 mm Xmax).
When I get the plane baffles done and the Tumults installed, I think I'm going to keep the Altecs running push-pull with another amp for movies only. Can't have too much boom-boom for movie soundtracks these days.
I think the Fostex is wonderful - open, detailed, dynamic.
With an Fs of 18 Hz and Xmax of 13 mm I haven't had the Altec woofers bottom out. I'm using a 15 Hz high-pass.
In the midst of going to a plane baffle for all three drivers. "Upgrading" the woofers to Adire Tumults (34 mm Xmax).
When I get the plane baffles done and the Tumults installed, I think I'm going to keep the Altecs running push-pull with another amp for movies only. Can't have too much boom-boom for movie soundtracks these days.
thanx guys for the information.
that's what i thought, Xmax isn't everything. If the cone is big enoug, it doesn't matter anymore. certainly if the Q is high enoug. Look at the XLS : only 12 inch; you would need only in surface more than two of them for an 18 inch;
but more important the Q is only 0.2; and with the drivers reported in the previous reply they are 0.8; so off course they need an Xmax of 25mm, because they have to be EQ like hell, and who whas all that power in his house, allright, i have got from a friend an bose 1801 amp with 450watt rms per channel, but why would i use that, my energy bill is sky high already.
thanx a lot guys, i was planning to go open baffle with a fullrange and supertweeter, i thought i would have to redraw for open baffle subs, and make it an sealed enclosure, but now land is in sight.
can you put some pictures to it with the 18 inch subs, i wanna see how you did that. I don't wanna build them in a H enclosure, takes to much space;: i wanna build them in a baffle with a width of 50cm, and then whings, so when i have to move them it is possible.
after the exams, i'm gonna look for a good driver here in europe,
but do you think an 15 or 18 inch eminence ? 35hz resonance; 058 Q;
thanx guys
that's what i thought, Xmax isn't everything. If the cone is big enoug, it doesn't matter anymore. certainly if the Q is high enoug. Look at the XLS : only 12 inch; you would need only in surface more than two of them for an 18 inch;
but more important the Q is only 0.2; and with the drivers reported in the previous reply they are 0.8; so off course they need an Xmax of 25mm, because they have to be EQ like hell, and who whas all that power in his house, allright, i have got from a friend an bose 1801 amp with 450watt rms per channel, but why would i use that, my energy bill is sky high already.
thanx a lot guys, i was planning to go open baffle with a fullrange and supertweeter, i thought i would have to redraw for open baffle subs, and make it an sealed enclosure, but now land is in sight.
can you put some pictures to it with the 18 inch subs, i wanna see how you did that. I don't wanna build them in a H enclosure, takes to much space;: i wanna build them in a baffle with a width of 50cm, and then whings, so when i have to move them it is possible.
after the exams, i'm gonna look for a good driver here in europe,
but do you think an 15 or 18 inch eminence ? 35hz resonance; 058 Q;
thanx guys
whoehoe, that looks nice, you only use on 18 inch per side, that's an option, i thought you would use two, even better you know, less money to spend. Something like that i'm gonna build also.
do you know how deep they go ?
oh yeah, do you use linkwitz filter ? and where do you cross?
thanx a lot already
do you know how deep they go ?
oh yeah, do you use linkwitz filter ? and where do you cross?
thanx a lot already
One candidate that I have on my OB driver list is the Italiavox Forte 12. OK, it's not built like a Rolls Royce but at under 40UKP each the specs are quite good.
The Italiavoxes are available in the UK from Nightfire.
I am going to use 4 12 inch drivers in a pair of W baffles, each firing through my main OB's which I have recently modified for that purpose.
An externally hosted image should be here but it was not working when we last tested it.
The Italiavoxes are available in the UK from Nightfire.
I am going to use 4 12 inch drivers in a pair of W baffles, each firing through my main OB's which I have recently modified for that purpose.
An externally hosted image should be here but it was not working when we last tested it.
Here's some prices and further info.
I have no association with Nightfire but Ian Warrener has been extremely helpful in this matter and obviously knows his stuff.
RSW rings a bell but I have looked at so many drivers, I can't recall where I saw it. Is it that Spanish firm by any chance?Somebody here used some 15 inch drivers from a Spanish outfit for his OB woofers.
I have no association with Nightfire but Ian Warrener has been extremely helpful in this matter and obviously knows his stuff.
RSW rings a bell but I have looked at so many drivers, I can't recall where I saw it. Is it that Spanish firm by any chance?Somebody here used some 15 inch drivers from a Spanish outfit for his OB woofers.
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