If all you want the magnetic woofer to do is to go down to 100 Hz, you can compromise and build a true Infinite Baffle and make the internal volume considerably larger than the Vas. That will cut off the back wave interference, but let the woofer be essentially free-swinging, which is the essential advantage of the dipole, I think.
The Vas of a speaker designed to go down to 100 Hz shouldn't be that much. The enclosure would not be big.
The Vas of a speaker designed to go down to 100 Hz shouldn't be that much. The enclosure would not be big.
I'm just thinking out loud here. Bas, am I right in thinking that you would quite like a dipole if you didn't need the equalization circuitry?
The EQ is to boost the low end, isn't it? I wonder if it's possible to have a line array and tune the comb effect to lower the high end instead.
Probably wouldn't work but may just be worth having a go with the old pvconsultants - Vertical Polar Response program for line arrays.
Jim G, I see you're out there. You're the line array man. What do you think? Can the comb effect be used for the benefit of humanity?
I'm too tired right now to play it myself but if anyone thinks that there may be some mileage in the concept ...
The EQ is to boost the low end, isn't it? I wonder if it's possible to have a line array and tune the comb effect to lower the high end instead.
Probably wouldn't work but may just be worth having a go with the old pvconsultants - Vertical Polar Response program for line arrays.
Jim G, I see you're out there. You're the line array man. What do you think? Can the comb effect be used for the benefit of humanity?
I'm too tired right now to play it myself but if anyone thinks that there may be some mileage in the concept ...
Bas, it's all about the chosen compromises, and making sure you're choosing the right compromises for you and the system you are planning to put together.
If you want it to be worth the effort, you have to increase the budget -
If you are interested in dipoles, you've got to eqalize -
If you are interested in a line source, a fellow named Pierre Henri made a very interesting post at
http://www.audioasylum.com/forums/HUG/messages/51782.html
I sent him an e-mail a couple of days ago wanting more info but as of this time he has not responded -
Bill Fitzmaurice also made an excellent post about line arrays-
You really might want to read that whole thread, it's about integrating subs with horns, but has a lot of good info relative to what you are tinking about at this point.
Last but not least here - I think you're on the right track to plan to crossover to subs at 100 HZ or so, trying to do it all with one sytem would be asking too much -
What I believe to be an important aspect for you is to incorporate that decision into this one - seperate but made jointly, if you decide about both at the same time you will have a much greater chance of success because your game plan will be more coherent.
HTH
Later
Ken L
If you want it to be worth the effort, you have to increase the budget -
If you are interested in dipoles, you've got to eqalize -
If you are interested in a line source, a fellow named Pierre Henri made a very interesting post at
http://www.audioasylum.com/forums/HUG/messages/51782.html
I sent him an e-mail a couple of days ago wanting more info but as of this time he has not responded -
Bill Fitzmaurice also made an excellent post about line arrays-
You really might want to read that whole thread, it's about integrating subs with horns, but has a lot of good info relative to what you are tinking about at this point.
Last but not least here - I think you're on the right track to plan to crossover to subs at 100 HZ or so, trying to do it all with one sytem would be asking too much -
What I believe to be an important aspect for you is to incorporate that decision into this one - seperate but made jointly, if you decide about both at the same time you will have a much greater chance of success because your game plan will be more coherent.
HTH
Later
Ken L
Hi Bas,
Have a look at this site:
http://www.euronet.nl/users/temagm/audio/index.htm
and of course: http://www.linkwitzlab.com/
An externally hosted image should be here but it was not working when we last tested it.
Have a look at this site:
http://www.euronet.nl/users/temagm/audio/index.htm
and of course: http://www.linkwitzlab.com/
Might be what you have been looking for bas
For that matter, might be what I am looking for also -
Pierre-Henri just replied to my request for more info - what follows I have cut and pasted from his e-mail -
________________
Hello,
Sorry for late answering but I was in vacations for a few days.
Currently I have not many more details that what I posted, but I will meet this guy again in the summer to have more details. Then I can keep you informed. My impression is that it is the best bass I heard except very large horns. XOver was 80 Hz, 12 drivers were used in two vertical arrays of 6. It takes a strong amp to have it work OK. Bill F comments on modes correspond to what the guy told me ( he is a speaker designer ), the other important thing about this design is to have many drivers in order to have a large radiating surface and little excursion from each driver.
____________________
Very interesting, I will post any further communications from him on this subject.
Later
Ken L
For that matter, might be what I am looking for also -
Pierre-Henri just replied to my request for more info - what follows I have cut and pasted from his e-mail -
________________
Hello,
Sorry for late answering but I was in vacations for a few days.
Currently I have not many more details that what I posted, but I will meet this guy again in the summer to have more details. Then I can keep you informed. My impression is that it is the best bass I heard except very large horns. XOver was 80 Hz, 12 drivers were used in two vertical arrays of 6. It takes a strong amp to have it work OK. Bill F comments on modes correspond to what the guy told me ( he is a speaker designer ), the other important thing about this design is to have many drivers in order to have a large radiating surface and little excursion from each driver.
____________________
Very interesting, I will post any further communications from him on this subject.
Later
Ken L
Thanks for all the suggestions all. Sorry for the late reply.
Just got back from holiday..
Good points Ken L, will have a look Pjotr...Maybe that is a good copromise..Planet10 but won't a big baffle defeat the line source type o solution?
Cheers,
Bas
Just got back from holiday..
That is 100% what I was thinking. Dipole..sounds good, don't have the stomach for eq at the moment.
Good points Ken L, will have a look Pjotr...Maybe that is a good copromise..Planet10 but won't a big baffle defeat the line source type o solution?
Cheers,
Bas
How about the MCM 55-1870 as used by Doc Bottlehead in his straight 8's?
Words used to describe this speaker are "Very dynamic; very fast;"
Plans can be gotten for $35 ...I'll just omit the tweeter. Driver around $10 per unit. (No secret coating recipe needed like Doc uses, as the coating is used to dampen high freq ...I'll be using them from 500Hz down)
Lemme know what you think.
Will have satisfied the line source part..plus a fast sound..to integrate with esl's ...just not dipole!
Cheers,
Bas
Words used to describe this speaker are "Very dynamic; very fast;"
Plans can be gotten for $35 ...I'll just omit the tweeter. Driver around $10 per unit. (No secret coating recipe needed like Doc uses, as the coating is used to dampen high freq ...I'll be using them from 500Hz down)
Lemme know what you think.
Will have satisfied the line source part..plus a fast sound..to integrate with esl's ...just not dipole!
Cheers,
Bas
That straight 8 design seems to be well thought of, there was a poster over at AA-HE, who had heard both the straight 8 and Hammer Dynamics and gave the edge to the Straight 8.
This also somewhat goes along with what Pierre-Henri said about the arrays of six 10" Peerless.
This is a very attractive solution - I will probably go with double H frame dipoles in my case, because it will suit my space requirements better -
However, you never know, it looks like a good bit of time may pass before I get to that particular point.
Later
Ken L
This also somewhat goes along with what Pierre-Henri said about the arrays of six 10" Peerless.
This is a very attractive solution - I will probably go with double H frame dipoles in my case, because it will suit my space requirements better -
However, you never know, it looks like a good bit of time may pass before I get to that particular point.
Later
Ken L
Hi Sy,
Found this via google..
Thiele-Small Parameter(Herstellerangaben)
Nennimpedanz/Gleichstromwiderstand: 8/6,4 Ohm
Resonanzfrequenz: 50 Hz
Gütefaktoren(Qms/Qes/Qts): 1,87 / 0,51 / 0,40
Äquivalenzvolumen(Vas): 9,8 Liter
Effektive Membranfläche(Sd): 75 cm²
Schwingspulenüberhang(Xmax): 1,3 mm
Cheers,
Bas
Interesting post by Ed Fallon (Part of the post)
....... The metal cone has resosance break up modes above 5khz which can be annoying. A well designed second order crossover around the 3khz range will work much better with this driver combo. If you are also using the same tweeter as Doc B., you will of course need to pad this down a few db as the 4 mid bass drivers will be maybe 92db 1w/m. Second order work well on the hi pass too. I'd put an adjustable lpad in at first so you can adjust it to taste and replace with a resistor lpad later.
This combo can be made to sound great as many Bottlehead customers have found. Doc has spent quite a bit of effort getting his S8's dialed in and it's very evident in listening to them.
Found this via google..
Thiele-Small Parameter(Herstellerangaben)
Nennimpedanz/Gleichstromwiderstand: 8/6,4 Ohm
Resonanzfrequenz: 50 Hz
Gütefaktoren(Qms/Qes/Qts): 1,87 / 0,51 / 0,40
Äquivalenzvolumen(Vas): 9,8 Liter
Effektive Membranfläche(Sd): 75 cm²
Schwingspulenüberhang(Xmax): 1,3 mm
Cheers,
Bas
Interesting post by Ed Fallon (Part of the post)
....... The metal cone has resosance break up modes above 5khz which can be annoying. A well designed second order crossover around the 3khz range will work much better with this driver combo. If you are also using the same tweeter as Doc B., you will of course need to pad this down a few db as the 4 mid bass drivers will be maybe 92db 1w/m. Second order work well on the hi pass too. I'd put an adjustable lpad in at first so you can adjust it to taste and replace with a resistor lpad later.
This combo can be made to sound great as many Bottlehead customers have found. Doc has spent quite a bit of effort getting his S8's dialed in and it's very evident in listening to them.
Hi Sy,
Glad I could be of some help! 32! Wow...looks like the ultrawhamodyne without the tweeter!
Another tip. The magnet and rest of the back are treated with a damping according to the bottlehead website.
Cheers,
Bas
http://www.bottlehead.com/valve/whamodyne files/page8.html
Glad I could be of some help! 32! Wow...looks like the ultrawhamodyne without the tweeter!
Another tip. The magnet and rest of the back are treated with a damping according to the bottlehead website.
Cheers,
Bas
http://www.bottlehead.com/valve/whamodyne files/page8.html
Hi Sy,
That sounds like gibberish to me
But there seem to be diffraction "issues" for instance a wider baffle or wings..such as on the "next" page ie. page 9 seem to benifit the sound of a box in this case. Where my natural inclination is to make a box as narrow as possible.
Anyway I would love to be kept updated on your progress.
Regards,
Bas
That sounds like gibberish to me
But there seem to be diffraction "issues" for instance a wider baffle or wings..such as on the "next" page ie. page 9 seem to benifit the sound of a box in this case. Where my natural inclination is to make a box as narrow as possible.
Anyway I would love to be kept updated on your progress.
Regards,
Bas
Been reading up a little...
If passive line level EQ is possible..I might just go for a dipole as well. (I thought the EQ was done by an added piece of active electronics)
Sy ....how are you going to do the EQ?
Also anyone..do dipoles subjectively sound as "fast" as conventially loaded speakers?
Cheers,
Bas
If passive line level EQ is possible..I might just go for a dipole as well. (I thought the EQ was done by an added piece of active electronics)
Sy ....how are you going to do the EQ?
Also anyone..do dipoles subjectively sound as "fast" as conventially loaded speakers?
Cheers,
Bas
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