Ripole question

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Ripoles are based on chambers loading the driver, thus changing the impedance of the speaker. This inter alia give a higher system Q and lowers the fc.

But is the ripole based on front and back chambers have symetric loading, ie that the normally bigger back chambers are due to driver and magnet are taking up room in the back chamber, while cone profile actually makes the front chamber bigger (-> expanding into the back chamber)?
 
But is the ripole based on front and back chambers have symetric loading, ie that the normally bigger back chambers are due to driver and magnet are taking up room in the back chamber, while cone profile actually makes the front chamber bigger (-> expanding into the back chamber)?
I haven't seen it mentioned particularly in the patent, but most ripoles seem to have that volume exchange making the chamber loads more symmetric. Still you have an "extra" side volume in one chamber and an "extra" obstacle in the other. I don't think that you need to turn special attention to it - it just happens that way.
 
my room is not very big, and I have two 18" per side loaded with 1500 watt (per side)
Have you had your ears (or your sanity) checked lately?! Why would that kind power be necessary even for very inefficient drivers? My system has 7" woofers (one for each channel) driven by about 60 watts per channel and will vibrate floors and rattle windows quite well. Maybe your goal is to compormise the structural integrity of the building you live in? I'm just wondering.

Mike
 
Thanks Rudolf!

Micheal; Although dipoles are very powerhungry when (a lot of) eq is applied in the bass-region, I hopefully will have some head-room with 1500 w per side ;-) better with too much than too little.

In the midrange region I have 120 watt per side available, but will probably not use more than half :)
 
Have you had your ears (or your sanity) checked lately?! Why would that kind power be necessary even for very inefficient drivers? My system has 7" woofers (one for each channel) driven by about 60 watts per channel and will vibrate floors and rattle windows quite well. Maybe your goal is to compormise the structural integrity of the building you live in? I'm just wondering.

Mike

Offcoarse, any 7" woofer in an average living room can shake floors and windows. But that's not an indication of quality, just an indication of quantity in the resonance region of your floor and windows, nothing more than that I'm afraid. Quality wise a 7" woofer simply cannot be compared to one or double 12" to 18" woofers in the lower region. Nothing beats square inches in that department. In my experience a 15" woofer with a sufficient motor assembly will work much much better even at whisper volumes then any 7" woofer ever manufactured. IMHO truly highend fullrange sound simply cannot be done with some 7" woofers. It will always hit a performance ceiling pretty soon and the only way to get around it is ditch to the small woofers. Offcoarse it can sound impressive at first with lot's of bass from such a small woofer but that's only quantity, not real live quality. Heard so many examples of it, all the fullrange minimonitor/bookshelf sized loudspeakers suffer from this, no exception. At least none I have ever heard in the last 30 years. Just a matter of physics, nothing more than that. You can not fool nature. for real bass a 12" woofer is the minimum.
 
Offcoarse, any 7" woofer in an average living room can shake floors and windows. But that's not an indication of quality, just an indication of quantity in the resonance region of your floor and windows, nothing more than that I'm afraid.
Did you sneek into my house and check out my stereo while I wasn't looking? ;) If you didn't, how can you be so confident that my woofers are lacking "quality?" In fact they are tuned to 40Hz with a .5 damping factor, and in fact, many who have heard it are impressed by how nice they sound. I've somehow managed to learn a thing or two about speaker building over the past 40+ years I've been doing this.
The point I was trying to make was that four 18 inch drivers being driven with 3000 watts in a SMALL room is lunacy, and I will stand by that statement. I'm very concerned about folks today with access to mega-watt amps connected to multiple drivers in small spaces damaging or outright destroying thier hearing. I'm pretty lucky after spending many years of my youth playing in a "garage band" (we obviously never "made it") that my own hearing came through relativly unscathed. Many of my friends' hearing didn't. Not a day goes by that I don't hear a virtual parade of fools going down my formally quiet residential street with thier boom-boom-one-note-bass crap, and all I can think about is how much they are damaging thier own hearing while annoying the hell out of everyone else.

Mike
 
7" will never play a church organ realistic.
I don't totally disagree with that, it's all more a matter of expectations. I never expected 7" woofers to do low bass like a huge woofer driven with oodles of power would. And in the interests of full disclosure, like Markus76, I listen to my system in the near field and therefore don't really need big woofers and lots of power to satisfy me. Right after I originally started building this system I ran into some hard luck economics, and then not long after the economy crashed. So I was compelled to be thrifty and had to make some tough choices on where I was willing to compromise and where I wasn't. Having said all that, my system is JUST capable of reproducing the low pedal played during the intro to "Also sprach Zarathustra", and I'm quite happy with how it sounds. However, none of that in any way changes my original point, that four 18" woofers driven by 3000 watts of power in a small space is rediculous to dangerous.

Mike
 
I don't totally disagree with that, it's all more a matter of expectations. I never expected 7" woofers to do low bass like a huge woofer driven with oodles of power would. And in the interests of full disclosure, like Markus76, I listen to my system in the near field and therefore don't really need big woofers and lots of power to satisfy me. Right after I originally started building this system I ran into some hard luck economics, and then not long after the economy crashed. So I was compelled to be thrifty and had to make some tough choices on where I was willing to compromise and where I wasn't. Having said all that, my system is JUST capable of reproducing the low pedal played during the intro to "Also sprach Zarathustra", and I'm quite happy with how it sounds. However, none of that in any way changes my original point, that four 18" woofers driven by 3000 watts of power in a small space is rediculous to dangerous.

Mike


I would still opt for a floor to ceiling array of 15" ripoles with my 3000w inuke amp (only cost $400) if I only listened at low to medium volumes, there's something about the quality of moving a lot of air I find. But I'd agree its a luxury rather than a necessity.
 
"It is not that I will play 120 dB when listening to music, but I strive for head-room. Further, a dipole-bass solution with for instance a12-16 dB eq at 25 Hz means that alot of watts are needed."[/QUOTE]

Not quite, I have 2x 10" dipôle per side feeded by 60 watt amps per speaker (4) and it is just fine.
 
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But is the ripole based on front and back chambers have symetric loading, ie that the normally bigger back chambers are due to driver and magnet are taking up room in the back chamber, while cone profile actually makes the front chamber bigger (-> expanding into the back chamber)?
Think so. To have perfect symmetry, both compression rate (output area), path length and volumes should be identical. Then you will have to take the driver assembly and diaphragm volumes into account.
 
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