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Post by Clive on May 3, 2020 14:10:20 GMT
I suppose the question is, does it move in the first place? I suspect not but John can check easily enough.
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Post by MartinT on May 3, 2020 15:30:06 GMT
It must move as an opposite reaction to the cone, but since the magnets are weighty the displacement of the corresponding opposite motion will be tiny.
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Post by Clive on May 3, 2020 15:34:57 GMT
It must move as an opposite reaction to the cone, but since the magnets are weighty the displacement of the corresponding opposite motion will be tiny. Yes...my estimation from what I've experienced is that any movement of the metal frame and magnet is much less than you get with most speaker cabinets. It's hard to detect any vibration with my basses or the PRVs I tried. |
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Post by ChrisB on May 3, 2020 17:55:01 GMT
It must move as an opposite reaction to the cone, but since the magnets are weighty the displacement of the corresponding opposite motion will be tiny. But the two centre drivers will move further as they are less restrained. My point is about relative, not absolute, movement. |
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Post by John on May 3, 2020 18:28:06 GMT
They drivers are located by screws to a specially built bracket
The wires just suspend everything in place
The drivers are all securly tightened to the bracket
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Post by John on May 3, 2020 18:58:15 GMT
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Post by MartinT on May 3, 2020 19:55:34 GMT
But the two centre drivers will move further as they are less restrained. My point is about relative, not absolute, movement. I would suggest that the mass of the drivers will have a much greater effect in restricting movement than the wires. Just my thought experiment, you understand. |
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Post by jandl100 on May 4, 2020 3:39:39 GMT
Any speaker on a wobbly base (eg the Townshend Podiums or my own Auralex platforms) would have similar issues of drivers displacing different distances as the higher drivers will wobble over a larger distance being further away from the pivot point. This would be exacerbated as the higher drivers operate at shorter wavelengths.
I hear nothing but improvements with my bases, I suspect the same with Podiums. The speakers are heavier than John's, though, so displacements will be smaller.
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Post by John on May 4, 2020 4:19:32 GMT
All I can say is to get the performance I get I would have to pay an awful lot of money to get the same performance.
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Post by MartinT on May 4, 2020 5:44:57 GMT
My speakers must move in reaction to the cones by a microscopic amount on the Podiums. As with Jerry, they bring only improvements.
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Post by ChrisB on May 4, 2020 7:27:13 GMT
But neither Jerry or Martin are using an array of drivers that deliver the same part of the signal. I still think that if the array is allowed to flex into a curve which alternates from convex to concave, no matter how small, it will result in a less than ideal condition.
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Post by John on May 4, 2020 7:42:41 GMT
I think you need to hear the speakers at some point and then decide
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Post by jandl100 on May 4, 2020 9:42:58 GMT
Ah, if only we lived in a perfect world.
All designs and implementations have compromises, you just have to find an imperfect solution that suits you.
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Post by Clive on May 4, 2020 9:56:07 GMT
The guy who is using this set up is not doing so for commercial gain. He rarely gets involved with forums as the discussions usually end up something like: "bass drivers with no cabinet or baffle - they can't work - no bass and so need massive eq plus they vibrate so will be rubbish".
Rather than being a theorist our pal is pragmatic, he tries out ideas and yes he measures them too. I agree with the above that all implementations are compromises - there are good reasons why baffless speakers are not generally applicable but they can sound really good.
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Post by John on May 4, 2020 10:22:58 GMT
I am not saying they are perfect but they certainly work in my system I get why people think they can't work as goes against people's experience
I think the biggest drawback is the looks and dealing with people thinking they cannot work
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Post by MikeMusic on May 4, 2020 10:50:01 GMT
They certainly *look* as if they cannot work, incomplete, work in progress.
We are used to the normality of cabinets.
Think I would like to have something like thin black cloth or similar to hide them. Only the front, not so worried about side or back.
How do you dust them ?
Carefully I imagine
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Post by jandl100 on May 4, 2020 11:13:06 GMT
They can't possibly sound even half decent, the whole concept is ridiculous - but I am also sure that they sound really good! I'd love to hear them.  Move out West, John, so I can easily pop over! |
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Post by ChrisB on May 4, 2020 11:35:17 GMT
I don't doubt they sound great.
You all seem to be completely missing my point. I am not doubting the concept, not one little bit. I'm suggesting a refinement.
One last try, then I'm giving up.
If the array is going to move, then it has to move as one item, because it represents a single driver as far as the frequency it is playing is concerned.
The 'problem' I have identified has an easy fix, I'm sure. I just think there's no harm in trying to address it - why would you not give it a go?. You'll never know unless you try.
Sticking a metal ruler to the backs of the drivers with the use of their magnetic properties might be all it takes, for example, to tie them together. Or doing as I suggested originally, and tying back the middle drivers to the support posts.
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Post by jandl100 on May 4, 2020 12:32:04 GMT
If I understand John correctly, the drivers are all bolted to a single backplate, so they are already rigidly connected.
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Post by John on May 4, 2020 12:47:40 GMT
 la1 by John Cahill, on Flickr To be honest this is the most refined I ever heard my system. If you look at the brackets you notice this keeps movements to a minimal. There is always going to be some movement, however, adding extra wires in the middle is not going to make much difference with this design approach. |
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