My open baffle dipole with Beyma TPL-150

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Hmmm.... can't imagine now, but I'll try to understand. Thanks a lot:)



Yeah, its not intuitively - at least in current mainstream technical thinking.

An early personal experience may help – as children we really loved to go on the swings (if that's the right word?)
I still remember that I always needed someone's help to gather some initial momentum – I simply could not start by myself.

There is total impulse balance!

Not sure though if that's a common experience - so many different backgrounds / cultures involved from people around here.
Also swings may have hung lower in *your* place.
:)

If you missed it and feel to old to fool around with the kindergarten children, you always can try the same experiment on a hammock
:D


For those drivers already installed on the baffle, what can be done? It seems all gaskets/spacers are not compliant enough. And it's hard to 'float' the whole assmebled baffle :(


you certainly could, but it would not work very well – no free lunch :(



Michael
 
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And here's more of the same, I mean *less*, baffle that is.

An externally hosted image should be here but it was not working when we last tested it.


Even more dipole EQ is required, but the 21" can handle it, and I have 1200W of clean power for each woofer.

Sound? After removing the mid/tweeter baffle and reducing the woofer baffle I am baffled ;) I've never heard anything like this, nothing that even remotely could sound like it either. There is SO much detail in the entire frequency range, and still its very very "musical", warm and relaxed sounding. All the grain and harshness that I thought were bad recording suddenly sounds clean.
 
... I've never heard anything like this, nothing that even remotely could sound like it either. There is SO much detail in the entire frequency range, and still its very very "musical", warm and relaxed sounding. All the grain and harshness that I thought were bad recording suddenly sounds clean.


That makes two of us! I'm glad you like it! I kind of felt like I was out on a limb, not using baffles, and surprised more people don't, because it is such an easy way to put a speaker together, and is sounds so good, at least to me. How loud do you listen at? Do you record music too?
 
could it be that much improved sound is due to reduced baffle edge reflections?
No. If anything, the edge diffraction is sharper and more pronounced off the driver flanges than with a baffle. I would guess that it is the better uniformity in polar response gained by going with a smaller baffle, as larger baffles tend to force operation above the dipole peak.
 
Browsing through the topics on the forum, it amazes me so much that poeple are talking about panel damping, enclosure stuffing... etc., while we OB lovers here are throwing away everything as we can! Gone the box, now even the baffle! WOW !!

It seems a nudist camp in speaker building here. :D

Sorry for the OT, can't help.
 
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That makes two of us! I'm glad you like it! I kind of felt like I was out on a limb, not using baffles, and surprised more people don't, because it is such an easy way to put a speaker together, and is sounds so good, at least to me. How loud do you listen at? Do you record music too?
It surely sounds good! Why on earth didnt I think of such a simple solution before? Sometimes I try to make things too complicated....

I am very careful about my listening levels. 85 dB RMS in listening posistion is my preference. With pop/rock that means 97 dB peak, and with classical up to 105 dB peak. Listening distance is approx 2 meters.

I used to record music, but these days I simply dont have time to do it anymore.
 
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No. If anything, the edge diffraction is sharper and more pronounced off the driver flanges than with a baffle. I would guess that it is the better uniformity in polar response gained by going with a smaller baffle, as larger baffles tend to force operation above the dipole peak.

Exactly like my experience. The frequency response without baffles is a lot worse than with baffles (more peaks and dips above the baffle peak), but the polar response is better. There is a deeper null at 90 degrees than with baffles.
 
OK, I guess I got it, just thought of an analogy: an air wrench vs screws on car's wheel.

Car being jacked up, wheels are free, the impact energy by the air wrench applied on the screws would not rotate the wheel, or only a very small degree.

:D

would say you got it partly - if only look at the non-movement of the jacked car
:D

But to be serious:
to make your picture work – you would have to sit or stand *on the wheel* you want to unscrew (simply turn the car to the side ;) ) and use a hammer instead of a air wrench – but more easily and comfortable you can do this experiment sitting on a swivel chair ....


If you don't like swings or swivel chairs ;) - another analogy is standing in a small boat and try to get it moving towards the shore by stepping forth and back - wouldn't happen - again 100% impulse compensation.

Michael
 
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But that is no problem at all. I just tested.

Yes you can !
In case your chair does not turn lightly you can make use of the "stick slip" effect.
Hopefully your speakers move more gently.
:)

Low Rms is the spec we would be looking for – though Qms – from which Rms is derived - sadly is a convolute of effects not necessarily related to mechanic friction only.


OK, I guess I got it, just thought of an analogy: an air wrench vs screws on car's wheel.

What you possibly mean here is inertia of mass – something different - not of so much interest in the context of impulse *compensation*.

Michael
 
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