PIEZO NXT type panel

[bjefferys]

Originally Posted by Garytr

Hi,
I have been following this thread, a few questions if I may?
Is there a difference between the Dayton and the buyout?
Parts-Express.com:*Surface Transducer Turns Virtually Anything Into A Speaker | CYBER09 stick on speaker exciter tactile transducers sound transducers nxt sonic impact 5029 5029 sound pads hidden speakers daex25 Marcato DIY projects fbr1
Parts-Express.com:*Dayton DAEX25 Sound Exciter Pair | stick on speaker exciter tactile transducers sound transducers nxt sonic impact 5029 5029 sound pads hidden speakers daex25 cyber121
Has anyone tried these?
Parts-Express.com:*Sonic Splash SSP 4.0 Transducer | full range shaker ibeam tactile bass shaker transducer tactile transducer butt shaker seat shaker
Gary

I just bought 30 (15 pairs) of the buyouts at PE. They should be here Monday.

[jzagaja]

Alexit lacquer on 12cm cone speaker. Damping is clearly visible.

[LineArray]

Originally Posted by jzagaja

Alexit lacquer on 12cm cone speaker. Damping is clearly visible.

Good result indeed ...

[el`Ol]

CSD of a paper tweeter after treatment with hardwax oil. CSD was as messy as the FR before (didn´t save).

[bjefferys]

Interesting read......

http://www.tnw.tudelft.nl/live/pagin...thesis MSc.pdf

[el`Ol]

Would be even nicer if there was a software freely available.
An alternative for the DIYer could be using a realtime impedance measurement based on a noise generator like the one in Arta and move the exciter in order to find positions with well-distributed modes.

[pol_bct]

hello all,
here is one of the latest versions of my stereo panel
http://img697.imageshack.us/img697/8061/p1111090844.jpg
8 transducers in a config inspired from Michael GERZON
2x at left & 2x at right, & 2+2 centered in the common return path
response measured a 2cm, 20cm & 2m, nice work of the syncRTA
the same with a "classic" RTA would be impossible
http://img692.imageshack.us/img692/7...o2cm20cm2m.gif
respectively green 2cm, blue 20cm, red 2m

and the same with a bass-box added (YAMAHA, blue trace)
http://img208.imageshack.us/img208/4440/gdpanobass.gif

POL

[LineArray]

Very balanced response, congratulations.

[LineArray]

Originally Posted by mkstat

I don't know if I have understood your question right but you can figure out by yourself what happens when you manipulate a certain factor in your panel.

For a panel with constant size the following interrelationships apply:

high stiffness → high wave propagation speed → low coincidence frequency → high efficiency → low modal density

low stiffness → low wave propagation speed → high coincidence frequency → low efficiency → high modal density

and:

higher mass → lower coincidence frequency → lower efficiency

lower mass → higher coincidence frequency → higher efficiency

Basicly there is a gain of efficiency above coincidence frequency.

It can be seen that the design parameters are conflicting (of course) and can not be adjusted independently.

The output from some pistonic action is not considered here.



If you keep the panel mass constant, the hard/damping/hard version will be most likely stiffer.

Regards
Markus

Hello Markus,

a verbose description of the parameter interrelations is helpful
but i feel for the effect of mass (density) there is a mistyping
in your former post concerning coincidence frequency.
I overlooked it, because you described the effect of mass
on efficiency correctly ...

I would put it this way:

Effect of stiffness variation, when other parameters are kept constant
-------------------------------------------------------------------

higher stiffness -> higher propagation velocity -> lower coincidence frequency
higher stiffness -> higher propagation velocity -> lower modal density
higher stiffness -> higher propagation velocity -> higher efficiency

lower stiffness -> lower propagation velocity -> higher coincidence frequency
lower stiffness -> lower propagation velocity -> higher modal density
lower stiffness -> lower propagation velocity -> lower efficiency


Effect of mass (density) variation, when other parameters are kept constant
-------------------------------------------------------------------------

higher mass -> lower propagation velocity -> higher coincidence frequency
higher mass -> lower propagation velocity -> higher modal density
higher mass -> lower propagation velocity -> lower efficiency

lower mass -> higher propagation velocity -> lower coincidence frequency
lower mass -> higher propagation velocity -> lower modal density
lower mass -> higher propagation velocity -> higher efficiency


For the propagation velocity i have not found a simple
english source so far, but i am shure someone will find a link
in english language ...

Biegewelle – Wikipedia

Kind regards

[jzagaja]

Part Express exciters attached to the window.