Thiel-small Testing Jig

[palesha]

Herewith attached 3 jig pictures. I have used first two of them. I find first to be better and giving consistence results. But there are many views about the fixture for thielsmall testing. I want view of the other friends of this group to share the experience.
Further Loudspeaker cookbook says that we have to use lowest signal level for testing thielsmall. Opinion about the signal level is also welcome.
MP

[Doug]

The jpg's that you attached are not attached LOL

Thiele/Small in itself is a "small signal analysis", which means everything is calculated at very low power.

When you use Thiele/Small parameters in most enclosure modelling programs what you get is an indication of the response you will get for any given box volume, based on low power applied to the driver.

In the real world, a speaker is a very non-linear device, and as you increase the power level to the driver the voice coil heats up etc. and the alignment of the enclosure changes. Usually the "Q" of the system will increase.

Some of the more expensive speaker modelling programs will allow you to model and predict what will happen as you increase the power level. One of these programs is called LEAP from LinearX Systems in the USA.

http://www.linearx.com

Hope this helps a little; DOUG

[palesha]

sorry friends,
Here is the image.