In lieu of xmax...

[BrentEvans]

Been thinking about this for several days since we discussed the Dayton 6.5 in another thread. Since there is no xmax figure for this driver, could we do some experimentation to find out how useful it is? For instance, taking measurements at increasing levels of power until THD reaches a certain figure?

I have a bunch of these in stock right now. I can knock together a sealed single unit enclosure or use my new cabs to do parties of six.

I feel fairly confident in doing measurements, but would like some input on the protocol to use to get useful data.

[Bill Fitzmaurice]

https://www.klippel.de/fileadmin/_migra ... t_Xmax.pdf

[Grant Bunter]

Brent,
I've seen references to the driver you're talking about, but that's about it.

Do you have any TS parameters or info for the driver at all?

To work out Xmax, the specs you need to know are voice coil length and the height of the magnetic gap.

Xmax = (Voice Coil Length - Height of the Magnetic Gap) / 2.

Yes, to some extent you can calculate with rising THD, but that's an inaccurate way to measure because the driver will continue to have output and high THD when beyond Xmax.

edit: if you're talking about the Dayton PA 165 I notice those figures aren't available on the PE site.
Perhaps you can get the answers you need though by hitting "ask a question", or contacting Dayton
direct...

edit 2: Now I see the problem, apparently Xmax = 0, presumably with an underhung coil...
As you were...

[Bill Fitzmaurice]

To work out Xmax, the specs you need to know are voice coil length and the height of the magnetic gap.
Xmax = (Voice Coil Length - Height of the Magnetic Gap) / 2.

That doesn't work with an under-hung coil. The Alpha 6 is under-hung, and Eminence used to list its xmax as zero, until they switched to Klippel.

[Grant Bunter]

Thanks Bill,
See edit 2 in my above post.

I had to go to the Dayton site to find out Xmax = 0...

[BrentEvans]

https://www.klippel.de/fileadmin/_migra ... t_Xmax.pdf

Yeah, I was thinking about something a bit less expensive than that. I had read through that already. I'm not as interested in measuring the actual xmax becasue I know the things work very well and have no need for the math, but knowing at what power level the speaker begins to distort would be interesting.

[LelandCrooks]

I remember seeing a diy Klippel several years ago on the net. It might be worth digging in google for.