FRD, ZMA files

[Wilk]

Where is a good place to get FRD, ZMA files from for use with passive crossover designer?

[Paul Ebert]

Well, Roman Bednarek has some here:

http://www.rjbaudio.com/Audiofiles/Driver%20FRD%20files.html

You can also 'roll your own' using jpeg files and splTrace. It's tedious, but it works OK. For jpeg files, go to zaphaudio.com.

Are there specific ones you're looking for?

[Dennis H]

It's a bit 'dangerous' using other people's files unless you know how they were measured. In a box, free space, or on a baffle with no box? Anechoic chamber or in a room with floor bounce, etc.? Are the FR and impedance files measured under the same conditions.

That said, most of the Dayton drivers have FR and impedance files on their website. They look like the FR files are on an infinite baffle so you'll need to simulate the box. The impedance files look like free air so, again, you'll need to simulate the box.

I still have a zip file (below) of Seas data with all the 7" woofers and the tweeters they sold at the time. I think maybe I got it from Zaph's site but I don't remember. There's a readme and a .jpg showing the measurement setup. Basically, everything is measured in a 'typical' box, mic on the tweeter axis so baffle step is being measured and you set all the driver positions at 0,0,0 in your software. That will give you an accurate sim at 1m on the tweeter axis but the off-axis sims will be off because you aren't accurately modelling driver positions on the baffle.

Bottom line, the files are out there but, if you really want it done right, you need to do it yourself.

http://www.crestviewcable.com/~catapult/Seasdata.zip

[Dennis H]

JonMarsh posted FRD and ZMA files for the Modula MT. I think (not sure) all the measurements were at 1m, mic on the driver axis, drivers in the recommended PE box.

http://www.htguide.com/forum/showpost.php4?p=174190&postcount=20

[dlr]

I have quite a few available for download

Where is a good place to get FRD, ZMA files from for use with passive crossover designer?

My Raw Measurements section has a fair list of drivers with measurements. The measurement conditions are detailed there.

I always use the same start time marker, so the excess-phase and thus the relative phase between drivers will be correct for my measurements. However, since you'll need to put them through something such as the BDS to add in the target baffle shape and then re-generate phase (using the FRC or other program), then the resultant phase will be minimum-phase. They are then still usable, but the offset required will be a bit of a guess.

I haven't detailed a means to take my measurements and used them after these manipulations. Most make an educated guess as to offset and will get you close.

[dlr]

Forgot the link

My web site is here:

Dave's Speaker Pages