![]() Go back to the measurements tab and measure the woofer (don't move anything). then click on the Use button beside last detected. ![]() ![]() Go to the second tab and select time zero locked. Change the Time Zero auto detect to highest positive peak. Go back to the measurement tab and click options for the measurement. Take a measurement of the tweeter with Holm and check the impulse, if it looks upside down (main peak going down rather than up) toggle the "Invert recorded Signal" tickbox on the first tab. Place your mic about 1M away on axis with the tweeter. Position your speaker as far from any objects you can preferably at an angle to any parallel walls (even better do it outside) Try for mid way between the floor and ceiling. Hi Thump Lump, what I suggest as a "test" of whether your measurements are ok or not is to do the following: My setup (mic some 80cm to the driver) limit the valid range to above 200-250Hz, under that frequency I have to measure near field, and merge the two measures. Looking at the impulse response it is obvious where the first reflection kicks in. The length of the gate is dependent of the space around, what is important is the difference in path from the straight distance from driver to mic and the reflected one. And of course you'll find this effect only after you built the enclosure.Įither way you should always use the quasi anechoic method with a gate, in order to leave out the reflected sound. a bump in the response in both the "natural" FR of the driver and the enclosure. The only problem with this approach is that if the enclosure adds some effect in the same way as the driver, i.e. The alternate method is to measure the drivers in the final enclosure. See here for this kind of setup: Zaph|Audio 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.īottom line, the files are out there but, if you really want it done right, you need to do it yourself.If you have access to an infinite baffle setup you could measure the drivers in such a way, so you can use the data and simulate whatever enclosure you want before physically build it. 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. I think maybe I got it from Zaph's site but I don't remember. I still have a zip file (below) of Seas data with all the 7" woofers and the tweeters they sold at the time. The impedance files look like free air so, again, you'll need to simulate the box. They look like the FR files are on an infinite baffle so you'll need to simulate the box. That said, most of the Dayton drivers have FR and impedance files on their website. 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. It's a bit 'dangerous' using other people's files unless you know how they were measured. ![]()
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