Dave's Speaker Pages
Tests and Analysis of the Seas DXT Tweeter
I started this site as part of a discussion on the Madisound Discussion board. It just kept growing as I found new topics that were of interest to me. I'm sure I'll find things to add or change over time, so I will update it occasionally.
The Speaker Builder article covers one aspect of CAD design that must be properly handled if direct measurements are not used. That is, if the drivers are modeled and the minimum-phase (Hilbert-generated phase) of that model is used instead of the actual phase response.
The diffraction section shows the predicted and measured impact of baffle edge diffraction on the driver raw response as well as an extensive set of measurements of baffles with felt applied for diffraction reduction.
The models section shows a couple of the electrical and acoustic models used to represent a driver and/or system. It is frequently used in CAD software.
The raw measurements pages are now for those taken on what I call my "quasi-IEC" baffle. The woofers are now measured on that one as well. Raw measurement text files either exported from LAUD v3.0 or CALSOD (with Hilbert phase using CALSOD) may be downloaded by anyone interested. Be aware, though, that they will only be quasi-anechoic (no baffle effects), so you won't get what these show. Tweeters will have significant baffle effects. Woofers and midranges will have baffle step loss. These files must be considered as useful more for some testing and learning than for any final designs. The files may be imported into the tools at the FRD Consortium, though, to get approximations.
Tweaks for Tweeters combines the rear chamber testing I conducted with a new tweak (well, not really new) using a material I came upon by accident. It's cheap, easy and worthwhile for almost any tweeter, in my opinion. I also now have another tweak, made to a Seas T25C003 and now the T25CF001. I recommend it to anyone using these drivers.
