SAMPLE CHAMPION REVIEW                             

Sample Champion

    I used MLSSA for years.  The best thing about it was that it is packed with features and performance - the drawback is that it costs over $3000 and is still a DOS program.

    When starting my own company, due to costs constraints I went out and purchased an LMS (Loudspeaker Measurement System) hardware/software set for around $1200.  I was impressed by the new 4.0 Windows version, which performs great. It uses a straight sinewave signal measured directly from the mic . The only downsides are its relatively high cost and the fact that it comes with a card for a computer ISA slot.  Good luck finding an ISA slot on a new computer.  I would guess that LinearX is working on a new PCI version, but they would have to wait to announce it so that they can get rid of all of their ISA card stock.

   At about the same time I purchased the LMS a few years back, I ran across the www.purebits.com website that sold a program called Sample Champion.   A fellow by the name of Paolo Guidorzi runs the site and also wrote all of the software code.  This programs uses an MLS signal, generated by virtually any standard computer sound card. 

   The first time I tried the software (two years go), there was little in the way of loudspeaker testing.  But Paolo has been hard at work listening to the recommendations of users, and new features and modules are continuously being added.   You can take impedance curves, frequency response curves (and overlay them), apply smoothing, perform various plots…print out the graphs or save them as graphic files.  Check out the www.purebits.com site for a comprehensive list of features.  This is a five star website, with everything laid out and organized for quick information gathering.   

    The program is Windows based and highly intuitive.  It is easy to learn and there is a quick help menu with text and helpful graphic instructions if you get stuck.  You can use your default windows mixer, the mixer application that came with your software, or even it’s own SC mixer window (which I had trouble getting the correct inputs to list – so I used the Windows mixer.) 

   The program does apparently use a lot of system resources; it basically requires you have other programs shut down when you are using it [NOTE FROM AUTHOR:  Recent versions have this problem fixed].  In addition, the PDF Help file must be installed separately from the program. 

    I curved a Curtis Mathes AS640 speaker using the Sample Champion and the LMS.  Using default parameters of both systems, the resulting frequency response curves were very close.  The microphone I used only had a bandwidth to 15K.  It would be nice to see a list of recommended microphones on the Purebits website.

     Here is a graph of a comparison between Sample Champion and MLSSA, taken from the Purebits website:

 

    Overall, I would strongly recommend this software to anyone requiring signal testing software.  If you are looking for loudspeaker measurement software and are on a limited budget, this performs as good or better than most of the stand-alone hardware “boxes”.  The ability to use your existing sound card is arguably less advantageous performance wise, but an undeniable convenience.  It all depends on your project priorities.   

    Be sure to check our the Purebits websites for current news, hardware requirements, and any known issues.

Charles Miltenberger
Vidsonix
10/03/02

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