Help measuring drivers!

[pat_staunton]

Hi!
I Bought a pair of Drivers and a SUB almost a year ago (Dainty) but unfortunately still could'nt get them together because I cant find the propper T/s Parameters (the ones posted on this forum dont match the serial Nos of the ones I have), So I downloaded the Speaker Workshop Software to measure them But my knowledge on electronics suck !!! is there anyone from Hyderabad India who could test them for me? Or someone walk me through the whole process? I really need some help here.

AND NOW THE SAD PART!!!!!!

I have 5 CNC Wood Working machines capable of making any Conceiveable Enclosure and tons of MDF but not the faintest clue as what size should the boxes be!!

 

[vdi_nenna]

There are several books on speaker box construction that show basic test rigs for getting T/S parameters.

David B Weems and Vance Dickason wrote a couple of books.
Testing Loudspeakers by Joe D'Appolito is very...scientific. If you are good at math, go for it.

You have the means to make test boxes, that's to hardest part, I thinks. I mean test boxes for calculating VAS, one of the three params you need.

http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=40&ObjectGroup_ID=72

Or, there is this contraption: http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=390-802

Good Luck,

Vince

 

[richie00boy]

Do you have a multimeter, a PC with soundcard and a good quality power amplifier with flat frequency response? I have a PDF of full instructions that I would like to have run through by a beginner such as yourself for comments/feedback. If you are prepared to spend a little while reading the 5-6 pages and conducting some tests then I will send you the document and I'm sure it will be a success for you. If you don't feel that you want to do this yourself that's fair enough, no problem.

 

[memofer]

Sorry to steer abit off topic, but, how does one measure the frequency response of an amp.?

 

[richie00boy]

With a signal generator and an (expensive) true RMS multimeter or oscilloscope or soundcard with flat response.

 

[wintermute]

Pat, have you downloaded the unofficial speaker workshop manual? http://www.audiodiycentral.com/resource/SWmanual/Speaker Workshop Manual 1.0.zip

Sorry to steer abit off topic, but, how does one measure the frequency response of an amp.?

This is what I use http://audio.rightmark.org/index_new.shtml in conjunction with a preamp between the amp and the PC (so as not to overload the soundcard (though if you are carefull and measure the output voltage before connecting to the soundcard, you could get away with not using the preamp.... The one I have was designed to be used with osciliscope software... As Richie00boy says, you need a good soundcard.... I have an Audigy II ZS, which IMO is excellent for this task.

Here is an example of a test I did of my amp, and the soundcard preamp a while back.... note that my amp is in the doghouse at the moment

http://home.swiftdsl.com.au/~tonywww/rmaa/series_200_pre_vs_whole_amp.htm

The SC preamp curve is the sound card preamp. the preamp only curve is the preamp section of my amp, and the other is the whole amp, pre and power.


this one http://home.swiftdsl.com.au/~tonywww/rmaa/preamp_compare_MKII.htm shows the freq response of the sound card, and the response of the soundcard preamp, before and after modification (basically increased the size of the coupling cap on the input of the preamp).

Tony.

 

[simon5]

This webpage might help you to measure the T/S parameters.

You'll need to break in the drivers maybe 24 hours or more before taking measures just to have more accurate T/S parameters.

http://www.diysubwoofers.org/measure.htm