poor mans measuring system...

[nerd of nerds]

hello. i don't have any "fancy" measuring equipment, and i wanted to measure some of the parts express 87cent speakers whilst trying some of the mods to see which ones work well...

is there an easy and simple way for me to do this? i have some boxes i but out a while ago that i could probobly use...

any ideas? i've never measured speakers before and this is mostly all new to me and i want to do this right

[bzdang]

Not easy or simple, but it doesn't have to be too expensive. Cheapest route may be www.speakerworkshop.com plus a Behringer ecm800 mic and a compatible preamp (or the Apex clones), and a wallin jig-2. Not too expensive but it will hurt your brain.

[johnnyx]

Praxis in demo mode (which is free) can measure the T/S parameters of your speakers, and measure their frequency response with RTA using a mic etc as in the above system. I find this easy to use, it sort of holds your hand as it leads you through the steps you need to perform the measurements. It won't hurt your brain quite so much, but it will still hurt. You will say, "but what does it all mean?" and be met with a deathly silence.

Look here

[nerd of nerds]

hmmm...

is there an easier way to JUST measure frequency response? or should i just go hog wild and measure everything...i really just wanted to see what the effects of the mods do to the speakers...

[Sandy H.]

If you are searching for changes to TS parameters, you could try Joe D's method from the Loudspeaker Design Cookbook. You could download SW to use your PC as a sine wave generator and a good DMM to measure the impedance characteristics. It will be an hour or two of writing down points, but for me, it was worth it to learn the what's and why's of the equations.

If you want frequency response, there would be more required. At least a mic/jig if you're lucky.

Sandy.

[johnnyx]

The RTA I described above will measure the frequency response of your mods. You just need a soundcard with a mic input. Use a condenser mic not moving-coil, (and definitely not a vocal mic)and the response will probably be good enough. Less hassle than a switch box and preamp.

[nerd of nerds]

hello...thanks for all you guys help...this forum rocks..


http://www.radioshack.com/product.as...5Fid=270%2D101

this is the mic i am looking at getting tonight...just so i can do some basic tests...

how do i go about setting this up? how far away should the mic be from the woofer? would it be good for me to guess 1 meter since most (all?) frequency responce graphs say 1m/1w?

i'm listening to one of these right now (the 80ish cent drivers from parts express) that are coated with dilluted elmers glue...it sounds pretty good...

thanks so much for helping a n00b like myself...

[johnnyx]

My first measurements were made with something very similar. They need power, eg a battery, to bias the built-in FET. Tie-clip mics use a similar insert, but have a battery compartment to bias the FET, so it would be self-contained. Some soundcards, like my old Turtle Beach Fiji, have (jumper?) options to provide this bias, again leading to a self -contained unit. Check your soundcard specs.

[mgmopar]

Hello,
I am too looking to make similar measurements. I was planing on using the out put of my sound level meter. Would this be fairly accurate, or should I too get a condenser microphone? (I am assuming that is what my meter uses.) I figured weighting C would give the full output range but I am not sure? If this is suitable it may save others from having to buy any additional equipment.

[Jimmy154]

Cheapest way is get panasonic capsole and get audiotester; total cost $5. Just search for my name and mic (or similar) and your should find a microphone thread started by alvaius I believe. If you find the thread you will see I used a 9V battery, a cap, and resistor, but if you use audiotester and mic input on your sound card you don't even need this setup. All you need is straw capsole soldered to wires that go straight to sound card.

I could never get SpeakerWorkshop to work, with the capsole.