What entry level equipment do I need to check frequency repsonse?

[GuyPanico]

I want to check the response of the speakers I currently have, and the speakers I plan to build in the future. I just need a set up that works, but it doesn't have to be perfect. Just good enough to build simple crossovers. Right now all I have is a reciever and PC. What else would I need besides a microphone? Please give me suggestions on what I should purchase. I'm really in the dark about what I need.

[Nanook]

a free frequency generator for the PC, into my preamp, and hook up the speaker(s) of interest. Really crude. I would suggest the True RTA software or similar, fully loaded for less than $100 USD. You do need a means of importing the microphone back to the comp, so you do need a Microphone jack.

A compant mankes a PDA program, it's just $28

I'm sure the loudspeaker gurus will chime in (I hope). planet10, zaph, scottmoose, etc. I'm kinda in the same boat.

As far as ball parking crossovers, etc, WinSpeak or similar can help with X-over design, but ultimately your ears are better than an RTA for listening--please trust them.

Or c'mon over to darkside and go fullranger!

[GuyPanico]

Is there a good enough mic that can simply be plugged into the soundcard?

[gootee]

To "check the response", you have to have something to respond to. So you need some way to get a calibrated signal to the speakers, so you can measure the response. I'm not an expert in this field. But I remember reading about simple/cheap software-&-soundcard-based solutions that are available. Someone will probably chime-in with a URL or whatnot. Have you tried searching diyaudio.com with keywords such as "soundcard speaker frequency response test", etc etc?

- Tom Gootee

http://www.fullnet.com/~tomg/index.html

-

[owdi]

The analog spl meter from radioshack has an output which can connect to your sound card, and you can find generic calibration files for it on the internet. That should be enough to get started.

http://www.radioshack.com/product/in...entPage=family

For measurments, forget TrueRTA, as you have to pay to get any kind of resolution. Try the free Arta. Very good software that is easy to use, and the demo version only keeps you from saving/opening projects.

http://www.fesb.hr/~mateljan/arta/

Dan

[GuyPanico]

I wouldn't mind spending $110 on the ECM8000 and Xenyx802 setup if they work well. Any suggestions on this combo? Is it something I could plug into a soundcard?

http://www.parts-express.com/pe/psho...number=248-625

http://www.parts-express.com/pe/psho...number=248-576

[Dave Bullet]

Ok, here's the basics

microphone
|
V
phantom power supply
|
V
mic preamp
|
V
Jig
|
V
Soundcard
|
V
Software

The bought way:
- Behringer ECM8000 for mic
- Behringer UCM802 (?) is your preamp and comes with phantom power to power the microphone
- Either make the Wallin Jig II (about USD$30) or make the Claudio Negro cable jig (about USD$10)
- Soundcard needs to be full duplex. If your PC / soundcard is less than 5 years old - you should have no hassles. SW (below) will check for you
- SpeakerWorkshop (SW) will do measurement and crossover simulation. It's free (www.audua.com). Takes a bit of time to learn.

You will also need some reference resistors for callibration of the jig / soundcard for use with SW
You will also need some damping material when taking measurements to put on the floor (minimise floor bounce) and a microphone stand to put the mic on tweeter listening axis

Hope the above helps.
David.

[GuyPanico]

Thanks Dave, that cleared things up a lot for me. The jig is my next obsticle. I havn't seen the Claudio Negro jig, but I know the Wallin is rather complicated for a newbie like myself.

[Dave Bullet]

I am a newbie too, and decided to build the Wallin jig.

It is quite easy. However, I'd only recommend it if you can obtain switches with a low contact resistance. My problem is that the toggle switches in NZ from our local electronics parts shop have high and variable contact resistance on the switches. This means you can't get the jig to stay at a consistent impedance when switching between modes. For example the jig has 3 impedance measuring modes used for measuring driver impedance as well as measuring crossover part values. The two modes for measuring crossover parts place either 4 ohms or 16 ohms resistance across the points used to measure the crossover parts. In my case (due to the switch volatility) - I get between 8 ohms and 125 ohms! depending on how the switch "feels"

I recommend you build the Wallin jig - but only if you can get low contact resistance switches. Eric's site posts the RadioShack parts numbers he uses. They should be ok. If you get any other switch types - be sure the contact resistance is small and stable.

The cable jig (see Claudio's site) is really just wires and a terminal block. The downside is you have to unscrew / screw in the different modes (cables and resistors depending on the type of test you are doing). The upside is it is cheaper and easier to implement.

Don't be put off - speaker building isn't that hard if you have a reasonable IQ. Like any new skill - it just takes time and patience.

Cheers,
David.

[Hornlover]

For a mic preamp, check here:

http://www.audio-kits.com/page/page/4071313.htm