Crossover testing?

[rgarrett7]

I'm looking for suggestions on good ways to test crossovers.

I did not design any myself, but I have been building them from plans on the Internet (most recently from Zaph audio). I do simple tests of connectivity using an Ohm meter. I could buy an LCR meter (and probably will), but that would only tell me the value of a component (versus reading it off the label. Ha!).

I don't have a signal generator or an oscilloscope, but I do have plenty of computer equipment. I would be willing to spend $100 - $200 to buy test equipment of one sort or another.

My main purpose is to check my construction. At this point, I can only check for really gross errors (short or open circuits; tweeter puts out high sounds, mid puts outer lower frequencies). I'd like to do better than that. I'd like to see that the circuit is doing what it is supposed to.

Recommendations?

 

[TLS Guy]

I'm looking for suggestions on good ways to test crossovers.

I did not design any myself, but I have been building them from plans on the Internet (most recently from Zaph audio). I do simple tests of connectivity using an Ohm meter. I could buy an LCR meter (and probably will), but that would only tell me the value of a component (versus reading it off the label. Ha!).

I don't have a signal generator or an oscilloscope, but I do have plenty of computer equipment. I would be willing to spend $100 - $200 to buy test equipment of one sort or another.

My main purpose is to check my construction. At this point, I can only check for really gross errors (short or open circuits; tweeter puts out high sounds, mid puts outer lower frequencies). I'd like to do better than that. I'd like to see that the circuit is doing what it is supposed to.

Recommendations?

You will have to have a signal generator and scope. That will tell you if your circuit is basically correct. However you will have to connect it to the speakers the crossover was designed for, in the enclosure. Then you will have to measure the frequency response of the total speaker, with accurate measuring gear.

Please understand that generic crossovers are useless. Crossovers have to be custom designed for the speakers they will be connected to.

Your budget for test gear is too low by a factor of at least 10 and then assuming you buy used.

 

[rgarrett7]

The crossover was custom designed by John "Zaph" Krutke. I'm willing to accept that he did a good job with the design. I wanted to confirm that I constructed it correctly, with something better than a visual inspection.

I performed a listening test ... it does sound pretty good, but then I'm half deaf and never had very good taste ... so probably not terribly accurate.

I don't make very wise spending decisions, but paying a few thousand dollars to test speakers that cost hundreds is a little too much even for me.

One other alternative, I have Denon 3808-CI receiver. It tries to equalize the speakers. The microphone is by no means reference quality, nor do I have an anechoic chamber, but that might show gross distortions.

I thought there might be software that would use your computer sound card to emit test tones and the sound card's ADC to measure frequency response. Again, not reference quality, but ought to be more accurate than my hearing.

 

[rgarrett7]

Possible answers

After I did a better job of defining what I was looking for, there are several software packages that look like they would do what I want. Two examples are Praxis and Cliowin. Those both look a little pricey. There are others that look significantly cheaper (and less powerful).

To refine my question, I guess I am now interested in audio measurement software priced at around $200 or less. Checking on Source Forge, I see there is at least one free package.

 

[mike c]

check these out:

Behringer ECM mic
http://www.behringer.com/ECM8000/index.cfm?lang=ENG

Behringer mic pre amp
http://www.behringer.com/02_products/audio_index.cfm?lang=ENG

Room EQ Wizard software (free)
http://www.hometheatershack.com/forums/rew-forum/

 

[WmAx]

check these out:

Behringer ECM mic
http://www.behringer.com/ECM8000/index.cfm?lang=ENG

Behringer mic pre amp
http://www.behringer.com/02_products/audio_index.cfm?lang=ENG

Room EQ Wizard software (free)
http://www.hometheatershack.com/forums/rew-forum/

I think it should be stated that the Behringer ECM-8000, in most recent models, has been said to be measured with rather significant deviations from flat amplitude response. It may be that the newest units are not suitable.

The LinearX M31 is a calibrated precision microphone. It is $175. However, when you include the cost of a Behringer ECM-8000, getting a calibration service done to it and shipping, you would have spent around $110-$115.

-Chris

 

[mike c]

quality went down?