Single sheet TH challenge

[Brian Steele]

Originally Posted by 4pyros

Can I cheak the resonance of the TH sub by cheaking the AC current with a DVM and looking for a Dip? Andy

Suggestion: Get a WT3 and use it to measure the impedance response of the TH. It will tell you all you need to know, including the resonance points, AND if there are any sections that need more bracing.

[4pyros]

Suggestion: Get a WT3

Ya I dont think I want to go that far to test one speaker, maybe I would measure the voltage across a resistor if I had to. Andy

[Brian Steele]

Originally Posted by 4pyros

Ya I dont think I want to go that far to test one speaker, maybe I would measure the voltage across a resistor if I had to. Andy

Believe me, once you starting building speakers, a WT3 is probably one of the best, if not THE best tool you can have in your toolkit.

You can take the long way around and hook a resistor in series with the speaker, and then use voltage measurements across that to calculate impedance at varying frequencies. A WT3 will do the same for you in seconds. It's worth the $$.

[4pyros]

Believe me, once you starting building speakers, a WT3 is probably one of the best

I believe you, But I am only making one speaker.

You can take the long way around and hook a resistor in series with the speaker, and then use voltage measurements across that to calculate impedance at varying frequencies.

Cant I do the same thing by measuring the AC current with a DVM?
Andy

[Brian Steele]

Originally Posted by 4pyros

I believe you, But I am only making one speaker.

Cant I do the same thing by measuring the AC current with a DVM?
Andy

Sure, if your DVM has an internal impedance of zero and it can measure current accurately for frequencies from 0 to 200 Hz or so .

[djk]

The woofer tester has an AC constant current source that drives the speaker and an AC voltmeter to measure the resulting voltage drop and then calculates the impedance from this data.

[Djim]

[djk]

No, put a 10KΩ in series with the driver and measure the voltage across the driver with a true RMS AC voltmeter.

[tb46]

Hi 4pyros,

I'm with djk, but a 1000 Ohm resistor is large enough. Then you can use the precision 10 Ohm resistor in place of the speaker for an initial calibration. If any of this is unclear, get a WT3 :-).

Regards,

[Djim]