Good morning everyone. So am looking for a Frequency generator to send through my speaker drivers and test them. I see a lot of knock offs on e bay and amazon? I can buy a used one but, am looking for one I can plug my speaker driver into and it does sweeps as well? Am looking more of a teaching and learning instead a click of a button by using my Woofer tester #2. I did see one on line from a science website about sound kit and Demonstration about sound and sand and patterns. How to It do with the earthquakes and other things. It only went up to 1Khz and I need it to go at least to 20khz or higher. Like the picture I posted? Thanks Jeff
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Why not just use software like REW? They do all kinds of things like that. Many other softwares do as well.
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Joined 2003
Especially for just audio band stuff into a speaker, a basic soundcard and a power amp will be the most effective solution, there's plenty of software to generate test tones, even if you have any phone with a headphone jack, there's an app for that..If you need a specific output voltage it's easy to just connect a multimeter to your amp output and adjust accordingly.
I have seen one old-school audio signal generator that had a built-in power amplifier capable of driving a loudspeaker. But that was quite a rare exception.
Most signal generators have a 600 ohm or 50 ohm output impedance, and cannot drive enough output current to connect directly to a typical loudspeaker, with its low impedance of 4 to 8 ohms.
On the plus side, these days it's easy to obtain a small, light, cheap class D power amplifier that you can drive from any signal source (including PC or 'phone), and which can drive a loudspeaker. This opens up an enormous range of possible signal sources.
I've measured frequency responses manually when I had no alternative. IMO, it's an incredibly tedious job. To get a decent plot, you have to measure at a lot of different frequencies (at least 20 or 30 per decade of frequency). Then enter all your data into a spread sheet, make a log-log plot, etc. So tedious! So error-prone!
That said, if you do want to do this manually, I spotted this old-school Wien-bridge audio function generator on Amazon.ca. The price is ten times lower than it used to be decades ago, in the heyday of such devices: https://www.amazon.ca/TIWWS-TAG-101...n/dp/B078LTJ8LP/ref=sr_1_5?crid=2G1S6APUCGWNC
Add a little class-D audio power amp between that signal generator and your speaker, and you're up and away.
Note that most of today's class-D power amps have bridged outputs, meaning neither end of the speaker will be at ground voltage...plan accordingly if you're going to connect an oscilloscope to the speaker-level signal!
-Gnobuddy
HP 3312A
HP/Agilent/Keysight/whatever-name-this-week 33120A
The 3312A can be had for not that much money through the various used gear dealers. Just make sure you get one that's calibrated or at least tested.
Tom
HP/Agilent/Keysight/whatever-name-this-week 33120A
The 3312A can be had for not that much money through the various used gear dealers. Just make sure you get one that's calibrated or at least tested.
Tom