My first Chladni patterns

Construction and repair of Classical Guitar and related instruments
Alan Carruth
Luthier
Posts: 3202
Joined: Mon Dec 24, 2007 6:56 pm

Re: My first Chladni patterns

Post by Alan Carruth » Tue Apr 09, 2019 4:37 pm

It takes time to learn anything worthwhile. At least with Chladni patterns you can post a picture and a frequency, rather than saying: "Well it's a sort of 'bap' sound when I tap near the lower edge, but more of 'wooo-woo-woo' if I hit it in the middle" .

SteveL123
Posts: 1265
Joined: Thu Feb 09, 2017 5:05 pm

Re: My first Chaldni patterns

Post by SteveL123 » Tue Apr 09, 2019 6:43 pm

Costantino Proietti wrote:
Sat Apr 06, 2019 4:04 am
I use the speaker in the picture, I don't know if it is the right one as it becames hot, but for now it works. For a signal generator I use an app for my smartphone ( Simple tone generator) and an amplifier with a microphone jack.
What are you using for an amplifier? Do you have specs for it? The pic says your speaker is 6 ohms. Most speakers are 4 or 8 ohms and is best if they match the amplifier. Even if they do not match, I don't think the speaker should get hot. Maybe there's a fault in the amplifier?

Do you have a volt meter? Put it on DC, auto mode and measure the amplifier's output terminals with speaker disconnected. You should get close to zero volts. If not, there's a problem with the amp.

Costantino Proietti
Posts: 72
Joined: Thu Jun 14, 2018 5:46 pm
Location: Rome

Re: My first Chladni patterns

Post by Costantino Proietti » Tue Apr 09, 2019 10:01 pm

Steve, I found the speaker of an old car that I scrapped. The amplifier is a Sony system player with a microphone jack where I connect my smartphone. But I don't know the features. I only know that after a while the speaker warms up. Since the system also has other speakers, as soon as I can check their impedance and do a new test with the woofer.
A fact is the most obstinate thing in the world. Bulgakov

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