Introduction
Checking him out
Under construction!
Some big-ass speakers
Together with the amplifier I also got 2 PD415P speakers. They are big professional speakers that can handle 700W and have a big ass 15inch woofer.
My father in law already opened one and accidentally tore one of the cables to the tweeter. I expected they need to be soldered so I got out my soldering iron. When I opened it up, to my surprise it was just a spring connector which held the cable in place
I tested the speakers by connecting the XH-M139 amplifier board to it and playing some music. Indeed, they only gave a very faint sound. My first guess was the separation filter where the connectors for the cables are soldered to.
This PCB was very simple, just a separation filter with a coil, capacitor and some resistors. The black and red wires are - and + for the big woofer, and the blue and yellow are - and + for the tweeter. I measured it with my multimeter and all paths seemed fine, so nothing was shorted or burned out. When I connected the audio cables directly to the cables for the speakers, I got some sound out of the tweeter and none out of the woofer ╰(￣ω￣ｏ). This didn't bode well. I disconnected the PCB to be able to just connect to the speakers directly, but this gave the same result. I then had the idea to measure the impedance to see if the coils were disconnected, which would tell me if the speakers themselves would be broken of not. The impedance of the tweeter was around 6.6Ω, which is fine for the 8Ω rating. The woofer however, gave no result at all. Sadly, this means that they actually blew it up :-O. I did the same for the other speaker and it gave the same result. Final verdict: they blew 'em up.
The amplifier has an output of 500W per channel, which can be combined into a single channel. The tennis club had one speaker hooked up to one channel, and I think they just blasted the full 1000W through it and blew them up that way.
Replacing is better than throwing away
I couldn't find any listings for the speakers on 2nd hand sites like marktplaats or ebay, but I did find the exact model of the woofer. It costs 60 euros, so I asked my father in law if their tennis club would like to buy them back for the price of 2 woofers, to use them as spares. I figured then they would at least get used more instead of being thrown away if I would take them to the recycling center.
UPDATE 01-12-2025: They agreed to repair them with the new woofers. I ordered them and I'll install them so they can be used again. I agreed they would pay for just the new woofers. Happy to have saved a piece of tech from the landfill!
I did tear the connector to the speaker cable of the tweeter on one of the connector PCBs, so I soldered it back together