Hi, Whenever I turn my stereo on loud it intermittently cuts out. It doesn’t matter if the ignition is on or not as the stereo bypasses the ignition: it still cuts-out when I turn it up. But is fine if I leave it on a lower volume. I may be wrong but I suspect it is when a loud piece of bass kicks in. The unit’s volume goes from 1-35 and the cutout point is between 17 & 20. So not at full blast. As Cyril is a noisy beast, this is an issue as you cannot hear the music unless turned up while driving... Any ideas anyone, I guess it might have something to do with the speakers but could do with some hints before I start pulling things apart? Sent from my iPhone using Tapatalk
Probably not enough power driving the amp (what is feeding it?), or possibly the amp itself has gone bad (how old is it?).
No idea on age, I have had Cyril for 7 years so older than that It’s a Kenwood KDC-241 I don’t to buy a new stereo if it’s the speakers. Can I test them by unplugging them one at a time Sent from my iPhone using Tapatalk
Although fairly reliable as a whole, electronics can fail at any time, even when new. Especially when a lot of formally respected giants offshore their production to cheaper labour markets.
An in-line choke (filter) commonly fitted on the 12v supply to suppress interference (such as ingnition circuit noise) can cause this as the power consumption at high volumes especially with bass notes fluctuates a lot and drags the supply voltage up and down. If it’s got one try bypassing it. Also an overly-thin power feed cable may struggle to provide enough power at high consumption levels. And low power rated speakers of course. Sent from my iPhone using Tapatalk
It could be the design then. Myself I'd have it apart and look for good solder joints especially where the power transistors are, and make sure the grease that connects them to the heatsink hasn't dried up (and re-apply new stuff anyway).
I got the cheap one now double don mirrors ur phone put a little amp on and sound mint Sent from my iPhone using Tapatalk
Its going to be either supply voltage drop causing shut down or current limiter or thermal protection circuits in the audio power amplifier chips triggering a shutdown. It claims 4x45W. Which is 180W or momentarily something like 15 amps , which is a massive current drain on a circuit wired with 10 amp type wires. . Of course it doesnt draw that much for long. The manual says 10 amps. All this means is specmanship and a bridged audio amplifier (one amp drives each side of the speaker so one side can go to 12 volts different to the other side in either direction - that gives about 18 watts into 4 ohms. My Sony claims 4x17 watts and that is much more realistic . If you have speakers in parallel, or speakers that end up as less than 4 ohms, it may be being forced to source too much current into the speaker and so it protects itself. The fix will probably be a better head unit, or use the low level preamp output, feed it to a separate amplifier. .. and open another can of worms.
Hi @Coda I did some playing around and it seems that it cuts out at a lower volume level on the CD (L17), about L22 on USB & L26 on the radio. As such does that make it most likely that the supply is the issue? The supply cable does seem very flimsy, by comparison to the connector on the unit. If it needs replacing, where’s the best place to take the feed from and in what size cable please? Sent from my iPhone using Tapatalk
Yes, I would expect the radio to work as it doesnt need a lot of digital logic to make it work. The USB and the CD will both be needing stable logic supplies - with the added feature that the CD may also being directly messed up with by vibration too. Looking at the spec sheet, the supply voltage goes from 11 to 16 volts on the head unit. At 11 volts there might even be a low voltage trip helpfully protecting your battery from being totally killed. So the voltage drop on the ignition feed might be enough. See if its worse if you turn the headlamps ~ 100 watts/8 amps or hazard flashers on ~ 80 watts / 7 amps drain .
