Yesterday the headphones sang like a hand-tuned work of art by Jasse, and today they sound like the band is playing through a wet mattress. A familiar situation. Fortunately, there is usually an everyday explanation for the drop in sound quality—and an even more everyday fix.
What went wrong?
The most common reasons for deteriorated sound quality on the VMK25:
- The ANC mode is set incorrectly. The ANC button on the left side of the VMK25 cycles through three modes: ANC on, transparency, and ANC off. In transparency mode the headphones intentionally let outside sounds in, which makes the music sound thin. Many people press the button by accident and don't notice the change.
- The Bluetooth codec has fallen back to a worse one. If your phone or computer has decided to switch from aptX HD to SBC, sound quality drops noticeably. This sometimes happens all by itself—especially after updates.
- The firmware is outdated. Jasse and the team tweak the firmware regularly. An old version can cause all sorts of weirdness, including audio issues.
- The cushions don't seal properly. It sounds silly, but the tightness of the ear pads directly affects bass response and ANC performance. Hair over your ears, eyeglass frames, or worn pads break the seal. The bass disappears and everything sounds tinny.
How to fix it
- Check the ANC mode. Press the ANC button on the left side panel and cycle through the modes. Try music in each mode. ANC on usually gives the best sound in a quiet environment.
- Do a reset. Plug a 3.5mm AUX cable into the headphones and unplug it. This resets the Bluetooth circuit. Simple, but it works surprisingly often.
- Remove the pairing and reconnect. Go to your phone's Bluetooth settings, forget VMK25, and pair the devices again. This forces the codec negotiation to start from scratch.
- Check the cushions. Sit down, put the headphones on, and press the cups gently against your ears. If the sound quality improves when pressing, the cushions aren't sealing properly. Move your hair behind your ears or consider new pads—they twist off and the new ones snap into place.
- Try with an AUX cable. Connect the headphones with a 3.5mm cable. If the sound is good wired but poor over Bluetooth, the problem is in the Bluetooth connection or codec—not in the drivers themselves.
If that doesn't help
If you've gone through all the steps and nothing changed, it could be a driver or amplifier fault. It happens—electronics are electronics. Send us a message at info@valco.fi, include your order number and a photo of the headphones. Jasse and the service team in Kajaani will set things right. We repair headphones, we don't throw them away.
During the warranty period (24 months) the repair is of course free. Outside the warranty we can still take care of it with a repair package.
And remember—every repair is one step closer to the Death Star. It'll be fine.
