FAQ
TL;DR: Burning speakers? In this case, “always the left front” and “2 speakers a week” flagged a bad output stage, not speakers. A basic AliExpress 2‑DIN can work, but expect noise and fit issues; fix wiring/grounding first. [Elektroda, gruniu, post #17165157]
Why it matters: This helps drivers decide whether to repair a Blaupunkt OEM unit or swap to an AliExpress head unit without frying more speakers.
Quick Facts
- Double‑DIN opening: 180×100 mm per ISO 7736. [ISO, 2004]
- Universal 2‑DIN units often need vehicle‑specific pockets/frames; expect installation hurdles. [Elektroda, D_Mrozu, post #17164921]
- Typical head‑unit power: approx. 4×15–22 W RMS into 4 Ω; ignore “50×4” peak hype. [Crutchfield, 2023]
- Most head units expect 4–8 Ω loads; 2‑Ω loads can overheat or trip protection. [Crutchfield, 2023]
- Engine‑RPM whine is usually grounding/routing; use a noise filter only after wiring fixes. [Crutchfield, 2023]
Why did my Blaupunkt burn the same speaker repeatedly?
Repeated failure on one channel points at the head unit, not the speaker. Squeal before failure suggests amplifier oscillation. A failed Zobel network or damaged output IC can cause this. Repair requires checking the R‑C snubber across the output and the power amp IC. Match speakers to the rated impedance. [Elektroda, matej1410, post #17164499]
How can I quickly confirm if the radio is at fault, not the speaker or cabling?
Do this fast isolation test.
- Swap left/right speaker outputs at the radio.
- If the fault moves sides, the radio channel is bad.
- If it stays, inspect the door harness and test with a known‑good speaker.
Keep volume modest during tests to avoid further damage. [Elektroda, jaszczur1111, post #17170925]
Do I need to replace all speakers to check for a short?
No. Measure DC resistance with a multimeter. A 4‑ohm speaker reads about 3–4 ohms. Remove the door connector and check for continuity to chassis. Swap one known‑good speaker onto the suspect channel for confirmation. Replace only failed drivers after testing. [Crutchfield, 2023]
What is the Zobel network and how can it blow speakers when it fails?
The Zobel (Boucherot) network is a resistor in series with a capacitor across the output. It stabilizes the amplifier at high frequencies. If it opens or drifts, the amp can oscillate ultrasonically. That overheats voice coils even when music sounds normal. Replace the failed parts during repair. [Elliott, 2014]
Could a damaged door wire be the real cause of burned speakers?
Yes. A chafed door‑loom wire can short the speaker lead to the car body. That overloads the channel and can burn drivers. It might only short when the door moves, creating a tricky intermittent. Inspect and reroute or replace the door wiring if insulation is worn. [Elektroda, gumisie, post #17170683]
Why couldn’t the repair shop reproduce the fault on the bench?
Bench tests often use different loads and voltages. Vehicle wiring and speakers present reactive loads that can trigger oscillation. Supply voltage and temperature also change in the car. Those differences can hide an intermittent until it is back in‑vehicle. [Elektroda, jaszczur1111, post #17165200]
Are cheap AliExpress 2‑DIN radios any good compared to brand units?
They work, but expect compromises. An installer replaced Vordon units with Sony and Kenwood, which sounded better. “There is no revelation - it works.” Budget units can be fine for basics, but quality and fit vary. [Elektroda, D_Mrozu, post #17164921]
Will a 12 V “noise filter” fix engine‑RPM squeal?
That squeal is alternator whine or a ground loop. Fix wiring first: ground the radio to bare metal, separate power and signal runs, and secure battery and chassis grounds. Add a noise filter or ground‑loop isolator only if wiring fixes do not stop the whine. [Crutchfield, 2023]
Will a universal 2‑DIN fit my car without extra brackets or trim?
Often not. Many cars lack ready pockets or half‑frames for generic 2‑DIN units. Expect to buy vehicle‑specific mounting kits and trim. Without them, installs are difficult and look unfinished. [Elektroda, D_Mrozu, post #17164921]
What power and impedance should I plan for with head units?
Most head units deliver about 4×15–22 W RMS into 4‑ohm speakers. Keep each channel at 4–8 ohms. Avoid paralleling speakers on one channel or using 2‑ohm loads on the built‑in amp. Use an external amplifier if you need more power. [Crutchfield, 2023]
Should I repair the Blaupunkt DX170 or switch to an Android/Chinese unit?
Repair preserves OEM fit and often better radio reception. Android units add features but can compromise sound and fit. As one member said, “I’d rather fix Blaupunkt than play Chinese CarAudio.” Choose based on features, cost, and install effort. [Elektroda, D_Mrozu, post #17164921]
Where can I get a schematic for the Blaupunkt TravelPilot DX170?
Search for a service manual by full model and board codes. Forum helpers asked for the diagram to diagnose output issues. If public manuals are unavailable, contact car‑audio service centers or Blaupunkt specialists who can source them. [Elektroda, matej1410, post #17164499]
it's a bit like you would ask, how does Mercedes with climate work for 2,000 PLN from a dealer.
