Help... missing sounds while playing mp3 through aux

**happymeal18** · September 1st, 2008 02:14 AM

Hi sirs... need your help and expertise on my car audio. Im not even sure if its the setup thats the problem or the HU itself.

Basically my HU is a pioneer DEH 2950... entry level HU with aux and mp3 in-dash. My main source of music is my creative vision m player which I plug via a 3.5 to 3.5 jack connector to the HU. my jack connector is already gold tipped so its a high end jack.

Anyway, sound is really good (together with mu subs, amp, and custom EQ in my player) however I noticed that in some songs (or probably most of the songs which I fail to notice since it's too negligible already), some instruments can't be heard. Even in some songs, the voice can't be heard.

When I half unplug the jack from the head unit, the missing instrument would be heard, however compromising the stereo sound turning it into mono.... but again the missing instrument sound or voice will be heard.

Just to give you some examples, when the jack is fully plugged to the HU, I won't be able to hear the guitar solo in my sharona, or the harmonica intro in crazy (by aerosmith).... I half unplug the jack, then I will be able to hear the solo and the harmonica (but the rest of the song will sound like mono)

I hope I was able to explain the problem clearly and hopefully you could suggest solutions to this problem.

Thanks!

**StraightSix** · September 1st, 2008 06:30 AM

It seems that you have the wrong kind of plug. Although you may have the right size (3.5mm), you must have the correct number of poles for each plug.

An ordinary stereo ear/headphone plug has 3 poles ... one each for the left channel, right channel and ground. Some devices need a fourth pole, ex: a control line for the device.

If your HU needs a 3-pole plug, use a 3-pole plug at that end. Consult your HU manual for the required plug.

If your MP3 player needs a 4-pole plug, use a 4-pole plug for that end. TIP: The supplied headphones should tell you how many poles it requires.

HTH

**happymeal18** · September 1st, 2008 11:30 PM

Thanks sir, i'll look into this!

**yapoy86** · September 2nd, 2008 08:35 AM

there are many possible causes for your problem...

here is what you should do to verify...

try burning a CD MP3 that contains the same music where you experience missing sounds... then check if it will recur to what you have described..

if it has possible that you have a problem on either left or right channel of your system... try controlling the balance from left to right and check if they have equal sound output...

if it has not recur possible cause of the problem is the jack you are using.. use another jack and compare... also check your player sound output via earphone and check if the sound you are referring as missing will be heard..

**siacojin** · September 2nd, 2008 09:04 AM

Originally Posted by StraightSix

It seems that you have the wrong kind of plug. Although you may have the right size (3.5mm), you must have the correct number of poles for each plug.

An ordinary stereo ear/headphone plug has 3 poles ... one each for the left channel, right channel and ground. Some devices need a fourth pole, ex: a control line for the device.

If your HU needs a 3-pole plug, use a 3-pole plug at that end. Consult your HU manual for the required plug.

If your MP3 player needs a 4-pole plug, use a 4-pole plug for that end. TIP: The supplied headphones should tell you how many poles it requires.

HTH

Whoa! I didn't know this! Very informative. Thanks! I have the very same problem but I'm experiencing it with my PC

**StraightSix** · September 3rd, 2008 10:44 PM

You're welcome siacojin.

It's the way the contacts inside the socket are laid out ... that when you have a plug and socket mismatch, a line will either be shorted or left unconnected. Hence, the problem happymeal18 is experiencing.

---

I've browsed the Zen Vision M website and indeed, the device uses a 4-pole 35mm connector.

You may have difficulties finding a 3-to-4 pole plug adaptor and vice versa, and a harder time for a pre-wired cable. So I've drawn up a simple diagram. You can use an existing stereo patch cable (3 poles) or one with a 4-pole plug on each end ... it doesn't matter because you don't need the 4th wire, and you only need to replace one plug.

The 3-pole plug goes to your Pioneer HU, and the 4-pole plug goes to the Zen Vision M player.

**happymeal18** · September 4th, 2008 12:39 AM

thanks for this. Anyway, when i use earphones on my vision m, its just an ordinary 3 pole jack, and the sound is complete. Does this mean the HU really has a bearing on the completeness of the sound?

**StraightSix** · September 4th, 2008 04:49 AM

In that case, you better check the integrity of the cable with an ohmmeter, testing for continuity from tip to tip, and for any shorts.

You can also try turning off any sound enhancement feature of the HU and see what happens.

**marv25** · September 29th, 2008 08:32 PM

i experience this a lot. its usually loose lang. i just got a new cable then ok na. but ang galing nga nyan minsan eh. klarong klaro yung backup vocals.