Just Got My Gp2x

[FastMHz]

I just got my GP2x and noticed as soon as I booted it the first time that the speakers were out of phase...the fix was simple enough, and involved opening it and flipping the wires to one of the speakers in the little white connector. I don't know if this is a common issue or not...you can tell if your speakers are out of phase because it sounds like the sound is inside your head instead of from the unit in front of you. After I reversed one of the speakers wires the volume was noticeably louder too, since inverted speakers cancel each other out.

 

[Ranma13]

Nice find, I noticed this too on my new GP2X. Guess I'll open her up tonight and flip one of the speaker leads.

Edit: finally managed to reverse the leads. MAN those screws on the back of the GP2X are hard to get off. I felt like I was stripping the screw with each turn! And putting them back on wasn't any easier either. But at least now I don't feel like the sound is emanating from the center of my head (it gives me headaches). I haven't noticed an increase in volume but there's definitely no distortion as max volume anymore.

 

[tshroom]

Interesting find. Is it a problem with the MK II ? A diagram or step by step pics would help many members brave enough to fix the problem.

 

[Alex.]

Mine might also suffer from this, I may look into it. thanks!

- Alex

 

[jmetal88]

Mine is very soft, but it does not sound like it's coming from the center of my head...

 

[FastMHz]

Hey guys - sounds like this is more common than I thought...If I wasn't afraid of stripping screws I'd pull it apart again and take pics...really it's very easy:

1. Take batteries out and remove 4 screws from back
2. Carefully lift off back cover. No need to remove motherboard or anything else
3. You'll see white connectors, bottom left and bottom right.
4. Doesn't matter which one you modify, pull one out carefully.
5. Use a pointy object to lift the plastic pegs so the wires slip out
6. Put them back in, reversed
7. Put it all back together and you're done.

Hope this helps.

 

[LordFu]

Hmm, is there a less subjective way to discern if the speakers are out of phase? I hate to open my 2x just for kicks. I'll listen closely to it when I get home and see if "the sound's coming from inside my head", but I really don't have the best hearing, due to allergies and too much loud music.

 

[jmetal88]

My GP2X has the speaker wires soldered directly to the circuit board. :blink:

Is that just a First Edition / Mk. I thing?

 

[FastMHz]

Alright everyone, I made some test tones here:

In Phase
Out of Phase

The tones start at the left, center, then right.

Now listen to both of them on your desktop. You'll notice that the inphase center sounds like it is coming from in front of you. The out of phase center sounds like it is "inside your head", and may seem to have less volume. Also, when you move your head side to side, the out of phase one will sound like it's shifting around in space.

Now play the in phase tone on your GP2X and see if it sounds in phase or out of phase. I don't really know of another way to demonstrate this. BTW; they're OGGs because MP3 seems to screw up the demo.

jmetal88 - Mine is a brand new MK2, just got it from gp2k.co.uk

 

[LordFu]

Thanks! That should make it much easier for me to tell.

 

[jmetal88]

jmetal88 - Mine is a brand new MK2, just got it from gp2k.co.uk

But mine is a Mk. I First Edition, and I was wondering if anyone else had their speaker wires soldered directly to the circuit board?

Oh... What???


My speakers aren't out of phase, but I can't beleive it wasn't 'till now that I noticed the left and right channels are swapped!

EDIT:

The headphones are the right way around though! What the heck is this? I knew the GP32 had this problem, but I thought Gamepark had learned from that and fixed it with this one! Wasn't there a FW patch to fix this or something? I remember reading about one, but I thought my channels were correct at the time.

 

[Ranma13]

Swapped stereo is a problem with the First Editions I believe, and the only patch I found was a mono to stereo fix.

Anybody else have a hard time removing the screws on the GP2X? It was a pain just to take them off, but when I was putting them back on, I felt like I was going to puncture through the GP2X with the amount of pressure I had to put on the screws just to get them to turn, and they weren't even completely screwed in yet!

 

[FastMHz]

Yup, the screws are a pain. The type of screwdriver you use makes all the difference though...make sure yours is the right size to fit completely and snugly in the screwhead...heck rub the screws on a bar of soap before putting them back in so they go in easier...

 

[jmetal88]

The screws on mine are just fine, but maybe it's the screwdriver I'm using (I prefer the ones with very large handles).

Well, I do know one way I can fix it, solder extension leads to the opposite side of the board. :rolleyes:

I likely won't do that until I install Radek's D-Pad. That's also when I plan to get the dust out from under my screen cover.

 

[Aninhumer]

Hang on, my PC speakers are the wrong way around :huh:

EDIT: They've been like that for years. I never noticed.

EDIT: Oh and I can't quite tell the difference between them, but that could be because of my speakers.

 

[gamefan999]

Alright everyone, I made some test tones here:

In Phase
Out of Phase

The tones start at the left, center, then right.

Now listen to both of them on your desktop. You'll notice that the inphase center sounds like it is coming from in front of you. The out of phase center sounds like it is "inside your head", and may seem to have less volume. Also, when you move your head side to side, the out of phase one will sound like it's shifting around in space.

Now play the in phase tone on your GP2X and see if it sounds in phase or out of phase. I don't really know of another way to demonstrate this. BTW; they're OGGs because MP3 seems to screw up the demo.

jmetal88 - Mine is a brand new MK2, just got it from gp2k.co.uk

I hear no difference between the two tones, they sound identical to me.

 

[dsd28]

Alright everyone, I made some test tones here:

In Phase
Out of Phase

The tones start at the left, center, then right.

Now listen to both of them on your desktop. You'll notice that the inphase center sounds like it is coming from in front of you. The out of phase center sounds like it is "inside your head", and may seem to have less volume. Also, when you move your head side to side, the out of phase one will sound like it's shifting around in space.

Now play the in phase tone on your GP2X and see if it sounds in phase or out of phase. I don't really know of another way to demonstrate this. BTW; they're OGGs because MP3 seems to screw up the demo.

jmetal88 - Mine is a brand new MK2, just got it from gp2k.co.uk

I hear no difference between the two tones, they sound identical to me.

To me as well. Although, I was using headphones to listen to them. Not sure if that makes any difference.

 

[FastMHz]

You should hear the difference on headphones as well. That's strange that some can't hear the difference...maybe some people are more susceptible to noticing than others. Well here is a description from crutchfield on speaker phase if it helps:

"When your stereo speakers are connected in phase, the drivers of the left and right speaker move in and out at the same time. When they're out of phase, the drivers of the left speaker move in, while those of the right move out. If your speakers have removable grilles, you can pop them off and actually see this.

Stereo speakers should always be connected in phase. Out-of-phase speakers sound "not quite right" — imaging is vague and there isn't as much bass.

To hook up your speakers in phase, just make sure that your positive receiver (or amplifier) terminals are connected to the positive speaker terminals, and your negative receiver terminals are connected to your negative speaker terminals.

It helps to pay attention to the markings on the wire — look for print, a stripe, or a rib that may be molded into the wire's jacket. If you find that your speakers are out of phase, don't worry, it's easy to fix. Just switch the positive and negative leads at one of your speakers (not both)."

 

[gamefan999]

You should hear the difference on headphones as well. That's strange that some can't hear the difference...maybe some people are more susceptible to noticing than others. Well here is a description from crutchfield on speaker phase if it helps:

"When your stereo speakers are connected in phase, the drivers of the left and right speaker move in and out at the same time. When they're out of phase, the drivers of the left speaker move in, while those of the right move out. If your speakers have removable grilles, you can pop them off and actually see this.

Stereo speakers should always be connected in phase. Out-of-phase speakers sound "not quite right" — imaging is vague and there isn't as much bass.

To hook up your speakers in phase, just make sure that your positive receiver (or amplifier) terminals are connected to the positive speaker terminals, and your negative receiver terminals are connected to your negative speaker terminals.

It helps to pay attention to the markings on the wire — look for print, a stripe, or a rib that may be molded into the wire's jacket. If you find that your speakers are out of phase, don't worry, it's easy to fix. Just switch the positive and negative leads at one of your speakers (not both)."

If it's an actual, physical thing, i.e. speaker cones vibrating at different moments, then how can this be simulated by mere tones? Especially if the tones being used are identical, "A 440", am I mistaken? You would have to invert the wave of one channel somehow, to simulate out of phase, no?

I am aware of the idea of "out of phase", being a guitar player, it's a common element in hardware electronics, usually accomplished when two guitar pickups are also not "beating" in synch with each other. There's a thinner sound and a slight quaver. But again, I heard nothing like that in those tones.

 

[FastMHz]

That's what I did, I inverted one of the tones in the "out of phase" ogg file.