Pipo M6 - Speaker Imbalance fix

[rceccleston]

Shortly after receiving my tablet, it soon became apparent the left speaker was muffled, when compared to the right.

I became inspired to fix the mechanical imbalances between the speakers, so I decided to dismantle my Pipo M6 with impressive results.



I was very impressed by the build quality and the branded Sandisk component's.



Upon closer inspection of the speakers outlets, it became apparent the width of the left channel was noticeably narrower with a wider support bar and square edges.



Compared to the right with a wider channel and a chamfered edge.



After reading a Russian translation, I took inspiration to remove both support bars to further enhance the output volume of both speakers.

Left outlet with a top view of the speaker.



Right outlet with a side view of the speaker.



After reinserting the speaker assembly and securing with an additional foam pad on the back of each speaker magnet, the end result is now perfectly balanced and significantly louder with a good mid range.

Understandably, the sound becomes distorted when the volume is pushed beyond 90% and the speaker cores generated a worryingly large amount of heat.

[mischa72]

This is a very nice result !!! Did you put the foam at the front side of the speaker (between cone and grill) or at the back side (at the "magnet")?

With what tool did you wide up the channels?

Reagrds,
Mischa

[rceccleston]

This is a very nice result !!! Did you put the foam at the front side of the speaker (between cone and grill) or at the back side (at the "magnet")?

With what tool did you wide up the channels?

Reagrds,
Mischa

After hearing of speaker rattles and seeing the narrow band of glue around the speaker grill, I installed a small piece of M3 pad on the magnet of each speaker.

Due to the good compression properties of the thin foam pad, the foam pad has compressed when the back of the tablet was reinstalled, holding each speaker in place firmly.

I used a sharp craft knife to cut through each support bar.

[mischa72]

After hearing of speaker rattles and seeing the narrow band of glue around the speaker grill, I installed a small piece of M3 pad on the magnet of each speaker.

Due to the good compression properties of the thin foam pad, the foam pad has compressed when the back of the tablet was reinstalled, holding each speaker in place firmly.

I used a sharp craft knife to cut through each support bar.

All clear

[rrileypm]

Kudos to rceccleston
Thanks!!!!!

[mischa72]

Do you have pictures of the dismantling?

Regards,
Mischa

[rceccleston]

Do you have pictures of the dismantling?

Regards,
Mischa

Sorry, I've uploaded all that I took.

This project was new and fluid since I couldn't find any other guides online.

Using two credit cards, I started prising the rear case molding off from around the volume switch, working around anti-clockwise to finish in the lower right corner.

[mischa72]

Okay, thanks. Would be almost the same as this movie: http://www.youtube.com/watch?v=pgJNtTgoJ_I

Regards,
Mischa

[rceccleston]

Okay, thanks. Would be almost the same as this movie: http://www.youtube.com/watch?v=pgJNtTgoJ_I

Regards,
Mischa

Yes, I used the same method as within your video.

[peqipex]

I haven't opened my PIPO yet, but my right speaker broke after 2 weeks. I want to avoid of sending the tablet back to China and pay for the postage an wait for at least a month to get it back.

Do you think that it is possible to replace the speaker by myself? Cut the wires, buy a new speaker with similar characteristics and size and solder it?

[rceccleston]

I haven't opened my PIPO yet, but my right speaker broke after 2 weeks. I want to avoid of sending the tablet back to China and pay for the postage an wait for at least a month to get it back.

Do you think that it is possible to replace the speaker by myself? Cut the wires, buy a new speaker with similar characteristics and size and solder it?

The speaker is a unique shape so maybe hard to source a replacement.

Your fault could she either the sound chip, poor soldering or the actual speaker.

Considering the speaker did work, its unlikely to be the soldering, since the wiring to well supported.

Does the headphone jack work on both channels?

[pulsar123]

I also followed the advice on the Russian forum 4pda.ru (I can read in Russian, so that helped), and wrote my own illustrated tutorial, with full resolution photos:

http://forums.redflagdeals.com/fixing-low-speaker-volume-pipo-m6-chinese-retina-tablet-1368411/#post17229248

My mod was a success - the volume became larger, and the left speaker now has the same volume as the right one.

[mischa72]

Great, now we have a black and a white tutorial .

Good an clear pics.

[freaksa]

I also followed the advice on the Russian forum 4pda.ru (I can read in Russian, so that helped), and wrote my own illustrated tutorial, with full resolution photos:

http://forums.redflagdeals.com/fixing-low-speaker-volume-pipo-m6-chinese-retina-tablet-1368411/#post17229248

My mod was a success - the volume became larger, and the left speaker now has the same volume as the right one.

I did the same thing as in that forum plus I put some foam at bottom edges to prevent sound from dissipating inside. Sound possibly 3x louder.

[pulsar123]

Has anyone who did this physical speaker mod tried the newest official ROM from PIPO (July 31; still SDK 1.0)?

Apparently, PIPO "addressed" the manufacturing defect with the speaker openings by lowering down the volume of the right speaker, so (1) overall volume became even lower, and (2) for those who did the physical mod, the left speaker became louder.

It looks like they will implement this in all the future official ROMs, so we should find a way to revert the balance back.

I looked around inside my ROM (which is still Riley 1.3a - the first beta with SDK 2.0), and it looks like this particular configuration file is the one to mess up with when trying to fix the speaker balance:

/etc/asound.conf

Specifically, the following line:

{name 'Speaker Playback Volume' value [31 31]}

From the line comment, the range for this parameter is 0...31, so in my ROM both speakers are set at equal and maximum volume setting.

I suspect what PIPO "fixed" in the newest official firmware was changing the second number to a lower value.

So if your newest ROM will have the left speaker louder, have a look at this file. If the second number is less than 31, you'll have to set both numbers to 31, and save the file and reboot the tablet. (For that, you'll have to remount "/" as read/write first, I believe).

I'm gonna give it a try now, to see if it indeed works.

EDIT: Actually, no. I changed all the three instances of that line in the file, from 31 31 to 31 0, rebooted, but the balance was the same.

I think I'll simply save this, and all other sound related configuration files to my PC. If in a future ROM I'll encounter speaker imbalance, I will diff the old and new files, to see what PIPO did, and will revert that.