Replace my current 2.1 [Need small 2.0/2.1 amplifier with about 20W RMS per channel + line out]

[Mlynek]

Hi,
I am currently running 2.1 speakers system with my pc, happy with the sound they produce (25W sub + 2x10W satellites), however one of the channels is quiter. Right now to balance the sound I am using Realtek's driver balance slider but it doesnt stay in one place and resets whe sound is muted.

What I have already considered
1. Easiest - Find a program to set the volume balance on hard percentage (e.g. 50% towards left speaker). I haven't found any program like that unfortunatelly.

2. Purchase different 2.1 speaker system and use the subwoofer from it - had z333 and didn't like it, every 2.1 system available currently in europe seems to have the power saving feature which is horrible so I will rather give up purchasing anything 2.1 new from the market.

3. Purchase 2ch car amplifier of about 30-50w 8ohm power and just run 2.0 system (the speakers I have currently hooked have about 6inch woofers + tweeter as they are not original with the sub).

4. Use my spare aftermarket car DAB (cdplayer/radio/stereo) for 2.0 .

I am open to any suggestions for new/used products but would like to keep my current bookshelfs, thanks

 

[AtaRo]

Common cause of uneven volume is usually a worn out volume potentiometer which can be replace if your into diy stuff.

First thing to try first is to swap the satellite, if the volume on the faulty channel is the same then it is safe to say that the problem is inside the sub.

Is the volume built in to the sub or is it a remote that you plug to the back of the sub.

What is the Model # of the sub/spk that you got?

 

[Mlynek]

The issue is 100% inside the subwoofer. Main volume knob is on the front which is actually very ergonomic as I can change the volume using legs without any cables or wireless remote , it is also another thing that I don't see on any new system . It could be the potentiometer (at the very very low volume it only plays the quieter channel but above like 2% volume the other plays louder) but I guess it is caused by something on the amplifier pcb because for good few years both speakers were plugged into the right channel as one of left channel's clamp broke (basically I had left and right signal on both satellites sound since my previous motherboard's sound card let me to tick mono output) so it could break something. I don't know how much help can I get with DIY on this sub here but I will post pictures in hope anyway

http://imgur.com/a/yctRf

There is poor access to the amplifier as cables hold it inside but I took photos from both sides, for me everything looks fine e.g. no swollen capacitors. But then again Im not a electrician

 

[EsaT]

Putting two speakers to one channel could definitely harm amplifier at high volumes because it halves the load impedance/doubles current and power draw.
Though output amplifier burning wouldn't cause lower volume...

Worn/bad potentiometer could definitely cause channel imbalance.

no swollen capacitors. But then again Im not a electrician

Bulging is just sure sign of imminent capacitor failure.
They can fail also other ways, like by simply drying out without any external signs.
That might be actually the typical failure mode for low power/"signal" capacitors.

How old is that speaker set?
Sure looks really cheap construction with that kind PCB and likely no name capacitors.
Can you check PCB's bottom side for bad solder joints?

 

[AtaRo]

You can try cleaning the volume pot with Isopropyl Alcohol Spray or contact cleaner, let it dry for a few minutes and then put a few drops of oil to the pot, baby oil is fine.

Check this vid on how to clean the pot the easy way, fast forward to around 4:20 https://www.youtube.com/watch?v=0QvOepREO4k

How's the volume on both channels at max setting?

Can you check what chip they used on the amp.

 

[Mlynek]

Thanks for the replies, the system is like 10+ years old branded manta and looks like this. Not a proper subwoofer and only goes down to 50Hz but is not boomy, don't need more for my pc as I have good hifi already. As you can see the potencjometr is on the front so I would need to dig all the way from the back to get access.

To see PCB's bottom I would basically need to dismantle the whole subwoofer so maybe later today.

What to you think about using car head unit with AUX and subwoofer out as amplifier?

EDIT: Oh and even if playing both speakers from one channel wouldn't cause it in short term, using them for years would sure wear the channel while the other was unused and stayed in good condition or I am wrong?

 

[Mlynek]

Okay I decided to drop the other ideas as they seem too ghetto or complicated for this forum

Anyone can recommend me 2.0 amplifier with line out? Don't have to be powerful, 20W RMS is fine. I have found many but none had line out. Thanks

 

[Mlynek]

Hi again, finally got my speakers to run properly. Eventually I have found good pioneer car stereo with sub-out for 15 quid (about 25RMS per channel) so I went with the deal.
Here is how the system is hooked up:

The PSU used is some old win-power model rated 450W with 25A on +12v, I doubt it would handle this much power though
I have taken out all the cables from it except for one green and black cable to keep it powered and one molex for the car stereo.

I still use the old subwoofer and overall the sound is clear.