Building 2.1 Audio

While the TPA3116 AliExpress amps are good value for money and they do sound good, you might have to give us more info on your planned system, like what speakers are you going to use, and where does the music come from (preamp, cell phone, streamer)? Also keep in mind that the 100W output channel for the sub woofer is for a passive sub.
I am using the same amp you linked to above for my bedroom system - two small full range speakers and a smallish passive sub. Music is played using Bluetooth from my phone. Works great, but definitely not high end hifi.
 

stv

Member
Joined 2005
Paid Member
I installed a very similar or identical amp in my nephews' bluetooth box. It works flawlessly since 3 years even with some rough use during parties.
However, it does not have a very linear treble response, xover frequency regulator only affecting bass output etc.

I already posted some information here some time ago. I'll try to find my post

Edit:
here it is
https://www.diyaudio.com/community/threads/crossover-in-2-1-amplifiers.398741/post-7338224
 
Last edited:
While the TPA3116 AliExpress amps are good value for money and they do sound good, you might have to give us more info on your planned system, like what speakers are you going to use, and where does the music come from (preamp, cell phone, streamer)? Also keep in mind that the 100W output channel for the sub woofer is for a passive sub.
I am using the same amp you linked to above for my bedroom system - two small full range speakers and a smallish passive sub. Music is played using Bluetooth from my phone. Works great, but definitely not high end hifi.
1. The system will have AUX from my desktop PC.
2. Bluetooth connection with mobile.
3. Connection with mp3 audio decorder this.
https://www.aliexpress.com/item/100...o.order_list.order_list_main.5.37381802y7veZq
I selected no amplifier.
4. I will buy speakers and subwoofer later.
 
This is a very nice amplifier, but the description at the link doesn't have the Bluetooth component on it.
For modern home audio 2.1 sound systems, this is a legacy.

After all, it's not just for lossless song files.
Through Bluetooth, we can quickly connect and play cloud music on Youtube\Facebook.
 

stv

Member
Joined 2005
Paid Member
Ok, then let's get serious. You need to define the parameters for your project:

  • Define your planned listening distance and spl requirements
  • define your lower extension requirements (bass)
  • define your listening location (fixed listening seat or not)
  • define your time and financial budget
  • define your skills (or your willingness to aquire skills)
  • define your possible loudspeaker size(s) and location(s)

then first comes the planning of your loudspeaker:
Active? Dsp? Passive? Full range? Multi way? ....

And only after the loudspeaker is defined you are able to select the appropriate amp/crossover system.

All these questions can be answered by reading through (several) threads here on diyaudio.
If you don't have the time to do this you may be better off with a complete system, a kit or you just follow one of several project descriptions you will find if you do a google search for "diy bluetooth box".
 
I agree with @stv – if you want more specific recommendations, then you need to give more specific details.

It sounds to me that you don’t have much now anyway (since you have not bought any speakers yet) and looking to build up a 2.1 system. If that is true, the TPA3116 amp you linked to is the perfect starting point. You can just plug and play. As I said – it’s excellent bang for your buck and includes everything (and all the controls) you want. You can stream music from your phone via Bluetooth or play music from your laptop or TV using the AUX input.

If you want to buy separate modules you are looking at a lot more money and things can get much more complicated.

My advice – buy that amp, you will not regret it. Spend the rest of your money on good speakers and a sub-woofer. Enjoy the music and sleep well.
 
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2.1 amplifier board. | Page 2 | diyAudio
Someone reviewed it here, with measurements.
TL;DR: it's not great. I also do not recommend Wuzhi-style amps (black-plated amps with silver knobs). They have many issues.
For the best 2.1 experience, you should use a dedicated 2.0 amp with line out and hook it up with a subwoofer amp, one that has a bass frequency knob (look for "Mono TPA3116" or TPA 3xxx chipset of your choosing).
Here's another choice, a "subwoofer preamp":
PRO1 JRC2068 HIFI Front Tone Board Stereo High Subwoofer Operational amplifier AMP Volume Controller Treble Bass preamp - AliExpress
They can be used with the ZK-3002 TPA3255 boards, or whatever amp that you like.
 
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Ok, then let's get serious. You need to define the parameters for your project:

  • Define your planned listening distance and spl requirements
  • define your lower extension requirements (bass)
  • define your listening location (fixed listening seat or not)
  • define your time and financial budget
  • define your skills (or your willingness to aquire skills)
  • define your possible loudspeaker size(s) and location(s)

then first comes the planning of your loudspeaker:
Active? Dsp? Passive? Full range? Multi way? ....

And only after the loudspeaker is defined you are able to select the appropriate amp/crossover system.

All these questions can be answered by reading through (several) threads here on diyaudio.
If you don't have the time to do this you may be better off with a complete system, a kit or you just follow one of several project descriptions you will find if you do a google search for "diy bluetooth box".

  • Define your planned listening distance and spl requirements --> 8-10 feet.
  • define your lower extension requirements (bass) --> i dont know about that.
  • define your listening location (fixed listening seat or not) --> speaker and subwoofer will be placed on fixed location
  • define your time and financial budget --> time is not an issue & budget is like as minimum one but not compromising good quality sound
  • define your skills (or your willingness to aquire skills) --> can you please elaborate more?
  • define your possible loudspeaker size(s) and location(s) --> speakers 50 + 50 watts and sub woofer will be 100w or less
 

stv

Member
Joined 2005
Paid Member
no worries, I will try to guide you through some decisions. I am no expert, so there may be better advice from others!
also keep in mind that you may be happy to just experiment and have fun developing your system, so you could just start without having definitve answers to all or to any questions.

1) listening distance: 8-10 feet.
this refers mainly to the necessary SPL (sound pressure level) your speaker must provide to allow your desired music volume.
you did not define your SPL requirements yet - here is a link to wikipedia providing examples for SPL.
an average SPL of about 60-70 dB is usually enough for music listening, of course depending on your personal taste (anyone correct me if I'm wrong!). also note that 85 dB over an extended time may already lead to hearing loss.

loudspeaker specification standards refer to dB SPL in 1 m distance with an input of 2,83 volts rms (anechoic, thus: without reflected sound from surrounding room, furniture etc).
as you will have a distance of about 3 meters from your speakers I would guess the necessary SPL produced by your loudspeakers in 1 m distance will be your desired SPL plus ~ 4-6 dB (considering you have 2 speakers and room reflections).
you also need to consider that music has peaks that are about 12 dB louder than the average.

so e.g. for 70 dB average SPL at your listening location your loudspeaker (one of two stereo speakers) needs to produce an estimated:

70 dB desired dB
+6 dB for listening distance
+12 dB crest factor
+2 dB "safety margin" (and easier to calculate!)
= 90 dB

usual loudspeakers have a sensitivity of around 80-90 dB at 2,83 V so you would need about 1 watt (for the 90 dB speaker) to 10 watts (80 dB speaker) of amp power for each stereo channel.
keep in mind: for doubling percieved music volume you need around 10 times the amp power or a speaker with 10 dB more sensitivity.

2) lower extension:
pop, rock and classical music usually have lowest bass frequencies around 40 Hz. EDM may be lower. film soundtracks even lower.
many commercial and diy speakers cannot reproduce 40 Hz with full SPL, which is fine if you are ok with that. a simple trick is to give the speakers a slight boost around 100 Hz to compensate for missing lower extension. If you whish to get all low frequency content of pop music with your desired SPL you need a woofer plus enclosure and amp capable of producing it.
a bass reflex box with around 10 litres with a 5,25 inch driver capable of around 4 mm xmax (maximum excursion) and around 20 watts of amp power may be enough to provide the bass extension and SPL as mentioned above. if you whish lower extension and/or higher sound pressure the woofer will quickly get quite big.

3) listening location:
if you stay at one listening spot all the time you could use (or want) a loudspeaker with high directivity (sound gets projected mainly in one direction).
if you want similar sound in a bigger area (or more persons in the room listening) you need a loudspeaker with low directivity (higher dispersion).

4) time and financial budget:
having much time is ideal, you can try to learn as much as possible before starting the project and you can modify and change the speaker/amp according to your needs!

5) skills:
if you want to build an amp and loudspeakers you may need electronics knowledge, soldering skills, woodworking skills.
planning loudspeakers from scratch usually requires knowledge of enclosure tuning and simulation, crossover simulation, measuring ...
as mentioned above: if you have time (and diyaudio.com) you can aquire those skills!

6) loudspeaker sizes and locations:
if your space is not limited and you (and your family) are ok with big speakers you may want to build (or buy) big good sounding floorstanding boxes and locate them with a comfortable distance to the walls.
if you need to place the speakers near (or directly on) a wall you need to consider the change of bass response.
also small boxes will usually not allow high bass output.

have fun!