I have long gazed at the Soundboks 2, wishing it were mine. And after a year of enforced saving (COVID) I have treated myself to a Soundboks 2 Speaker.
At the time of purchase there was a choice between getting the Soundboks 2 and the "New Soundboks", the Soundboks 3 (?).
However, after watching lots of reviews on YouTube, I decided on the Soundboks 2. The main reasons was I liked the sound better, the secondary reason was that was £300 cheaper . . . .
I watched the above video and, the Soundboks 2, to my ears sounded better. Less harsh I thought. I like a soft mellow bass rich sound, a bit like the kind of sound you would get from an old school valve amplifier.
Soundboks 2 - 2021 Review - Finding
My Soundboks 2 arrived in early December. I was patient and waited until Christmas Day to open it. The sound was very pleasing at low to moderate volumes, but become harsh at higher volumes.
In my opinion the bass / treble balance is lost at higher volumes, and the tweeter become jangly and unpleasant at higher volumes also.
Don't get me wrong it is a great speaker, very well built and the battery lasts for ages (days) for normal listening. It will also likely out last me, and be handed down to my kids it is so well built.
The switches and the build of the casing is bomb proof. I love that.
Soundboks 2 - 2021 Review - Context
So you might ask what speaker am I comparing this to? Well it is a home made one, that I have "perfected" over the last few years.
I like to dance to music that is bass heavy, and I like to feel the bass whilst still not hurting my ears, with over inflated treble and mid range.
The specs of my home made speaker are as follows:
TPA3116 2.1
24V Power Supply
12mm exterior plywood cabinet.
Salvaged 8 ohm speaker drivers and tweeter complete with original crossovers.
JBL 2 ohm 10" sub woofer
After a few weeks of listening I can safely say that I prefer the sound from my home made speaker. It quieter in treble and mid range, but still pack mega punch in the bass area.
I will post a youtube video, with comparison soon:
I have a
couple of home made TPA3116 boom box (es). I was looking at ways to
connect these two up to a single source, and after trying a splitter
cable, decided to try pre-amplifier to boost input signal.
The result were that I destroyed my amplifier board and had to spend £7.50 on a new one. I would guess that these cheap amplifier boards are built to deal with a certain level of input power, and although the overall power was increased, and did not sound distorted, damage still occurred.
Burnt Out Inductors - Too Much Current through a thin wire?
The TPA 3116 board used already has a pre-amplifier built in. 2 x NE5335 chips. I decided to try pre-amping gain using a Behringer HA400 Microamp, as stated above this did increase the volume considerably, but had I checked the temperature of components on the board I would have found that bad things were happening.
No doubt this post will annoy some people as I showed disrespect for the electrical engineer process, and ignorance of basic concepts, but I just like to try things out and see if it works.
This is a series of photos on the construction of a TPA3116 2.1 Channel Potable Speaker. The speaker uses wooden casing, up-cycled driver units, a 12v battery and can be adapted to run on main power also. If you would rather watch this on You Tube then please click here > TPA3116 Build Video
Finished Thing
TPA3116 is an amplifier, which runs on a variety of voltages. This "2.1" variant has stereo speaker out puts but also a third channel of sub-bass. This is my second build with this amplifier and it works well.
TPA3116 2.1 Speaker Build - Shopping List
For this project you will need the following. However, please do not be afraid to substitute materials, or even the amplifier board itself, for another model. For a smaller speaker you might try the PAM8610 which is a good little amplifier. For a very small speaker you might try the PAM8403.
I should also point out that if you are using recycled driver units, and they are still in the speaker case, why not re-use the case as well. You could glue, screw or bolts the two speaker together, and mount all wiring in side the speaker. This would avoid costs of buying wood.
For my speaker I used:
12mm Shuttering Ply - Main cabinet / box
9mm OSB (thin sheet wood - speaker grill support)
Screws
Two Part Filler
Paint (Optional)
Fabric or Cloth or Mesh
Amplifier Board
Speaker Cable
12V to 24V boost convertor
Switch
3.5mm jack cable
Driver Units
Insulation tape
Tools
Drill / Electric Screw Driver
Jig Saw
Tape Measure
Soldering Iron
Solder
Pencil
TPA3116 2.1 Speaker Build - Using Recycled Speakers
Making the box is perhaps the most demanding part of the whole project. As mentioned above perhaps re-use you speaker cabinets if you are recycling. I had some large sony speakers and the cabinets were fiar quality (not very weather proof though) and could have been bolted together, and used as is.
Most speakers will have 2 or 3 driver units inside.
Once you have removed the driver units from their original cabinet have a look on the rear of the speaker to try and figure out what ohm rating they have. For this project 4ohm speakers are best, but 8 ohm are OK, although the speaker will be quieter overall.
TPA3116 2.1 Speaker Build - Speaker Holes
You will need half a 4 x 8 sheet of ply to make this cabinet. Plywood is good, because you can get it wet, unlike MDF which swells when wet. Shuttering ply is a low garden water resistant ply, which can be sourced from most builders merchants.
Before you cut the panels, cut the holes for the speakers, it is easy to use a jig saw when the board is still in one piece.
Cut holes for driver units.
Try ou the driver units frequently to check fit.
Do not make the mistake of drawing around the driver unit and then cutting, the hole need to be large enough that the screw holes sit on the wood.
Mark past inner edge of screw hole.
Rest the driver unit where the hole is intended, then mark the very inner most edge of the screw hole. Do this for all the screw holes. Then take away the driver units and join up the marks to make a cut circle.
Cut Line Smaller than Full Diameter
TPA3116 2.1 Speaker Build - The Cabinet
Once you have cut your speaker holes (for mounting driver units) you can continue with the rest of the cabinet. The front panel of the cabinet is the deciding factor in term of measurements for the rest of the cabinet / box. Take care cutting this panel, to ensure it is square.
Taking Shape
Cut the sides the same size as the front panel. Cut the top and bottom the same BUT 24mm wider to account for overall. Always cut bigger if you are unsure. You can always cut off excess with the jig saw although this results in a messy finish.
Blood, Sweat . . . but no Tears
Once the cabinet is complete you can paint it, and add a front mesh cover. This could be stapled in place or glued, or anything really. Just have fun choosing what ever you have laying around and do it!
At 24V (max voltage) you are building a 40W amplifier. It is a class D amp, very efficient, so you get a lot of noise for those 40W RMS.
Hopefully your board came with a wiring diagram. This will show you which wire go in which clamps etc. Here I am running 2 x 8ohm speakers run paralleled to give 4 ohms.
Board Mounted on Steel Plate or Plastic Sheet Material
The board is supported using the 3 potentiometers, that control volume, treble, and bass. You could use the mounting holes also, but I find this unnecessary.
A 12V battery feeds a 12V to 24V boot converter. This is better than 2 x 12V batterys, as 2 x 12V batteries linked in series can be 28V fresh off charge which is too many volts! 24V is maximum.
The power switch on the side of you build, should switch the BOOSTER on and off.
Externally, cut a neat hole, and then drill holes in this for RCA Sockets, Volume Knobs and Toggle Switch. Finally, you can add two protruding bolts, that can be used to charge the battery without opening the cabinet up every-time.
Not all TPA3116 2.1 boards are made equal, if you are driving 8 ohm speakers get a board with high "gain" (36db) as this will help with output.
TPA3116 2.1 Speaker Build - Conclusions
On completion you will have a loud speaker that give very good low bass sound. The cost can be a bit high, but for me this was becuase of the wood. I bought a 4' x 8' of plywood, why cost £40. But I still have over half left. . . . the battery would also be a significant cost.
Total cost disregarding these would be £20, with the added bonus that you can fix it when it breaks. You built it after-all. Oh! Its pretty heavy.
If you would rather watch this on You Tube then please click here > TPA3116 Build Video
This page title should also have "low cost" added. All of the below boards cost less than £8 / $10, so make for a very low cost project, just be aware you will need to power these boards, and for the louder options below this can cost 2 or 3 times the cost of the board itself.
The below descriptions are boards I have owned and tried. All chips (8403, 8610 etc.) will behave differently depending on the boards used. For example if a specification says 24V, but you board has 22v capacitors, then you will not be able to run the max voltage.
Also just because a board has more capacitors and knobs on it does not mean the chip will be louder or better. The best results I find come from the most simple boards.
The top slot goes to the the PAM8403, this is the size of a postage stamp, and you can run it from a USB power supply, or 3 x AA batteries or a single lithium cell.
Its power is rated at 3W, but it is incredibly efficient, producing a room full of sound, when using 4ohm speakers.
My favorite class d amplifier, fiddly but fiesty!
If you have an old hi-fi speaker of any sort hanging around you could convert it to an active speaker, for perhaps just £2 / $4.
I have placed this board at number 1, because it is:
A versatile low cost amplifier
Very easy to power
Very very efficient
Good quality sound at all volumes
A lot of volume when considering low cost of board and power supply.
Note: You can not run 1 speaker from this amplifier, both of the outputs have to be used to avoid damage to the chip. I have run a tweeter from left and woofer from right to get around this which is OK.
The PAM8610 is the logical step up from the PAM8403, it requires a higher voltage to work, and the low volume sound quality is not overly good, but it produces a very high volume for such a small amplifier. Get the basic board if you are buying with no heatsink or volume control, you do not need one.
These is s light deterioration in sound quality at low volumes which some might find annoying. This can be well powered from 8 x AA batteries, or a cheap 12V wall socket transformer. If you are running this amplifier from a SLA or Car Battery be a bit careful, because these sometime creep over 15V with some chargers.
This amplifier is comparable in output to the PAM8610, the sound is a lot cleaner to. But this is offset by the difficultly in proving 24V to power it adequately, it will work from 8V but you will have very low power levels until you reach 18V upwards.
I tried a complex 3 channel board, perhaps give a simple one a go.
That being said this is a versatile amplifier that will run on a very wide voltage range. The sound is crisp and clear at all volume levels, although high volume sound will be distorted if you are using an under powered supply.
I used a 3 channel variant of this board which is so say 50 + 50 +100W, but is no where near this loud. Perhaps the board which uses NE5532 pre amplifiers. And the gain is fairly low.
Voltage: 8V to 16V - Will go higher on some boards.
Output: 2 x 50W (Official) 2 x 15W (Real World)
This is actually a AB class amplifier, which is fairly inefficient. However it is small and cheap and reasonably easy to power. The sound is far richer than any of the above amplifiers, with a warm sound many will fine pleasant.
It is not great for running from AA batteries but will run well from an SLA battery. It cannot be run from AA batteries as the power requirement is to high.
Top 5 Class D Amplifier Boards - 5 - OEP3W or XTP8871
Cost: £1 / $2
Voltage: 2.5V to 5V
Output: 3W Mono / 5 W Mono
I couldn't quite decide between these two they are both excellent boards that they can be powered from a USB port, requiring only 1A of power. Mono is easily achieved my mash together the positive and negative input wire. You then one have to find one speaker to use these amps, which lowers the costs still further.
I have recently built portable battery powered speakers using a PAM8403 and a PAM8610. They are very efficient "Class D" amplifiers and can be run on high volume for hours and hours on one set of AA batteries (1.3ah).
However, I would like more bass! So I have tried this TDA2030A "Class AB" board to see how it compares. The TDA2030A is almost identical to the TDA2030. The former have a slightly higher max wattage rating.
This amplifier can be built on to boards that can handle up to 22V although 36V is achievable in some applications. I was limited to 16V by the capacitors that were installed on my pre built board, purchased from ebay (fluxworkshop).
TDA2030A & TDA2030 Amplifier Observations - Current
This is perhaps the TDA2030A amps most troubling characteristic. It requires 3.5A of current (max current), this means that with anything other than top end AA batteries such as "Eneloop" you will not be able to run this on AA batteries. They would also drain quickly even if you could!
The limiting factor it appears with the use of AA cells is the battery holder box. After testing one of the springs had melted and slumped.. I have read elsewhere that the cheap AA battery holders are only good up to about 1.5A.
So . . you will need a power supply from the mains. . .or lithium high drain cells or an SLA Battery. Again the battery holder for the lithium cells will have to be good quality.
By comparison the PAM8403 and a PAM8610 draw about 1.0A of current which is ideal for use with AA batteries and cheap holders.
I tried the following batteries:
6 x AA 1.3ah Uniross Batteries in Holders - Not Good
5 x 4.5ah NiMh (Battery Pack from Silva Headtorch) - OK
1 x 12V SLA (Actually LiPO4 but in SLA Type Package - Nominal current 7A) - Fine
To get good performance out of this amplifier you will need to run it higher than the minimum voltage of 6V, in fact even at 9V the output is distorted and low power. The sound is clean when at low volume (60db), but push past that level and the sound is terrible.
I have read else where that this chip sings better at 22 volts, but I can't try that. I can report that at 15V (SLA fresh off charge) it performs well. Running with no distortion at full volume (70- 75db).
The board I purchased came with a very small heatsink. It looked small to me, so I salvaged a heat sink from an ancient graphics card and used that. I also applied some thermal paste between the chip and the sink.
A Larger Heatsink - Perhaps Not Required
The TDA2030A (or TDA2030) as I configured it does not generate very much heat, the heat sink as pictured above get slightly warm to the touch, so a small heatsink, such as the top picture in the post would probably be OK.
TDA2030A & TDA2030 Amplifier Observations - How Loud
I would estimate 75db, specs say 85db. So specs say around 10 time more than I do! But this is running at 22V instead of 16V.
In comparison to PAM8403 the TDA2030A is louder, but PAM8610 running at 12V and 1A is far far louder.
The sound quality of this small "Class AB" amplifier is pretty good. It has better than the "Class D" Amplifiers that I have tried.
I would describe the sound from this amplifier as richer, than the other class D offerings. There seems to be more depth to the sound, it is less flat than the Class D amps.
I am sorry for the subjective nature of this appraisal, but that is the best I can do.
