I've recently discovered the wonderful world of bass shakers / tactile transducers.  Speakers without the cone, that add a "shake" to games.  As is my nature, instead of spending a few hundred dollars on a safe choice of equipment, I've spent a few hundred dollars on an array of dirt cheap amps most of which I'll never use again!  Go figure :)

What I've found is really interesting.  While similar on paper, these amps perform very differently from each other.

To make sure that ALL of the amps I tested don't suck,  I used this stack as a benchmark.  Clearly if no amps come close to a more expensive alternative then it's a bust.  The ones I've selected compare just fine.  After all, rack gear is just circuit boards and a big power supply. 

It's not as hard as you might think for a $10 amp circuit to do a good job with transducers or exciters because they aren't "hifi" devices.  In a stack like this that I use in my PA it has to work really hard to convey an entire spectrum of sounds with fidelity at high volume. That's hard.  The circuitry is designed to work with the common amplifier spectrum of 20hz to 20,000hz.  Most amplifiers of any quality have this range as their goal, except for sub bass woofer amps that tend to list a specification range typically 20hz to 200hz.  Note that the low frequency is the same?  Even audiophile equipment doesn't aim lower. Why would it put effort into creating a good response down where audiophile speakers don't work, when that would no doubt mean sacrificing in other areas that are more important.

That doesn't mean that all amps do well throughout the same range.  An amp that states it goes down to 20hz will have some life at 18hz.. but to drive something at that frequency it has to be cranked.  In the tactile world,  there do exist shakers and amps that can create an impact down to 5hz, but I'm not jumping into that world right now, and not expecting the equipment I'm testing to go that low.

What I'm looking for are amps that can pair with transducers and:

1. Drive devices at 5/10 on the dial or less.. ie, they are overpowered for the application.
2. Run cool
3. Run the transducers as cool as possible when pushing them hard.

The results are subjective.  I'm not scoping the output from these amps.  I'm not even going to state frequencies where they excel because  although most transducers have a stated resonant frequency that's not really the point.  At the end of the day the most energy felt by a device attached to a driving chair is a combination of:

• the resonant frequency of the device (known)
• the resonant frequency of what it's attached to (varies)
• combined with the weight of the person impacting any isolators thereby impacting the extent to which other parts are part of the vibrating system (varies)
• combined with the mass / bmi of the person because they have become part of the vibration system (varies)

That means that for the transducers I'm testing,  my mounting method, isolators, weight and BMI might mean that an amp gives massive punch at 32hz, whereas a kid in the same chair (less weight, more mass) could conceivably get the same level of energy at 34hz.  2hz doesn't sound like much but when you start fine tuning effects, you'll learn that it's a lot! 

It goes further than that!  I might feel I might perceive most energy at 32 hz on the side padding of my seat as a 8/10 and 30 hz as a 6/10.  Someone with a higher mass might feel 32 hz as 6/10, but 30hz as 8/10!  The complete opposite!  Different parts of the human body have their own resonant frequencies so at some frequencies may create a standing wave in that part of the body which is perceived strongly, even though attached equipment wouldn't see the frequency curve in the same way.

Science (and more math than I ever want to do)!

This doesn't mean that presets are useless. While the theory is horribly complex,  the real life differences between people in the same rig is going to be narrow, BUT  the difference between different rigs is likely to be significant.

The good news is that all this unknown is knowable for your own setup.  You don't need to know WHY something feels strong, you just need a way to work out WHAT feels strong.   

Sit in the seat, connect your phone or PC to any amp / transducer  / configuration and use a frequency app to send a signal.  You'll quickly find the resonant frequencies / where you feel most energy.  You'll likely find 2 or more throughout the usable range of the device that "peak".    Many such apps can send multiple signals so add in a second signal and experiment to find frequencies that your specific install is happy to handle simultaneously without lowering the impact of the primary.  It's kinda fun. You'll notice that your setup can't hit 5hz, but if you send it a 30hz and 35hz signal at the same time, you'll get a 5hz "experience".   Food for thought! Such a valuable exercise in getting the most out of effects tuning in software like Simhub.

Keep reading and I'll tell you SPECIFIC amps that I think best match specific needs, but here's some background.

I've focused mostly on the sub $20 amp circuit boards readily available from Amazon and eBay.  If you're willing to wait a week or two the same amps from China are about half the cost, and in fact my favorite amp can be bought for a whopping $4!

The biggest thing I've found is the chip is important! The one commonality between the amps that work well is that they are based on the TPA3166 D2 chip and I run all at 24 volts .  

Case in point,  the most expensive I've purchased at $29.  On paper this looks like it should be killer!

• Stereo 160w per channel
• Onboard cooling fan
• Large Heat Sink

Seemed like the PERFECT choice to drive my AuraSounds to replace the previous best choice which was overheating.  Well in fact it sucked. Nothing of any substance below 60Hz, and that's something I found with any amp circuit based on the TDA7498E chipset.  If you're going to experiment with boards or mini amp, buy ones that state they use the TPA3116 / TPA3116 D2 chip.

How much can you save by doing some DIY? Consider this comparision. (Note Don't buy either of these)

Let's say you want to dabble in tactile and buy two transducers. What are your total costs?

Ampbox: $70

Ampboard: $10 board + $20 power supply + $5 misc = $35

That's ok, but look what happens when you decide, just like Oreos, that you need more transducers!  You buy another pair.

Ampbox: + another $70 = $140 total

Ampboard: + $10 + $5 connectors = $50 total because you can share the power supply across 2 or 3 amps with no problem.

It starts to get significant.

You want to max out your 7.1 soundcard and use all the channels.

Ampbox: $70 x 4 = $280 total

Ampboard: (Amps: $10 x 4) + (Misc: $5x4) + (Power: $20x2) = $100 total! 

.. and that's playing it safe and not sharing all 4 amps on the same power supply.

There's one amp on my recommendation list below that comes so complete it's almost like the box amp, but with many you'll need to do a little bit of DIY.  Fortunately there are some really nice non-solder components that make life very ease.  Here's a few things that will definitely be useful. 

While you can always run speaker wire straight to the board, I find that using these little connector blocks is so much nice.  When I started getting obsessed with testing I bought a bunch of these wooded boards from The Dollar Store (for $1 believe it or not) to create a modular setup.  I remove the pins from the cable organizers on the bottom left and use the white plastic parts to mount the circuit boards.  Some wire of course. Red / Black for power and e.g. Blue / White for speakers to keep things clear.

Here's an example of a setup I used at one point that demonstrates various boards options.

• I ran speaker cable from each board to the connection blocks on the right for easy hookup / changes
• Power block second from right for power hookup. Left and right boards are hard wired power.  Middle board has a power connector so wired that in (not connected in the pic)
• Boards mounted to the wood with a small screw through the cable organizers. 

I've now created a more modular setup around The Dollar Store boards where I can easily swap amps in and out for testing without having my living room look like a bomb has gone off.  The bottom board has input for 2 power supplies and the amp and amp pairs are added to their own board.

This is important!  If you are a console gamer* and are taking an audio feed from your console to feed through shakers then your choice of amp is much more limited because you should only be feeding the lower frequencies to the shakers.  In other words, using subwoofer type amps.  This is where I started because I didn't know any better.

* some console games can feed telemetry across the network to a PC for full tactile experience, e.g. Forza Horizon 4 on XBox.

If you're  a PC gamer, or using games that can feed telemetry to software like SimVibe or Simhub, then you can, and should, use a wider frequency amp.  

Both types covered in recommendations below.

I saw a recent thread about amps where someone suggested using Swiching Power Supplies designed to be built into LED setups.  At the time I was using a 10A Laptop brick type 24v power supply and was happy with it.. well almost.

I kept getting a cyclic squawk through a couple of channels.  I wasn't sure if it was a ground loop issue, if I was trying to draw too much power or what, but it got annoying enough that I bought one.

https://www.amazon.com/gp/product/B0196PXMTU/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

.. and it solved the problem.  Still not sure exactly what the problem was, but I am running 6 amps and it could be a number of things.  This unit:

- runs all day long without getting hot

- solved my problem

- feels like a ore industrial solution.

It's now what I would recommended ***IF*** you have some confidence around electrical work.  With a typical power supply you're just messing with 24v, but with this you have to physically wire it up to the mains. 

I achieved that by cutting up a normal computer power cable and double checking the wiring color to work out what was Live, Neutral and Ground. 

Happy to have solved my annoying clicking noise! 

As stated I'm not entering the deepest of the deep here.  I've tested:

• Buttkicker LFE Mini (4ohm) :: Success
• Dayton Audio TT25-8 Puck Transducer :: Great success
• Dayton Audio DAEX32EP-4 Exciter :: Great success
• AuraSound AST-2B-4 :: Extreme success

To inject some personal opinion on these for what it's worth, first some context, I'm not a pro sim gamer and not trying to get to that level.   I get more satisfaction from creating a solution for my casual gaming that is straight forward, elegant and bomb proof.  I'm more inclined to focus on creating an 80% tactile experience for 20% of the price of the ultimate solution.   I'm also ok buying stuff on a whim, testing it and letting it go.. even though in the long run I've really not saved any money over buying the more commonly used equipment. 

The search for the ultimate cheap amp circuit continues on this one, UPDATE: but progress has been made!

Like many people,  my first purchase.  I don't love it, but mostly because it's been a tough one to match an amp to.  Of the units I've tested so far, it does have the best bass response, but has a tendency to piston slap down around 25hz which is really annoying.  

This shaker is very flexible when it comes to amplification!

Gotta say.. this is my favorite.  At $54 each this is for sure the most vibration energy per dollar.  The fact that you could club a bear to death with it is a bonus.  It's strong enough that putting it between your rig and your seat is an option.. a very very energy efficient option if you're using a car type seat.  I have the front of my seat mounted to my rig with some rubber washers to try and add some isolation,  and the back of the seat resting on top of these.  They are mounted to a horizontal platform on the rig using small vibration isolators. The result is astonishingly efficient.  

Reasonably flexible when it comes to amplification.

PERSONAL OPINION :: I'm not a big fan of either of these as the energy they emit is comparatively low. There is very interesting research going on nearer  the end of this discussion thread on how a matrix of AEX32EP-4s can be used on a fiberglass seat to create amazing tactile experience so I don't discount their value.  If you're looking for the ultimate tactile experience I recommend you get involved in this thread and try the multi DAEX32EP-4 setup.  I have no doubt that 6 or 8 of them can create the kind of vibration desired, AND with programming generate better effects.

My problem with both of these is that I've just bought a pair of each and have been trying to find a use for them only to drive them too hard in an attempt to feel them over the bigger transducers. My bad!  I just get into driving with headphones on and by the time I'm done I've pushed them too hard.

Here are various winners out of the pack.

Available cheaper on eBay and I've seen it on Amazon cheap too around the $20 mark with another seller (YEMIUGO) that looks identical.  This seller DAMGOO has a $16 version with no heatsink. Not sure how that would work out as I can already get this version hot.

This is as easy as it gets.  Screw terminals on the back for speakers,  audio jack on top for input, a volume knob and a socket for power on the back.

It pairs really well with smaller Dayton puck and exciter.  It will run all day long without getting hot below half volume.  It's the only board that comes with a nice heatsink base, and printed aluminum top making it more presentable than most.  The downside of that is that if you use it as shown there are no holes left to mount it to a board.

It CAN drive a pair of Aurasounds well, but after 10 minutes it's so hot you can smell it.  This seller, DAMGOO, includes a nice note and an email address - and they respond to emails!  I had a nice chat with them about our niche market.

If you're willing to put a bit more connecting work in, this is a step up for smaller transducers.  It has a bit more lower end power.  Definitely a little more inconvenient in that there is no traditional volume knob and no audio input jack. Volume is controlled by two small pots on the circuit board. That means you're going to want to dial this in relative to other amps, then use source volume (PC etc.) if you want to lower it. 

For audio input on this one,  I cut the supplied audio jumper wire and added a female 3.5 jack.

Strangely I found this could NOT drive two Aurasound shakers.   It kept cutting out like it was tripping an overload protection.  It's what I use on the smaller pucks / exciters.  

Say you were going to use 4 sets of  DAEX32EP-4 in stereo the pricing on this would be something like:

$40 - 10A 24v Power Supply  

$10 - Misc connectors

$44 - 4 circuit boards

That's under $100!

This was super interesting.  The stereo amps were all getting hot driving these units so I started playing with dual MONO circuits.  I ran various TPA3116 amps side by side,  left vs right to compare them in real time and it was eye opening to see the variation in results.

Not so much in terms of frequency output, more in terms of heat.

• I had one that was great and the shaker ran cool, but the amp ran hot.
• I had one that was great where the amp ran cool, but the shaker got really hot!
• I found one that runs cool and the shaker stays cool! Eurethra!

This shows how small variations in circuitry can impact compatibility with specific devices, no doubt related to ohmage.

This is THE ONE.

Clearly this is from the same family as the previous stereo board.  I bought the last one on Amazon at the $12 price point so the listing is gone,  but if you search the web for:

"TPA3116DA DC 12V 24V 100W Mono Channel Digital Power Audio Amplifier Board TPA3116D2 Large Capacity Board"

you will get results including this version from various locations.  Amazon listing at $15 right now with a different seller and lots of eBay options.  I've ordered a bunch of them from China through eBay for $4 each!  That's astonishing considering how good they are at driving these larger shakers.

Pretty easy to setup.  I used a $4 "Headphone jack repair"  from Amazon to split the input between the boards.  There's a small volume control on the board to adjust volume.

This can push these transducers all day long without overheating, and without heating up the Aurasound transducers. Definitely a win!

If you're running a BK off game audio then you need a sub bass woofer amp, see below.  If you're running it off telemetry software like Simvibe or Simhub, I have FINALLY found something that works well.

Important.  I'm using a 4ohm Mini LFE.  

If you're using the transducer from the Gamer 2, or a Concert Mini then you have a 2 ohm unit and the results may vary. Having said that,  this little recommended amp seems the best all rounder, so it's worth a try!

I have had ALL KINDS of overheating issues with my BK.  It has two levels of overload protection:

1) A circuit that cuts out when the thing gets hot.  I'm not sure what this component is at it seems to be on the underside of the small circuit board inside the BK and I didn't want to stretch the wiring to get a good look.  If you're using your BK and it starts to cut in and out, this is in play.

2) A 72 degree thermal fuse.  Once it blows.. it's toast.  I don't understand why they include this fuse in the circuit because when I contacted support and told them this component had blown they told me that's the end of the road.  "Not replaceable or repairable" which is totally bogus.  I bought one on Amazon for 80 cents and soldered it to the board and I'm good to go.

Now that it's up and running I retested the BK with various amps, and found that the same mono amp ideal for the AuraSound is the best by far.  I've been using them on my 3 AuroSounds and didn't want to rewire, but took the time today and it's very good.

The previous best was a different TPA3116 mono amp, but the other little unit just shined.  To give you an idea of difference, I switched the BK to use mono on the pedal board.  I had it running with just bumps turned up to the level that it wasn't creating piston slapping sounds.  I could run it all day long at that level without it getting more than warm. When I switched in the best amp,  it did the same STONE COLD so to really push it I added in the Simhub "Engine Noise" effect, which is very rich and therefore very hard on shakers.  Previously I haven't been able to use this effect for more than 15 minutes at meaningful volumes before the thermal cutoff started to play up.  I just drove the SNOT out it for over 30 minutes and with bumps AND engine, and it's fine.  Running somewhere between "cool" and "hot".  Awesome!

Meh.  Considering I melted mine I can't really say I've nailed this.  If you've blown your BK amp (seems common) and you're looking for an alternative to use with game audio, then here are a couple of things to try, but if you do I'd really like to hear from you how they compare to the BK amp which can go down looow. 

Who knows though, maybe I've been expecting too much from my BK and drove it too hard which is why it got hot.  All I can do is tell you that both of these amps will run a BK all day long, as long as you make sure the BK is not getting too hot.  If it gets hot, it will go through a phase where it starts to cut out as the first level of defense.  If you keep going you will blow the thermal fuse.

The problem with both of these amps is that they don't go HIGH enough.  They claim a range of 20hz -180hz (with one having an adjustable max) but if you turn the volume up to get decent response at 60+ hz then you blow things out around 30.   When you turn it down so you don't blow out the low rev burble, you get nothing above 50hz.  

When I get my BK fixed I'll test it with some other amps and add a full frequency amp section to this. 

Pretty easy to hook up. Audio in the top, speaker at the back then terminals for power, so either wire something in or create a dongle with a power female connector.

It worked fine.  The frequency sweep is a bit unnecessary because really you want all of the frequencies that it can offer.

Here's one that showed promise because there is DIY info out there on how to mod to increase the frequency range which would also make it a great contender for the AuraSounds.  Much confusion though, none more so than by the vendor I bought from who has annoyed me intensely at their inability to understand what I'm trying to tell them. 

Here's the Amazon product pictures.  It's V1 of this board that I'd love to find because clipping the two orange capacitors on the bottom edge make it wider frequency response.  Removing another in the center makes it full frequency amp.

Scrolling down this SAME LISTING they show V2 of this board, and how to modify it!  Great!  Give me either one!

.. but if you actually place an order, what you get is v3 of this board, which is different again and while I'm sure I could modify it by trial and error I've found better amps for my needs since.

Unfortunately no matter how I try to communicate this to the seller they don't get it.  Same result with an eBay purchase.  Bottom line, no matter what picture you see of this amp online, the chances are you're going to get a v3 shipped.

The v3 is very capable though.  It's probably got a fuller response than the Option 1 amp, but annoyingly the power jack is not the standard size requiring either an adapter,  or taking the power socket off and soldering power straight to the board. 

That's all for now.  If there's another cheap transducer you'd like me to test against my bank of amps drop me an email.  Address in the footer.  As a conclusion if I was doing it all again I'd just buy this amp and create mono and stereo board setups with it.  Get 10 of them for $5 each from China and just be done with it.  It helps that I have a headphone amp in my setup that I can reach down and trim volume with, but even so.. this little amp wins the big prize.

I'm on the lookout for the perfect preamp board to mate to a pair of these amps, and I'm having a tough time finding the spec I like:

•  Phono plug or 3.5mm jack audio input for easy connection
• 24v DC power (so it's all running off the same source)
• audio out from the preamp via the same kind of screw down connector as the amp, so no need for additional hardware
• Volume, Bass, Treble as a minimum.

If anyone can find one, let me know and I'll test it out.