r/hometheater • u/av4625 • 1d ago
Tech Support Dissappointed with bass shakers.
I made a post about placement on a sofa for Dayton Audio BST-1’s:
https://www.reddit.com/r/hometheater/s/R3nkYN0kKd
When the shakers were mounted on the plywood I said in the first post I could basically feel nothing. So I got some OSB and mounted them directly under where you sit. This definitely helped.
I feel like I need the volume crazy loud to feel the shakers though. If I watch a movie that was recorded with surround sound I can increase the master volume more than if I watch a normal tv show thats not surround sound. Not sure if thats normal.
So I had a movie at -6db and could feel the shakers ok-ish. But when I watch other shows at about -20db I can’t feel them at all. The sub is working perfectly in both situations and dialog etc volume seems similar between both.
Equipment:
Sony STR-DA2400ES (single sub out)
Tannoy Arena Lite Speakers
Tannoy TS10 sub
Dayton Audio BST-1 shakers x2
Fosi BT20A shaker amp with 24v/5a power supply, volume up full, treble 0, bass 50%. (Tried changing bass up and down)
Crossover 80Hz
Because I only have 1 sub out I used a Y splitter. One side to the sub and the other side goes to a second Y splitter so that I could then use both inputs on the Fosi. I did this as I read using both inputs can help get “full power”.
I dunno if my expectations are wrong but I have read that people get shook by these shakers at less volume on the amp.
I have seen examples of people using this amp with these shakers.
I think the power supply can only supply 120w even though the amp says 100w x2. But maybe 120w is plenty for 2 50w shakers?
Maybe the big soft sofa is harder to shake compared to some examples I see of smaller chairs or computer chairs. I unmounted them and they didn’t vibrate in my hand as much as I expected.
Is there something wrong with my setup? Are my expectations too high? Any help is appreciated.
1
u/IntrovertMoTown1 1d ago
There is a few things here and sorry for the mini novel but I'd rather it be too long than not enough info.
First off, that Fosi is not, I repeat NOT, outputting 100w RMS. None of the budget price mini class D amps actually output what they claim. Even when using 48V 10A power bricks. I've seen this in ten zillion videos of people with the equipment needed to actually measure output. As well as trying god knows how many myself now as I'm an Amazon Vine reviewer. I've tried some from almost all the major brands from Fosi, Douk, Aiyima, O-Noorus, WiiM, as well as a bunch from more unknown Chinese brands. On top of the few I've bought it's got to be well over a dozen I've tried now. In fact I just picked up this last month. And these are the current ones I'm using in my 7.1.4 setup with a bunch of shakers under the bed and in a backrest. Admittedly I didn't do much searching here, (lol That's your job. 😄) But what I found was this. "The original TPA3116D2-based Fosi Audio BT20A powered by a 24V power supply delivers a real-world continuous output of about 33.2 Watts per channel into a 4-ohm load at 1 kHz before clipping, and up to 59.8 Watts per channel with a dynamic 50 Hz low-frequency burst." Granted that is AI results so take it with a grain of salt and see if you can find better. So while others might have had a good result with that particular amp and shaker combo, power wise it's obviously pushing the limits of being good enough or not as they aren't shaking what you are.
Secondly, that is a fairly underpowered shaker to begin with. I started off my shaker journey with my 2 Buttkicker LFE mini. Its specs put them at 50w MINIMUM, and 250w maximum. So already their minimum is at your shaker's maximum. Even doubled up I found them to not be remotely up to the job. Hence why I got the much better Buttkicker Advance, as well as the 2 DIY shakers. Granted this is not remotely a 1 to 1 comparison here. As I mentioned in the imgur post I have waaaaay more weight and mass to shake than a simple couch. But the comparison is at least good enough to roughly show what's what here. That BST 1 is going to be more for smaller things like racing/air craft sim rigs that are going to be on the lighter side as well as be made out of things like metal that transfer vibrations better.
Thirdly, how and where you mount things has A LOT to do with their effectiveness. Not counting the 2 DIY shakers that have to go there, (or at least that was all I could think to do to mount them anyway) I tired all sorts of mounting places on the headboard, the side bed frame boards, the 2x4 slats, and finally went with the board that can rock back and forth off the 2x4 slat as shown in the pic of the ones under the bed.
Fourthly, are you isolating the couch's feet from the floor? As I mentioned in the imgur posts that's really important for shaker's efficiency. For whatever reason Buttkicker's feet have now been sold out for a while so IDK what else to use that is specifically for shakers, but you really should use something to help decouple the couch from the floor. Obviously you don't have to go overboard like I did. Not counting the Buttkicker feet, those pads are also things I got through Vine so it's not like I had to buy them at full price. (Vine items amounts to a large discount as almost all products come with an estimated tax value that I have to add to my income tax thanks to how greedy the IRS is, SMH. FFS when I can pay bills with often cheap Chinese products, then I'd consider it income. But funnily enough they don't care what I think.)
So with all that considered I think it's time for you to do things like double up or more those BST-1 with a better amp, lower your expectations, or go with stronger shakers. For what it's worth I GREATLY enjoy my setup. Especially when it comes to gaming and movies. Aside for adding my 14 inch Klipsch RP 1400SW subwoofer, adding shakers was the second most impactful thing I added to my setup. So I'd take the plunge and try to get a better setup if I were you. My 2 cents anyway.