I'm getting ready to build a very small bluetooth speaker using the blue Sanwu 3118 mono board. My main aim is getting an ok(ish) bass response. Since I already know that my box is really too small for any meaningful bass I would also like to add a simple bass boost, something like 6dB at 50Hz. I'm a total noobie at all of this so I reckon a passive design would be easier? I'm fine with losing gain.
The other thing I need to understand is what effect different input voltages will have on the output wattage. From what I've read I can run this with a pack of 3 18650 batteries like the one in the screenshot below but I can't find a way to figure out what that gives me.
Any help will be greatly appreciated!
The other thing I need to understand is what effect different input voltages will have on the output wattage. From what I've read I can run this with a pack of 3 18650 batteries like the one in the screenshot below but I can't find a way to figure out what that gives me.
Any help will be greatly appreciated!
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First of all, TPA3118 is a class-d amp, so this thread should be there. And there already is a thread about this chip, and you could use that to ask your questions.
We would really like to know, what is that small box? 0,1 liter, 1 liter? What driver are you using? With correct box you could gain some bass boost.
And regarding that boost, it can not be done by passive components. You can only attenuate with passive filters. So basically you could attenuate everything else but the lower frequencies to get that "boost"
Yes, TPA3118 will work with that type of pack. You can check the output with specific voltage from here, page 10 onwards: http://www.ti.com/lit/ds/symlink/tpa3118d2.pdf
We would really like to know, what is that small box? 0,1 liter, 1 liter? What driver are you using? With correct box you could gain some bass boost.
And regarding that boost, it can not be done by passive components. You can only attenuate with passive filters. So basically you could attenuate everything else but the lower frequencies to get that "boost"
Yes, TPA3118 will work with that type of pack. You can check the output with specific voltage from here, page 10 onwards: http://www.ti.com/lit/ds/symlink/tpa3118d2.pdf
Firstly apologies for posting this in the wrong thread (can it be moved?) As for the boost I didn't express myself properly. I understand I can't add passively, which is why I said I don't mind losing gain. I suppose the correct question would be how to reduce everything above 50Hz by 6dB. The box I'm planning to build will be around 0.6 litres and I'd like to use the Tectonic Elements TEBM35C10-4 BMR. To my mind that would be a good way to go for a small mono design due to its wide directivity.
That looks exactly like what I was looking for, so the lower value capacitor the wider the curve, what determines the amount of drop I get? Big thanks!
to get more drop, lower the value of R2 (or increase the value of R1)...of course, you'll have to tweak the cap value...
Ok so it's s bit more complicated (always seems to be the case since I started learning about this stuff). Is there an equation/set of equations that can help me understand without having to constantly ask noobie questions?
yes...but depending on your background, it might not be too easy...of course, the alternative, of just simulating it in LTSpice has its problems,too...
but this file would get you started...
but this file would get you started...
> my box is really too small
If you have a 3-inch driver in a 4-inch box, there's no point in boosting 50Hz, even 80Hz. There may not be enough output below 150Hz to boost without slapping.
I know the attraction of tiny boxes. But in any battery power rig, BIG CONES (and boxes) do more for output and battery life than any cleverness of boost or voltage.
If you have a 3-inch driver in a 4-inch box, there's no point in boosting 50Hz, even 80Hz. There may not be enough output below 150Hz to boost without slapping.
I know the attraction of tiny boxes. But in any battery power rig, BIG CONES (and boxes) do more for output and battery life than any cleverness of boost or voltage.
I'm super confused at this point. For the tectonic elements idea I used this:http://www.tectonicaudiolabs.com/wp...gn-for-TEBM35C10-4-BMR-Driver_WSG_12OCT18.pdf
I was also considering the Dayton Audio MD65-4. I was playing around with speakerbox lite and ended up with a O.6 litre box with FB and F3 values just over 70Hz. I checked back today and FB has now been replaced by QTC, not just for my driver but also for any driver I looked up...
I was also considering the Dayton Audio MD65-4. I was playing around with speakerbox lite and ended up with a O.6 litre box with FB and F3 values just over 70Hz. I checked back today and FB has now been replaced by QTC, not just for my driver but also for any driver I looked up...
I had a look at that driver in WinISD. Were you planning sealed or BR? 0,6 liter sealed has -3dB at 118hz. With BR you could get something below 100hz, it has -3dB at around 73hz. Tuning with regular port will be almost impossible, so I would advise to use a passive radiator.
Thanks, which of the drivers are you referring to? Either way I'm thinking 2 3" PRs, still haven't decided on which ones
also am I completely wrong in assuming there's a bug in speakerbox lite if it gives me QTC as a box parameter?
I made the simulation with the Tectonic Elements TEBM35C10-4 BMR.
Qtc = value for the damping provided for a driver in a sealed enclosure
Qtc = value for the damping provided for a driver in a sealed enclosure
That's what I thought but now I get results that look like this for any driver/box calculation:
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Please disregard the whole QTS/FB thing, I just realised my mistake, think might need a bresk from speakers, getting a bit obsessed...
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