I’m currently working on a Cadian Lasgun project but I’m ordering electronics for the internals. I’ve come to a bit of a standstill for speakers though.
I want this thing to be loud, so I’m planning on puttting dual 31mm (4OHM 3W) speakers, wired in parallel, inside the lasgun pointing outward through vents on either side. My main worry is blowing an amplifier. Is this setup fine, or is it going to tear a hole in space and let warp demons into my house?
Much appreciated. For the Emperor
Edit: board will be Proffie v2.2 since 3.9 seems overkill. Not sure if that changes anything but figured I’d clarify
Proffie 2.2 and 3.9 use the same amplifier, so it’s the same.
Two 4 ohm speakers in parallel basically equals one 2 ohm speaker, which is too low, and is likely to damage the amplifier. (See this thread for details.) If you want to use two speakers, you can, but they need to be 8 ohm amplifiers.
Note that the wattage specifies how much power the speaker can handle, not how much it will use. You can hook up a proffieboard to a 100-watt speaker, as long as it’s 4 ohms or more, it will be fine. (But it will of course still only provide ~3 watts of output.)
There are other options for getting more volume, you could:
use bigger speakers. Larger speakers are better at moving air, so they provide more sound even though they don’t use more power. (See example here: https://www.youtube.com/watch?v=tljbajKx-z4)
Hook up an external amplifier of some sort. One of the simpler choices is to use ENABLE_I2S_OUT and then buy some I2S amplifiers from adafruit or something. They have a breakout board that uses the same amplifier that the Proffieboard uses, so you could power the other speaker with that. Alternatively you could buy a much bigger/stronger amplifier to get some real punch.
Make sure the “porting” of your build is good. Good porting creates twice as much sound from the same wattage. A good speaker case is built with good ports, but obviously we don’t usually have room for that in a prop. Also, acoustic porting design is very nearly a lost art, so it’s hard to do right…
That makes a lot of sense. Going to start looking around for some speakers. I have some old ones I salvaged from a sound bar but they’re too thick for my project unfortunately, but it might be worth testing to see how a proffie handles 2 8ohm 15 w soundbar speakers in parallel lol.
Chassis design is underway, and while I was doing that I had an idea that I thought I’d ask about. Has anyone tried making a blaster that had a solenoid or actuator to simulate recoil?
I’m not really sure how a Proffie standalone would handle that or how it would be coded, but I was curious if it were possible.
It should be possible to use solenoids. Proffieboard FETs have a bypyass diode, which is more or less a requirement when you connect a coil to a FET. Without it, coils tends to turn FETs into spark plugs, which is not what you want…
You can hook up x2 4 Ohm speakers in SERIES, or x2 8 Ohm speakers in PARALLEL, they will work the same and won’t blow the amplifier because total impedance in these cases will be either 8 or 4 Ohm. Also if you really want the best sound I recommend to go with x2 TITAN 32mm speakers from ShtokCustomWorx
Here’s the chassis so far, I’m reprinting the board holding piece since I made the battery housing too small.
Currently mulling over if I want to use LED rings, Tri-Cree, or maybe even a pixel connector for the light source. Not sure what the standard is but it could be cool to have a blade inserted for firing pictures. I’d have to figure out a way to secure it though
Got the switch housing modeled (shoutout my local RadioShack for having the right one) and had to reprint the handle pieces because I dropped and obliterated the last pair. Oops.
Also ordered a red-red-white tri-cree for the barrel. Will update when it gets here. Might try to get it wired up to sound at least to give it a shot.
Unfortunate update, the clearance on the speakers was less than I thought and after installing and testing the speakers were completely deafened by the plastic housing. I’m currently running one speaker box offset to the center, but a less jank setup is in the future for sure.
Still waiting on my tri-cree to arrive. Will update soon
Lasgun sound test, only one of the two speaker boxes due to the issue stated previously. Going to swap them out for the original set I planned on using.
On the plus side, this actually works for me since the boxes were too large and I was going to redesign them anyway. This gives me a lot more leeway. So sort of a win?
In your experience, does the case and second thing make any difference in the sound? Does it sound more/less/better/worse now that you cracked it open?
