Resonance and bass effect for speakers

[Vlad Doon]

Hi, maybe some of you are searching the holy grail of the perfect and accurate movie-like hum and iddle sound. In my (humble) opinion, the sounds aren't low enough, so my question is, would it be possible to mount a speaker like some kind of sub-woofer ??? or this has no sense ??
If not what would be possible to obtain a similar low effect ??

[Crystal Chambers]

The best thing I can say is in my limited experience and a lot of reading here, with a reverse sound speaker set up and enough resonating space I've found it to be not quite as bright/loud but more of a warmer sound. While it's not quite as loud with the pommel blocked off it's still plenty loud and sounds nicer. And then the best part is having the sound coming from more then the pommel..like the rest of hilt and more ideally the blade.

Aside from this there have been studio tests by sound techs and everything.

I thought maybe the use of wood would change the resonance, like a wooden tube in front of the speaker, but I've yet to try and haven't heard of anyone else doin so either.

[Jonitus]

I've experimented with sound a lot over the years, and have come to the following conclusions:

1. Most of the soundboards we use in hilts (with exception of the Crystal Focus which allows for custom sounds), don't have sounds with enough bottom-end to have much in the way of real bass.

2. The speakers we use (even the good ones here at TCSS) don't have the capability inherent to their design to play low frequencies with much effect. Most of our small hobby speakers have a range from 250Hz to 20kHz. Decent bass is below 120Hz...where we can't get to.

3. The things you can do to a full-range stereo speaker to boost bottom end response are largely not practical in a saber, because of the room they take up. This includes baffles, chambers, poly-fill, membrane, phase coupling, chambers of different materials, etc.

4. Some things you can do to help the clarity of sound are to:
a. Make sure you vent sound from both ends of the speaker. Resonance works in either direction, since the diaphragm is moving back and forth
b. Make sure your resonance chamber is not too long nor too short (about 1 to 1.5" is fine), and make sure it fits snugly in your hilt. "tight" coupling like this will help the vibrations of the speaker to transmit through your hilt and it actually works somewhat like a vibrating motor. Kind of cool.
c. Pick a good material for your resonance chamber. PVC is about the best I have found. Acrylics, polycarbonate, aluminum...too hard and the sound is harsh.
d. If using the TCSS speaker holders, try drilling some holes where the backside of the speaker will be. You'll be surprised at the increase in apparent volume (because you are taking advantage of resonance in both directions), as well as the clarity of your sound.

[Vlad Doon]

Wao, thanks to you both for the detailed answers. I see it clearer now. I might test a pvc or a wooden chamber (not too long and tight speaker, as you said) , and maybe I'd experiment with an inverted speaker to a "vented" hilt (thx crystal C.). If I understand well, as the speaker's sound vibrations propagate either in front and behind it, I have to take care of both front and rear spaces as two types of resonance chambers ?!
Anyway, I can see now the limitations of our sabers speakers (thank for your super complete info Jonitus), but the marvelous thing about saber making is there is a lot yet to discover and experiment.

May the force be with you

[pipster79]

there is a thread at the top of this very section that has many techniques and ideas for resonance chambers. read thru it and try what you can. best thing is to play with it till you find what you like. myself i find 1 inch pvc pipe couplers work fantastic, they hold the speaker snug like a glove with no glue and they have a small lip in the center that the speaker can sit on.

[Sunrider]

Here's some test data for front of speaker resonance. Soon I will do a full hilt test.

http://forums.thecustomsabershop.com...ead.php?t=9608

[Vlad Doon]

Thanks to you all, I can experiment without wasting effort and time with useless settings. I couldn't imagine someone has been experimenting with sound the way you did sunrider. just awesome and valuable work..

May the force be with you all

[Novastar]

I'm gonna echo three key points Jon made... which are:

* Drill some holes in the hilt (some people don't like this, as... it could 'wreck' a movie hilt, but... it helps for resonance

* You MUST have some "room" between the speaker and the very end of the pommel... uh... well, if you want to make GOOD use of resonance. Just as an FYI... most of the MRFX/HFX sabers did/do NOT do this!!

* Resonance room "in front" and "in back"... is exactly right, as... YUP... the speaker moves fwd and back or... in and out. Whatever you want to say.

Now... on the last point I just re-iterated... it's TRUE that the bloody magnet is (obviously) on one end of the speaker... and so it is sort of the "worse" end of the speaker for getting resonance... but still. Just the same, it's nice to have space "behind" the magnet-end also.

So... what Jon said--it's friggin' AWESOME advice. Should be stickied, and his experience alone tells the story.

Vlad (and any newcomers)... you'll find that sound is indeed 50% of the battle around here. Many of us spend a LOT of time trying to get more bang for the buck (so-to-speak)... and much experimentation, trial & error and certain "known to be effective" things have been discovered.

But yes... for NOW (2010??)... big, boomin', thumpin', bangin', rumble-in-the-bronx style bass... ... ...

... ... ain't practical/happenin' in an LED saber. ... ... ... For now.

[Vlad Doon]

Thx Novastar for the synthetic info. it has helped me a lot.
I'm aware we can't have bass boost effects with "sabers" speakers. I was just trying to find more low iddle sounds . In fact, IMO, you've reached the top level with the soundcard and sample stuff (The cds are a bible) , so now, I must focus on the speaker and resonance chamber, Thank you all for the valuable tips.


May the force be with you all

[tinfoilhelmet]

perhaps some experimentation with active equalization, 2 output speaker and amp phase reversal techniques and compression is in order?
easy to say, harder to do, eh?