The Boominator - another stab at the ultimate party machine

I'm at building this year's boominator now, trying carefully to get everything right.

Saturnus, the principle drawing of the port you have made in Google Sketchup has the dimensions 48mm x 104mm. If I remember correctly you have to round the port. But with rounding the port, what should I do? I could run over a router on the edge, curving the mouth on the outside and inside. Or are you supposed to arc the 48mm dimension? (I've seen a couple of people do the latter).

Last year I only did the first thing.
 
I'm at building this year's boominator now, trying carefully to get everything right.

Saturnus, the principle drawing of the port you have made in Google Sketchup has the dimensions 48mm x 104mm. If I remember correctly you have to round the port. But with rounding the port, what should I do? I could run over a router on the edge, curving the mouth on the outside and inside. Or are you supposed to arc the 48mm dimension? (I've seen a couple of people do the latter).

Last year I only did the first thing.

It's 30x120mm rounded in the ends. 36mm deep.
 
I can't see if there's anything wrong.

And the amp is turned all the way up? Basically it has to be at maximum at all time. And you control volume with the source.

Yeah, at maximum. Maybe it's just my sense of loud that's skewed a bit - My girlfriend and parents thought it was loud. Or maybe the input from my phone is to the low side. Anyways, the sound is great and it's loud enough for most occasions.
 
How can i lower the volume on the piezos? Just by adding more resistors?
I don't notice any difference between 33 and 115 ohm.. (metal film resistor)

Resistor do not dampen piezos. Capacitors do. As the piezo is 130nF, add a 0.13uF cap in series to dampen by 6dB. That's probably too much though.

Note that this cap should be in parallel with the series resistor, not in series with it.

Rough dampening values to test:

-1dB = 22nF
-1.5dB = 33nF
-3dB = 67nF
 
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Yeah, at maximum. Maybe it's just my sense of loud that's skewed a bit - My girlfriend and parents thought it was loud. Or maybe the input from my phone is to the low side. Anyways, the sound is great and it's loud enough for most occasions.

Actually I've found that iPhones and iPod Touch products give the loudest output. More than a lot of other phones and more than the iPod Nano or the iPod shuffle.

At least that's my experience.
 
Hi Saturnus! Awesome boombox! :)

I dont have cash to build a boominator. And I dont need mine to be that big, so I wonder if you could make a sketchup for an box with 2 HP-10T and 2 QLM-1005. I want them to be on the same side, because I'll use my box when we play beachvolley. I want the sound to be directed in one direction.

If you have time for this it would be awesome! :D thanks
 
Hi Saturnus! Awesome boombox! :)

I dont have cash to build a boominator. And I dont need mine to be that big, so I wonder if you could make a sketchup for an box with 2 HP-10T and 2 QLM-1005. I want them to be on the same side, because I'll use my box when we play beachvolley. I want the sound to be directed in one direction.

Thanks.

I could but I won't. The Boominator is based on exploring the bipolar speaker principle for use in free field environments. It makes no sense to make one with speakers on just one side as that would require a complete redesign. And it would destroy the very basic principle on which the Boominator is built.

I also sincerely think that for your use, a bipolar speaker (speakers on both sides) would be far better suited.

Should you decide to make your own speaker, I will strongly recommend not using the HP10T as it is not designed for compact enclosures, and the QLM-1005 isn't one of the best Motorola/CTS copies out there either.
 
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Saturnus, as discussed on the facebook page. would it be an incredibly stupid idea to move the Basreflex lower, and then install a handle at the top so that they are seperate. and still install the piece of wood to stiffen the sides, where the port would normally be?

(i know that any changes to the design, is considered as a downgrade of the quality)

but instead of doing like Phadreas orange Boominator :)
 
I have been thinking about installing an amp9 as a supplement to the amp6 (as Camp friost did it). I am unsure about the advantages and disadvanteges by the amp9 compared to the amp6.. I know this has been discussed before, but i couldn't find where, so here is my question

an amp9@24V will consume 4 times the power as the amp@12V (neglecting quiescent currents and other small losses). How does this correlate to the perceived loudness? (I am guessing that the SPL will only double while the power quadruples)
 
an amp9@24V will consume 4 times the power as the amp@12V (neglecting quiescent currents and other small losses). How does this correlate to the perceived loudness? (I am guessing that the SPL will only double while the power quadruples)

Sort of correct. It will appear to more forcefully but not quite twice as loud but will use 5 times the power (other losses included).
 
Alright i get you point :) - Should have said raised by 3db i guess! so in summarry the gain in perceived loudness will be minimal compared to the extra power required! - i May reconsider if the amp9 is worth the effort then! - Thank you saturnus

That wouldn't be correct either. It's +6dB increase in SPL when you double voltage or quadruble power (same thing).