The Boominator - another stab at the ultimate party machine

It was not hard :) It doesn't need to be perfect. You can do with a "stiksav" and some screws and you will be fine. It will get a bit heavy though because of the extra batteries, but you could leave them out if you want. You could use only 1 battery and an Amp6, which will make it lighter and not as long. But go for it! It really is not difficult if you don't need it to be absolutely perfect :)

we'll only be having one amp6 and two 7,2 Ah batteries so I don't think the weight will be a problem, now I'm just looking forward to start building :D
 
Btw, I bookmarked all the posts from this thread that I found useful in order to build a Boominator - thought I would share It with you guys.

And thanks to all the persons who participated in this thread, especially Saturnus :)

General design information
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-12.html#post1536139
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-20.html#post1679589
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-27.html#post1738505
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-77.html#post2366742

SketchUp file
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-78.html#post2367144

AMP related
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-75.html#post2312723
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-84.html#post2472847
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-209.html#post2646067

Resistor related
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-19.html#post1676491
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-37.html#post1862795
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-39.html#post1873631
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-69.html#post2281949
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-93.html#post2511682 including #922 and 923

Piezo related
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-43.html#post1885911
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-61.html#post2212458
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-61.html#post2213020
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-62.html#post2213747
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-77.html#post2365970
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-100.html#post2529783
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-116.html#post2550820 including #1152
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-151.html#post2572717
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-171.html#post2591419
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-185.html#post2608557
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-195.html#post2617406
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-204.html#post2636445

Batteries and power consumption
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-25.html#post1718421
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-66.html#post2247841
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-66.html#post2247898
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-84.html#post2472676
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-176.html#post2602727
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-224.html#post2676594
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-224.html#post2676823

Solar panel related
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-78.html#post2380251
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-80.html#post2444529
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-85.html#post2477172
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-97.html#post2522253
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-97.html#post2522677
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-110.html#post2538482
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-117.html#post2552732
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-187.html#post2611683

Where to buy stuff
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-26.html#post1718431

Schematics and wiring
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-29.html#post1742547
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-87.html#post2486550
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-115.html#post2550803
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-130.html#post2560397
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-166.html#post2584008
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-168.html#post2585373 including #1675
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-179.html#post2606317
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-180.html#post2606453
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-188.html#post2612667

Center braces
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-22.html#post1680882

Cabinet related
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-21.html#post1679847
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-22.html#post1680903
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-51.html#post2102290
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-58.html#post2202014
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-86.html#post2480254 including #854, 855 and 856
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-93.html#post2514185 including #925
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-98.html#post2522699
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-99.html#post2522971 including #982, 983, 984, 985 and 986
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-106.html#post2538099
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-107.html#post2538184
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-108.html#post2538332
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-110.html#post2539098 including #1095, 1101 and 1105
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-111.html#post2539357
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-111.html#post2542222
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-112.html#post2543403 including #1118
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-114.html#post2546386
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-117.html#post2552911 including #1170
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-195.html#post2617532
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-202.html#post2631850

Misc Q&A's
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-95.html#post2517245 including #946
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-107.html#post2538256
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-117.html#post2552739 including #1168
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-189.html#post2613674 including #1885 and 1894
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-194.html#post2617343 including #1940
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-202.html#post2632278 including #2017, 2018, 2020, 2021 and 2022


Plywood and paint
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-190.html#post2613995 including #1897, 1898, 1899, 1900 and 1905

Sawing
http://www.diyaudio.com/forums/attachments/class-d/218626d1302873924-boominator-another-stab-ultimate-party-machine-boominator_cuts2.png

Cabinet finish (danish)
http://roskilde-open.dk/blog/sadan-samler-du-kabinet-ordentligt-og-laver-et-paent-finish

Tools
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-117.html#post2552726

Pictures
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-74.html#post2295893
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-75.html#post2325140
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-79.html#post2443791
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-114.html#post2550455
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-170.html#post2591182
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-187.html#post2611386
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine-193.html#post2615520
http://s1080.photobucket.com/albums/j338/MarcusNordlander/boominator/?albumview=slideshow
http://www.minhembio.com/forum/index.php?showtopic=262694&st=0&gopid=2913948&#entry2913948
http://imageshack.us/g/593/89049866.jpg/


2011 Boominator meetup
http://roskilde-festival.dk/uk/tv/?mid=D8431830
 
Aah! I think I'm getting a hang of WinISD now.

Meanwhile I've been looking at some ports online and found a really cheap one 7,5 cm (cross area 44,2 cm2). I put this WinISD and it calculates 5,63 cm port length. There should be no problem in using this instead, right? It's still the same tuning 69,8 hz. I'll just have to cut the port exactly 5,63 cm :)

I'm building half a boominator for another camp and they are on a tight budget, so this port is appealing.

Rubenn, did you end up cutting your 75mm port of at 5,63cm? And if so, was it satisfying? - I've got the exact same port, and would like to know if 5,63cm is the works :) Thanks.
 
I think I actually chose the tuning as 82 hz with a port length of 2.53 cm. So I sawed a part of the tube off. It was actually pretty satisfying. Good tight bass. But I reckon it will be better if one would "perfect" it.

Remember that I also chose the IMG Stageline SPA-10PA as the HP-10W wasn't available at the time :)

Question for Saturnus actually regarding this function in WinISD: How does one find the optimal tuning frequency for the specific driver? Because there is clearly a difference when choosing another driver :)
 
Question for Saturnus actually regarding this function in WinISD: How does one find the optimal tuning frequency for the specific driver? Because there is clearly a difference when choosing another driver :)

That depends on what you consider optimal tuning ;)

winISD is a little cumbersome when finding the optimum tuning frequency as it (as it should) uses different calculations depending on the speakers Qts. However, for one that does not want to use standard tunings that approach is useless. You have to use the winISD online tool, plot in the 3 driver specs and find the "optimum" Vb and Fb there. From those numbers you can calculate your own tuning frequency depending on Vb and desired Qtc by hand.
 
That depends on what you consider optimal tuning ;)

winISD is a little cumbersome when finding the optimum tuning frequency as it (as it should) uses different calculations depending on the speakers Qts. However, for one that does not want to use standard tunings that approach is useless. You have to use the winISD online tool, plot in the 3 driver specs and find the "optimum" Vb and Fb there. From those numbers you can calculate your own tuning frequency depending on Vb and desired Qtc by hand.

Enlightening information. Still, some things make me wonder.

When designing a boombox for outdoor use, what are you looking for? I guess that the rise +3 dB just around the downward rolloff frequency is wanted. Are you just messing around with Vb and Fb until you get something that looks usable?

This is what I see:
An externally hosted image should be here but it was not working when we last tested it.


Here I just put it some random values in Vb and Fb and used the specs from the HP-10W. But as I can see you are apparently tweaking the tuning frequency somehow to be 69.8 hz (or whatever the new tuning frequency for the HP-10W was) down from the previous tuning frequency of 82 hz. That's where I can't follow you anymore :p

I hope this is not me being stupid and asking silly questions, but it could be cool to fully understand the meaning behind everything related to boomboxes - of course :D
 
When designing a boombox for outdoor use, what are you looking for? I guess that the rise +3 dB just around the downward rolloff frequency is wanted. Are you just messing around with Vb and Fb until you get something that looks usable?

No, I think I've said it 5 times already in this thread. Use the winISD online. Click "optimum". note the resulting Vb and Fb.

Then to get Q=1.207 instead of Q=0.707 divide Vb with Pi and multiply Fb with square root of 2. That gives Q=1.207 with a +2.82dB peak which is optimum for an outdoors boombox. Very simple.

For other tunings, use other calculations. Don't just assume you can just fiddle around with winISD setting blindly, and think it works in real life. It usually doesn't.

Note. The tuning frequency (defined by Fb) was never 82 Hz for any version of the Boominator. New or old. The 82 Hz was the lower 0dB point which is the outdoors equivalent of the tuning frequency, ie. the lowest frequency the speaker can realistically produce.

The tuning frequency, Fb, is in standard calculation equal to the lower -3dB frequency but that's not relevant when your have another tuning Q than the "optimum".
 
Last edited:
@ rubennn,

What are your thoughts on the half Boominator? Are you satisfied with it's performance?
(I'm sorry if this has already been answered but this is a pretty huge thread.)

I'll just answer that with a quote, since i also needed info on that subject some time ago :p

I can vouche for the half boominator. It works for me and worked for my camp also. There are 2 major cons and 3 major pros for building such a boombox. Deciding how much they each weigh is up to you:

Half boominator:
Pros:
- You'll save money
- Half the power use at max. vol. due to system impedance being 8 ohm instead of 4 ohm (and thus also lowering output - see cons)
- The boombox weighs less

Cons:
- As far as I can recall you lose 6 dB in sound pressure level at max. vol. because of the 2 drivers instead of 4 and system impedance is 8 ohm instead of 4 ohm.
- Sound quality is compromised and phase problems may occur (still WAY better than any store bought boomblaster!)

I like both the half boominator and the full boominator. But I would advise you to build the full boominator if you are going to be 16 people. If you wanna party with a half boominator you should be less than 10 people - it's simply not loud enough.
 
Let me also put it like this (in addition to what Kostecki posted):

For next years Roskilde Festival I'm planning to building the full boominator. I want to host small techno/house parties for my friends at the festival camping site.... And for that I need the full boominator (maybe also with a more powerful amplifier, but I'm not sure about this yet) :)