The Boominator - another stab at the ultimate party machine

What makes the recommended construction grade plywood different from regular plywood is the fact that it's glued with and surface coated with epoxy resin which makes it much stiffer and harder than all other types of plywood. So if you want something to stick to it you must either sand it, or use epoxy resin for gluing as epoxy resin will chemically bond to the coating resin. It's also a much better alternative than wood glues as it's creates very solid joints without needing clamping, and it has excellent joint filling capability as it doesn't shrink under curing as wood glues does which makes the need for siliconing the joints afterwards redundant.

Just note that it's also a fair deal more expensive, and make sure you read and follow the safety instructions.
 
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I was looking through this thread for advice on different types of glue and sealant and I just want to make sure that I got it right.
- Use a chemical metal product like this PLASTIC PADDING KEMISK METAL - Best.nr. 1139 for glueing the woofers to the center brace and the outer cabinet.
- Use a non-corrosive acrylic sealant like this Bostik Diy Akrylfuge - køb online hos SILVAN for sealing the cabinet airtight.
- Use epoxy or regular wood glue for the cabinet depending on courage/budget.
Is this more or less correct?

Also, I got the plunge router from elextra.dk which was recommended somewhere in this thread and I was wondering if I can make the holes for the woofers using the straight router bit that comes with it?
I think I read somewhere that spiral bits are considered superior, but since I already got the straight bit I might as well ask.
Since the recommended plywood is a pretty hard material, is it possible/recommendable to cut through all 12 mm at once or should I adjust the depth stop on the router to do it in 2-3 goes instead?

Saturnus, I think it's no secret that you're a perfectionist (which is probably a good thing since the Boominator wouldn't exist otherwise) but how important would you say that the rounding of the holes in the center brace is?
I'm asking because my router skills are very limited and I would love not having to do it.

I was thinking about making a DIY grill for the port out of chicken wire, speaker cloth and impregnation spray to help keep moist and dust out of the cabinet. Is this doable or will it affect the air flow too much?
 
Also, I got the plunge router from elextra.dk which was recommended somewhere in this thread and I was wondering if I can make the holes for the woofers using the straight router bit that comes with it?
I think I read somewhere that spiral bits are considered superior, but since I already got the straight bit I might as well ask.
Since the recommended plywood is a pretty hard material, is it possible/recommendable to cut through all 12 mm at once or should I adjust the depth stop on the router to do it in 2-3 goes instead?

Saturnus, I think it's no secret that you're a perfectionist (which is probably a good thing since the Boominator wouldn't exist otherwise) but how important would you say that the rounding of the holes in the center brace is?
I'm asking because my router skills are very limited and I would love not having to do it.

You should do the woofer cutouts in 2-3 turns. I made the mistake doing it in 1 turn, which after a few cutouts made my router bit break in 2 pieces because it got too hot.

A straight bit should be just fine for the cutout.

Rounding with a router is not difficult at all and it's kind of fun too in my opinion. So I would recommend doing it :) (just make sure the piece of wood you want to round is held tight by something so it doesn't slip).

Happy building :)

EDIT: You could look up some youtube videos about using a router for rounding and making circular cutouts. That helped me a lot.
 
I saw this on elextra.dk today:
https://elextra.dk/main.aspx?page=article&artno=H20587
My thoughts were that it could be used to plug into the 12V socket when you want to charge the batteries with an external charger. You would avoid the hassle taking the batteries out of the boominator to charge them. Is this a slick solution or a dumb thought? :)

I think that it's a smart plan.
I'm going to do kind of the same but with Neutrik Powercon instead. Also if you need to attach an extra backup battery. NEUTRIK NAC3MPA-1 POWERCON - Thomann danske Cyberstore NEUTRIK NAC3FCA POWERCON - Thomann danske Cyberstore
 
You don't need a trafo with the AMP6-B, you can choose which sensitivity that suits your device.

Quoted from 41Hz.com
  • The amplifier input stage, inside the Tripath chip
    Is of the operational amplifier type. The maximum possible voltage the input stage should handle is about +/-2V peak to peak (4Vpp=1.41 Vrms). You can set the gain of the input stage so that it matches your signal source.
    The gain is calculated as for a normal inverting operational amplifier: Input Gain=-1*Rfeedback/Rin V/V. The minus sign is due to the fact that the input stage is inverting (ignore).
    On the board, R2 + R4 are the Rin and R5 + R6 are the Rfeedback. With the kit, there are four 22kΩ resistors and two 56kΩ (and/or 82kΩ). With these resistor values, you can choose one of three different input sensitivities as shown in table 1 below.
    If you use other input resistors, they should be of a low noise (metal film) type.

R-in, R2+R4 - R-feedback, R5+R6 - Input-gain - Suitable signal source.
22 kΩ - 82 kΩ - 3.7 - Even more sensitive input (Ipod)
22 kΩ - 56 kΩ - 2.5 - For older type portable MP3/CD player with built in volume control.
22 kΩ - 22 kΩ - 1 - General use
56 kΩ - 22 kΩ - 0.4 - (Pro) preamplifier with fairly high output signal
82 kΩ - 22 kΩ - 0.27 - Even less sensitive if needed
 
What a great thread. :) Lots of good information here.

I've started planning next years festival sound already, and will probably use all of the components of the boominator for the speaker box.
Tripath amplifier, 4x HP10w and bubble piezos.
Being a big camp with a lot of ideas, we will go for a cart solution however, as we need more room for lights and a small bar.


A big must-have is the ability to play mp3 from usb drives, so everyone can contribute with their own music.
The easy solution would be to install a head unit from my car, but as I've learnt from this thread, that would be an unnecessary drain on battery power.

Instead I've been looking for a better solution. Something like this:
1.5" LED MP3 Player Module with Remote Controller/FM/USB/SD (3.7V) - Free Shipping - DealExtreme
An externally hosted image should be here but it was not working when we last tested it.

All basic needs covered, display and remote is a bonus. The input voltage is tricky at 3.7v however. And a $8 pricetag suggests a pretty low quality.

VMP3202-3.3V High Efficiency DC-DC Module - Free Shipping - DealExtreme
I'm guessing this will do the job of supplying ~4v.

I wouldn't mind paying more for a better quality player, with better controls and a more detailed display, but I'm in need of ideas here.

Have any of you builders gone down this path? :)
 
What a great thread. :) Lots of good information here.

I've started planning next years festival sound already, and will probably use all of the components of the boominator for the speaker box.
Tripath amplifier, 4x HP10w and bubble piezos.
Being a big camp with a lot of ideas, we will go for a cart solution however, as we need more room for lights and a small bar.


A big must-have is the ability to play mp3 from usb drives, so everyone can contribute with their own music.
The easy solution would be to install a head unit from my car, but as I've learnt from this thread, that would be an unnecessary drain on battery power.

Instead I've been looking for a better solution. Something like this:
1.5" LED MP3 Player Module with Remote Controller/FM/USB/SD (3.7V) - Free Shipping - DealExtreme
An externally hosted image should be here but it was not working when we last tested it.

All basic needs covered, display and remote is a bonus. The input voltage is tricky at 3.7v however. And a $8 pricetag suggests a pretty low quality.

VMP3202-3.3V High Efficiency DC-DC Module - Free Shipping - DealExtreme
I'm guessing this will do the job of supplying ~4v.

I wouldn't mind paying more for a better quality player, with better controls and a more detailed display, but I'm in need of ideas here.

Have any of you builders gone down this path? :)

Single cell Li-ion and LiPo are both 3.6-3.7 V.
 
A few questions for those of you with boominators who have heard your boxes next to other boxes/systems:

1. How does a goldwood gw-1058-driven boominator compare to an hp10w-driven boominator?
2. Have you heard any boominators at the festival that really stood out? What components were they using?
3. How does the boominator compare to the podzuma? I have heard the podzuma in person, and it is very impressive for its size.
 
A few questions for those of you with boominators who have heard your boxes next to other boxes/systems:

1. How does a goldwood gw-1058-driven boominator compare to an hp10w-driven boominator?
2. Have you heard any boominators at the festival that really stood out? What components were they using?
3. How does the boominator compare to the podzuma? I have heard the podzuma in person, and it is very impressive for its size.

I'll let those who have built it with the GW1058 instead of the HP10W comment on their impressions as I actually haven't heard a Boominator with the GW1058. I have however heard other speakers with the GW1058 and it's my impression that the difference isn't that great. The HP10W is just better all round. And especially mid-range performance is better.

At the Boominator meet-up at Roskilde Festival I think FMpressure's Boominator with it's PHT407 tweeter stood out. And after that one, all the Boominators with the bubble tweeters.

Well, I have heard the podzuma. And let me tell you, it's an entirely different league altogether. The Boominator is vastly better in every aspect.
 
Jeg har ledt i lang tid og kan ikke finde NTX3711 Bubble Tweeters nogen steder :S

Nogen der har et link til hvor de kan købes ? :)

:cop: translation from google translate
I've been looking for a long time and can not find NTX3711 Bubble Tweeters anywhere: S

Anyone have a link to where they can be bought? :)
 
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They are sold on eBay in 10-packs, but restricted to buyers in United States and Canada sadly.
HORN BUBBLE TWEETERS 3.5" 10 PACK PIEZO PA DJ (NTX3711) | eBay

I'm going to need at least 4 of these for my build, so I think I'll order them through ShopUSA or similar service.
Maybe we can arrange a groupbuy, since they are in high demand for boominator builds. :)

You'll have no luck with that auction (yet?) the listing has ended and they don't have any in stock.

For the last month I've been waiting for them get them in stock again. All I've been told is that they are still on backorder.
 
Let me point out some of the issues i had this weekend when i tried to get further with my project:

  1. I tried to glue the grill on top of the HP10 and let me tell you that it is an mess. Maybe i tried to do something that i was not suppose to do but glueing the grill without it's rubber thing around it is nearly impossible so i gave up.
  2. Next i was thinking how to mount the driver to the plywood from inside with the grill (without rubber and without sealing gasket since i don't need it) between the plywood and driver ?? Hmm. I know saturnus said that i should glue the driver but as i said in 1 it is impossible for me. Anyway i decided on screws but even with screws i need really big ammount of silicone sealing around if no air is supposed to go out. Especially around the screw holes on the HP10W. You all did this ?
  3. I made holes for the tweaters and i accidentaly got to close to the port handle so i now need to cut some of the plywwod off so i have enough space to mount the tweeter os be careful with this one.
  4. Since i wanted to mount the drivers i figured out that i can't mount them before i paint the roundings for the HP10W because i won't be able to do that with the driver inside. I will only paint the roundings becaue i will paint the whole thing when i am done and the screw holes from the rest of the box are filled with polyfilla.
Anyway i didn't get to do any of these. I only looked at the parts and i had to rethink the strategy because i am really nervous that there will be air comming in into the box if i don't seal the HP10W correct if possible. I feel that the grill is really getting in the way to seal the box correct. My grill have sharp edges when i take the rubber thing off. Is your the same ?

/donnib