The Boominator - another stab at the ultimate party machine

you mention the amp power being limited by the the laws of physics - but this class D amplifier Class D Audio TI-300 Amplifier - PRODUCTS

(another candidate, as mentioned earlier on in the thread - further up the page) puts out more power than the amp9, i take it pushes the voltage rails higher than Vsupply for the amp?

Nope. It doesn't have a built DC-DC converter so it outputs exactly the same as the 2x100 Sure or the amp9b which in all cases is:

RMS output = supply voltage squared / double the impedance * efficiency

Wrms @ 24V into 8 ohms = 24 x 24 / 8 + 8 * 83% = 30Wrms per channel
 
hi, i would like to hear if any of you guys have some suggestions for an assembled ta2020 amp, i see the assembled amp6 at 41hz is out of stock atm.
but i basically want a board for the same setup as saturns' box in terms of speakers, batteries, solar panel..
I saw alot of people had problems with the cheap lepai boards dying but was looking at something like these and wanted to hear if you have any opinions in terms of do's and dont's

MKIII Tripath TA2020 PCB 25watt Class-T amplifier
or this
Tripath TA2020 PCB 25Watt Class-T Audio Amplifier Board

or maybe something totalt different ..
thanks.
 
At £10 for an TA2020 board I think there's no competition. You should definitely try it out in my opinion.

I have been using that 10£ TA2020 (red PCB) for months now and it works and sounds really great :)

I build a small pair of stereo speakers for my PC (using a pair of Monacor 3'' fulltone speakers, SPH-30X) and I use the red TA2020 Amp to drive them and I think they are a perfect match.

IMAG0909-1.jpg


I also have a Lepai for experimental use ;)
The Lepai sound quality is poor compared to my other TA2020 but the Lepai has a bit higher input gain so I might use it for a festival boombox

IMAG0912-1.jpg
 
The PHT407N P.audio driver

Boominator Signature recommended parts:

Woofers: P.audio SN10MB series II (no alternatives)
Tweeters: P.audio PHT407N (or similar high dispersion, high sensitivity and high quality tweeter horn)
Amplifier: 41Hz Amp9basic (or other 4 channel Tripath based amp)
Filtering: active at 2.4KHz with passive correction (or mix PLLXO and passive filters)
Batteries: up to 3 12.8V 6.8Ah LFP packs (no viable alternatives to the LFP pack, they're superior in every way to any other battery type)

The P.audio PHT407N tweeter has a power handling of 20 watt. Will that be enough when comparred with the Amp 9 basic? That has a output with 50W.
 
Hello again.

I've been waiting for this for half a year...now we are beginning on our new Boominator for Roskilde '11 :D

We'll start out slow though by discussing features, so one question:

Do you have any detailed plans on a subwoofer for you Boominator?

I've searched the thread, but only found old entries. What do you think of an external Horn Subwoofer to go with the Boominator? Do you know of any pros and cons?

I'm afraid that it will be a too 'directed' sound, and I'm not sure if that is good enough in an open space.

I see that you mention that you have planned to use a passive sub, but with it's own batteries. Does this mean that there will be an output cable from the Boominator's amp to the sub, and a power cable from the sub to the Boominators batteries? How much will this effect the loudness of the music overall?

I'm thinking about installing a 1-channel amp in the subwoofer to make it active, and therefore not lowering the output of the Boominator itself.

Any thoughts on this?
 
Some images

By the way, look at all the joy the Boominator can bring :D


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@Roskilde. In '10 we build a wagon of an old wheelbarrow with two compartments isolated with polystyrene(?) (Flamingo in Danish) to keep a lot of beer cold and within reach.

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@Roskilde. In '10 we added a signal-split mini-jack output for the other Boominators to hook up to. Here two of them are playing together. Some known DJ played a set on it a bit later.

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We are three camps, and each of us have our own self-build Boominator. All playing the same signal in one chain. Taken just before:

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Outdoor party in a park in Copenhagen. ~100 people, probably more.

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Party in the park.

An externally hosted image should be here but it was not working when we last tested it.
 
Hello again.

Do you have any detailed plans on a subwoofer for you Boominator?

I've searched the thread, but only found old entries. What do you think of an external Horn Subwoofer to go with the Boominator? Do you know of any pros and cons?

Getting efficient deep bass down to 40 is nearly impossible without a horn, and horns will weight so much.

Isn't the clear point of compromise going to be cutting efficiency in order to save weight?

I think these are the best option:
http://www.tb-speaker.com/detail/1208_03/w8-1363sb.htm

I have one in my car. Check out the reviews on parts express for reassurance that quality control is reasonable.

These weight about 5 lbs each and are 88 db at around 70-80 Hz. Two of them together will break 90 db. They work in ultra-small enclosures around 10 liters, which doesn't matter except that it keeps weight down.

From 35-100 Hz, in BassBoxPro simulations they hold their own with all the subwoofers I've tried, pound for pound. In fact, I can't find anything that will be as loud and deep at this weight and in an enclosure as small.

With 35 watts, the should produce about 104 db freefield with a 35 Hz tuning for sound quality.

If you play with the port tuning and move it upwards, you can get many db more. In BassBoxPro, if you set the tuning in a 10 liter box to 80 Hz, the efficiency skyrockets to 116 db at 80 Hz!! I can hardly believe this result, and I imagine the bass will be "one note." But, it is loud.

I'm curious if anybody else has took a stab at real bass in a portable speaker this size.
 
If you play with the port tuning and move it upwards, you can get many db more. In BassBoxPro, if you set the tuning in a 10 liter box to 80 Hz, the efficiency skyrockets to 116 db at 80 Hz!! I can hardly believe this result, and I imagine the bass will be "one note." But, it is loud.

That's because you're doing something wrong ;-)

A 84 dB/w/m sensitive driver will never produce anything close to 116 dB unless feed by more than 1600W RMS which sort of defeats portability.
 
ThokN, it was so nice to visit your camp (Fri Ost). I also saw the other one at Roskilde. The blue one in the pics I didn't see. Always very nice to see that people are enjoying their home built stuff. :D I'll stop by for more beer at this years Roskilde :D

The current sub I use is just a large flight case that I use for all the camping equipment, tents etc, it's about 320 liters internally and I've mounted 2 15" cheapo pro woofers (not car crap) in the bottom. It's driven by a class D amp (not tripath) running on 24V. Works pretty well, was cheap, and I didn't need to build anything else since I already had the flight case (it was a surplus one of a series I built for Martin Group).
 
Didnt the author build this on based on suncell energy or am I lost in space? :)

I am the author and designer. Do you mean solar cells? If so, those that I used in the original version is not produced anymore, they were surplus from a production run for miniature space satellites, and were quite pricey.

However, a standard 15W amorphous solar panel with the casing stripped away fit perfectly on top with 4mm to give on each side.

Here's an example of where you can buy it but they're available all over the world in both plastic and alu casing, but since you don't need the casing just take whatever offer is cheapest and easiest for you to get hold of: http://www.frys.com/product/4980041
 
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That's because you're doing something wrong ;-)

A 84 dB/w/m sensitive driver will never produce anything close to 116 dB unless feed by more than 1600W RMS which sort of defeats portability.

You have to keep in mind that 84 dB/w/m is the average across a wide band, and this driver is around 88-89 db/w/m where the kick beat in music lies (where the boominator has no boom). That is your first mistake. Then recall that ports can add some bass boost.
 
You have to keep in mind that 84 dB/w/m is the average across a wide band, and this driver is around 88-89 db/w/m where the kick beat in music lies (where the boominator has no boom). That is your first mistake. Then recall that ports can add some bass boost.

The kick is in the midbass between 100 and 150 Hz, precisely where the Boominator is designed to have the most "Boom".

And no, it doesn't make the slightest difference if the sensitivity had been 88 dB/w/m in the desired range. You looking at the chart wrong, the chart is at 2W, or 2.82V into 4 ohm, so 84-85 dB/w/m is the correct sensitivity of that driver. A port, no matter how it's tuned will not add 30 dB to the sensitivity. I doubt it's even possible in a several hundred meters long horn.
 
Hi Saturnus

I have been reading a lot about your (and others) boominator build and I'm currently working on a smaller version myself. I just can't figure out how you use the magnet-to-magnet configuration of the speakers.

Is it called bipole, dipole or isobaric??
And does your "push-pull" work at all when you are using a ventet enclosure?
Would this work with a fulltone speaker as well?