Worlds Best Boombox - Custom Pearl Orange Diamondboxx - CLEAN and LOUD

[deathcards]

don't forget to stretch before break dancing

[Miguels]

I'm glad tony got his knowledge from here...

The only thing the diamondboxx needs is a cassette player

Edited July 17, 2015 by Miguels

[Broke_Audio_Addict]

I'm glad tony got his knowledge from here...

The only thing the diamondback needs is a cassette player

As horrible of an idea as that is it would be pretty awesome with a cassette player just for nostalgia.

[Hayime]

Wow, that thing just rocks. Amazing. Now I want to buy it.

Will it be shipped to GErmany too?

I really think about to buy this..

[TonyD'Amore]

Great product! Props to Tony for developing it. Audio done right; active crossover, subsonic filter, thick enclosure, high quality drivers.

I can understand the discussion about the price, but quality costs money. Mass produced injection molded speakers with D-cells may be cheaper, but that's reflected in the sound. Judging by the cycle life claim he is using LiFePO4? Very nice. Is Tony on this forum?, I would like his explanation on the choice for class A/B. That stuff eats away battery while it doesn't sound much better than a well-designed class D.

I laughed when I saw:

Two 2 inch (51mm) Helmholtz resonators, tuned to 45 Hz

In the description

Because 'ports' didn't sound fancy enough?

Thank you sir!

The choice of Class A/B was based on two things - Sound quality and idle current. These are both suprior on a class a/b amplifier. Advantages of class D amplifer are size and better effiencency under some conditions, not all. Size was not a concern as the size requirement for the woofer airspace was the determining factor there. Efficency was a wash. So Class A/B it is, and it sounds great!

Just trying to give Dr. Helmholtz some love and respect

Idle current shouldn't differ too much I think? What are your findings?

The main thing is that class AB uses about 4 times more power with music at max volume.

Waste of battery IMO. Class D is also much more suited for mass manufacturing (SMD, sinking via the PCB).

I saw on your FB page that you were searching soldering techs down to 0603. There's no way your handassembling this (right?).

Do you mind sharing some internals, maybe via PM, I always like to see the engineering work of others.

Idle current is quite different on the two. Like double on the class D. In my opinon Class D is better suited for higher power applications, and where sound quality isn't as much of a priority as price. The amplifier PCB is designed for manufacturing and uses SMD parts and some through hole parts. The parts are machine placed. At continuous full volume I agree, a Class D amplifier would be more eff, which possibly could allow us to use a smaller capacity battery. But with the idle current being higher, at low volume the eff gain is nulled. We chose to let the battery cost a bit more and enjoy the sound this system produces. How do you figure class AB uses 4 times the power with music at max?

Edited July 17, 2015 by TonyD'Amore

[Jesse van der Zouw]

Edit: whoops, posted with the wrong (facebook) account. I'm the same guys as lutkeveld

My findings are based on theoretical calculations and practical findings, if you are able to prove me wrong with actual measurements: great! be my guest.

The difference lies in the effective efficiency between AB vs D:

http://sound.westhost.com/articles/pwm-f1.gif

As you know: music isn't a continuous load, but rather a peaky load with a crest factor of at least 10dB

If you look at -10dB (10%) on the graph you see the huge difference.

But full power on your beastly machine is very loud, maybe on normal listening levels (couple of mW) idle current is the dominant factor.

Edited July 17, 2015 by Jesse van der Zouw

[TonyD'Amore]

My findings are based on theoretical calculations and practical findings, if you are able to prove me wrong with actual measurements: great! be my guest.

The difference lies in the effective efficiency between AB vs D:

http://sound.westhost.com/articles/pwm-f1.gif

As you know: music isn't a continuous load, but rather a peaky load with a crest factor of at least 10dB

If you look at -10dB (10%) on the graph you see the huge difference.

But full power on your beastly machine is very loud, maybe on normal listening levels (couple of mW) idle current is the dominant factor.

I award you an A for effort sir. However the devil is in the details and the marketing info. That graph is erroneously drawn to make Class D look better than it is. The x axis is drawn lineraly in power. It should be drawn as a LOG. This would make the difference between the two look much less though, and would exploit the crap out of the fact that Class D has LESS efficency at very low levels.

The graph in that .gif should have the x axis drawn as:

0.0001%, 0.001%, 0.01%, 0.1%, 1%, 10%, 100% ... NOT 0%, 10%, 20%, 30%, 40% and so on.

Class Dismissed

Edited July 17, 2015 by TonyD'Amore

[Broke_Audio_Addict]

Wonder how many amplifier topologies this kid has developed?

I'll bet it's 0

Edited July 17, 2015 by Broke_Audio_Addict

[Miguels]

this guy really has no idea who tony is

youre arguing against an engineer who designed amps for a living

here are pictures of the most efficient amp aver made.. even after the years no person has come close to building something like it

Tony Damore Posted - 12/06/2006 : 9:36:39 PM

Hey guys thanks for the props!! Yes it is true the idea came from a defibrillator. It seemed silly to me that all these guys in the db drag lanes need to have 1/2 of their vehicle full of batteries and alternators to maintain a decent B+ voltage for a few seconds. That and the fact that the amount of total energy all those batteries contain is huge and they are only using a fraction of it during their burp. It is like taking a NASCAR car to a drag race. A vehicle that is designed to go 200mph for hours on end probably isn't the best design for a 1/4 mile burst. So when you look at the way a defibrillator is used its like burping an amp. Defibrillators don't have massive power cords that need mega amps at 220V, in fact some of them are portable and run off a very small battery. Why, because they don't need to shock someone for hours at a time, just a quick burst. They just draw a small amount of power continuously during 'charge up' and once all the energy they need is accumulated they release it all at once. With the operation of the defibrillator in mind, I tried to apply it to car audio. I set off to build a prototype which was based on (2) T1500.2 output sections, I had to liquid cool the MOSFETs because even the FETs in the T1500.2's were not big enough to handle the kind of power I wanted. By keeping them very cold they could be pushed beyond their limits. (This may be the radiator ect... part of the story that someone posted). Then I needed a way to store a bunch of energy, electrolytic caps and some of the carbon based caps that are commonly used in car audio were not even close to being capable of storing the amount of energy I needed, so I used 12 small motorcycle batteries in series to get 140+ Volts. Then I built a power supply that would convert 12VDC to 140VDC to 'charge' these batteries. I got this contraption all put together the night before the Annual Rockford Fosgate Employee Sound-Off. I didn't really how much power it would make exactly, but to try to shorten this long story it ended up putting out 15,030 Watts RMS! This is how 15k Watts became the goal for a 'real' amp. The first step towards making it a 'real' amplifier was I had to eliminate the array of batteries. I began searching high and low for something that would do it. I found a company that makes capacitors for hybrid cars and large wind turbines. These worked perfectly. The caps I ended up using are 400 Farads, and there are 180 of these in the T15kW. Then I needed an intelligent power supply that could monitor these caps and add energy to them as needed, and it had to be fast, really fast if this amp was going to play music and not just a burst. So during music these caps are charging, discharging, charging, discharging. The power supply in the T15kW can charge the caps 35,000 times per second. Of course many other things had to happen like finding MOSFETs that could handle it, a way to keep it cool without antifreeze and car radiators ect. The final product met all the goals and then some. The main idea is that with this technology the amplifier can put out more power during transients or bursts than the car it's connected to could supply. Again thanks for the props, look for hybrid technology to hit our smaller amplifiers in the near future. PS if you guys would like to see pictures of the original liquid cooled proto I'll post them. This proto was eventually dubbed the D'Fibrillator. haha

--------------------------------------------------------------------------------

Tony D'Amore Design Engineer Rockford Corporation

Edited July 17, 2015 by Miguels

[Smoove]

this guy really has no idea who tony is

youre arguing against an engineer who designed amps for a living

here are pictures of the most efficient amp aver made.. even after the years no person has come close to building something like it

Tony Damore Posted - 12/06/2006 : 9:36:39 PM

Hey guys thanks for the props!! Yes it is true the idea came from a defibrillator. It seemed silly to me that all these guys in the db drag lanes need to have 1/2 of their vehicle full of batteries and alternators to maintain a decent B+ voltage for a few seconds. That and the fact that the amount of total energy all those batteries contain is huge and they are only using a fraction of it during their burp. It is like taking a NASCAR car to a drag race. A vehicle that is designed to go 200mph for hours on end probably isn't the best design for a 1/4 mile burst. So when you look at the way a defibrillator is used its like burping an amp. Defibrillators don't have massive power cords that need mega amps at 220V, in fact some of them are portable and run off a very small battery. Why, because they don't need to shock someone for hours at a time, just a quick burst. They just draw a small amount of power continuously during 'charge up' and once all the energy they need is accumulated they release it all at once. With the operation of the defibrillator in mind, I tried to apply it to car audio. I set off to build a prototype which was based on (2) T1500.2 output sections, I had to liquid cool the MOSFETs because even the FETs in the T1500.2's were not big enough to handle the kind of power I wanted. By keeping them very cold they could be pushed beyond their limits. (This may be the radiator ect... part of the story that someone posted). Then I needed a way to store a bunch of energy, electrolytic caps and some of the carbon based caps that are commonly used in car audio were not even close to being capable of storing the amount of energy I needed, so I used 12 small motorcycle batteries in series to get 140+ Volts. Then I built a power supply that would convert 12VDC to 140VDC to 'charge' these batteries. I got this contraption all put together the night before the Annual Rockford Fosgate Employee Sound-Off. I didn't really how much power it would make exactly, but to try to shorten this long story it ended up putting out 15,030 Watts RMS! This is how 15k Watts became the goal for a 'real' amp. The first step towards making it a 'real' amplifier was I had to eliminate the array of batteries. I began searching high and low for something that would do it. I found a company that makes capacitors for hybrid cars and large wind turbines. These worked perfectly. The caps I ended up using are 400 Farads, and there are 180 of these in the T15kW. Then I needed an intelligent power supply that could monitor these caps and add energy to them as needed, and it had to be fast, really fast if this amp was going to play music and not just a burst. So during music these caps are charging, discharging, charging, discharging. The power supply in the T15kW can charge the caps 35,000 times per second. Of course many other things had to happen like finding MOSFETs that could handle it, a way to keep it cool without antifreeze and car radiators ect. The final product met all the goals and then some. The main idea is that with this technology the amplifier can put out more power during transients or bursts than the car it's connected to could supply. Again thanks for the props, look for hybrid technology to hit our smaller amplifiers in the near future. PS if you guys would like to see pictures of the original liquid cooled proto I'll post them. This proto was eventually dubbed the D'Fibrillator. haha

--------------------------------------------------------------------------------

Tony D'Amore Design Engineer Rockford Corporation

So much :wackit3: :wackit3: :wackit3: in this post.