20 KW amplifiers

[Pete Fleming]

Hey to each their own. I believe however that you are misinformed on a couple of points. Firstly, Switch mode power supplies most certainly did NOT originate in this application. Secondly, power of this magnitude is not uncommon in pro-audio applications, which makes me wonder just how likely it is that real developments in this area will influence main stream or even audiophile circles. Contrary to what you may believe it is not difficult to make a high power driver when efficiency and quality are not factors, the reason none were available before is because demand for this type of device was too low to concern manufacturers.

Having said the above, I agree there is a technological challenge involved, indeed quite considerable from a DIY perspective. I’m not sure if I would agree with your analogy of drag racing, maybe “monster trucks”, or those cars that jump around by remote control (what are they called anyway?). Certainly past-times that push the envelope. Expand it? Maybe not.

Good luck with the project anyway.

Cheers,

Pete Fleming

PS One question. Why maintain the 12 (13.8) V system in the car? If the main power consuming devices in the car are the amplifiers then why not chose the appropriate voltage for that application and reduce this rail to 12V for the normal car systems. I’m sure it would be possible to have an alternator custom wound, and it sure is a hell of a lot easier to reduce DC voltage than increase it.

[Sawzall]

Not misinformed, but realistic. Sure switched mode were not first used in cars - but I would bet the first time commerically widespread. Carver was using these type amps in pro audio in the early 80's - I know, I probably flew a thousand of them over the years. They were not cheap, just more efficent and light weight (and when you needed 40 or 50 of them, it counted). You still stacked Crowns or Crests on the floor for the subs since they really sucked for low freq. Nowdays, you can buy a 2kw/2ohm amp for less than $800 all day long. But I am willing to bet that more switching poweramps are sold for cars than all other applications.

Your statement about drivers is incorrect in that power is important, but so is efficiency as well as extension. We both know that only a few dB of driver efficiency drop would waste an absurd amount of power when at this extreme level. Secondly, drag racing enticed kids to "soup up" their cars, so parts makers made those parts. No, they were not pure race parts, but they were performance. Car makers noticed it too - therefor the muscle car era.

As for the voltage, its the rules. Sure it would be easy to just bank up some batteries for the voltage of your choice - infact, most of these do have battery banks - but the rules stick you to the 13.8v.

And I agree with you, good luck to your project, yeehaw. Enjoy it - and thats what this forum is for... and all little bickering aside, everyone here will be glad to help anyway they can.

[yeehaw]

First thing i would like to say is this site ROCKS!!!
everyone is so helpfull and very informed (i see i have a way to go). I have so many ideas now on what i can try... ill have to see what i can do on my budget though. keep up the good work

[jteef]

most of the heavy hitters use 1-2 1kw-2kw commercially available amplifiers per voice coil on their speakers. with even 2 DVC speakers, you can begin to see how expensive this "sport" is. The most famous car uses 48 10" square kicker solobarics with 48 kicker zr1000 amps. I'd venture to guess thats more powerful than half of the radio stations in america.

I think the rules for dbDrag anyways is that all equipment must be unmodified and available to the public. So DIY amps are out :/ The maximum voltage limit is 18V. The cars that win require so much more effort and money than the cost of equipment used, but they are indeed engineering marvels.

A lot of the rules are pretty stupid. but all forms of competition have them. like restrictor plates(nascar) or treaded tires(F1). When will we have a no rules "bring what you got" racing series? I'd like to see somebody turn a 30 second lap at laguna seca. dbDrag has the 40hz-80hz window.

jt

[Pete Fleming]

Ah, there are “rules”. Well ok.

Sazwall perhaps we are talking about different things, however I am referring to Switch Mode Power supplies, which was the term you used (or implied by “switching power supply”). Next time you turn on your computer or your television ponder for just a few seconds as to what powers them. Switch mode power supplies have long been used in domestic situations as the offer very high efficiency, and have a high tolerance to input voltage variation. Indeed it’s not difficult to make them “universal voltage” capable. Unlike linear power supplies a large transformer is not required, hence for high power applications is cheaper to manufacture.

I suspect what you are referring to is actually an inverter, and would not doubt it gained popularity in this application.

Cheers,

Pete Fleming

[blmn]

yeehaw,

Try http://www.corzus.com.br, they have an competition amp called matrix wich delivers (they claim) 3500W continuos (bridged mode) for a few seconds.

I reached 800W continuous in class B using mosfets at output and now I´m trying to reach 1500W using Tripath or HIP4080 circuits.

As some fellows said in this thread, the SMPS project is not an easy task, but it´s possible to do. In your case, however, SPL competitions not allow DIY prototypes in most cases.

[km]

hi.

we design and build high power pwm amplifiers/modules and were interested in testing them in db drag competitions.

when we read the rules we werent that interested any more, the rules dont say anything about music , they "measure" the loudest one note tone in a given car for 10 secs. (correct me if im wrong)

i suggested using a fog horn (hehe)....

some of the competitons i saw were powered by chargers as the batteries and wiring in the cars were totally useless for high power applications.

12v and 5000watts should give like 400a of current

i still think that a 1000w car amplifiers mates (only) with a 1000w car speaker as none of them are really more than say 50 w

using them with pro audio equipment can cause destruction (let alone some homour...)

bye k madsen - http://www.cadaudio.dk

ps. as some of you may have guessed we come from the pa business ....

[bawang]

Yeehaw, don't know if you're already into the car audio stuff seriously. IMHO you DON'T need 5kW to power a sub in a vehicle for anything short of being the next world SPL champion.

My own installation consists of 2 nos of 4-channel high quality power amps rated at 4 x 50W each. One of them, when running in the bridged mode churns out 2 x 100W each (4 ohms) and 2 x 200W (2 ohms).

Using an active crossover, one amp runs in a 4 channel configuration driving front and rear speakers while the other amp runs in the 2 channel mode driving 2 nos of 12 inch subwoofers, mounted in a sealed box of suitable size, Q total of 0.7.

And the point is, it gets bloody loud, enough to shake nearly everything in the vehicle (a 4 wheel drive SUV!) including stares from passerby!

[Myren]

1 HP is something like 746 watts, plus or minus twenty watts. So yeah, it is concievable you could be draining 50 horse of engine power if your cars sucking down mad crazy wattage. Then again, some cars these days have the horse to spare.

Not to say I aprove. I value my hearing.

[Myren]

There was also talk of implementing a 44 volt system, or something in that area. That would reduce the need to have AWG -4 cables going to the amp.