am i going slightly mad?

[dannym2710]

ive fitted a 600w amp, running 2 300w 6x9" speakers and a sony head unit running 2 130w focals,and i should shortly be getting another amp and a sub to go in.its in a defender.am i mad?

[Marc Lurie]

Yes.

[dannym2710]

quite a definite anser there, cheers.

[bvudzichena]

Not really.

I've heard of a Series SWB with 2 x 1000W subs, 2 x 250W 6x9" and 2 x 200W 7" speakers all driven by a collection of amps.

[Rex Hunt]

And you still won't hear the music at over 30mph!

[phopwood]

Why bother. But I guess it will sound good when you are stopped. I would tighten up all the bolts first, they will rattle.

[Marc Lurie]

Not really.

I've heard of a Series SWB with 2 x 1000W subs, 2 x 250W 6x9" and 2 x 200W 7" speakers all driven by a collection of amps.

That's "make-believe" Watts of course. Genuine 2.9kW of audio is more than enough to kill someone. Certainly enough to cause permanent hearing damage at about 3 meters.

Ohm's Law is quite specific on this point. 2.9kW at 12 Volts means 241 Amperes. A Class A (typical audio amplifier) amplifier is around 50% efficient. That means that you need to feed the amplifiers 482 Amperes of current.

At that level of current there are all sorts of issues that start to make a significant impact. If the connections are not correctly soldered, there WILL be a fire. Cables will need to be THICK (I don't have the recommended standards handy, but I'd expect them to have to be around 45mm2 or larger). The vehicle's battery has to be commensurately larger too. So does the alternator

Even if you look at the speakers themselves, you can see that these power levels are a farce. In the case of the "1000W" sub woofer, here's the maths... P=I2R therefore a 4 Ohm speaker has to handle √1000÷4=15.8 Amps. Almost 16A through that flimsy speaker coil wire... not likely. You would need 1mm2 wire at least in the speaker coil.

Of course, I come from an industry that measures power according to Mr. Ohm's law, so I'm a tad pedantic, but it really irks me when these audio guys fabricate performance figures under the guise "real science".

They're almost as bad as the Hiclone people... Ooops, I've opened a can of worms. ;)

[Marc Lurie]

Before I forget... AFAIK, the highest audio power ever produced was at a "The Who" concert where they generated 73,000 (genuine) Watts of audio.

Now comparing the "power" of 2.9kW in Bvudzi's example to 73kW shows a difference of about 13dB (rough figure, I can't be bothered to do the maths). To think of a vehicle being only 13dB down on a rock concert puts everything in perspective... It simply can't be done at 12V.

[bananahead]

There was a black defender on ebay a while ago. IT was absoloutely stunning.

Black, with land rover decals, land rover decal embossed on the rear, tinted windows, really nice alloys. This wasnt a offroad land rover it was more boy racer land rover exept not lowered and not fast!

Anyway this thing had TONS of speakers in it like the ones at the boy racer shows, and it was really cool.

So no i dont think youre mad i think if you enjoy it then do it :)

BTW he had mounted a lot of speakers on the sides in the back (it had no rear side windows), pretty good so you still have that space.

[dannym2710]

oh im not going the boy racer route, i jsut enjoy a little bit of rock music now and again, plus i got everything ridiculously cheap.building it into the cubby box.its still going to be a battered old red defender at teh end of the day, and its still going to be run offroad everychance i get

[Matt_300tdi90]

Before I forget... AFAIK, the highest audio power ever produced was at a "The Who" concert where they generated 73,000 (genuine) Watts of audio.

Now comparing the "power" of 2.9kW in Bvudzi's example to 73kW shows a difference of about 13dB (rough figure, I can't be bothered to do the maths). To think of a vehicle being only 13dB down on a rock concert puts everything in perspective... It simply can't be done at 12V.

That's right, they hold the record at 126dB, Charlton Athletic Football Ground in 1976, probably a contributing factor to all the members (with possible exception of Keith Moon) deafness.

[dannym2710]

i believe that roger daltrey was partially deafened by keiths drum kit after he packed it with a little too much explosives as a finale to a tv appearence.it also resulted in a fair few shrapnel wounds in the audience too i thing

[Matt_300tdi90]

i believe that roger daltrey was partially deafened by keiths drum kit after he packed it with a little too much explosives as a finale to a tv appearence.it also resulted in a fair few shrapnel wounds in the audience too i thing

Almost right, it was Pete Townshend link to youtube video (http://www.youtube.com/watch?v=nr81olQ1ibk)

[dannym2710]

i thought it was but i couldnt think of the name.

[Marc Lurie]

That's right, they hold the record at 126dB, Charlton Athletic Football Ground in 1976, probably a contributing factor to all the members (with possible exception of Keith Moon) deafness.

According to the information I have been able to find, the sound level at the concert was 126dB, measured 50m away from the speakers. Because we have to use the "inverse square" rule when dealing with dB's, 126dBA at 50m equates to around 143dBm (about 143dBA at 1 meter away from the speaker.)

So a genuine 3000W in a vehicle would be around 120dBm. A decent drum solo would almost certainly pop every rivet in a Land Rover. :D

[Madoobri]

I saw the original Who in the 70`s :band: never been the same since ... eh what was that???!!! :p

[Matt_300tdi90]

I saw the original Who in the 70`s :band: never been the same since ... eh what was that???!!! :p

:mad: Madoobri, i now hate you :p How can i convert my Defender to a time machine? :D

[dannym2710]

hmm,i wish i had the oppourtunity to see the who live in their day,and queen, and guns n roses

[bvudzichena]

I saw Queen live...

[Marc Lurie]

I also saw Queen live.

The one concert I missed, and will hang my head in shame for eternity for doing so, was in 1992. Madness had their final concert, I was in England, and I didn't go!!! :(

[vzh7gk]

So a genuine 3000W in a vehicle would be around 120dBm. A decent drum solo would almost certainly pop every rivet in a Land Rover. :D

Quick way to get the roof off :D

73

[series3-2007]

talking about big speakerage

then take a look at this the MTX Jackhammer

http://www.mtx.com/caraudio/products/subwoofers/jackHammer.cfm

[series3-2007]

mtx

these are just pure crazy

http://www.youtube.com/watch?v=IDWYpq61aec&feature=related

http://www.youtube.com/watch?v=BvXY-Cgpz68&feature=related