Ok, this is getting absurd, 60KW of subwoofers in a truck. - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 03:50:16 am
content: Ok, this is getting absurd, 60KW of subwoofers in a truck:

author: rx8pilot
author_rank: Super Contributor
timestamp: September 24, 2018, 04:18:59 am
content: What? Speak up!Never knew it was so fun to lose your hearing.

author: Bud
author_rank: Super Contributor
timestamp: September 24, 2018, 04:30:48 am
content: I hope they not run it while driving as it seems to put quite a resonant stress on the vehicle, which may disintegrate one day in the middle of the highway if they do.

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 04:55:09 am
content: Quote from: Bud on September 24, 2018, 04:30:48 amWe need to visually figure the resonant frequency of that truck, and feed that guy a virus .mp3 song with the tone at a random spot for the right amplitude and frequency... Kaboom...

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 24, 2018, 04:56:44 am
content: That's a ludicrous amount of power. Zero practical use but pretty crazy. Just the cooling fans of all that amp/power equipment makes it sound like a data centre in there lol.

author: John B
author_rank: Frequent Contributor
timestamp: September 24, 2018, 05:09:58 am
content: Just keep in mind that in a world of peak power bragging rights, the average power is a far more modest value. Even then, expect the definition to be stretched to the limit. It's like shorting out a big cap and saying its 60kW.Just for comparison, here's a 60kW genset:

author: raptor1956
author_rank: Frequent Contributor
timestamp: September 24, 2018, 05:16:32 am
content: I've never understood the need to dick wave how much audio power you have and that much power in a vehicle of that size is about 3 orders of magnitude beyond anything you could safely use in that space/volume.Years ago I was driving along a country road when I came upon a small car with smoke billowing out of it so I stopped to see if I could help. The driver was a young guy of about 21 years of age and he explained that he'd just installed an audio system and this was his test ride with it. I asked how he powered it and he explained that he'd wired it directly to the battery so turning the car off would not cut power. I had him pop the hood and discovered some 18ga or smaller lamp cord connected to the battery so I grabbed one of the wires and was able to yank it off with one tug. I few moments later the smoke began to die down. Turns out he'd used this same lamp cord throughout and the smoke was coming from carpeting that was being heated by the wire. Who knew that high power and low voltage spelled even higher current and that running high currents with small gauge wire would be a problem -- certainly not this Einstein of a kid.About 5 minutes later the fire department arrived but the smoke/fire was out. Maybe I should have watched the car burn to the ground. Wonder if insurance would cover the loss if the work was done by an idiot without regard for the safety implications.Brian

author: raptor1956
author_rank: Frequent Contributor
timestamp: September 24, 2018, 05:20:04 am
content: Quote from: John B on September 24, 2018, 05:09:58 amTrue enough, but then a pro grade camera flash unit can output about 100kW while studio strobes can do as much a 1MW. Of course we're talking less than a millisecond pulse duration. That that kind of power can be provided by a battery powered unit running on 4-AA batteries/cells is pretty amazing.Brian

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 05:25:06 am
content: Quote from: John B on September 24, 2018, 05:09:58 amHis setup looks like 4x 370 amp 13.7v alternators + 6 truck batteries plus a bunch of additional super-caps.4x370x13.7 = around 20000 watts sustained.6 batteries at 250 amps for around 4-5 minutes, = 20000 watts for around 4-5 minutes before drain begins.So I say, for a few minutes, it is possible he can drive 40000 watts. With the super caps, around 5 seconds at full 60000 watts.Long term, he can only sustain 20000 watts if he can keep those alternators cool, but, not the way they are stacked together. They'll overheat and fry.And by the way, those 4 alternators would drag around 30-40 horsepower from the truck motor.

author: John B
author_rank: Frequent Contributor
timestamp: September 24, 2018, 05:33:41 am
content: I'm not doubting it's a lot, but still I remain cautiously sceptical. For starters I'd like to see all the wiring and connectors. My experiments trying to run a couple of kW off 12V have shown me how hard it is pushing around hundreds of amps.

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 05:40:17 am
content: Quote from: John B on September 24, 2018, 05:33:41 amIt's shown in the video. Look at that huge steed buss bar in the trunk with all those 2 gauge wires running in parallel, with the super caps just behind them. He says all his batteries are all mounted under the amps at the bottom of the truck.The generator you pictured is quiet, cooled, designed for continuous activity under full load and multitudes of circumstances holding 50/60hz ac sinewave with a large fuel tank. What this guy has done with his truck is unsustainable long term, but, with music, he only demos the system for a few minutes at a time with the motor revving. It illustrates though he can hit some note at full power and plow through a song with bass lines up in the 40kw range, it cannot be sustained. But what he has is more real than those Aliexpress/Amazon 4kw sub-woofers with a small amp the size of a shoe-box.

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 05:52:30 am
content: I just re-listened to the video where he describes his hardware. I think he said he is using lithium batteries??? Can anyone else confirm, I cant hear clearly over the fans.Seek to 22 seconds into the video...

author: vk6zgo
author_rank: Super Contributor
timestamp: September 24, 2018, 08:59:01 am
content: There is also the quite definite possibility that he lies on his teeth.

author: wraper
author_rank: Unknown
timestamp: September 24, 2018, 09:44:24 am
content: With those 84db low sensitivity speakers, on top of that without a decent box, it's easy to make 60kW sound as loud like 6kW or even less on good speakers. The measure theirdickspower, yet it's not even representative of how loud their setup is.

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 09:53:35 am
content: Quote from: wraper on September 24, 2018, 09:44:24 amAhhh, so he has a good old 1-2% electric power to acoustic power efficiency...I may personally have really good efficient 250watts/channel stereo, but, I still cannot even approach the breeze and vibration that guy is producing...

author: coppice
author_rank: Super Contributor
timestamp: September 24, 2018, 09:59:43 am
content: When turning up the volume on the stereo seriously affects the vehicle's gas mileage you've gone too far.

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 10:09:28 am
content: Quote from: coppice on September 24, 2018, 09:59:43 amI needed that...BTW, lets install this system in a tesla roadster and shorten it's range a few fold, or, watch it slow down with every bass beat...

author: wraper
author_rank: Unknown
timestamp: September 24, 2018, 10:32:52 am
content: Quote from: BrianHG on September 24, 2018, 09:53:35 amIt's just need to be low frequency and confined space to get that vibration. They are basically sitting within a subwoofer so it looks impressive. But actually it's not THAT loud as you might think.

author: dmills
author_rank: Super Contributor
timestamp: September 24, 2018, 10:40:55 am
content: Do NOT underestimate that efficiency thing, 84dB/W is crap by the standards of decent PA kit, which is typically 20dB better then that (My Nexo Apha rig was 107dB/W @ 1m, but rolled off hard below about 40Hz or so).20dB is 100 times the power, so 40kW into 84dB/W speakers is only as loud as 400W into the good stuff.Now the good stuff is typically large with very large and complex enclosures and is **Expensive** but less so then 40kW of power amp and all the supply cables and faffing about that goes with that.It typically also does not go stupidly low (There are exceptions), the tradeoff being made in car stuff being massive low frequency extension into a closed cabin Vs efficiency in a box radiating into an acoustically large environment.For really silly stunts see the Americans CB Burnoffs, redneck but you have to admire how far they can push it.

author: drussell
author_rank: Super Contributor
timestamp: September 24, 2018, 10:48:13 am
content: Dude needs more efficient speakers!... LOLA couple decades ago, I hit136 dBin an SPL competition with just360 watts RMS. Of course, I was using two of my 2 x 18" bass bins (which are >102 dB @ 1W/1m) from my PA system in the back of my van.Really ticked off the guy that had spent about $5000 on Phoenix Gold amplifiers and Dr. Crankenstein subwoofers to have me roll in there with a couple $129 Pyramid PB-300G amps and two PA speakers. I beat him by 2 dB in a head-to-head tie breaker.We just did it for a lark. A high school friend had noticed that there was a competition coming up and mentioned to me "Hey, how loud do you think your van would be if we put two of your bass bins in there? Here, borrow my amp."Ahhh... what fun...

author: Fryguy
author_rank: Regular Contributor
timestamp: September 24, 2018, 10:57:24 am
content: This is a really crappy setup in this car - I worked with a group of car audio nuts for a couple of years and started with my own car at a car hifi competition in 2006 . No , my ears are fine - i started in a sound quality competition with a total of 740 W RMS @ 4 Ohms - not SPL (Sound Pressure Level) .So i have seen a lot - windows blown out of cars , concrete filled car chassis , car doors bolted tight with 24mm screws 10 cm spaced around and much more .Have you ever heard the entire roof of a 4000 sqm trade fair building rattle because someone forgot to close the door on a car . . . there's a lot of fun in this .Let's see - there are 8 power amps SunDownAudio SCV-7500D rated at 1750W 4Ohms , 3500W 2Ohms and 7500W 1Ohm - if they are analog amps @ 4Ohms they will need about 300 A each for that or about 175 A if they are class D . For 7500W @ 1 Ohm class D they need about 750 A each . The power terminals take about 50 sqmm each pair - x3 = 150 sqmm - good enough . This might actually be real . . .I can't see any fuses installed in this car - great work ! We use 500A fuses from electric forklifts for this kind of installation .The amps are rated to work up to 15,5V so a 4-cell LiPo set might really be installed under the car .Some SPL-nerds at the car hifi show here used 8 single cell solar batteries in series running the amps @ 16V !Anyway - this car moves a lot of air - really loud is something else .

author: BrianHG
author_rank: Super Contributor
timestamp: September 24, 2018, 11:38:06 am
content: Quote from: Fryguy on September 24, 2018, 10:57:24 amI just love that orange/white beach towel at 10min 10sec into the video, in the window. It just looks so cool.

author: Fryguy
author_rank: Regular Contributor
timestamp: September 24, 2018, 03:12:51 pm
content: Yes that looks nice - a cavemans oscilloscopeA few pics from my car hifi time . . . No , i never made anything like this !

author: bob225
author_rank: Frequent Contributor
timestamp: September 24, 2018, 04:26:19 pm
content: 60k watts peak maybe (edit. 20-28k rms), 2000w is enough to rip steel panels and/or crack glass, exo would be proudI wonder if they bbq off the amps heat outputI do like SQ setups, I use to run alpine pdx amps, rainbow comps and a 12" alpine type-r, But my tastes have changed and its all about the OE look with everything hidden

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 24, 2018, 04:44:42 pm
content: You people do not understand!If you face the subwoofers rearward, they willadd to the thrustprovided by an aircraft grade APU that powers the contraption.That will cut at least a second from your standstill-to-100Km/hr acceleration time.I hope people realize that I am joking.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 24, 2018, 11:07:21 pm
content: The Mythbusters built a mechanically driven subwoofer and managed to set a world record with it. I wonder if it might be possible to do even better with a pulsejet or a bunch of firecrackers going off in sequence.I wonder why voltages around 12V is still the norm for extreme car audio. Do they not realize they can go 48V and still be within the low voltage safety limit? Or just accept the fact that working with high power requires safety precautions and go straight for 400V or so.

author: rx8pilot
author_rank: Super Contributor
timestamp: September 24, 2018, 11:36:11 pm
content: This is not really the sport for critical thinkers.If I was trying to set a record - I would at least go with 240VAC and use pro audio amps. It would be easier to wire up for sure.With that said, I used to own a generator rental business with 60Kw and 120kW mobile plants. The 60Kw weighed about 3500lbs on a trailer so maybe about 2000lbs for the plant itself. Cummins 4BT at a little over 100hp and a Marathon alternator.So pulling the 60Kw genny on a trailer connected to the truck with 4x Cam Lok connectors on #2 type W cable. No problem - anyone can go deaf if you put your mind to it.

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: September 24, 2018, 11:49:26 pm
content: Did anyone notice that in the video they never actually played any music?I just hope that sort of contraption never comes around my neighbourhood. I might just have to do something about it.

author: langwadt
author_rank: Super Contributor
timestamp: September 25, 2018, 12:11:56 am
content: Quote from: John B on September 24, 2018, 05:33:41 amonce you start adding piles of alternators and batteries you might as well go for a high voltage DC system

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 25, 2018, 12:34:57 am
content: I think this guy parked his van under my window last night...

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: September 25, 2018, 02:45:10 am
content: In the movie "Mad Max: Fury Road", does anyone have an estimate on audio output power on a vehicle fitted with a large array of speakers which was depicted in the movie?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 25, 2018, 03:55:37 am
content: I thought all the higher powered car amps used boost converters, though running direct from 48v or more would be more efficient

author: BrianHG
author_rank: Super Contributor
timestamp: September 25, 2018, 04:33:34 am
content: Quote from: mikeselectricstuff on September 25, 2018, 03:55:37 amThey do. As for 48v, remember they want to mass produce these amps and the majority of users will only have one of them, if not, even smaller ones. All auto outlet centers are geared and knowledgeable with the 12v system and alternators and 12v batteries in cars. You don't want to make something fancy and efficient and cool if you can only sell to a fraction of a fraction of a fraction of users who would setup a 48v alternator in their car with 48v batteries.Me personally, put me in the fraction of a fraction of a fraction of a fraction of a fraction of a fraction of a fraction of a fraction of a fraction of 1 percent as back in the late 80s & early 90s, I has a 120v inverter in my car and even a HiFi VHS with 8 hours of uninterrupted music on 1 cassette at basically full CD quality transferred from my home CD player, and it could never skip when playing back like car CD players of the time as well as me having to buy 2 copies of each CD I liked. It was kind of funny that I had a 'Sony' VCR remote in the frot of my car to select and play music. I used the VHS tape index functions to allow me to skip to any key album or son on the 8 hour tape.Tell me, who here has seen or even used a Sony SLV757 VHS HiFi VCR in the rear of the trunk of their car for hiss free perfect sound 8 hour tape playback with seekable indexing?And yes, when I crossed the border to the US as I used to on many road trips, you bet the odd time they looked in the trunk, I was questioned and had to demonstrate it was my audio playback system.

author: oPossum
author_rank: Super Contributor
timestamp: September 25, 2018, 07:43:44 am
content: There are car audio amps that run directly from a high voltage DC supply. Typically an EV battery pack or equivalent.http://www.stetsom.com.br/en/produtos/high-voltage/Taramps also makes them, but their website is currently dysfunctional, so I can't provide a link.

author: BrianHG
author_rank: Super Contributor
timestamp: September 25, 2018, 08:15:09 am
content: Quote from: oPossum on September 25, 2018, 07:43:44 amWith a few one those 'Force Ones' and 16 to 32 huge woofers, you can decelerate a Tesla with every bass boom, both electrically and with the breeze...

author: drussell
author_rank: Super Contributor
timestamp: September 25, 2018, 08:39:49 am
content: Quote from: mikeselectricstuff on September 25, 2018, 03:55:37 amAnything except the smallest automobile amplifiers most certainly do have switching power supplies in them. That's where I learned about TL494 and SG3524s and stuff...I built my own 1000 watt car amplifier decades ago once I realized what a TL494 was...It is justfarmore efficient when drawing insane power to use something higher than 12 volts. The input currents required at such low voltage are a hindrance at such high power levels.

author: drussell
author_rank: Super Contributor
timestamp: September 25, 2018, 08:50:36 am
content: Quote from: BrianHG on September 25, 2018, 04:33:34 amNot a57SLV7, but I used my Mitsubishi HS-U55.I thought I was the only one to do "crazy" things like that.For long road trips, I used an inverter made from a really crappy, early Pyramid amplifier that used a 12 volt transistor circuit with step-up transformers (egads!) that was unfit for audio, so I added another step-up transformer, added a sine wave generator and ran my little DJ source PA rack that had the 2 CD players, my Sony TC-WR820 tape deck (very nice deck) and the Mitsubishi HS-U55 HiFi VCR (which also has index search, very handy)...Ahhhh... Good times...

author: BrianHG
author_rank: Super Contributor
timestamp: September 25, 2018, 12:19:19 pm
content: Quote from: drussell on September 25, 2018, 08:50:36 amOMG. The fact that it's around 25 years later and I find another wacko like me!However, it's been clearly established at the time, though not the loudest sound system in my Acura Integra, it was noted that I did have the best refined sound in town... (I like and select quality over quantity) I guess a 1k$ VCR blows away any car audio junk at the time. Home made inverter too for the VCR. My first full wave mosfet bridge rectifier design with a transformer.Ooops, typo, the VCR was a Sony SLV-757.