I worked for a amp manufacturer that built speakers for philips when times were lean.
Because screw drivers often slip and go through cones, Philips would send spare drivers for every shipment. These spare units were kept and then for fun one day, were built into a wall of sound. Multiple pro amps were bridged and then the factory was rocked till the drivers went into meltdown🙂 I wish I were there for that.
Because screw drivers often slip and go through cones, Philips would send spare drivers for every shipment. These spare units were kept and then for fun one day, were built into a wall of sound. Multiple pro amps were bridged and then the factory was rocked till the drivers went into meltdown🙂 I wish I were there for that.
Yeah, I worked for a retailer that would plug woofers into 120v wall power to blow the voicecoil to help customers that caused cosmetic defects (as mention above, screwdriver into surround, cone or whatever) and had no factory warranty coverage on said issue. I use to love to watch. I was not worried about getting hurt as I stood several feet away. It was fun. Ironically, the Rockford Fosgate POWER woofers could last a LONG LONG time. Some never burnt out! Pretty much all other woofers would blow.
I also heard a rumor that the BOSE 901's could be plugged into a wall and not burn up. I would be bummed if they didn't blow up 😀 😛
I say blow ^%$% up.
I also heard a rumor that the BOSE 901's could be plugged into a wall and not burn up. I would be bummed if they didn't blow up 😀 😛
I say blow ^%$% up.
In a previous life I ran the service department at the largest Olson Electronics store in the US. I plugged every speaker that we sent back for warantee credit to make sure it wad DEAD. If they just sounded bad, we got them right back.
I also tried "testing" a few speakers with a guitar amp played through a Crown DC300A "booster".
I got a big bunch of car speakers when the local K-mart went out of business about 10 years ago. All cheap stuff. I used them to make low powered guitar amps. A 10 watt tube amp can blow up an "80 watt" 6 inch Pioneer speaker in about 10 minutes. The cheaper Audiovox speakers didn't blow.
Some people worry about fried speakers and......how many Jackass movies are there, and how many kids have watched them?
Hopefully the OP had tennis shoes on, concrete is a pretty good conductor.
We had two metal cabs. in our paint shop, one side was "hot" due a broken lamp - the second cab was touching a copper pipe...talk about a booby trap. I measured a full 120v across the chrome handles.
We had two metal cabs. in our paint shop, one side was "hot" due a broken lamp - the second cab was touching a copper pipe...talk about a booby trap. I measured a full 120v across the chrome handles.
I learned about bare feet on concrete or terrazzo floors AND hot chassis radios on the same day back in the early 1960's.
We did that with a high-end video card that worked for a while and quit. Sent it back like 3 times, each time they said there was nothing wrong with it. The 4th time we 60-hertzed it. Gave us a new one that time, and it worked perfectly.
Blown my share of woofers for fun, too. The best was an old alnico coax, with a blown tweeter and a deteriorated cone. Pieces of cone went flying, in addition to the arcing and sparking. In my defense, I *did* use a light bulb limiter - ten 100 watt colored PAR38's from my DJ setup. This was back in the days when I got flamed on rec.audio for not buying a variac and suggesting that light bulbs are just as good for testing amps.
The other was one of those OEM white cone square frame woofers that I got dumpster diving. Took full clip from a Phase Linear for a lot longer than it normally takes to blow an 18. Power compression must have pushed it up to 40 ohms, because it would just not die. I resorted to plugging it in for the final kill.
My lab horns were broken in by wiring the drivers in series and plugging them in. Technically, it's only 60 volts per driver but it still involves a wall socket. Produces a very loud hum - would be great for firing at boom cars as they drive by with their one note bass. It's a great test for leaks and rattles.
Shows how times have changed, blown VC is user abuse and certianly not warranteed by any manufacturer or distributor in the UK!
Times have indeed changed. I ran that service department from 1971 to 1972. The usual car stereo was an 8 track player hanging under the dash or mounted on the transmission hump (all cars in the US were RWD). Compact Cassette decks were just comming on to the scene. Nothing had more than 4 watts per channel except for a few people's (like me) DIY effort. Nothing had enough power to blow the VC. The usual failure mode for a speaker was a rattling sound where the coil former was scraping the magnet. It was caused by moisture, dust, or cone warpage from the Florida sun. All the Jensens lost their blue foam surround, but they usually outlasted the warantee period.
Since open VC's were not common, they were replaced.
We sold raw drivers to the DIY crowd and carried some quality name brands, as well as house branded junk. We sold a 12 inch coaxial driver for $8 that generally lost its foam surround. Plugging one in would just generate a thump from the woofer, no smoke, no excitement. The tweeter would hang in there for minutes to hours until the crossover cap exploded. It is informative to listen to all the high frequency junk on the power lines. Our store was about 1000 feet from the University of Miami campus at the end of frat house row. You could hear power drills, and what sounded like data (remember this was 1972). The motor in the mechanical cash register came in loud and clear too.
Tricks to play on a store manager with a morning hangover.
Super glue had just been invented. I simply glued a quarter to the glass counter top and watched as the manager and several customers tried to pick it up. A disgruntled salesman glued said manager to his chair.
Gather two small vacuum tubes that have a glass tip on the top. Hold each one under water while snipping the tip off with wire cutters. The vacuum will suck watter inside. Shake about 1/4 of the water out. Place one tube in each of the two tube testers, and dial the heater voltage up to 2 or 3 times normal. Shut down the store for nightly closing. Gather all employees in the service department to watch the manager read the newspaper at store opening in the morning. Two dead vacuum tubes $0. Ratty old drugstore tube testers $200. Expression on bewildered managers face at the site of two whistling mini - geysers....priceless!
Wow, they have changed!
The coin trick was practiced by some friends of mine from West Germany, they'd weld a nail on the bottom of a 5Mark coin (around $3 at the time) and go to East Berlin and nail it between some paving cracks and watch as the poor East Germans tried to recover it.
An old favourite of mine was to give a colleague the number for Buckingham Palace and say "Liz rang, can you call her back?" and then wait as he called the palace and asked for "Liz". Another was farting in the trunk of a car and then locking the fitter in...thankfully I've grown up a little since then!
The coin trick was practiced by some friends of mine from West Germany, they'd weld a nail on the bottom of a 5Mark coin (around $3 at the time) and go to East Berlin and nail it between some paving cracks and watch as the poor East Germans tried to recover it.
An old favourite of mine was to give a colleague the number for Buckingham Palace and say "Liz rang, can you call her back?" and then wait as he called the palace and asked for "Liz". Another was farting in the trunk of a car and then locking the fitter in...thankfully I've grown up a little since then!
With my responsible hat on I would point out that connecting speakers to the mains is dangerous, and is borderline on breaking the forum rules on dangerous practices.
Anyway 120 VAC is for wimps What about us Europeans who only have 220 -240V to play with
240V / 8 ohms / 30amps = 7200W =
So remember to use an isolating transformer!😀
Anyway 120 VAC is for wimps What about us Europeans who only have 220 -240V to play with
240V / 8 ohms / 30amps = 7200W =
I agree completely. Although when people are about to commit such acts, I am not one to correct them. I usually find a place that is safe to view from and enjoy the view. Or I might hold the camera. I think Darwin invented "reality" t.v.
True. But the power supply for the amp intended to run the speaker at that voltage is isolated so there is no current path back to Earth GND. Thus if you are in contact with Earth GND and touch one of the outputs at that voltage you will not get electrocuted. This the reason why un-isolated circuits that are not designed to be connected to mains are taboo on this fourm....and it is a good reason IMHO. Monkey see monkey do.......unsuspecting monkey gets shocked!
There are many amps in production capable of 120 volt (or more) output that have the "-" terminals tied to chassis and earth ground.
The Crest CA12, for instance, is capable of 126 volts peak each channel.
A clipped QSC PLX 3602 (also "-" earth ground) is capable of putting out 120 volts from one channel for a few seconds before it's circuit breaker pops (three times in a row) in to a 4 ohm B&C18SW115-4 speaker.
The speaker was undamaged, and testing continued once I realized that I had been turning down the HF crossover output instead of the LF 😱.
At those power levels, touching a speaker lead is a shocking experience...
Art Welter
So I should go buy one of those surplus pole pigs that show up on E-bay from time to time, eh?
I read someplace that Cerwin-Vega dealers used to plug a speaker into a wall outlet to impress customers. That may have been safe because of the box tuning.
If you use banana to 1/4" speaker cables, and reverse the polarity at the amp (to get the phase correct), the 1/4" plug shell will be hot. Or if you bridge an amp, the 1/4" plug shell will always be hot. Speakons are a better idea.
As for blowing up marginal woofers, why not?
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If you use banana to 1/4" speaker cables, and reverse the polarity at the amp (to get the phase correct), the 1/4" plug shell will be hot. Or if you bridge an amp, the 1/4" plug shell will always be hot. Speakons are a better idea.
As for blowing up marginal woofers, why not?
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I remember an audio shop near where I lived that used to get woofer returns from customers that were "partially blown" or slightly damaged. They had a jig set up in the back room that plugged into mains power to fully kill woofers before they were sent back for warranty replacement.
I hung out there for a few hours once and it was quite a shock, no pun intended, when they did one when I wasn't expecting it. 60hz at wall socket power is quite loud.
I hung out there for a few hours once and it was quite a shock, no pun intended, when they did one when I wasn't expecting it. 60hz at wall socket power is quite loud.
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