11 ways to blow speakers ~ oh what fun!

[Rog]

I have managed to reduce quite a few loudspeakers to devices which fail to produce sounds to my satisfaction. I present some of the ways in which I have managed to do this, in the hope that you will refrain from emulating my experiences. Please bear in mind I am talking from a bassist's perspective. Feel free to add your own inventive methodologies to the list...

1. Simple overpowering.
Presenting a 100W output to a 30W speaker seems to cause the speaker to simply die. I suggest you more carefully check the speaker wattages before plugging in an amp head. I did this on stage with an 18" Goodmans bin, during the Battle of the Bands.

2. Speaker mis-labelling.
In the days before 15" speakers became popular, we used to use 4x12 quad boxes for bass. I upgraded a cab with Rola 12ux50 (50W, 12") speakers and before I knew it, I had blown a couple. Further investigation revealed that the + and - terminals on the speakers were merely decoration and bore only random refrence to actual polarity. Thus I had 2 pulling and 2 pushing air at the same time in a 4x12 sealed cabinet. This resulted in excessive cone movement which the speakers failed to enjoy. I humbly suggest that you carefully check the polarity of all replacement speakers with a 9V battery. Make sure they all push the same way with the same polarity applied.

3. Unexpected transients.
Bass seems to create waveforms of high amplitude when an amp is cranked up. These peaks may exceed the speaker's specifications. Despite the movies we see with sparks/flames etc coming from the cabs, all that has happened in my experience has been either silence or heavy distortion, as the speaker coil expanded and rubbed along the magnet's pathway, or expanded to such an extent that the cone jammed. I have learned that the region above 7/10 on many amps can lead to this happening. Accordingly, I use 5/10 as the max volume on any amp I play. If it isn't loud enough then I need a bigger amp.

4. Holes in the cones.
OPK (other people's kids) may not understand that your gear is not a toy. They may actually think that poking sticks through the speaker grills is fun and that the tearing sound this makes is supposed to happen. There comes a point when the cone is unequally suspended as a result of this and bad things happen. I suggest you keep band gear isolated from OPK. This effects may also occur when you are mounting the speakers and your screwdriver slips....

5. Gravity and inertia.
If a cab is dropped with sufficient force, or chucked off the stage when you're stamping your feet with pique, it may transpire that intertial effects and gravity work together to move the magnet assembly a mm or so - resulting in cone drag which your speaker hates - so will you. Advice - be careful with speaker cabs. I always transport my cabs lying flat in my car boot, so that the big bumps in the road are mainly up+down, rather than sideways through the speaker axes. I have only once had problems with transporting my gear in the vertical, rather than horizontal mode - but once was enough.

6. Paper cones do not like beer.
Filling up the speaker cones with beer while the cab is lying down is to be discouraged. Bad things happen. 'nuff said.

7. Mixing wattages.
If you have speakers wired in series, do not have a low wattage speaker in the chain. They get upset. Advice - use similar power-capable speakers at all times.

8. Underpowering.
You'd think that driving a 100W speaker from a 30W amp would be fine, wouldn't you? But no. However, under certain circumstances, a dimed and overdriven amp will produce a highly distorted signal to the speakers. This heavily distorted signal may damage your speakers. Believe me - this is true.

9. Speakers do not like mains power.
I went through a stage where I had flashing lights in my quads (hey, it was the '60s). If the wiring to said lights is crappily done, it is possible for the wires to fall off the lamps and fall onto the speaker wires. This is a bad thing. 'nuff said.

10. Always have your speakers mounted before trying them.
I have found that trying out a new amp through a speaker just sitting on the bench is not a great way to enhance sound. Without a baffle board and cabinet, it sounds very thin indeed, so one cranks up the amp a bit more to get better sound. Before you know it, the speaker gets pissed off and quits on you. Remedy - always try out amps with speakers in an enclosure.

11. Clean cabinets.
Fibreglass batts and loose nails, staples and screws floating round inside a cabinet can have deleterious effects upon speakers. Ensure all cabs are vacuum cleaned thoroughly before you close them up.

I'm sure there are other ways I've done speakers in, but that's all I can remember at this time... you?

[stark]

I I upgraded a cab with Rola 12ux50 (50W, 12") speakers and before I knew it, I had blown a couple. Further investigation revealed that the + and - terminals on the speakers were merely decoration and bore only random refrence to actual polarity.

Yup, I have a pair of 12UX15s and the +ve and -ve terminal are in opposite positions on each of them.

Luckily, I tested them twice before i wired them up.

[Mike_Hosking]

not with pro gear, but installing car stereos, this i do alot coz my mates are retards and they dont kno how to, occasionally the screw driver will slip and hit the speaker cone, not yet gone through one, hope i dont either.

[sgt mukuzi]

yea dropping pedals on them makes em brok 2

my kids regulary fill my single 12 with small pieces of wood plastic and metal
nice. thanks for the tips R

[Gelato]

not with pro gear, but installing car stereos, this i do alot coz my mates are retards and they dont kno how to, occasionally the screw driver will slip and hit the speaker cone, not yet gone through one, hope i dont either.

My speaker destruction has been limited to car stereo speakers as well. I've had a few screwdriver slips that have gone through speakers, but they've all been 6x9's, so no great loss there at all. Worst was when I smoked a pair of JBL subs, each was 1500W RMS and the amp was only putting 1100W RMS to them. Running at ~2 ohms with a 55Hz tone into them. Got 143dB just before the smoke started coming out.

Oh well, they weren't mine anyway

[Rog]

143 db???

holy hell!!

For the workplace, the Occupational Safety and Health Administration (OSHA) proposed these permissible noise exposure times:


85 dB and higher - prolonged exposure will result in hearing loss
90 dBA - no more than 8 hours per day (examples - lawn mower, truck traffic, hair dryer)
95 dBA - no more than 4 hours per day
100 dBA - no more than 2 hours per day (example - chain saw)
105 dBA - no more than 1 hour per day
110 dBA - no more than ½ hour per day
115 dBA - no more than ¼ hour per day (preferably less)
140 dBA - NO EXPOSURE TO IMPACT OR IMPULSE NOISE ABOVE THIS LEVEL (examples - gunshot blast, jet plane at takeoff)


The National Campaign for Hearing Health states 85 dB is the threshold for dangerous levels of noise.


The National Campaign for Hearing Health's Toxic Noise Guidelines (exposure times and decibel levels that cause hearing loss)


85 dB 8-hour period
85 - 90 dB 2-hour period
90 - 100 dB 1 to 2-hour period
100 - 110 between 2 and 15 minutes
110 - 120 less than 30 seconds
130 dB ANY EXPOSURE WILL RESULT IN PERMANENT HEARING LOSS

[Gelato]

Don't fret Rog, I wasn't in the car at the time This was in the days when I used to compete in car audio competitions (the little known organised side of the "boy-racer-doof-doof scene") I even managed to get 140dB in my 1974 Mini Cooper in a comp once with no speaker blowage

[TMG 03]

I sometimes where ear plugs at band practise.

Its get hard to sleep some nights when you get home with the ringing.

[Simonski]

the ringing is the best bit, I once tried to work out what pitch it was, but couldnt get it down

[GrantB]

the ringing is the best bit, I once tried to work out what pitch it was, but couldnt get it down

lmao! I think mine's F...I would have preferred C but hey, I had no choice in the matter.