Testing Speakers

[UP Simon]

Short of actually attaching speakers to decoders does anyone have a quick easy and safe way to test a speaker?
Got a Soberton 8x12 I’m installing and want to make sure it’s ok before I hook it up

Thanks

[peteski]

If you have a multimeter, set it on the lowest Ohm (resistance) range and check  the speakers resistance.  It should be around 8 ohms.  That (along with visual inspection for damage) should give a good indication that the speaker is good.

You can also take a 1.5V battery (Like a AA or AAA) and attach a lead to each terminal, then touch the leads to the speaker terminals for a split second (don't dwell on it, just touch the leads for a very short time). You can do this repeatedly. You should hear audible clicks or scratching sounds when the leads contact the speaker terminals (since the battery voltage will deflect the speaker cone).  At 1.5 Volts the 8 ohm speaker will dissipate around 0.28 Watts of power, so that should be safe for a speaker rated for 1 Watt.

[MK]

You can also take a 1.5V battery (Like a AA or AAA) and attach a lead to each terminal, then touch the leads to the speaker terminals for a split second (don't dwell on it, just touch the leads for a very short time). You can do this repeatedly. You should hear audible clicks or scratching sounds when the leads contact the speaker terminals (since the battery voltage will deflect the speaker cone).  At 1.5 Volts the 8 ohm speaker will dissipate around 0.28 Watts of power, so that should be safe for a speaker rated for 1 Watt.

This is a good trick and I use it all the time with hifi speakers using a AA battery.  Just "spark" it by swiping the lead quickly on the battery like as if you are trying to hot wire a car. 

[nstars]

You can also take a 1.5V battery (Like a AA or AAA) and attach a lead to each terminal, then touch the leads to the speaker terminals for a split second (don't dwell on it, just touch the leads for a very short time). You can do this repeatedly. You should hear audible clicks or scratching sounds when the leads contact the speaker terminals (since the battery voltage will deflect the speaker cone).  At 1.5 Volts the 8 ohm speaker will dissipate around 0.28 Watts of power, so that should be safe for a speaker rated for 1 Watt.

Be careful, the Soberton 8x12 is rated at 0,25W with a max. of 0,5 W (see https://www.digikey.nl/product-detail/en/soberton-inc/SP-1208/433-1130-ND/6099104).

Marc

[peteski]

Be careful, the Soberton 8x12 is rated at 0,25W with a max. of 0,5 W (see https://www.digikey.nl/product-detail/en/soberton-inc/SP-1208/433-1130-ND/6099104).

Marc

I thought that these were rated for 1W  max.  Still, straight 1.5V across its terminals should be safe if the test is performed in the way it was recommended.  For extra safety, a 10 or even 22 ohm 1/2W resistor could be added in series with the speaker.  Even higher values can be used, but the audible click will get weaker and weaker with higher value resistors.

[Cajonpassfan]

If you have a multimeter, set it on the lowest Ohm (resistance) range and check  the speakers resistance.  It should be around 8 ohms.  That (along with visual inspection for damage) should give a good indication that the speaker is good.
...

I have a "sound gone dead" BLI PA unit and suspect the speaker (this has happened on another unit some time ago).
Is it safe to test the speaker as described above while it is still attached to the (Paragon) decoder?
Thanks, Otto K.

[MK]

I would disconnect one lead so you are not back feeding anything back to the decoder.  But, it's only 1.5V from a battery, still...

[Cajonpassfan]

I would disconnect one lead so you are not back feeding anything back to the decoder.  But, it's only 1.5V from a battery, still...

I'm not talking about using the battery method described earlier, but the Ohm meter.
And I'd rather not be unsoldering/soldering, hence my question....
Otto

[nstars]

An ohm meter also uses a current to determine the resistance. You may also measure the 'resistance' in the decoder s unsoldering is probably the best method.

Marc

[Cajonpassfan]

Good point. Thank you.
Otto

[Steveruger45]

As a slight side note on the ohm meter measuring resistance using a current.  On its lowest setting of 0-200 ohms, it is good tool to light up a 3v led, which is handy if you want to see if an led works or find its polarity should the visual polarity marks be unreadable.

[peteski]

As a slight side note on the ohm meter measuring resistance using a current.  On its lowest setting of 0-200 ohms, it is good tool to light up a 3v led, which is handy if you want to see if an led works or find its polarity should the visual polarity marks be unreadable.

While handy, this is not universally applicable. It depends on the multimeter's internal design and in the type of battery it uses.

[Steveruger45]

While handy, this is not universally applicable. It depends on the multimeter's internal design and in the type of battery it uses.

Pete is undoubtedly correct in the universally applicable bit, I will qualify my earlier statement.  It works a dream if you have one of those free  Cen-tech digital multimeters from harbor freight tools, which I’m reasonably sure many do have.

[Steveruger45]

This is a good trick and I use it all the time with hifi speakers using a AA battery.  Just "spark" it by swiping the lead quickly on the battery like as if you are trying to hot wire a car. 

Hot wiring a car !    Are you from New Jersey by any chance ?   😁😁😁

[craigolio1]

Get a 3.5mm headphone cable, cut one end off, attach one channel to the speaker leads and play some tunes from your phone?