Karaoke Forums

How does one know a speaker is going to blow?
Is there any TEST besides just listening to know ?

last night one of my speakers made a "noise" for lack of a better word.
The bartender told me later she thought she saw a FLASH (spark) from the speaker.??? ( I didn't see or smell anything?)

The show finished without any NOISES or problems and everything sounded FINE from both speakers. I'm just worried about THURSDAYS nights show, I don't want to get there and have a PROBLEM half way through the show.

If I set up tonight in my basement and just listen to them is that a good TEST ?
Do I need to push them a little to hear any problems ?( ie hip hoppy music)

Yes listen to them.
Also push the cones physically.
See if you can hear any scratching.
It would help if you could meter them for Ohms resistance.

Your ears are your best tool though.

+1 on the use of your ears. Really the only way to tell is by listening. You can do some physical checks like Jerry suggested. Push the cones in and out gently by hand and see if they're binding or making any unusual noise. You can do some impedance measurements across the voice coil that can sometimes show indications of a problem, but really the best way is just to listen. You can also take a look and listen as you move them around to see if anything sounds loose.

I'd recommend doing an A-B test between your speakers. Play the same program material through one and then the other (if you use music make sure you used either the same channel or run it in mono). Listen to all the different instruments and vocals and see if you notice any differences from one speaker to the other. One thing that can help with this as well is to listen to the drivers in the cabinet separately. If you have 2-way woofer+horn, find out what the frequency is for the internal cross-over between them. Use your EQ to eliminate everything above that cross-over frequency to isolate and listen to only the woofer. Do the opposite to isolate the horn and see what it is doing. Do the A-B testing between the speakers this way and it will make it easier to identify where something just isn't right and will also help you identify the culprit.

Also, consider that if your speakers are active, a pop and a flash may very well have originated from the amplifier itself. Amplifiers are even trickier because many times they don't exhibit any signs of failure until they just give up the magic smoke and no longer operate. This is where driving it at different levels and listening can help you identify a problem. There are electrical measurements you can do that would help as well, however this is pretty advanced and requires a pretty good technical knowledge of the amplifier.

I would definitely recommend going ahead as you plan to test them out before your next gig. Obviously you don't want to get there and have something blow up half way through your show.

_________________
DJ Tony
Let It Rip Karaoke

They are passive Peavey PR15's.... I guess the best is to just LISTEN in a controlled enviroment without the noise of a BAR.

I'll give them a listen tonight and post results.

THANKS GUYS!!!

How do you like these speaks? I have a set and I love them!

Chances are the 'spark' that was seen is the speakers tweeter protection mode kicking in which is basically a little light bulb built into the crossover that lights when it gets to a certain wattage/volt.

_________________
LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

I love them for what they are -- lightweight - They sound good for small to medium venues where heart thumping bass is not required. They put out a decent bottom end for typical karaoke applications

Sound like that would be the best thing to have happened ?

Better than a blown horn for sure. But what was the 'noise' you heard. Almost sounds as if you were overdriving the amp. What is the amp again that you are trying to match those speakers to?

_________________
LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

Last night I wanted to get my back up amp some work so I was using a
new Behringer PMP1680S which I think would be fine.
Normally I use a Yamaha EMX512.

Hopefully no perm damage

Agreed. I love them for their light weight and paired with an 18 sub, boy oh boy, things get good then.

Haven't gone the SUB route yet although I understand the overeall sound would be night and day with one.

It's really amazing. I'm using one of those JBL 500 watt powered subs. A bit pricey but light as well. The over all sound is warm and "emotional".

This happened to one of my PeaVey 215's a couple of years back. I didn't get any audio or visual indicator; just noticed that suddenly I wasn't getting any highs. Upon removal of the passive crossover I saw the bulb filament was broken. I thought at first that it was a fuse, but learned differently later on. I guess it buffers momentary power surges, but if the surge is too big or too long, it'll just open the circuit. I keep a few bulbs on hand just in case, but haven't had any problems since.

The one thing I noticed is that mine was soldered in to its clips; to prevent loosening while handling the speakers I suppose. And while the solder joint is a good idea, it sure limits your ability to change them out quickly if you need to. I didn’t re-solder.

_________________
EveningStar Entertainment & Events
JR & Michele LaPorte
Peoria, AZ

Well I didn't get a chance to listen to the speakers before last nights show ..luckily for me .. Everything sounded fine. I listened to each speaker very carefully through out the night and they sounded fine. No noise/buzz/distortion etc.
Could have been as suggested a spike fdrom pushing them a little too hard.
Or it could have been the powered mixer I used that night which is brand new but a back up. who knows . Thanks for the responses and I'll be sure to keep an eye on the meters and lights in the future