Understanding and Preventing Tweeter Damage (ie fried or blown)

candyliquor35m

Since tweeters don't grow on trees and I'm seeing tweeter damage posts on the rise here, maybe a sticky is needed to explain why it happens and how to prevent it.

The most likely cause is pushing your amp/receiver past 12 o'clock or past halfway on the volume. That's what I was told when I joined the forum and I've lived by it ever since with no fried or blown tweeters so far.

If you want to understand how a amp works, this thread has a link to Bob Carver's White Paper on his Sunfire amp:

http://www.polkaudio.com/forums/showthread.php?t=41600

dkg999

I prefer my tweeters fried in a light beer batter. Flash frying in very hot oil is recommended and will bring out the flavor of the batter a lot better. Serve them up hot with some ice cold woofers, and ooooweee that's some good eating.

If you get tweeters that have a capacitor growth on them, throw them away as they have went bad.

steveinaz

Every amp is capable of putting out more than it's specified power. The problem is, when you get past the specified point of distortion (maximum "usable" power), the amp begins to clip the signal. This hard clipping should be heard by the listener as compression or out-right distortion/cone break-up. The best way to keep yourself out of trouble is to look at the Sound Pressure Level (SPL) at a given wattage.

Let's say you have:
- an amp capable of 200watts @ 8ohms
- speakers with an efficiency rating of 88db 1watt/1meter

Now, let's see how much loudness (dB's this system can produce at 1 meter):

88dB...1watt
91dB...2watts
94dB...4w
97dB...8w
100dB...16w
103dB...32w
106dB...64w
109dB...128w
111dB...256w

One approach (do so with care; make sure your speakers can handle these SPL's):

Note that power has to be doubled to get just a 3dB increase in perceived loudness or SPL. You see that somewhere between 109dB-111dB your gonna exhaust your usable wattage from the amp (clip). So use an SPL meter, such as Radio Shack's model, and play the system slowly approaching the 106dB level (for safety sake). Note how loud the system is playing---now you have a reference for what you shouldn't go past. Looking at the volume knob position won't help you much, as sources vary in output.

steveinaz

2 things to know:

- tone controls and/or equalizers can be tweeter killers if not setup properly
- you should hear the distress before it does any damage. If the music is sounding edgy/raspy--turn it down.

nikolas812

steveinaz wrote: »

Every amp is capable of putting out more than it's specified power. The problem is, when you get past the specified point of distortion (maximum "usable" power), the amp begins to clip the signal. This hard clipping should be heard by the listener as compression or out-right distortion/cone break-up. The best way to keep yourself out of trouble is to look at the Sound Pressure Level (SPL) at a given wattage.

Let's say you have:
- an amp capable of 200watts @ 8ohms
- speakers with an efficiency rating of 88db 1watt/1meter

Now, let's see how much loudness (dB's this system can produce at 1 meter):

88dB...1watt
91dB...2watts
94dB...4w
97dB...8w
100dB...16w
103dB...32w
106dB...64w
109dB...128w
111dB...256w

One approach (do so with care; make sure your speakers can handle these SPL's):

Note that power has to be doubled to get just a 3dB increase in perceived loudness or SPL. You see that somewhere between 109dB-111dB your gonna exhaust your usable wattage from the amp (clip). So use an SPL meter, such as Radio Shack's model, and play the system slowly approaching the 106dB level (for safety sake). Note how loud the system is playing---now you have a reference for what you shouldn't go past. Looking at the volume knob position won't help you much, as sources vary in output.

I found this interesting... I feel pretty confident I can keep from frying my tweeters.:D But out of curiosity how would you do the SPL test?? Would you use a disc with test tones on it( pink noise ). Or would you do it while listening to a music CD?

I know when I go to find reference level on my system I use test tones. When the SPL meter hits 75db I note where the volume is on my pre and then use that spot for reference level listening on music CD's.

Is this the correct way for finding reference levels?


Nick