I blew out my tweeter on my Polk tsi300.

What receiver? You could have been clipping and blew it.

Thats a common problem. It happens when you set the volume too high and drive the receiver into cliping. The good news is that those tweeters are easy to find.

Some times tweeters just break.

Obtain a new tweeter from the manufacturer and install it yourself, or have an audio specialist do it for you.

In warranty? Then talk to the dealer.

If it happens again, this is nature's way of telling you that something is wrong.

You may need more robust or more efficient speakers.

Blowing a tweeter is one sure sign. It's a $200 speaker, it won't do concert or true theater levels.

I did that a lot whith NHT's. They just can't play as loud as I like. Now I have actual cinema speakers that can play etxremely loud and clean.

The relevant spec is sensitivity, given as SPL for 1 watt. That goes hand-in-hand with maximum rated power. More power and more SPL per watt = louder without fried drivers.

http://www.polkaudio.com/products/tsi300

For example the TSI 300 is rated at 90 dB/watt and up to 150 watts.

I can turn 150 watts into a relevant kind of dB using the equation dB = 10 * log10(watts) the answer is 21.75 dB, so the maximum rated SPL for a TSI300 1 meter away is 111.75 dB, which is loud but not overwhelmingly so.

Now I will pick out a Klipsch RF62 which is a far more expensive speaker:

http://www.klipsch.com/rf-62-ii-floorstanding-speaker

Sensitivity is 97 dB/Watt and maximum power is 500 watts peak (whatever that means)

500 watts = 27 dB above 1 watt. 97 + 27 = 124 db which is really, really loud.

Caveat: This analysis is based on hedge words such as "peak" but is presented for educational purposes, not as a product recommendation.

For $200, what are you expecting?

For example my benchmark speaker in this price range is the Infinity Primus 363:

http://www.harmanaudio.com/search_browse/product_detail.asp?urlMaterialNumber=P363BK

Recommended Power Amplifier Range 10 - 200 watts
Sensitivity (2.83V @ 1m) 93dB

200 watts = 23 dB above 1 watt

93 + 23 = 116 dB maximum rated output. Also its a 3-way system which usually cuts the tweeter some slack.

I don't consider the 116 dB versus 112 dB to be a super big issue, but it is fun when the numbers run a little in your favor! ;-)

Remember, at this point I'm diagnosing your tweeter failure as a random failure. Kill another tweeter and I'll change my diagnosis to a systematic failure requiring either more moderation on your part or new speakers.

You pays your money and you makes your choice! ;-)

True, but more than a few manufacturers post phony specs, Klipsch being among the worst. The only way to make a fair comparison is with measured SPL charts. Most manufacturers don't have them, and IME there are only two reasons why. The first is that they don't have any, the second is that they do but they don't want you to see them. In any event there's not all that much difference in the sensitivity of different brands of speakers. They all use similar drivers in similar enclosures, all adhering to the same laws of physics.
If you want to go louder you need a combination of a larger box, larger drivers, more drivers, higher power ratings and higher price. There does come a point of diminishing returns with price, but still no $200 speaker is going to give reference levels. A $200 tweeter will.

I am not a big fan of the Polk sound, but aside from that I would skip Polk for their new logo alone, good god it is sickening. Apparently Polk just wants 14 year old girls to buy their products.

I have the Polk Monitor 75T's and I haven't blew a tweeter yet, and I turned it up good and loud watching Avatar and Dredd..

I'm pretty sure its your receiver. It's rated at 80W x 5. I'll assume that's measured in stereo mode, so it's really more like 30-35W x 5. If you're turning it up too loud, you could definitely run into power issues..

There was another thread on here with blown tweeters on that dude's Monitor 70's and it was his 2nd blown tweeter, only probable cause is too little power.

So in other words, you probably want to upgrade your receiver if you like it LOUD.

The Polk's aren't THAT weak, sure they're not going to go as loud as some, and as Arnold said you can't expect much out of $200 speakers, but you're not actually providing the "150 watts" that it is rated at, even at peaks.

If I'm completely wrong, I'm sorry, but this has just been my experience from a long time of trollin threads.

http://en.wikipedia.org/wiki/Clipping_%28audio%29

Again, I'm pretty new at this still, and so someone more experienced will probably come in and stomp on what I just said. But it COULD be the cause of the blown tweeter.

Too little power results in clipping. Clipped peaks cause speaker damage. I blew the tweeters in my monitor 70's by pushing my denon 1611 to +5 on the volume scale, obviously my fault.. Upgraded to an onkyo 809 and all was fine until I moved into my new house with a larger space and having my listening position much further away from my speakers. Blew the second tweeter without even trying. Added an xpa-5 and no more blown tweeters at or near reference level volume readings.
Lower power receivers are fine as long as you respect the volume levels and turn it down when you hear distortion or harshness.....and don't have your main listening position too far away.

These two statements are made there:
1. Because the clipped waveform has more area underneath it than the smaller maximum unclipped waveform, the amplifier produces more output power. (See the waveform to the right for an example.) This extra power can cause damage to loudspeaker components, including the woofer, tweeter, or crossover, via overheating.

That is not correct.


2. In the frequency domain, clipping produces harmonics at higher frequencies than the unclipped signal. This additional high frequency energy has the potential to damage a loudspeaker's tweeter via overheating.

That's almost correct. What it should say is that clipping produces harmonics at a higher percentage than in an unclipped signal, and the resulting increased power density in the high frequencies has the potential to damage tweeters, and midranges for that matter. Woofers are not affected.

People will give anecdotes saying otherwise, but careful study suggests that it is often an audiophile myth.

The audiophile argument is that when you clip music you always increase the energy that is sent to the tweeter because clipping adds harmonics to the music.

Reality is that clipping music can definitely change its harmonic structure, but the change can go either way depending on the music itself. Many modern recordings have a ton of high frequency energy, and clipping actually reduces the high frequency energy in them. Clipping makes them sound muddy, which I hear happening more often.

IME musical recordings such as orchestral recordings will probably have their high frequency content increased by clipping, but much good bright modern rock and roll will actually suffer a decrease in high frequency energy due to clipping. I have measured this on the test bench.

The remaining effect is that a more powerful amplifier can deliver more power and in the end it is always more power that damages the speakers. The question is how does that more power get applied - by clipping or by simply turning up the volume?

I can see where a person who listens to a certain kind of music and gets clipping with a smaller amplifier, will put in an amplifier that has more unclipped power, then avoids the clipping, and if the listener doesn't exploit too much of the added power, he might save wear and tear on his tweeters.

I feel that in general, and this is more of an opinion than an actual scientific fact, that swapping in a more powerful amp will usually result in more power being applied to all of the drivers in a speaker, and thus there will be a greater possibility of speaker damage. If the new amplifier has considerably more power, this is much more of a possibility.

Many of the amplifier upgrades I hear about are fairly minimal, such as adding a 150 or 200 wpc outboard amp to an 100 wpc AVR, and it is more likely that a person who really doesn't push that much harder than the ACR can do unclipped, will indeed save his tweeters with the larger amplifier. If you want your system to play twice as loud you would need a 10x more powerful amp, and few audiophile power amps have that sort of power.

When I had my 1611 I would NEVER dare go past -10 in my room lol! You crazy!

I have looked at this situation very carefully, both with simulations and on the test bench, and it is definitely observable. In the end a clipped wave becomes like a square wave, and a square wave has the same energy in it as a DC signal with the same peak value. As long as the signal is more like a sine wave or a collection of sine waves, its energy will always be less. Here are the statistical results of a simulation:

Sine wave (unclipped)



Square wave (clipped)



You can see by comparing any of the statistics for RMS power that the square wave (clipped) has more area under the curve and thus contains 3 dB more power.

Just want to remind you guys that volume control settings are uncalibrated until you calibrate the receiver with a SPL meter or something like it (Audyssey), and so whatever number you read off the volume control, it is what it is, but it means nothing in particular.

I own a pair of tsi100 and those can go really loud. I have never blew a tweeter.

When you say calibrate does that mean the same as setting all the speakers to 75dB with a test tone?

Those yamaha avr's are know to go low on watts when driving 5 and 7 channels, and that is why he blew that tweeter http://www.hometheater.com/content/yamaha-rx-v871-av-receiver-ht-labs-measures