Do I need bigger speakers with 220 watts? (1 Viewer)

[Charbel]

OK, while my Paradigm Studio 40 is "in the shop" I`m wondering if they are`nt suitable for the 220 wpc Parasound amp. It seems I damaged the speaker and am not looking forward to another episode. Of course I will be more careful next time with the volume dial. Is there anyone with similar amp/speaker combination that has had any problems? Are you very cautious about the volume? How can I tell when the speakers are hitting thier limit and to back off on the dial? or do I just need bigger speakers 60`s 80`s?

 

[Saurav]

You should hear the sound starting to get compressed and strained. If you damaged those speakers due to sheer power even though you didn't hear any change in the speaker's sound, I would be very surprised. Of course, with an amp that's much more powerful than the speaker's rating, you're always running the risk of a friend at a party cranking up the volume and then hitting play, and you're finished.

 

[James Edward]

Speakers are almost ALWAYS damaged by lower powered amps driven into clipping. I bet almost anyone here will recall that as they moved up in power, blown speakers became less and less of an issue. As for what Saurav said, tell your friends to stay away.
That being said, when tweeters get damaged, it is usually from amp clipping. When woofers get damaged, it is usually from too much power. I read another post of yours where you state that there is no sound whatsoever coming from your speaker, so it is probably crossover/input connection related.
I'm pretty sure Paradigms also use 4th order, 24 db per octave crossovers, which also help to protect the drivers, by sending a narrower band of frequencies to each. I would chalk your episode up to some bad luck. Unless it sounds distorted, you really should be fine.
I have a 250 watt per channel Adcom amp, and I love the look on the faces of people when I hook up their small speakers to it. They inevitably sound fantastic, and surprise the heck out of the owner.

 

[AjayM]

That being said, when tweeters get damaged, it is usually from amp clipping. When woofers get damaged, it is usually from too much power. I read another post of yours where you state that there is no sound whatsoever coming from your speaker, so it is probably crossover/input connection related.

You just said the same thing, but differently. Clipping is another form of over-powering.
Andrew
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[James Edward]

AJay-
No, I didn't. When I say 'too much power', I'm referring to an unclipped, undistorted signal. A clipped signal is too much power with a distorted waveform, as a result of an overdriven amp.

 

[Patrick Sun]

Clipping is when the amp is not capable of producing the necessary amplitude of the signal that it's been asked to produce, so the amp is running out of available current to drive the speaker, which means the waveform of the signal is squared off and distorted. I would NOT consider this to be over-powering the speakers.
Clipped waveforms start to take on the look of square wave shapes/frequencies, and to produce this kind of wave form, you basically are sending higher and higher harmonics well over 20,000Hz to the speaker's crossover, and that causes the capacitors in the tweeter crossover to fail and they are left in an open-circuit condition (so no current gets to the tweeters).
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[AjayM]

quote: No, I didn't. When I say 'too much power', I'm referring to an unclipped, undistorted signal. A clipped signal is too much power with a distorted waveform, as a result of an overdriven amp.[/quote]
But both are to much power...or "over-powering". Not under-powering, the thing is that when you drive a small amp into clipping, it's sending out a lot of power (just not clean and listenable), which fry's speakers. You blow the speaker typically from exceeding it's thermal limits or it's mechanical limits. Thermal limits are thermal limits, wether or not the amp is clipping or not you have sent to much power to the speaker (hence you said clipping kills tweeters, to much power kills woofers). Tweeters generally don't have as much "fudge" room (and typically have lower power handling) as woofers do.
Andrew
Quoted from here, http://www.cabasse.com/notice/warranty.htm
quote: In order to spare you the exclusion of the warranty, the following are phenomena apt to cause these damages.
1. Clipping of the Amplifier:
When an amplifier is clipped, two different conditions may occur:
First, when driven into clipping an amplifier can deliver an effective power level that is much higher than its nominal power rating, possibly exceeding the loudspeaker's peak power rating. Typically, a good 70 W amplifier can deliver 140 W during clipping. The 70 W nominal power rating is obtained with low distortion while the 140 W output level contains an unacceptably high level of distortion. Thus the amplifier is rated at 70 W, but has the capacity to deliver higher power levels during clipping.
The second condition results in a frequency offset in the musical spectrum. When an amplifier is clipped overtones are generated. For example, a frequency of 400 Hz generates, during clipping, overtones of 800 Hz, 1 200 Hz, 1 600 Hz, etc. This means that the tweeter and midrange drivers must accept much more power thin flat which is normally present in music, This could lead to driver damage. [/quote]
So as Patrick mentioned you have the overtones problem, and the over-powering problem, that you're right mostly happens when people have to small of an amp, and then over-drive them (a low-end 50w amp in an el-cheapo reciever isn't going to drive 80db/1w-1m speakers to some people liking).
Go to Parts express and buy one of those 1w amp kits, build it and hook it up to your 150RMS main speakers and crank it as loud as you can and tell me if you blow your speakers.
[Edited last by AjayM on August 07, 2001 at 02:27 PM]

 

[rin]

Charbel,
Hopefully, you just had a bit of bad luck with that speaker and when you get it back you will have no more problems. I am currently using B&W 602's whose power handling specs state a range from 25w to 120w. My amp delivers 220w per channel into 8ohms(which is the impedance of the B&W's) and I haven't had a problem even though I crank it up quite often.
rin
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My Home Theater
So Cal Area HTF Movie night

 

[AjayM]

Charbel,
Hopefully, you just had a bit of bad luck with that speaker and when you get it back you will have no more problems. I am currently using B&W 602's whose power handling specs state a range from 25w to 120w. My amp delivers 220w per channel into 8ohms(which is the impedance of the B&W's) and I haven't had a problem even though I crank it up quite often.
rin

Here's an example of why you haven't had a problem, and probably never will have a problem with "over-powering" your speakers...simply because it will get to loud.
We know that in order to go up 3db in volume, we need to double the power.
B&W 602 90b sensitivity.
90db = 1watt
93db = 2watts
96db = 4watts
99db = 8watts
102db = 16watts
105db = 32watts
108db = 64watts
111db = 128watts
114db = 256watts
Now that's the theory, in your room it may vary a little. Not many people listen to music anywhere near that volume, so you have lots of headroom available (I'm worse, I have 350watts going into 92db/1w/1m).
I'm with Rin on this one, I think you just had a touch of bad luck...
Andrew
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[Charbel]

Very good explanations about power/clipping etc... I`ve learned alot. Now for another question, Can you "almost" blow a tweeter? or capacitor? I`m sure my right speaker is ready to go if I gave both L and R the same abuse? and center for that matter. I would think that I should examine the right speaker(the one that did`nt blow) if thats the case. Or are they either good or bad NO in between?

 

[Chu Gai]

I hope they were covered under warranty....assuming the speaker didn't blow to a manufacturer's defect, it certainly sounds as if they were abused. generally speaking a more powerful amp will be kinder to your speakers as previous posts have indicated since clipping is not likely to be an issue. Just what did you do to cause this to happen? The Studio 40's have a reasonable sensitivity and I can't imagine anyone playing them at listening levels above Paradigm's recommended sustained maximum of 140 watts (go to their website for particulars) as that could conceivabley generate sound levels in the vicinity of 110 db...

 

[Charbel]

"I can't imagine anyone playing them at listening levels above Paradigm's recommended sustained maximum of 140 watts"
I do listen VERY LOUD. I know, I did`nt get the right speakers for the application, but I knew even less than I know now when shopping for speakers. I think it`s too much of a coincidence that after 10 minutes with the new 220 watt amp (after using the 100watt AV receiver) that the speaker stopped working. I gotta think it`s due to abuse. I guess I`ll be more careful when the speaker gets fixed. I just like it loud and clean. I`ll have to use my SPL meter to gauge how loud it is and remember the volume dial # AND NEVER EXCEED THAT AGAIN. lol hopefully.

 

[AjayM]

Paradigm Studio 40
Sensitivity In Room/Anechoic 91/88db
Recommended power handling - 15-180watts
Max input power - 140watts
So using the 91/88db setup we get....
91db = 1watt 88db = 1watt
93db = 2watts 91db = 2watts
96db = 4watts 94db = 4watts
99db = 8watts 97db = 8watts
102db = 16watts 100db = 16watts
105db = 32watts 103db = 32watts
108db = 64watts 106db = 64watts
111db = 128watts 109db = 128watts
114db = 256watts 112db = 256watts
So if the max input power is 140 watts, you can only get to the 110-112db range before you run into problem...and the above is with a steady signal, not counting for peaks in the music, so if you are running right up to the ragged edge and encounter a peak in the music/movie you are going to be running past the power handling of the speaker.
Andrew
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[Chu Gai]

hell, just buy yourself a pair of avantguarde's if you want it loud....personally i can't conceive of anyone sustaining those sound levels on their ears for an extended period of time

 

[Lewis Besze]

First, when driven into clipping an amplifier can deliver an effective power level that is much higher than its nominal power rating, possibly exceeding the loudspeaker's peak power rating. Typically, a good 70 W amplifier can deliver 140 W during clipping. The 70 W nominal power rating is obtained with low distortion while the 140 W output level contains an unacceptably high level of distortion. Thus the amplifier is rated at 70 W, but has the capacity to deliver higher power levels during clipping.

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