[midgetspy]

Hey all I just ordered some new speakers and was talking about my receiver/amp with the guy at the store and he warned me I could damage my speakers if my amp isn't powerful enough. Upon reading the manual that came with my speakers it explained that the amp could supply "dirty" power to the speakers at high volumes which could damage them. This got me thinking so I went and looked up the specs for my receiver and speakers:


Onkyo TX-SR605: specs

Paradigm Mini-monitor: specs

Paradigm CC-290: spets

Paradigm ADP-190: specs


So my first questions is basically I don't understand the cause of this. Shouldn't the receiver have a max volume that is low enough that it would never output "dirty" signal that could damage the speakers? How can I know how loud is too loud? Where I bought the speakers he said if I hear distortion/crackling then it's too loud, but by then it could be too late.


Looking at the specs for my receiver and speakers it looks like my fronts and surrounds are approximately within the proper range but my the center power output could be too low. Will I run into problems driving the CC-290 with my Onkyo 605? If so is there any solution other than buying a new receiver?


Here's a summary of (I think) the relevant specs:

Front L/R


Receiver

90 W + 90 W (8 ohms, 20 Hz-20 kHz, 0.08%, 2 channels driven, FTC)

105 W + 105 W (8 ohms, 1 kHz, 0.7%,2 channels driven, FTC)

110 W + 110 W (6 ohms, 1 kHz, 0.1%,2 channels driven, FTC)


Speaker

Suitable Amplifier Power Range: 15 - 100 watts

Maximum Input Power: 80 watts

Impedance: Compatible with 8 ohms

Center


Receiver

90 W (8 ohms, 20 Hz-20 kHz, 0.08%, 2 channels driven, FTC)

105 W (8 ohms, 1 kHz, 0.7%, 2 channels driven, FTC)

110 W (6 ohms, 1 kHz, 0.1%, 2 channels driven, FTC)


Speaker

Suitable Amplifier Power Range: 15 - 175 watts

Maximum Input Power: 125 watts

Impedance: Compatible with 8 ohms


Surround L/R


Receiver

90 W + 90 W (8 ohms, 20 Hz-20 kHz, 0.08%, 2 channels driven, FTC)

105 W + 105 W (8 ohms, 1 kHz, 0.7%, 2 channels driven, FTC)

110 W + 110 W (6 ohms, 1 kHz, 0.1%, 2 channels driven, FTC)


Speaker

Suitable Amplifier Power Range: 15 - 100 watts

Maximum Input Power: 80 watts

Impedance: Compatible with 8 ohms

 

[JOHNnDENVER]

Well, there is the specs and then there is the real world.

It takes a very high end, engineered amp to crank max and be clean.


You will be fine....


If you listen closely you can easily tell if your runnign out of power, generally if you obtain the highest volume you may ever use and you still have good fidelity your good to go.



It is a backward concept though.... To much power rarely blows speakers, it is actually to little power where the amp struggles and starts clipping. Voice coils on speakers hate clipping. Tweets and mids tend to be the more common victims.

 

[Aaron Gilbert]

It's a common misconception that using a lower powered amplifier/receiver is more dangerous to speakers than a high powered one. This is not the case. Distortion per se doesn't kill speakers - too much power does. Certain types of distortion can result in more power to be sent to the speaker, certainly.


Regardless of that, with any speaker/amplifier combination, it's important to drive neither the amplifier/receiver nor speakers into distortion. If you can follow this simple rule, you will be safe from overdriving the speakers electrically (unless the woofer/tweeter engineer has seriously goofed in their design - extremely rare). You still won't be protected from physically overdriving the woofers, especially in ported speakers. For that, you'll want to select appropriate crossovers for them in your receiver's speaker setup menus. With those Paradigms, I'd select 80Hz for the surrounds, and either 60 or 80Hz for the front speakers.


Another nice feature of many receivers these days (your Onkyo included) is that you can set a maximum volume. This will allow you to restrict the maximum power sent to your speakers, thus protecting them. This can certainly restrict dynamics, but only if you needed that extra volume to begin with. If all the speakers run off your receiver are crossed over to the subwoofer, their power requirements will be dramatically reduced, and it's likely you'll never need volume that goes to +15dB over reference!


It's worthwhile, if you have some old junk speakers and stereos, to play around at near maximum volumes (hopefully these are weak systems) to get an understanding for what distortion sounds like. Many people just don't know the difference between clean and distorted sound. Of course, a lot of damage is done at raucous parties, as drunk listeners tend to be much less aware of the actual sound quality.

If you understand what distortion sound like, and you know your source material, you can safely combine almost any combination of loudspeaker and amplifier/receiver.


I hope that made some sense.

 

[Aaron Gilbert]



Quote:
Originally Posted by JOHNnDENVER /forum/post/15501005


...

It is a backward concept though.... To much power rarely blows speakers, it is actually to little power where the amp struggles and starts clipping. Voice coils on speakers hate clipping. Tweets and mids tend to be the more common victims.

I would almost completely disagree with this. Too much power is almost always the culprit when speakers are blown. Further, with a passive speaker, assuming a typical crossover configuration, clipping will not affect a tweeter at all - but the extra power created by clipping your amplifier certainly can. The reason that midranges and tweeters seem more susceptible to clipping, is because they are less capable of handling substantial power than the woofers, especially for extended periods. A woofer driven to high levels, especially in the bottom two octaves, will have plenty of air movement to cool it's voice coil - assuming you're not driving the amplifier into full square waves. That's not to say you still can't be sending the woofer too much power, just that they can handle it for longer. Midranges and tweeters on the other hand, barely move at all, and the excess heat has no where to go.

 

[Knucklehead90]

The guy at the store was looking to make a sale. If he is at all knowledgeable about audio he'd have known the Onkyo you have is plenty capable of high volume/current with little danger of clipping.

 

[MichaelJHuman]

Some of the best stuff I ever read on clipping was over at Elliott's site - sound.westhost.com. But it's pretty technical.


The simple answer is turn your volume down when the sound quality worsens. This has always been obvious to me. At a certain point, it's still getting louder, but it starts to sound harsh. I am unsure where the point of clipping occurs, but there's no reason to risk it. Even with my rock music damaged hearing, I can hear a point where the sound gets harsher. I then reduce volume. Simple enough.


The technical explanation is that there's two ways to damage speakers.


1) Exceed it's mechanical limits

2) Exceed it's thermal limits


1) does not seem common. But I can over power the small bookshelf speakers in the bedroom. It sounds HORRIBLE when I do. I assume I am hitting the excursion limits of the woofer. It's obvious, at least in that case, I need to reduce volume.


2) In all cases, as mentioned above, exceeding your thermal limits is a result of too much power. Paradoxically, this can occur with a lower powered amplifier. As to why this is, it's a bit technical. A lower powered amp is going to clip sooner than a higher powered one. When it clips, it can cause the tweeters to receive power they were never designed to handle. Speakers are horrible inefficient, and much energy sent to them becomes heat. Too much heat in your drivers such as tweeters can damage them.


Obviously a high powered amplifier could achieve the same thermal overload. The common thinking is that this is much less common than the clipping scenario.


The bottom line - don't run your system to the point of audible distortion.

 

[Aaron Gilbert]



Quote:
Originally Posted by MichaelJHuman /forum/post/15502159


Some of the best stuff I ever read on clipping was over at Elliott's site - sound.westhost.com. But it's pretty technical.

I have read that site, excellent material.

Quote:
Originally Posted by MichaelJHuman /forum/post/15502159



...

2) In all cases, as mentioned above, exceeding your thermal limits is a result of too much power. Paradoxically, this can occur with a lower powered amplifier. As to why this is, it's a bit technical. A lower powered amp is going to clip sooner than a higher powered one. When it clips, it can cause the tweeters to receive power they were never designed to handle. Speakers are horrible inefficient, and much energy sent to them becomes heat. Too much heat in your drivers such as tweeters can damage them.


Obviously a high powered amplifier could achieve the same thermal overload. The common thinking is that this is much less common than the clipping scenario.

...

This is all correct. What many people don't realize, and salespeople often also don't realize, is that the amount of extra power which can be presented once the amplifier gets into clipping, is depedent upon the rated output power of the amplifier. If you were to drive the amplifier into full square wave output (extremely rare), you could present twice as much actual power to the speaker as the amplifier would normally be capable of. But, say you have a 20 watt amplifier, that's still only going to be 40 watts. Whereas if you jump up to a 200 watt amplifier, thinking you'll never drive it into clipping - indeed that may be true. But you still have five to ten times the amount of power with which to burn up your speaker's voice coils.