M80 v2 clipped speakers? Are they broken?

Posted by: markmd

M80 v2 clipped speakers? Are they broken? - 02/14/11 05:01 PM

I am new to the whole audio world so forgive me for my stupidity. I recently bought some axiom m80's and I hooked them up to a technics sa-424 1981 4ohm 2x50watt RMS receive with 12 gauge wire.

I proceeded to play music of my computer to the receiver at medium levels in my 12x14 room where the speakers are placed about 1 meter apart on each side from me.

I didn't hear any weird popping noises or anything odd coming from the speakers but I'm afraid I may have damaged them after using my old receiver. Is there any way I can test my M80's to make sure I didn't damage them? Hopefully I didn't clip the speakers at the level I was playing them at.

Any insight would be appreciated. And yes I have a 500 watt emotiva coming to replace the receiver.
Posted by: ClubNeon

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 05:07 PM

If you didn't hear anything odd, why do you think you damaged the speakers?

It isn't speakers that "clip", but an amplifier that doesn't have enough power to reproduce the signal at the level being requested. More simply, if you turn the volume up too loud, and the receiver/amp can't deliver what you're asking, then you may experience clipping.

Hard enough clipping for long enough time will end up damaging speakers. But unless you did something like that, there's little to be worried about.
Posted by: J. B.

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 05:11 PM

i would have loved to answer that one, but you're too fast, CN. ;-)
Posted by: SirQuack

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 05:20 PM

What preamp or receiver are you going to use with the Emotiva amp? An amp can't replace a receiver, it gives you the amplification but you will still need a receiver or a preamp.
Posted by: J. B.

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 05:37 PM

markmd, you might find this informative:
http://www.peavey.com/support/technotes/

in the "power amplifiers" section, click on this one:
How Much Power For My Speakers? - PDF Format (229KB)
Posted by: markmd

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 05:58 PM

Interesting.

So is 50watts rms per channel enough for sub 90db listening? I mean in my small room I dont think im even touching 80db.

It will be a couple of weeks until i get my denon 2808 with the emotiva. SHould I just unhook the speakers till then to play it safe?

I thought I read that these speakers at 1 watt rms produce 90db at 1 meter.
Posted by: alan

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 06:21 PM

Hi markmd,

Yes, you should be able to play the M80s quite loud in your small room using the Technics amp without worrying about clipping the amplifier's output. Keep in mind that "quite loud" subjectively is about 85 dB SPL at your listening seat. "Very loud" would be 95 dB SPL. So if your Technics needed to produce 1 to 4 watts to produce 85 dB, then peaks of 95 dB would need ten times the power at 85 dB, so about 10 to 40 watts, which is still within the output capabilities of the vintage Technics. (Power demands are logarithmic in nature, so doubling the amplifier power only produces a "slightly louder" increase of 3 dB. "Twice as loud" subjectively needs 10 times as much amplifier power.

No need to unhook your speakers. Just don't crank up the Technics past the "very loud" level and you'll be fine.

Regards,
Alan
Posted by: SirQuack

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 06:47 PM

What Alan says, it only takes a few watts to play very loud, the Axioms are very efficient. The 2808 alone would give you more power than you most likely ever use in that room.
Posted by: markmd

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 07:22 PM

Thanks for the help everyone. I did some close listening at each driver and tweeter and I think everything is perfectly fine at my medium listening levels.

I want to find an spl meter so I can get actual DB numbers for reference.

I can't believe how good the m80's sound compared to my old JBL's even with this vintage technics. The bass is very clean and really punches when it needs to.
Posted by: tomtuttle

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 07:33 PM

That's great, Mark.

Enjoy!

But... If it sounds bad, turn it down. wink

They make pretty decent SPL meter apps for both the iPhone and Android now.
Posted by: JohnK

Re: M80 v2 clipped speakers? Are they broken? - 02/14/11 09:17 PM

Mark, welcome. Considering your listening distance of not more than 10', 50 watts would produce a sound level of about 103dB(per speaker, 106dB for two)at your listening position. If your receiver is still in good working condition you have no good reason for concern at any reasonable listening level.
Posted by: markmd

Re: M80 v2 clipped speakers? Are they broken? - 02/15/11 10:58 PM

I downloaded TrueRta SPL software and hooked up the best standing mic I had (100$ sennheiser).

Looks like im hitting about 80db max at what I consider to be quite loud.

This measurement is with mic placement a foot away from the speaker.
Posted by: alan

Re: M80 v2 clipped speakers? Are they broken? - 02/16/11 01:44 PM

Mark,

What's important is the sound level at your listening seat. Yes, 80 dB SPL is quite loud but if you set up the microphone at your listening seat, it will better indicate the output of the speaker and the contributions of room reflections.

Alan
Posted by: DanLW

Re: M80 v2 clipped speakers? Are they broken? - 02/16/11 05:48 PM

Just out of curiosity, let's say he did turn his 50W receiver all the way up, and fed the M80s a square wave. I know square waves have a lot more power than an unclipped sine wave, but given that the M80s can take a rated 400 watts, and 1200 watts is unofficially the point at which the drivers blow, could a 50W amplifier really damage the M80s? I mean, If I can feed the M80s a 400W sine wave at 10KHz, why not a "50W" square wave? (50W in quotes because I'm not sure how to figure out how many actual watts the speaker would see)

My guess is either the crossover or tweeters would overheat, if anything.
Posted by: MarkSJohnson

Re: M80 v2 clipped speakers? Are they broken? - 02/16/11 08:12 PM

Yes. Clipping will damage tweeters before a lot more clean power will.
Posted by: Ken.C

Re: M80 v2 clipped speakers? Are they broken? - 02/16/11 08:13 PM

I would hazard a guess that's because clipping would cause more power to go to the tweeter than normal loud volume, considering that tweeters normally operate at far lower power than woofers.
Posted by: Argon

Re: M80 v2 clipped speakers? Are they broken? - 02/17/11 07:37 AM

Originally Posted By: MarkSJohnson
Yes. Clipping will damage tweeters before a lot more clean power will.


Not to mention ear drums.
Posted by: alan

Re: M80 v2 clipped speakers? Are they broken? - 02/17/11 09:01 AM

Yes, and as the output waveform of the amplifier becomes more severely clipped, the waveform starts to resemble pure DC power (the audio signal to a speaker is normally an AC signal), which will then fuse the voice coils of the woofer(s).

That is what happened when an Axiom customer using one of those ridiculous low-powered single-ended tube amplifiers (less than 5 watts per channel) tried to drive M22s full-range in a big room.

Alan
Posted by: J. B.

Re: M80 v2 clipped speakers? Are they broken? - 02/17/11 09:45 AM

"That is what happened when an Axiom customer using one of those ridiculous low-powered single-ended tube amplifiers (less than 5 watts per channel) tried to drive M22s full-range in a big room."

Wow, unbelievable!
Posted by: Lampshade

Re: M80 v2 clipped speakers? Are they broken? - 02/17/11 09:52 AM

Alan,
that hurt my feelings. smile Can you ask Ian to design a full range single driver crossoverless speaker with 99db efficiency that will cost about $400 so I can use it with my 2 watt per channel SET?
Posted by: DanLW

Re: M80 v2 clipped speakers? Are they broken? - 02/17/11 03:36 PM

Originally Posted By: alan

That is what happened when an Axiom customer using one of those ridiculous low-powered single-ended tube amplifiers (less than 5 watts per channel) tried to drive M22s full-range in a big room.

Alan


Wow! I guess that answers that question!