Can home audio speakers handle inputs from instruments?

[PortalKeeper]

What kind of home speakers are you talking here? THX requires undistorted sound pressure of at least 105dB at listening position. If your speakers cannot do that, they do not qualify for real hi-fi. All serious speakers I had were safe for 110dB or higher.

say KEF R7s

 

[DVDdoug]

I'd be very careful if you care about your speakers!

There's an old JBL paper (spkpwfaq.pdf) that says a musical instrument speaker should be rated for twice the power of the amplifier.

C. For musical instrument application, where distorted (overdriven) output may be a musical requirement, the system should be powered with an amplifier capable of delivering only one-half of the IEC rating for the system.

And, I'm not sure if that's enough if you have a tweeter because tweeters can't handle the power of the woofer, or midrange, or full-range guitar speaker.

Compression or "saturation" will also make it worse because although the peaks are clipped/limited, the average power (which heats-up the voice coil) keeps increasing.

I also don't trust that consumer speaker manufacturers are following the IEC power rating standards. I don't even know if JBL pro still uses IEC power ratings.

 

[mhardy6647]

I also don't trust that consumer speaker manufacturers are following the IEC power rating standards. I don't even know if JBL pro still uses IEC power ratings.

I think they just make up numbers -- that's certainly what they did in the 1970s.

 

[ThatSoundsGood]

The audio interface is assumed to have hi-Z inputs so it can handle the pickups on an electric guitar or bass. I am still a bit confused on how the dynamic range plays into blowing/heating drivers up. If you for instance have an amp that goes to full power (according to spec) at 5V input, a DAC that goes exactly to 5V output on full volume, and a speaker capable of handling the amplifier’s max power rating, wouldn’t you be good no matter what volume you put the system?

Well, I cannot give you a full scientific explanation. Theoretically, you're correct. But I have done this plenty and I find it very important to be careful with a bass guitar through regular speakers. I have heard the cone on my woofers cry for help and nothing was being "clipped". They just couldn't handle what was being sent to them. Guitars are much safer because they have a lot less low frequency content. Also, I was using an active bass and they have more output, which shouldn't matter since I was going through an interface, but it seems to be more powerful. So, I have no science for you on this, but maybe you could do the experiment and let us know. But please don't blow up your speakers in the process.

 

[rynberg]

I have also wondered this and the advice I have always been given is not to do it as it may damage the speakers, even at low volume.
Doesn't make any sense to me. Aren't the speakers reproducing the same sounds when you play recorded music?
I haven't been brave enough to try.

No, they are not reproducing the same sounds...the signals on the recordings are are massively compressed and limited with frequency shaping, even on a wide dynamic range recording. My drums easily have a dynamic range exceeding 130 dB...obviously guitar/bass/vocals are less extreme but still much, much larger than on any recording. As someone mentioned, you also have the chance of pops, etc., that have extreme dynamic range.

 

[Mr. Widget]

I was wondering whether it would be safe to use an audio interface (with an electric guitar or keyboard or microphone plugged in without any EQ or compression) with active or passive home audio speakers such as KEFs or Revels. Speaker companies have told me not to do this multiple times; one of them said it has to do with dynamic range. If it’s not safe, could you please explain why?

You have to define "home speakers". Your typical dual 8" tower with a 5" mid and dome tweeter will get vaporized by anything less than very low level playback.

That said, old school horn based systems with a sensitivity of 96 dB or higher and a 100 watt rating or higher will likely play loudly enough that you will lower the gain and they will handle what you throw at them. It is still a good idea to use some zener diodes or other form of tweeter protection just to be safe, but the speakers I run in my house can easily handle live sources.

 

[Sokel]

can only go up to 5V,

...while the normal, nicely recorded playback summed spectrum will bang at 1V, 1.5V tops (and I mean tops, including true peaks) at line level, balanced, for average playback.
Imagine throwing a 5V zap at it, which you can easily do with an instrument.

 

[ssashton]

Well, I cannot give you a full scientific explanation. Theoretically, you're correct. But I have done this plenty and I find it very important to be careful with a bass guitar through regular speakers. I have heard the cone on my woofers cry for help and nothing was being "clipped". They just couldn't handle what was being sent to them. Guitars are much safer because they have a lot less low frequency content. Also, I was using an active bass and they have more output, which shouldn't matter since I was going through an interface, but it seems to be more powerful. So, I have no science for you on this, but maybe you could do the experiment and let us know. But please don't blow up your speakers in the process.

Same here. I've spent a lot of time in recording studios with electric instruments directly plugged in ti line / high-Z inputs and played through the monitors. If you do not use a compressor or at least a high pass filter to remove sub-bass you are going to see your cones flying and flapping about. Might be okay with mains that use 12" to 18" woofers, but not mid-field monitors 5" to 8" cones.

You want to pass through a processor like Izotope Trash to apply compression, limiting and model box / amp distortion. Then you will be fine and extremely happy Most players said this sounds better than their practice amps through good active monitors. Make sure latency is low in your driver settings.

 

[mixsit]

I have also wondered this and the advice I have always been given is not to do it as it may damage the speakers, even at low volume.
Doesn't make any sense to me. Aren't the speakers reproducing the same sounds when you play recorded music?
I haven't been brave enough to try.

Your post here right off with PortalKeeper's.. "plugged in without any EQ or compression" went.. 'click here ..this be 'old musician recorder guy stuff kicking in
I read through the thread to see where things lead before coming back around. Most of the various cautions and issues get brought up. What 'clicks so well is.. the particular lines here kind of almost touch around all of them. To go right to it how bout.
The instruments do get record processed. Eq trimmed' for example, 'levels controlled etc. Good example. Guitar, into an amp. Slap the strings a bit our speakers jump.. a good bit. Mic on the speaker- typically moderates that low end stuff. Regardless, high pass filter's apt to be finishing the tracking job. Vocals quite similar.
So plugging straight in for the most part our speakers are very easily not seeing the same things.