Any way I could have damaged my speakers?


Yeah, so I was changing out some interconnects on my preamp while it and the amp was on.  I temporarily pulled out the rca cables that connect to the amp from my preamp and heard a screech from the speakers. Playing some music now and sounds fine but I'm obsessive compulsive. Any possibility I damaged anything?
benfica1
Post removed 
Yeah definitely not recommended but have done it several times over the years. If your speakers sound fine they are fine. Dont over think it.
Many speakers can take short term bursts of high level power/distortion. You may have gotten away with it. 

Years ago I sold a friend a beautiful pair of Canary Audio Zama Speakers. I set up his rig. Years later he rearranged the basement where he was using them. He wired it wrong and when he put power to it he blew out the speakers. Tough lesson. 

My advice is when you don't know what you are doing ask someone else before screwing around with it. Cheer up, it could have been a motorcycle accident. There are some hobbies where screwing up costs more dearly.  :) 


Easy mistake to make. Like Douglas says don’t make a habit out of it. Unlikely to have damaged anything if all sounds good. They can take more than you think.
Thank you all for the reassurance. Listening to Hell Freezes over - Eagles right now and sounds really good. Have to say, this hobby may not be life or death if you make a mistake but the serenity it can deliver is priceless.
As long as you did not let out the “magic smoke” your equipment is fine. Once you let out the smoke the equipment runs on you can’t put it back in lol. 
I ride and am not scared to fly through traffic but I'm terrified to tighten a rectifier or power tube socket with a screwdriver or dental pick, I don't know how to drain a cap. I always hear people use the term lethal power in the cap. Glad you didn't blow anything I do what you did sometimes but I know it's wrong, I don't like to turn tube amp off and then power it right back up, I know that can be a problem too

2 too many times for me, now I shut everything down before playing with Cables.
Always turn off the amp when changing wires at least, what I do, if I want to change wires on the safe side I turned off all my systems...
Stevecham 3-6-2019
Amp off first. AOF!


Millercarbon 3-6-2019
Uh, why? When its so much easier to simply change input?

The OPs issue occurred when he disconnected the RCA cables connecting his preamp to his amp. If the amp is powered up when that is done, as it was in this case, that could easily result in a brief transient being applied to the speakers corresponding to the amp’s maximum power capability, at an arbitrary combination of frequencies. With most of that power very possibly being in the treble region, where the power handling capability of the speaker is probably lowest.

The reason that happens is that when an RCA plug is inserted or removed there is a brief instant during which the center pin is connected but the ground shell is not connected. The amp or other component receiving the signal that is on the center pin responds to the voltage difference between that signal and its own circuit ground. Normally its own circuit ground is at essentially the same potential (i.e., voltage) as the circuit ground of the component supplying the signal, since the return conductor of the interconnect provides a direct connection between the circuit grounds of the two components. But if the signal connection is present while the ground connection between the two components is not present that voltage difference is uncontrolled, and will depend on the happenstance of the impedances between each component’s circuit ground and its chassis/AC safety ground connection, and on how the AC safety grounds of the two components are interconnected in the AC wiring and/or any power conditioners that may be in use, and on AC leakage currents that will be induced into that path to some unpredictable degree by the power transformers of the components.

Interconnections using XLR connectors are much better in that respect, because they are designed such that upon removal the ground connection is only removed after the signal connections are removed, and upon insertion the ground connection is applied before the signal connections are applied.

Regards,
-- Al

P.S:  I suspect that Millercarbon's response was a joke, but I thought I'd answer anyway for the benefit of others who may read this thread.

I made that mistake once...It sounded like someone shot a gun off in my room...Speakers were fine though..
I was having a ground issue with my tt and was wiggling the inter connects. I had the volume up to hear and one channel came off the tt.  I grounded the pin to the ring with my finger and got a super high pitched sound and blew both tweeters.  Scanspeak 2908 be domes,  $1100 a pair.  Everything off when working with cables.  Don't risk it!!!
Thanks for all the responses. It's interesting to hear everyone's take and different experiences and nice to hear that I'm not the only one who's made this mistake before.

@almarg ... Holy sh**t... What a technical explanation of what happened. A lot times in life, things happen that can't be explained or you think they can't be explained but you certainly did in this instance.

This happened with my favorite speakers that I've ever had so I'm just happy they're fine.
@almarg  "If the amp is powered up when that is done, as it was in this case, that could easily result in a brief transient being applied to the speakers corresponding to the amp’s maximum power capability, at an arbitrary combination of frequencies. With most of that power very possibly being in the treble region, where the power handling capability of the speaker is probably lowest. "

Could be that my saving grace was that I have a decware amp that only delivers slightly over 2 watts per channel?
Could be that my saving grace was that I have a decware amp that only delivers slightly over 2 watts per channel?

No question about it. It’s hard to envision a speaker that could be harmed by a 2 watt tube amp, even if the speaker is highly efficient (which I presume it is), and regardless of what part of the frequency spectrum that 2 watts occupies.

Generally speaking, though, I suppose it would be at least slightly possible that some amps might themselves suffer damage as a result of being briefly but severely overdriven, with a contributing factor perhaps being arcing of the tubes that could occur. But in general I would expect that possibility to be slight, due to the brief nature of the transient, and it certainly doesn’t appear to have happened in this case.

Best regards,
-- Al

I just committed a similar misjudgment but wasn’t so lucky.
 I was installing new speaker cable using banana plugs but didn’t remove the spade lug already attached to one of the amplifier leads. Actually played fine until I tried removing the spade lug.  It wouldn’t come off easily.  When I tried forcing it off I heard a terrible screech in one speaker.  The speaker still played, but when I compared it to the other speaker there was a definite deterioration in the sound.
Most likely blew the tweeter.  I sent both the amplifier and the speaker out for repair.

Sorry to hear of your loss.

I made a boo boo a few weeks ago.  I was trying to figure out why I did not have sound after changing around some interconnects.  I had left the volume open on a preamp and changed sources, bone head move.  At first I wasn't sure I damaged the speakers but after listening it was apparent something it had lost its magic.  It ended up being a damaged Synergystic Blue midrange fuse not the speaker.  Now I turn everything off everytime.  Hopefully lesson learned.