Sierra 1 & bass distortion?

[883]

I am running on Onkyo 705 with 5 channels (no .1 and I probably do as much 2 channel as 5...). While watching The Dark Knight Rises Blu-ray, I noted a few instances where my front left Sierra 1 and to a lesser extent the right seemed to have a slight rattle (I was attributing it to additional "detail" in the background of the movie and not a rattle). The element that has me concerned however is when Fox takes Miranda on the elevator/platform down to the reactor and the elevator hits bottom/stops. A heavy bass signal is sent which made the speakers (and yes, it came from the speakers and not the room) --esp. the front left-- sound like a rattle was coming from them. This is the secondary concern however. The primary concern is that the speakers (left front in particular) created a sound with that base signal similar to what one would expect small speakers from a child's toy (or inexpensive external computer speakers) to create if hooked up to play one of the lower registers of a pipe organ or bass heavy rap etc.

Initially, I wondered if it was actually the sound editing, but playing it at a very quiet level seemed to resolve this. Volume was set at 70 (for those with familiarity-- I know, there can be a lot of variables). Suffice it to say that it was not exceptionally loud and the distortion could be replicated at about 63 up.

So the questions:

1) MOST IMPORTANTLY: Does any of this seem to suggest that my speaker may in fact be damaged OR may have suffered damage? I have never heard this from these speakers, but then I have never watched this disc until tonight. I would not expect moderate volumes from a reasonably powered receiver and outstanding speakers to do this.

2) What is anyone's guess as to what happened?

Thank you for knowledgeable insight.

[curtis]

Do you use a sub? The speakers are running fullrange?

Probably sent some pretty low frequencies at an output level that caused excessive port noise....or maybe bottom out the woofer(although I have never read that happening).

[883]

Curtis,

Thank you for the reply. I know a great deal about "listening" but considerably less about the technical elements of what the speakers are "doing"...

No ".1" signal. In other words, no subwoofer. Yes, the fronts are set to full range. There is no doubt that it was a VERY low frequency that was put out at that point. Again, although the volume was somewhat high it was nowhere close to being what most would consider especially loud (and I am only sitting about 8.5' back for this particular setup).

I've never heard of excessive port noise with the Sierra 1. What can you tell me about it? If the woofer was "bottomed out" would that cause damage? Again, I really did not have things set very loud.

I am thrilled with these speakers and am truly hoping there is nothing wrong with one (or both).

[883]

Anybody able to answer?

[curtis]

The excessive port noise would sound something like a "flutter", caused by more air/velocity than was it was designed for.

Yes, bottoming could hurt the driver, but if anything was damaged, you would hear it during normal use.

[883]

Well, when I worked on replicating the sound with the volume starting low and gradually increasing each play time I positioned my cheek and ear relatively close to the port to attempt to better hear what was happening. There was certainly a tremendous and very sudden rush of air out of the port (almost felt like a small fan but in a burst). I don't know how to really describe the distorted bass sound other than if you have used a pair of cheap/small ear-phone jack type speakers plugged into a computer playing back music with any significant bass at a moderate volume. Can port noise sound similar to clipping? I certainly hope that is not what I heard (and come to think of it, don't figure that between the Onkyo and the Sierra 1 in a conservative set up and moderate volume this would be the case).

I presume the damage from bottoming a driver would be something that would be readily apparent then-- yes/no? I would expect that the volume should need to be set quite high as well.?.? What type of sound/indicator would I expect to hear from such damage? I have not been able to sit and listen since then due to other demands, but the little I did, did not sound objectionable.

Thank you so very much Curtis for sharing your time and information and any extra answers you can provide regarding these questions/concerns.