Axiom Home Page Forums General Discussion Technical Questions Ideas on the noise I'm hearing from my new 500?

Ok, as most of you know I got my new 500 yesterday. I can't even describe the WOW effect I'm experiencing. Movies rock my world and music comes to life in new ways I've never heard before. That is the good news...

Before I tell you about the news that scares me a bit, I'll tell you a little about my current environment. I installed the rubber pads versus the spikes, didn't want one of those darn things dropping on my foot like Bridgman I don't have carpet installed yet in the basement so all my speakers are sitting on concrete. I do have some carpet remnants through in the area to make it more comfortable for now when watching movies. I plan on placing the sub in the left corner to follow what some of you described as being the best placement for starters. For now I placed it along the shorter right wall, where my 350 was sitting just to test it out.

Below is a picture when I only had the 350, this is where the 500 is currently placed.


Anyway, now for the nervous news. I'm hearing noises coming from the port below the woofer. Not sure if this is similar to what NEW2AXIOM described recently and had to get a replacement? Anyway, using the SPL meter and test tones from my Denon 2805, sitting in the prime position, I set everything to approx. 75dB's by adjusting the levels on the receiver as the pink noise cycled around the room. What is interesting, the level on the 500 had to be set to -10dB on my receiver to achieve the 75dB reading. I have the volume on the sub currently set to 9'o clock as the manual states to start, and I have the trim setting to Flat mode, as the manual explains for a larger room, and bypass on the crossover.

Anyway, I took a variety of music down tonight to test cd's. I brought The Doobie Brothers Greatest Hits, Chicago 17, and George Strait Chill of an Early Fall. These CD's have many songs with good low bass. Anyway, I started with the Doobies, and was singing my heart out, dang it sounded so good when the 500 kicked in....then I moved onto Chicago 17. I don't remember the song, but I thought I was hearing a vibration. So I turned off the main speakers and just had the sub jamming out the low freq's. There were certain low notes that when played, I would hear a vibration. When I got down on my hands and knees I could tell it was coming from the port below the woofer. It seemed when I place my fingers in the port and applied some light preasure the vibration diminished or stablilized. So then I moved on to George Straight's CD, this has lots of low bass, I experienced the same thing. There were certain low notes that gave me the same vibration.

So what do you think guys and gals? It is not as easy to hear when you have the 60's rocking along with the 500, but I'm a little concerned? Maybe I need to set a piece of scrap carpeting under the rubber feet to simulate when I get a carpet and padding? I would think the rubber feet would be enough though as some people have hardwood floors under their 500. Can having it close to the side wall make internal vibrations? I have it about 3-4" from the side wall currently. This is temporary until I get everything setup and move it to the Left side. I checked all the fasteners and they all seem snug....

Thanks, Randy

If someone else with a 500 can play some music with a lot of lowwww bass, and turn off the mains so you can only hear the sub, do you hear this same internal vibration coming from the port? I just clicked my "Front" speaker button on the remote to cycle to the "B" channel, which I have nothing hooked to that, but it allowed me to shut off my 60's on the "A" channel.

It seemed to be more apparent when I increased the volume to around -10 to -15 dB's on the receiver...

Randy

In reply to:

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I have the volume on the sub currently set to 9'o clock as the manual states to start,...

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This could be part of the problem. The manual actually says "VOLUME: Set this midway to the 9 o’clock position for initial setup." You could possibly have the 500 volume set too hot. The off position of the volume knob is around 4 o'clock. So, "midway" between 4 o'clock and 9 o'clock, would be halfway between 6 and 7 o'clock. I found that was still too hot. I ended up with the volume knob set about half way between 5 and 6 o'clock. At this setting I could match the rest of my speaker's SPL with my receiver's sub setting at 0 dB.

However, the fact that you could reduce or eliminate the port noise by holding the port could mean the port itself is loose. If you feel that's the case, by all means, give Axiom a call and discuss the problem with them.

Thanks Jack, I'll have to experiment some more. My interpretation of that sentence, was 9'oclock is the midway point of the highest setting. I think they left a comma out, it should have said "Set this midway, to the 9 o'clock position for initial setup." I could be wrong, but if they intended to say midway of 9 o'clock, why would then not just say put it at 6 or 7 o'clock for initial setup? I'm just curious.

I guess I don't understand why they would even have a volume control that goes much higher if it would cause problems?

Randy - You mention setting the subwoofer to "10 dB" on your receiver. That usually means "+ 10 dB" ... back the receiver to "0 dB" for its output and increase the volume on the back of the subwoofer until you achieve 75 dB again.

You may be clipping the DACS in the sub.

Well, I'm not saying moving the volume on the 500 to a lower setting will solve the problem, but let us know if it has any effect, will ya, Randy?

If you look at my original post I said -10dB's. I placed the sub at 9 o'clock as I understood the manual to read for initial setup. After using the pink noise test, I had to turn my receiver down to -10dB's for the sub to get the meter to read 75dB's. I just figured since the 500 had a bigger amp compared to my 350, that is why it had to be so much lower. It just suprised me as Alan has always said to put the receiver on 0dB's and adjust the volume on the sub to reach your desired settings.

I'm no expert, believe me...

thanks Jack, I'll have to try again tomorrow, the rest of the family is in bed right now, and I don't think the wife would be to happy.

Got it - I missed the "-" on the line above the 10 dB. You are keeping the Dacs from clipping by doing this. Call customer service tomorrow - you should be hearing nothing from the port.

Man I hope it is not an issue of having to get another replacement. I think I pulled something hauling this bad boy downstairs, ha ha.

I'm no speaker expert, but to me the port is made of some form of plastic, not sure of the thickness? I would think there could be the potential of vibrations at real LFE's? Obviously the ports on the 350 were of a different material.