Buzz from front left 340 - Any thoughts??

[bri1270]

:confused: Last night I noticed a very slight buzzing sound coming from my front left 340M. I shut the source off (tv at the time) and it was still there. It's only that one speaker. Any ideas what might cause this? The volume of the noise does not change with an increase or decrease in the volume. And again it's only that one speaker so I really don't think it a ground loop.

Thanks,
Brian

[Eddie Horton]

Swap the main speakers. If the buzz stays on the left side, I'd check the receiver. If it switches places and comes out of the right side, I'd suspect the speaker and call Ascend.

[bri1270]

Brilliant idea eddy, thanks. One more thought, could it be emi/rfi?

[bri1270]

Okay swapped speakers and got the same thing, so it's either the amp or "noise"...whew

[sensibull]

Here (http://www.ecoustics.com/Home/Accessories/Power_Conditioners/Power_Conditioner_Articles) is an index of articles that may help...

Not all of them are still valid links, but this one (http://www.audioholics.com/techtips/setup/avhardware/groundloopcableTV.php) and
this one (http://www.mastersonaudio.com/tips/20040915.htm) seem pertinent.

[bri1270]

Thanks.

Wouldn't a ground loop be present in all of the channels though, not just one? And aside from that, all of the HT outlets are grounded in the same place, so theoretically there should not be a problem. I'm going to try switching a couple of channels around to see if it's the amp. It's not really noticeable unless I place my ear to within ~6" but I don't want it to hurt my speaker.

[sensibull]

Wouldn't a ground loop be present in all of the channels though, not just one?

Probably. I'm no expert, just offering some info. I think the second link I sent you talks about picking up radio noise, not ground loop.

[metalaaron]

Okay swapped speakers and got the same thing, so it's either the amp or "noise"...whew

make sure you don't have any cables dangling around, especially RCAs that might be touching something. any new devices in the house (telephone, etc.)?

[bri1270]

I wasn't being critial Senibull, I was noting something I picked up in the link that you provided. It said that a ground loop typically occurs if you have two components that have different grounds. In my case, everything is running to the same 60Amp box which is grounded correctly (according to my little three light tester).

All of my cables are seperated (audio w/audio, video w/video power w/power etc.), wrapped, and strapped to the rack in separate "trunks."

When I get home from work I am going to check that channel on my amp, I have a sneaking suspicion that's where it's coming from. When I received my Ascends, I went through and changed on of the channels that was powering a rear to the front. I didn't notice the noise before.

If that is the problem, I would rather use that channel in the rear and not in the front, given the location of my rear speakers, I won't hear it at all.

[Quinn]

You might try changing out the speaker wire for that channel and see if that is an issue or the interconnect.

[bri1270]

okay, so I checked all of my connections, and changed the channel on the amp, and it's still there. I'm pretty confident that it's emi...the speaker outlet is right near a switch panel. I thought when I installed it I had put the speaker wire far enough away, but I think there's just too much going on in that particular location.

Thanks for your thoughts everyone.

[Eddie Horton]

Correct me if I'm wrong, but I thought speaker wire was pretty much immune from all but super high amounts of EMI. I'd check for problems with interconnects instead.

[curtis]

So it is always the left main....even after changing the amp channel?

All sources too?

[bri1270]

Yep it's always the left even after changing the amp channel. Eddie might be right though, I guess it could be a bad cable. The connections are all tight, nothing is loose.

And it's all sources as well.

[bri1270]

okay, well I got up early this morning, so I figured I'd try a few more things. I changed the RCA cable from the receiver to the amp, I changed the speaker wire out, I tried changing a few diffrerent channels on the amp. I finally decided to bypass the amp completely and go from the speaker directly to the receiver amp instead of the external amp...buzz is gone! I think it might be the pre-out on my receiver. Deductively, that's the only possibility, I tried switching and changing everything and the only time it went away was when I bypassed the pre-out. Any ideas what would cause that in a receiver? I was running 5 channels through the pre-outs to a B&K AV5125.

I'm in the process of another remodel in the family room. I'm building the TV and the components into the wall. In the adjacent room, I will be able to access everything very easily from behind, and I'll see if maybe I missed something but for now, I'll just keep it the way it is. It's not like the receiver will be working too hard. I'm also pretty sure that I'll be installing an IB subwoofer...looking forward to that. (4 x 15" drivers).

If anyone has any thoughts on the receiver thing, please let me know, b/c it's really pi&^ing me off...it's a brand new Pioneer Elite 54TX.

[jimsiff]

So you get buzzing in your front left channel, and only your left channel. The buzzing always comes from the left channel. At this point, you've swapped cables, speaker wire, checked for cable management issues, etc. You've bypassed the B&K amp and the buzz goes away. You're thinking the pre-out is the issue. That could be.

I re-read the thread, and it's hard to tell exactly what steps you've taken and in what order. You've got a 54tx pre/pro running to a B&K AV5125, then to Ascends in a 5.1 setup, right?

Here's the steps I'd take to isolate the issue completely:

(You've done most of these, just not sure of order)

1) Eddie's step from page 1. Physically swap the L and R speakers. Don't just swap speaker cables on the amp. If the buzz stays on the L, it could be your L speaker wire, B&K amp channel, interconnect, or 54tx pre-out. If the buzz moves to the R channel, it's the speaker, and call Ascend. If the buzz stayed L, go to step 2.

2) On either your 54tx or the B&K amp, switch the interconnects for the L & R channels. You want the 54tx L -> B&K R, and 54tx R -> B&K L. If the buzz stays on the L side, you can rule out your 54tx pre-out and interconnect. If the buzz moves to the R channel, the problem could be your 54tx pre-out or interconnect. Use a known good interconnect to determine which of the two is the problem. If the buzz stayed L go to step 3. Return your interconnects to their original state.

3) On the B&K amp, switch the speaker wire for the L and R channels. You want the B&K L -> R speaker, and B&K R -> L speaker. If the buzz stays L, the problem is either speaker wire or a funky RFI/EMI or ground loop problem as you've ruled out your pre/pro, interconnect, amp, and speaker. If the buzz switches to the R speaker, then the problem is probably the L channel on your amp.

Good luck...

[bri1270]

I'm actually in the middle of installing an in wall cabinet to house my gear. I will check all of this stuff again when I can easily get at it from the back. I'm pretty sure I isolated the receiver as the problem, but I wasn't very procdural, so I may have messed it up. When I re-do my tests, I'll write everything down, and be a bit more methodical...as opposed to the bull in a china shop approach. For now, I am bypassing the amp and running through the receiver.

On the plus side I just ordered 4 of the AE Stryke IB15 subwoofers for an infinite baffel install. That should be interesting.

Thanks for the help Jim. I printed this page out to help with isolating the problem. I should get to it within the next few weeks.

[jimsiff]

Nice! Those IB15's should work out great. Do you have any idea what you're going to power them with? Let us know your impressions of the IB setup when you get that finished. I don't make it over to the IB forum very often, and it would be cool to get an impression from an Ascend owner.

You're probably right about the pre/pro, but it's good to make sure. Let us know how that turns out. If it's the 54tx, I really hope you bought authorized. Pioneer can be difficult to deal with for Elite service unless you have proof of purchase from an authorized dealer.

[bri1270]

Sorry for the delay in response, I've been a little busy. I think I am going to go with either a Behringer EP1500 or an Alto Macro 1400(Italian pro amp, supposed to be very good and relatively inexpensive) to power the 4 IB15's. Whilst ripping the room apart, I noticed that the wall I want to dig in to is load bearing, so I had my brother in law come over and take a look (he's owns a construction business), we've decided to put in an LVL so that I won't have to deal with any beams at all...which will be VERY SWEET. Anyway, I'll definitely let you know how that sounds when it's done (probably not for a couple of months).

As for the receiver - of course I didn't buy from an authorized dealer...if I had, it wouldn't have any problems. But like I said, I want to better document the troubleshooting process before I make a final diagnosis. It still could be the amp, maybe it was too much of a load for it or something. I think B&K might hedge their power specs a bit.

[bri1270]

I had another thought, but I don't know if it's possible...Will a pre-amp go into clipping? Anyone have any idea?

Also...how about running a 200 in tandem with a 340C...2 center channels...any thoughts?

Thanks