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May 4, 2004

Re: Buzzing sound from L1®

Dan; both T-1s are on a power strip and I also tried hooking them straight to the wall outlet and I still get a hissing noise out of the "remote side". That is the side were you use the trim nob to adjust the volume. The wired side with the RJ-45 jack connection doesnt make any noise. The L-1s are about 7 feet apart max. I am going to read the wiki for stereo setup and see if that helps. Channel 4/5 is a mono setup which explains why the bass sounds the way it does with two L-1s connected. I will post what happens after I try your recommendations.

Cap; yes, I just downloaded the updates which weren't on the T-1 because I just got it yesterday but last night I loaded the updates. Thanks for your suggestions.
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May 4, 2004

Re: Buzzing sound from L1®

Ok, I tried the recommended setup but I don't use my PC connection. I am running from my mixer out to the T-1. There is no instruction how to setup that way. The recommended setup is from PC to USB and then Master Out and Aux Ou. Since I have the model II (2) I run one of my L-1s from the RJ 45 Out of the T-1 to the Input of the L-1 RJ-45 (Tone Match Port). From my mixer I am running XLR out to 1/4TRS stereo into line 4/5 of the T-1. Right side (master is not used as per illustration) and left side is connected to Aux out on the T-1 to analog in on the second L-1 powerstand. The good news, the noise is gone now but the bass and high frequency are off phase. If I turn the aux ouput volume up on the T-1, the bass sounds great, as soon as I turn the master up for the other channel it loses bass when both sides are playing. Any suggestions????
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May 4, 2004

Re: Buzzing sound from L1®

Just to go along with the settings on the T-1 Wiki (T-1 Stereo Output using two L-1s), I hooked everything up as the diagram says to the USB on my PC using PCDJ Reflex on my PC. I am still getting the music out of phase so this tells me the T-1 is not dividing the two channels correctly in phase because it is designed as a mono or single channel device. If I use one side, the bass is very heavy and the highs are clear especialy if I add a packlight and two more B-1s. If I switch on both sides using both L-1s, the bass is very weak and out of phase. I tried every single way of hooking this up and I still get the same result, out of phase bass. Good thing is, the noise is now gone and that apparently came from the gain (or trim which ever you want to call it) being set too high on the T-1 and too low on the L-1 (trial and error). Looks like if I want true stereo and in phase bass, I am going to need a second T-1. The only thing thus far I haven't tried is a cable that is not Tip Ring Sleeve (TRS) I guess you call that a mono or TS cable. I will try that as Dan stated to see if that works.

What a day Smile
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May 4, 2004

Re: Buzzing sound from L1®

I tried a mono cable and it didnt work, bass still out of phase. I was hoping to get this resolved because we have a jam session at work for our summer cookout and a few guys are bringing guitars while I DJ and this would be a major plus if I could get the sound issue corrected. One tower won't due while I am playing outdoors with about 600 people outside the Pentagon. I will be using my full aresenal for this event.
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Re: Buzzing sound from L1®

Hi Ron,

I've lost track - have you tried putting the B1s together? (Physically grouped together).

If you have the B1s separated, the phase cancellation could be happening in the air.
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May 4, 2004

Re: Buzzing sound from L1®

ST; yes, the B-1s are grouped together two by two side by side.
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Re: Buzzing sound from L1®

quote:
The good news, the noise is gone now
Lest we lose sight of that, I'm glad THAT issue has been taken care of!

quote:
but the bass and high frequency are off phase

Hmmm...
I'm wondering if the issue might be the (slight) difference in signal processing delay between the digital and analog outputs and the current spacing of the L1's ... or a funky T1.

A few thoughts on how we might validate this conjecture:

D) Verify it is NOT a 'dual mono' issue. Two ways to check for that possibility:

D-1) Separate the two L1's (and their associated stacks of B1's) by at least 20 feet. If the 'cancellation' is really a 'dual mono' cancellation, this separation should eliminate it for much of the listening area.

*** This may be all you need to do for your outdoor gig coming up -- particularly if you don't have time to do the more thorough diagnosis possibilities I outline below. ***


D-2) Use a truly common analog signal between the two L1's. To do that, you'll need a "Y" cable (and a separate means to power the T1, if that is to be tested as well).

Put the two L1 columns as close as you can get them, and put the two stacks of B1's side-by-side behind them (as a 2x4 stack, if using the A1's).

-- Initially, use one channel from your mixer. Feed it through the "Y" to both "L1's" (the T1 is not involved in this part). Start with just one of the two L1's (turn the Trim on the other all the way down). Get to a comfortable listening level with just one L1, then turn up the trim on the other L1 -- what happens to the sound? With the columns and the B1's physically real close, you should not be getting much 'dual mono' cancellation. If you do, it would primarily be in certain bands of the mid-upper frequencies, not the low frequencies.

-- Assuming that is good (direct from one mixer channel), try both mixer channels direct to the L1's (without the "Y"). It should sound just as good, or even better, than it did using one mixer channel and the "Y" cable.

Let's call this setup above (D-2) the "Mixer Direct" approach.


E) Now, to check out the T1:
Leaving the two L1's real close, go back to the "stereo T1" setup, with one mixer output into (say) Channel 1, going to the T1's Master output. The other mixer output goes into (say) Channel 2, and that output is directed SOLELY to the AUX output (its channel volume would be all the way down, and the AUX setting would be Pre-fader, so it's volume is controlled only by that channel's Trim)

E-1) If you have a separate T1 power supply, you should be able to verify that the sound from this setup is the same as what you got with the "Mixer Direct", by using both the analog outputs (Master 1/4" and Aux 1/4") from the T1.

Does this sound the same as the "Mixer Direct"? If not ... then something is really 'funky' -- it should sound the same (the various Trim knob settings may be different in order to get the same volume from both L1's, but the resulting sound should be the same as with the "Mixer Direct" connections).

If the same sound, all is good with the T1 connections.
If different, then it may be that the T1 is bad (e.g.: has one of the connections reversed between the Master and Aux channels).


Now, assuming that the "fully analog with T1" is o.k., it's time to test if it is the digital vs. analog delay that is the issue.

E-2) Remove the analog cable from the T1 Master (both ends of the cable!), and power the T1 using the digital cable ... which also will provide the "Master" audio output to that L1 (the one that no longer has a 1/4" cable in it).

What does that do to the sound?

============
If you don't have a separate T1 power supply, then you can't really do setup "E-1" ... but you may still be able to tell if there is a significant different between "Mixer Direct" and the T1-based connections. If so, call Bose Support -- the normal additional delays between the Master digital and the Aux analog should be so small as to not be noticeable without very careful listening.
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May 4, 2004

Re: Buzzing sound from L1®

Dan; I tried everything that you suggested except the part with the T-1 requiring the power supply because I don't have one and it is not needed with the L-1 model II. Without the T-1 I get balanced sound out of the left and right and combined it sounds even better. As soon as I connect the T-1 one side sounds great but when I connect both sides it's out of phase and the bass is literally cut in half.

No matter which way I hook up the T-1 minus the way with the power cord connected, it still sounds out of phase with high frequency and low. It seems as though there is something crossed inside. Even if it were two mono channels (the T-1) the sound should still be in phase. Here is an example, if you cannect one speaker to your home stereo and play a song, you will hear the music play. If you connect a second speaker up to the same source considering it will handle the lower impedance, you will hear a significantly lower bass when you turn it up and it will still be in phase if the speakers are properly placed. The only way it will be out of phase is for one of the speakers to have the polarity crossed. If the T-1 has an input or output connection cross wired (negative to positive on one side and positive to negative on the other) it will cause the channels to sound out of phase.

My gig is next week and time is not on my side right now. I will call Bose support to see what they say. I know for sure it's not my L-1s, B-1s or cables because they work fine without the T-1 connected.

Thanks for all your help.

Ron
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May 4, 2004

Re: Buzzing sound from L1®

Dan; I called Bose Tech Support this morning and they are going to send me a power supply today so I can try the method you recommended so that I have two analog signals using the Master and Aux ouputs. If this works it will fix the out of phase sound problem I am experiencing with one analog channel and one digital.

quote:
E-1) If you have a separate T1 power supply, you should be able to verify that the sound from this setup is the same as what you got with the "Mixer Direct", by using both the analog outputs (Master 1/4" and Aux 1/4") from the T1.
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Oct 8, 2006

Re: Buzzing sound from L1®

Go to RADIO SHACK.
Buy some "Ferrite chokes"
Attach them to your XLR cables.
That's a quick troubleshoot attempt.
Worth a shot, and still good to have in your arsenal of "fixes"