Date: Wed, 27 Aug 1997 17:53:24 -0400
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: Gary Mceachern <gmceachern@MEDIAONE.NET>
Subject: Re: Stereo Wiring
Chris
Your troubleshooting and logic is fine a sfar as you've gone. I would
suggest trying at least one more test before deciding it's the amp
causing the buzzing. Reverse the LF and RF speaker wires at the amp. If
the RF speaker now buzzes and the LF doesn't, it's a safe bet the amp is
the culprit. If the LF speaker still buzzes you either got another bad
speaker or the speaker wiring or mounting is at fault.
If the speaker is bad (possible but not probable), reversing the LF and
RF speaker should cause the buzzing to follow the speaker. Make sure
there isn't anything obstructing or pushing into the back of the
speaker.
A few questions/comments:
Is the the buzzing occurring at all listening levels?
1.) If it only happens at higher listening levels, is the LF speaker
getting more signal than the RF? (amplifier gain control or balance
control will affect this). Make sure you are not simply applying too
much power to the speaker. Sit and listen with your head in the middle
between the speakers to determine this. More power may be being directed
to the LF speaker because the drivers listening position is so far off
axis from it.
2.)If you get this buzzing with the volume all the way down (off) the
buzz may be the result of a grounding problem. If this is the case it is
most likely present on both speakers. Maybee just a little louder on the
LF side? Check for bad or unintentional grounds on all system
components. Speaker wiring generally should not be grouned to the
chassis.
Are you boosting the bass control?
This may significantly reduce the maximum undistorted playing level and
increase the possibility of buzzing. Keep in mind the 4" speaker doesn't
produce bass efficiently. If you don't have a "high pass" crossover
blocking the deep bass from getting to this speaker it may buzz
particularly when played at higher levels.
Gary
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I have a question regarding the wiring of my stereo. I recently
installed an after market Sony CD Head Unit, Boston Acoustic 4"
speakers, Sub-Woofer and an Amplifier. Wired everything up and it
sounded great for a month. The other day one of the speakers started
buzzing! Pulled the speaker and exchanged it for a new one. New
speaker also buzzed.
Checked the connections at the amplifier and visually everything seemed
fine. There are two coax cables that come from the head unit. Cable
A (Left Front Amp In) and Cable B (Right Front Amp In). If I unplug
Cable A, LF speaker stops working and RF speaker plays beautifully. If
unplug Cable B, RF speaker plays and LF speaker plays and it buzzes.
If I take Cable A and plug it into the RF Amp In, RF speaker plays
beautifully. So I deduce that the signal reaching the Amp is OK....am I
correct? The fact that both RF and LF play when only one signal is
being sent to LF Amp In leads me to believe there is a bad ground? Am I
close? I tried grounding the Amp body but nothing happened! What could
cause this?
I am a Financial Analyst, are there any electrical engineering types out
there that could help me? If my reasoning is sound I'll just return the
Amp and tell them about the ground leak. However, I don't want to be
laughed out of Magnolia Hi-Fi when I bring in my Amp.
Thanks in Advance of any Advice!
Chris P. Seattle, WA
'89 Oil Burning Jetta "Jake"
'87 Wasserboxer GL "Lewis"
'82 Oil Burning L "Billie Rae"
