Weak Background Vocals

This is a weird one. On a few songs (and only on a few), the background vocals are very weak. An example is the female background vocals in Frank Sinatra's "That's Life." But also, the lead vocals are weak in the Beatles' "When I'm 64." This is only happening on a few songs and only on our big system. The same CDs sound fine on other CD players. I've tried adjusting everything and tried cleaning the CD heads, both with no change. Any idea what the problem could be?

Scott

[Cpt Rick]

Ok, so if I understand it right Scott, only the CD player you normally use on the big system does this, but if you plug another CD player into the same system it works fine?

If you take the CD player from the big system, and plug it into a different system, does it still do it?

If it can't be narrowed to the CD player, what else is in the loop before the speakers?

Definitely not the CD player(s) or board because the songs all sound fine in the headphones. And as I said, its only certain songs. I've checked everything except perhaps trying a different CD with the same song(s). Its very maddening.

The entire system is four speakers, equalizer, crossover, bi-amped, mono.

Scott

[ November 13, 2002, 12:36 PM: Message edited by: Scott S ]

[Cpt Rick]

Just a curios thought, have you tried switching to stereo instead of mono?

Depending on where you're getting the headphone output from (mixer, CD players, etc.), it could be in stereo output, whereas the actual signal you are hearing on the system is mono. Does make a difference.

That would be the only thing that might make sense, as the vocals in question could be panned to one side or another, and don't always come out with the same output level in mono.

The other question I would ask is whether this just started happening, and if so, what did you change?

I don't like running stereo because the sound quality just isn't as good, but I did try these songs in stereo mode a few weeks ago (while setting up for a gig), and got the same result. As to when it started, I can't say for sure. I recently put in a new equalizer but it was doing it before that and the new equalizer made no difference. I know it was OK in July 2001 because that was the last time before a couple weeks ago that I played Sinatra's "That's Life." There are probably about 6 or 7 total songs that I've noticed a problem with in about the last 3 months.

Scott

[djxtreme]

wait, you said you usually play in MONO? becasue stereo is BAD? is that right? from everything i know...it's better to play in stereo...

[Cpt Rick]

Maybe yer getting old Scott [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

Seriously though, have your ears checked, could be you lost some response at certain frequencies that is causing it. Mines changed, I can tell by my EQ settings now and how they were 20 yrs ago.

The only items left are the crossover, the amps and the speakers, which might have lost something in a given frequency, but I would expect the only one to be the speakers, and that's pushing the envelope.

The chances of solid state components losing a given frequency in a decode of an sudio stream are not likely - what's more likely is to lose the whole decoder PROM, in which case you wouldn't hear anything.

One thing you could try without cost, is to rip the songs in question into wav files, and then run them through a spectrum analyzer to see if any frequencies went "flat" for some reason.

[KJDJ]

Check your mid/high speaker wiring polarity (+,-)
Sounds like you are out of phase on one of the mid/high cabinets. If your speakers are out of phase anything that is dead center in the mix will create a mode and cancel out.
If it isn't the speaker wiring check the mid/high lines between the active x-over and the amp. If the connectors aren't molded type open em up and check them.

Let me know what you find!

[ November 19, 2002, 12:04 AM: Message edited by: KJDJ ]

[KJDJ]

Oh and why is it doing it on just some songs?

Most older songs like Frank Sinata's use no vocal effects like stereo reverb therfore there is no differece at all between the right and left as it relates to the dead center vocals.

This is how vocal elminators for karoke eliminate vocals and why they don't work well on heavily prossessed pop vocals.