That damn hiss!

[Jim Casey]

Ok...I'm getting tired of hearing the hiss in my system. Maybe it is just me but it seems to me that it shouldn't be there.

Changed wires, replaced components, I must be stupid or something, please help!

[DJ Dr. Drax]

Where is your mixer master set & where is your amp settings at?

That should tell us where the hiss is coming from & why it's there.

[Jim Casey]

System setup is as follows..

Numark DM 1200 Mixer out to BBE 362 Sound Prodessor, out to Ross 15 CH Stereo EQ, out to Mackie 1400i Amp, out to JBL EON 1500s (non-powered)

Levels as follows

Mixer at about 50%
BBE at 6
Ross EQ is at zero on both sides with my channels favoring more bass
Mackie Amp at about 30-40% (which until recently I did not know was low)

I use two Wireless Mics

Shure SM 58
Sennheiser 100 series

[Cpt Rick]

Alright, I'll be the one to ask the question that we all know needn't be asked, but sometimes can solve the problem quickly:

Is everything grounded properly to a common ground?

The next question I would ask is does your mixer have an effects loop, and if so, why aren't you using it?

But, what I would do is take all the pieces apart, start with just mixer, amp and speakers and then add everything in one at a time until you find the source of the hiss. I have hiss on my system, but I know in fact that it comes from the mixers EQ section. So, I know how to deal with it.

[DJ Dr. Drax]

I don't beleive you have a ground issue, Ground issues produce HUM, not hiss. HISS is NOT a sign of poor grounds. HISS, it is a sign of system noise, It is typically called shot noise. This can be introduced in cables if located too close to high energy devices, or other places, but the places to look are several. Here are a few.

First place to look is the BBE, try completely removing it, not just using the bypass. BBE's are notorious for having noisy stage gain in it's processing.

Next place is your mixer. How old is it? sometimes the faders will wear & this will lead to an increased noise floor in the mixer.

Jim your amp is NOT LOW at all. Turn the amp down all the way. Then try this, turn up the mixer to 75% or more, where ever the unity gain position is for that mixer. Place the channel fader also at unity, now Play a typical track, Now turn up the amp to the normal volume is acheived that you use. Then listen to it with no music. I will bet that it will be considerably quieter yet still produce the music you seek at the volume levels you desire.

If it is not significantly quieter, then I would look at having the mixer tested with bench gear. That is the ONLY way to really measure the noise floor on it.

[ November 03, 2002, 06:00 PM: Message edited by: DJ Dr. Drax ]

[Jim Casey]

Thank you very much for the advice Drax!

It may be a cable thing...

In my main cube, on the top I have an 8 outlet power strip for my lights, a couple spaces below that I have my mixer and directly beneath, my dual CD controller

On the bottom end of the cube I have my Power Conditioner/Light Module, Dual CD Players directly beneath, BBE beneath that, two receivers for the wireless mics, and a Consumer CD Player that I use for a 3rd and/or backup

all plug into one main power strip...so I only use one outlet at any gig...

Hope that is helpful too (Can ya tell I'm not a technical whiz)

Thanks again Drax!

[DJ Dr. Drax]

might be but I REALLY REALLY doubt it. If we were talking about HUM, that would be another story, but HISS, that snow on the TV, FM radio type HISS, is another thing.

After revieweing the specs on the gear you state, I am pretty sure you will find that the Hiss is a result of having the mixer set too low, & the amp set too high. That or your mixer is at issue.

Did you try the test I suggested?

[Jim Casey]

I will be tomorrow afternoon (hopefully in an atmosphere above 30 degrees as we are in the ddep freeze here!)

Thank you for your suggestions! I will be printing them out and going step by step!

[Cpt Rick]

I have to agree with Drax, if it's definitely hiss, then it's probably one of the components, not the cables.

One of the biggest problems I've found through a gazillion tech support calls, is that although people differentiate between hum and hiss, they seldom articulate it during the call or post.

So, I always go with the LCD in this case, then work up from there. I think the only way to isolate it is to take it apart and put it back together piece by piece until the noise comes back.

[Steve Fernino]

Sometimes, certain gear has more hiss than others....Different combinations of gear can make it worse. There are setting to help minimize the hiss (as Drax mentioned), however, if you find that one piece of gear is contributing more than another of the same type....I would upgrade when you can, to something with a higher noise floor.

For example... The powered EV 100 has lots of hiss even with the power turned all the way down...No matter what system I use it with.

The Mackie 1530 has practically nothing....
The hiss with the 1530s is totally system dependant.

Maybe the Numark mixer has alot of hiss?
I don't know alot about that particular mixer, however, my experience with multiple CDMix1 and CDMix2 units has basically given me the conclusion that they are noisy units. Lots of hiss...and even some digital "whine" on the mic channels. The 2 is better than the 1, but it is still there. We were using these for ceremony work...we have since retired most of them and are going the route of a Mackie board for ceremonies.

Also, if the hiss is at a minimum, but it is just a personal annoyance to you... You can purchase a noise gate. When set properly -
all signals pass through without hesitation ....however, during moments of silence, the hiss is blocked as the gate is closed. I wouldn't use this piece as a bandaid...however, it can give you that extra little bit of peace if even the slightest hiss irks you.