Like

Negative volume

 

Colleen
Unregistered guest
Can anyone tell me what would cause my receiver (Panasonic SA-HE75) to show volume in the negative decabels instead of postive. I can hear it fine, it's just in the negatives instead of postives.
Thanks.
 

Gold Member
Username: Project6

Post Number: 1560
Registered: Dec-03
by design:-)
There is probaly more to it than that but I ignore it, hah!
 

Gold Member
Username: Project6

Post Number: 1561
Registered: Dec-03
here's a small read on the subject
http://hometheaterhifi.com/forum/archive/index.php/t-61.html
 

Colleen
Unregistered guest
So there's nothing I can do about it? I have to listen at -60?
 

Bronze Member
Username: Petergalbraith

Rimouski, Quebec Canada

Post Number: 80
Registered: Feb-04
What's the problem? The negative scale is much more useful anyway...

I assume that 0dB is the max output the amplifier give with a saturated input voltage. Everything below is okay, anything above might lead to clipping. The fact that you listen at -60 means you have a lot of headroom. Efficient speakers in a small room?
 

Silver Member
Username: Rh1

Post Number: 156
Registered: Jun-04
colleen...Peter is right about headroom, you are in a good situation if -60 souunds good to you
 

J. Vigne
Unregistered guest


Put a piece of tape over the "-", now you're listening at 60dB. Isn't that better now? How do you feel about speedometers?






 

Colleen
Unregistered guest
Peter, it is a small room. I don't know if they're efficient speakers or not. They're the speakers that came with a RCA Home Theatre. The receiver crapped out so we replaced it with the panasonic. 0dbs is as high as it goes. I just wanted to make sure that it wasn't the way I had hooked it up that was causing this. For example if I had the negative and positive speaker wires crossed would this happen?
 

Gold Member
Username: John_a

Post Number: 2148
Registered: Dec-03
It is OK, Colleen. Don't worry.

dB (stand for "deciBell") is a measure of sound pressure. It is all relative, so a minus value just indicates a decrease compared to some arbitrary reference point, which, in your case, seems to be "as high as it goes". Each time you subtract 10 dB (equals one Bell, named after Mr Bell), you go down to about half the previous perceived loudness. In theory you can do that ten times (-100 dB, or minus ten Bells) to go from earsplitting (the threshold of pain) to the quietest sound still audible to humans.

By the way, if you get the wires crossed it will do no harm, but two speakers should be same (both crossed or neither crossed) to get the best sound, particularly in the bass. It makes life simpler to connect + (red) on the speaker to + on the amplifier and - (usually black) on the speaker to - on the amplifier for both, or all, channels. Your speaker cables should be coloured or marked in some way so that you can easily tell which of the two strands is which, at both ends. The dB meter will not be affected whether you get that right or not, but you will probably hear that it sounds better of you get it right.
 

Bronze Member
Username: Petergalbraith

Rimouski, Quebec Canada

Post Number: 82
Registered: Feb-04
Colleen,

Everything is fine with your wiring. The dB scale is much better than an old 1 to 10 dial. It actually tells you how loud you are playing relative to the maximum the receiver can pump out. At -60 dB, the receiver is outputting one millionth of its rated power (60 dB = 6 orders of magnitude). Your panasonic is rated at 100W per channel (not all driven at the same time), and so at -60 dB it is outputting around 0.0001W per channel. It's not very much, is it?

I'm surprised. I listen to quiet evening TV at -50dB or so (in the basement so I listen louder than I would if I were in the living room), quiet jazz at -40dB, loud music at -20dB and very loud music at -10dB. But my speakers are very efficient. I'm surprised that HTIB speakers would be loud enough at -60 dB, but I won't argue with you.
 

Colleen
Unregistered guest
Peter,

Well my husband was trying to sleep so that's probably why I only had it at -60. Just wait till Sunday when the NASCAR race is on. Then we'll "crank it up".

Thank you all for the info. I feel much better. I was sure I had screwed something up.
 

Colleen
Unregistered guest
John,

I double check my speaker wiring when I get home just to make sure I've got it right. Thanks for the great explanation.
 

Gold Member
Username: John_a

Post Number: 2151
Registered: Dec-03
Colleen,

You're welcome. Let us know.

Best wishes.
 

Bronze Member
Username: Bleustar

Pensacola, Florida

Post Number: 88
Registered: Jul-04
Nascar at -10dB is the standard at my neighbors house too.

I hope your mind is at ease.
 

J. Vigne
Unregistered guest


Glad to hear you like speedometers.



 

Gold Member
Username: John_a

Post Number: 2155
Registered: Dec-03
J.,

I suspect many freeway pile-ups in fog result from drivers relying on just their perception of speed, rather than on reading the speedometer, too, and thinking a bit. I would also prefer to fly with a pilot who reads his altitude meter occasionally. It is not irrational to wonder what those numbers mean!
 

J. Vigne
Unregistered guest


I wasn't implying that is is irrational, John. I just hadn't been an a-s-s* lately.



*They won't let you put that word on here.



 

Silver Member
Username: Myrantz

Post Number: 713
Registered: Aug-04
"I would also prefer to fly with a pilot who reads his altitude meter occasionally"

That's old school John. The first thing they taught my son at flying school was:

Stick forward - trees get bigger
Stick back - trees get smaller

It's a darn lot simpler!
 

Gold Member
Username: John_a

Post Number: 2160
Registered: Dec-03
J.,

I took your point. How it sounds is the issue. I could also see Colleen's, too.

Mr Rantz,

Yes, you have to be able to do that, too. I am an old school Old Dog, as you know. Reliance on altitude meters alone has sent several Airbuses into mountains, I recall. Not sure what alternative you have when you can't see the trees at all, though.
 

Silver Member
Username: Myrantz

Post Number: 715
Registered: Aug-04
Mister A

Not too many alternatives. They also taught this:

If you are flying at night and your engine fails, turn on the landing lights. If you don't like what you see, turn them off!
 

Gold Member
Username: John_a

Post Number: 2162
Registered: Dec-03
Please replace with "Mr" with "My"!

This is scraping the barrel, but flying four older models, in formation, Bond style, always make sure you can see the other Bristols.

I think it got incorporated into British Aerospace.
 

Silver Member
Username: Myrantz

Post Number: 716
Registered: Aug-04
John A Esquire,

Ah! It's the simple things in life! These days the poor pilots have a lot more to worry about than flying the darn planes.
 

Gold Member
Username: Project6

Post Number: 1570
Registered: Dec-03
"Stick forward - trees get bigger, Stick back - trees get smaller "

Keep pulling the stick back and the trees get bigger again:-)
I think I heard that in a movie somewhere.
 

Colleen
Unregistered guest
Thank you everyone for your help and also for the flying lessons!
 

Gold Member
Username: John_a

Post Number: 2168
Registered: Dec-03
Colleen,

Keep an eye on the cabin pressure above -10 dB.

Good luck!
 

New member
Username: Mitchbd

Post Number: 6
Registered: Feb-04
Forget the trees... leave it in the capable hands of us air traffic controllers, and be sure to read the instruments!

BTW - Reading the last few posts here makes one wonder what it was all about anyway!
 

Gold Member
Username: Project6

Post Number: 1602
Registered: Dec-03
LOL, these things do tend to get off topic!
« Previous Thread | Next Thread »

Facebook

Shop Related Deals

Directory

Main Forums

Today's Posts

Forum Help

Follow Us