Riddle me this Batman, is my speaker blown?

 

BDJ
Unregistered guest
I just bought a set of brand new Yamaha floorstanding 3 way bass reflex speakers, NS-555 model. The speakers are 100W nominal 250W max. The piano black finish is georgous. Anyway, I bought a new Yamaha receiver, model HTR-5840. It produces 600W, 6X100W. I've only hooked up the two floorstanding speakers thus far. Hook up the Dvd player and pop a CD in. I turned on the reciever and the display shows the volume at -30. I think to myself, thats odd, what the hell is there a negative for. So I turn the volume up to about +10. Then all the sudden the sound kicks in, almost knocked me over it was so freakin loud. I immediatly turned the volume down. Turns out it should be on the negative side. So im retarded, what can I say.

Anyhow, I played a few different CD's and it sounds like some of the bass is distorted sometimes. Sometimes I think the CD's are just old, etc. The thing is, deeper bass sounds better on it, but the mids sound fine. Somewhere in the middle of that range it sounds funky. I know speakers can be damaged when played too loud for too long, but im talking 2 seconds at most. Can it mechanically be damaged that quick? Im not sure if it is the CD's the speaker's, or I am just paranoid. I know I spent alot on this stuff, and cant afford to have blown a speaker within 1/80th of a second. Is there anyway to test the speakers other than by listening? Like I said it is hard for me to tell. Sometimes it sounds awesome, and sometimes it sounds like it is distorted somewhat. Help me if you can. Thanks.
 

Gold Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 6101
Registered: May-04


If the voice coil was damaged by being forced out of the magnetic gap for even a short amount of time, the speakers could have suffered some damage. The best way to check would be to take the speakers back to the shop where you made the purchase and have them check the speakers against a known good pair.


 

Varit
Unregistered guest
It sounds like you blew the speaker. On many receivers, +10 is extremely loud and you never make it to the positive numbers for normal listening. No matter what wattage rating the speakers are, the Yamaha receiver is probably also pumping out distortion at that volume setting, too, which is no good. A voice coil can be partially burned...does it smell at all? The partial burn could cause rubbing, too, which might be what you are hearing.
 

Silver Member
Username: Touche6784

USA

Post Number: 638
Registered: Nov-04
thats what a manual is for. wont be too surprised if those speakers are toast. just tell em you never thought of figuring out why the volume was negative and explain.
 

BDJ
Unregistered guest
yes, +10 is extremely loud. Ive turned the volume up slowly, and distortion begins around + 2 0r 3, somewhere in there. No there was no smell, like I said, it was only for a second. I can't compare the speakers, I ordered them. Not even sure where they would be sold locally. It's still hard to tell. Pink Floyd sounds great. Some parts of an Eric Clapton album sounded funky though. Physically speaking from the outside they look fine. There are two woofers, on each tower. Does anybody know of a way to test them?
 

Gold Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 6104
Registered: May-04


Take the grills off the cabinets and push very slowly and smoothly around the dust cap at the center of the driver. If you hear any rubbing or scraping, you've damaged the speakers. Other than that, there is nothing you can do to test the driver. Box them up and send them back telling the seller they are damaged/defective and asking for a repair/replacement.

Otherwise, you will live with the problem and learn the lesson of inconvenience of ordering of the internet. It is a difficult lesson to learn, but one that brick and mortar shops tell you can happen.


 

Silver Member
Username: Frank_abela

Berkshire UK

Post Number: 948
Registered: Sep-04
When Jan says push, he means push lightly. The way I do it is with my fingertips on the cone of the drive unit (not the dust cap in the middle!) and push in the driver. You should feel no friction. If there's any rubbing or scraping, the drive unit is fried. Proceed to the next drive unit.

If the units are free in their movement, then there's probably no damage done. The question then becomes, how loud do you want to listen to these things? If +10 is the maximum volume of the amp (some go up to more than that), then I imagine that +2 is still pretty loud. Pretty much all amplifiers begin to distort when you get close to their limits. Some amplifiers begin distorting at just half way around on the volume dial! This is with a relatively strong input signal such as a CD player. Some devices such as tuners or record decks have lower input signal and so you can use more of the volume.

In order to find out how loud the amp will go, make sure there is no signal playing and turn the volume all the way and keep turning until the volume setting simply doesn't go any higher no matter whether you can turn it further or not. That's your maximum setting. Now turn it back the other way until it won't go any lower. That's your minimum setting. Now you can work out where half way or above is situated. Use that as your rule of thumb for volume.

Regards,
Frank.
 

Gold Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 6107
Registered: May-04


But, Frank, that method doesn't take into account linear taper or log taper vc's. Nor does it really explain input voltage to output voltage. Half way (12 O'Clock) on a digital read out is not the same as on an analog vc.


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