Speakers Blown???

doohan

Right boys and girls here's one for you...

I have a set of JBL floor standing high end speakers and a high end NAD amp. If the volume goes past 4/5 the speakers start dropping the sound and any louder they don't transmit any sound at all.

My question is, is it the amp or they speakers.? I don't have another set of speakers to test with so any help would be appreicated. This only started happening recently I used to be able to have the volume louder than 4/5. Oh and only my Hi-Fi separates go through the amp (all NAD by the way).

One thing I have thought about if it is the crappy connectors (I am just using the basic red/white ones)
Cheers
A.

Slaphead07

It's probably the amp "clipping" whereby if things get too loud it cuts out. To check if the speakers are blown just press the woofers diaphram in gently with the tips of your fingers, if there's a grating sound then they're blown, if it's smooth and quiet then they're ok.

On the subject of cables... NAD and JBL are decent gear but you're not hearing it through those interconnects and I presume similar quality speaker cable.

Buy one good interconnect and link your CD to amp with it. Sit back and listen. I promise you'll hear detail and bass/treble that you didn't know was there. I'm not going to say which interconnect to get but IMHO a decent 1 metre interconnect will cost €150 - €200 so don't think something for €30 is a real bargain.

Speaker cable starts at basic 79 strand stuff (although you might try mains "twin & earth" cable first... some like it!) or you could try Nordost basic flat cable at €9 a metre.

Red Alert

I would very much doubt a NAD Amp / JBL Speaker combination would be able to be driven loud enough to blow anything without first blowing your ears off. The Amp may be getting too hot, as some pro audio amps (like the Crest VS or QSC RMX's) reduce the volume if they get too hot, and only cut out for a serious sustained overload.

What source were you listening with? Anything connected to the Tape Out's on the amp?

doohan

Slaphead07:

Speaker wire is a high grade good quality. I will check the woofer thing when I go home (new house so no interweb connection yet). I have a very good interconnect from the CD to the AMP and the same thing is happening. Also I have turned off soft clipping.

Red Alert

Any source tuner/cd/tape. I will double check my connections again tonight. Should anything be connected to the tape out??Can really remember. I have the amp on the top of the stack with nothing covering it so hopefully that might help too.

Thanks for your help guys. What I will do is take a photo if I can't get it working tonight and you can give me your opinion.

Cheers

Red Alert

NAD soft-clipping shouldn't be kicking in at those volume levels - remember that we percieve audio on a log scale - to get 3dB of a difference you have to roughly double the power, so unless you're pretty near full volume, or you have a very 'hot' source going in, you won't be near the amp's clipping point.

I suspect that the soft-clip or overload protection circuit in the amplifier could be kicking in. The interconnect and speaker wire quality will really have nothing to do with it at all. If wiring was dodgy I'd expect erratic or unpredictable behaviour - not what you're seeing here which seems to be reproducable.

Some amps have issues with the input impedance of components on the tape out, but it should never really matter. Best advice for testing is to unplug everything apart from the CD player and go from there.

doohan

Thanks Red. I will do that this evening and post up the results tomorrow.

Cheers

Slaphead07

doohan wrote:

Slaphead07:

Speaker wire is a high grade good quality. ...... I have a very good interconnect from the CD to the AMP and the same thing is happening.

So what do you mean in pragraph 3 of your original post?

doohan

Slaphead,

The only good interconnect is the one I have from the CD to AMP. Apologies that I didn't mention the speaker wire before.

Cheers