How many headphones can my avr handle?

[admin_exported]

Hi guys

I have paper thin walls so mostly have to watch at low volumes to avoid annoying the neighbours

I figured i might as well get a few headphones and use them on occasion - especially if the neighbours are making intrusive noises themselves.

So i bought a splitter and a 4 m headphone extension cord and a 2nd set of headphones for the wife.

When I plug the second set of phones in - the volume drops. What exactly is at work here (double resistance or half??) or something else affecting volume?

Secondly - just how many phones can I use without any issues - can I damage my amp by overloading it eg splitting agaion into 4 headphones? I must confess I have no idea how the headphone socket functions - obviously it carries more then just a signal - its somewhat amplified but beyond that im in the dark?

 

[Anonymous]

No-one knows?

 

[Petherick]

When you plug in the secont set of phones, the volume drops because the same amount of power is being used to power the 2 sets. So each one will operate at about 3db lower than before (depending on whether the 2 sets are the same or not). I would say go careful not to overload the amp, but other than that, I doubt it'll be a problem. Yes, the impedance will effectively be 4ohms if each set is 8ohms, but again, depending upon the phones, they'll probably be higher than 8ohms anyway.

 

[Anonymous]

THANKS for that - makes perfect sense.

What would constitute overloading the amp though - do I judge it in terms of speaker overload eg if it is specified as a 8ohm and 6ohm capable device for speakers - would the same apply to headphones?

 

[Petherick]

What are the phones? Do you know what the nominal impedance is - I'm guessing it's somewhere in the 75ohm area, not 8 or 6.? And bear in mind that this IS 'nominal' and not necessarily the true impedance at all frequencies and under all conditions. What I meant re. overloading was really driving them hard - which probably isn't the same as driving speakers really hard, since phones move a lot less air and use a lot less power. The specification for the phones should give an efficiency figure (db/W), so check this out and report back!

Cheers

 

[Anonymous]

Hmmm i am using a mixed bag

Sennheiser HD202's which are 32 ohms but i cant find their efficiency only that they run to 115db

Sennheiser cx300's which are 16 ohms and run to 112db

Vivanco SR210's - had for years and cant find specs on em even online

Not a load to go on - but i guess all i wonder is if i can safely run 4 sets of these sorts of phones without damaging the amp - perhaps i should call Denon themselves

 

[Petherick]

Hi again. Sorry for the delay and a happy new year to you.

Calling Denon seems the safest option if you're using 4 sets. Good luck.

 

[Anonymous]

Petherick

Many thanks for responding and happy new yr to you too!

 

[Alantiggger]

Happy New year then to all of you ... I've never noticed a 'drop' in sound when connecting a second set of headphones whether it's from my amp or mp3 player ... strange.

 

[Anonymous]

hmmm for me - the drop occurs when you actually plug the 2nd set into the splitter as opposed to say when i add the splitter to allow for the 2nd set - just in case there was confusion as to when it is noticable.

ie one headphone - std sound

one splitter introduced with one headphone attached - still standard sound

2nd headphone attached to splitter - sound diminishes.