Do I need an amp if I mostly play light Jazz music??

In my experience, amp necessity is not related to music genre, but to the quality of the recordings you are listening to, and to demands of the headphones.

I am an HD650 happy owner, and I can grant their sound changes a lot between simple "headphone outs" and amps, and between amps and amps, whether I'm listening to rock, jazz or classical.

What is your source?

If you actually expect transients of 160 dB, yeah, you'll need an amp for that (probably a heavy-duty one, too.)

I don't even know if the HD 650 is capable of 160 dB. Sensitivity is 103 dB @ 1 mW, which if I remember the rule of thumb, means that you'd be at ~500 Watts. I don't think you can dump that much power into HD 650s, even for a short time.

According to some sources full symphony can peak at 120dB.

If you have some well mastered classical that preserves the majority of the live dynamic range you could need all that power if you want to listen at "live" levels.

Quote:

Originally Posted by maverickronin 

According to some sources full symphony can peak at 120dB.

 

I can confirm it! My source would be a Audio Engineer...

That is the highest level estimate I have ever seen for a classical concert, but not too unreasonable when you consider it is peak rather than RMS volume.

As for 160db in rock concerts: that is ludicrously loud. By ludicrously loud, I mean loud enough to have heavy metal concert goers covering their ears and howling. There is no conceivable reason anyone would ever want to produce anything of that amplitude for pleasure. Wikipedia assures me that music never, ever, gets anything like that loud. Even if you did want music that loud, you would push the headphones beyond their mechanical limits in a flash trying to get the volume that high.

The HD650 is worth amplifying (beyond the level of your MP3 player output) to reach dynamic peaks without clipping at reasonable volumes, but it is not an excessively hard to drive headphone. Do the maths, decide how loud you want it to get and choose amplifiers that can provide that much power. A certain NwAvGuy has various charts on his blog which will help you with this: he also uses the HD650 as his example throughout. Have a gander at that and it should give you a good idea.

160 dB would blow your headphone drivers and your ears. Apparently that would vibrate the air so much it dims flashlights (I like to think of the capslock as a loudness joke).

100 dB peaks are nothing, even an HD650 wouldn't need an amp for that.

Quote:

Originally Posted by Head Injury 

160 dB would blow your headphone drivers and your ears. Apparently that would vibrate the air so much it dims flashlights (I like to think of the capslock as a loudness joke).

 

100 dB peaks are nothing, even an HD650 wouldn't need an amp for that.

Hmm...

162 U.S. FESTIVAL ROCK CONCERT 1983. 10 SEPARATE STACKS, AMPS = 400,000 WATTS (N) -REF.1.1983,-REF.3.

how many threads can I legitimately post this link to in 24 hrs?

http://gilmore2.chem.northwestern.edu/articles/hearing_art.htm

really dynamic recordings may have 20-24 dB instantaneous peak to ave SPL ratio - but this is very rare, even for Jazz or Classical

listening at 100 dB ave is live club loud - and shouldn't be indulged in for hrs at a time, not every day - the OSHA standards are lax compared to EU recommendations for sound exposure

but from that base up to 120 dB SPL could be seen as "needed" audiophile dynamic headroom

in fact really rare clipping is hard to hear if the amp behaves - doesn't "stick to the rail", give oscillation bursts on recovery

Quote:

Originally Posted by umvue 

I heard that because sometimes some rock music can instantaneously go to 160dB, so an amp is necessary to prevent clipping at such instants.

 

But what if I mostly only listen to light Jazz music that tops out at 100dB?? Does that mean I don't need an amp even if I use HD650?

It is the other way around. For the same average loudness, more power is needed for music with higher dynamic range (classical, jazz), and less power is needed for usually heavily compressed popular music (rock etc.) that can sound very loud already with a few mW of peak RMS power.

 

Quote:

Originally Posted by Iniamyen 

Sensitivity is 103 dB @ 1 mW

Actually, it is at 1 V (this way of specifying sensitivity is common for Sennheiser headphones), as confirmed by these measurements, from which a sensitivity of about 103.8 dB/Vrms can be calculated.

Quote:

Originally Posted by maverickronin 

 

Hmm...

 

162 U.S. FESTIVAL ROCK CONCERT 1983. 10 SEPARATE STACKS, AMPS = 400,000 WATTS (N) -REF.1.1983,-REF.3.

That is unlikely to be enough for 160 dB. 400,000W is about 56 dB more than 1W, and speaker sensitivity is usually at most about 90 dB at 1W and 1m distance. I am not sure about the sensitivity of those speakers, but the distance was obviously much more than 1m, and the maximum power was not used continuously either.

Quote:

Originally Posted by stv014 

That is unlikely to be enough for 160 dB. 400,000W is about 56 dB more than 1W, and speaker sensitivity is usually at most about 90 dB at 1W and 1m distance. I am not sure about the sensitivity of those speakers, but the distance was obviously much more than 1m, and the maximum power was not used continuously either.

 

Several things - First, it says at the bottom of the chart that all the values are normalized for 1 m distance.

Second, PA speakers as used for events and concerts are far, far more sensitive than typical home speakers.  They're almost always horn loaded, and the biggest ones can be extremely efficient with sensitivities of up to 110 dB at 1 W/1 m or maybe even higher.

160 dB peak is a the peak sound pressure when you are shooting a gun, and that peak lasts far less than 1 second.

Do 160 dB peak in a rock concert? At the listening position? I'm skeptical.

And even it it were true, that's no reason to want to reproduce those levels in your home, it far too dangerous.

BTW, 160 dB peak translates into 150 dB average for most recorded pop/rock music, so say goodbye to your hearing.

Quote:

Originally Posted by khaos974 

160 dB peak is a the peak sound pressure when you are shooting a gun, and that peak lasts far less than 1 second.

Do 160 dB peak in a rock concert? At the listening position? I'm skeptical.

And even it it were true, that's no reason to want to reproduce those levels in your home, it far too dangerous.

BTW, 160 dB peak translates into 150 dB average for most recorded pop/rock music, so say goodbye to your hearing.

I'll repeat again for those that have trouble reading, "it says at the bottom of the chart that all the values are normalized for 1 m distance."

I have no idea about the veracity of the numbers but I do not think 162 dB is entirely unfeasible for 1 m away from the PA stack at the loudest known concert.  At 20 m away (perhaps a typical listening distance) that's "only" 132 dB.  Still absurdly loud, but not unthinkable for concerts where hearing damage is the norm.

Quote:

Originally Posted by BlackbeardBen 

Quote:

Originally Posted by khaos974 

160 dB peak is a the peak sound pressure when you are shooting a gun, and that peak lasts far less than 1 second.

Do 160 dB peak in a rock concert? At the listening position? I'm skeptical.

And even it it were true, that's no reason to want to reproduce those levels in your home, it far too dangerous.

BTW, 160 dB peak translates into 150 dB average for most recorded pop/rock music, so say goodbye to your hearing.

I'll repeat again for those that have trouble reading, "it says at the bottom of the chart that all the values are normalized for 1 m distance."

 

I have no idea about the veracity of the numbers but I do not think 162 dB is entirely unfeasible for 1 m away from the PA stack at the loudest known concert.  At 20 m away (perhaps a typical listening distance) that's "only" 132 dB.  Still absurdly loud, but not unthinkable for concerts where hearing damage is the norm.

I know that, it was just another way to give a sense of scale to the OP.