Sound Presure Level (SPL)

[Eric Toline]

To a degree you’re correct. A given amount of power will create “X” spl in “Y” speaker/hp’s before the amplifier goes into clipping and overloading the drivers and creating distortion. At too high an SPL and you can’t distinguish seperate sounds and you put your hearing in serious jepordy. Less is more.

Eric

[Ben Edwards]

Thanks Eric,

That kind of helps, I think;) The reason I am asking is because the Sony Z1 video camera puts out feeble level through the headphone output and I am trying to work out if there is a easy way to find how ‘efficient’ headphones are. By efficient I mean how much volume they create for a given signal.

Or maybe there is a inline headphone amp I could use but I would rather not have an extra bit of kit.

Ben

[Eric Toline]

Your problem is not the headphones, it’s the headphone amplifier in the camera. Most are notoriously weak in output level. Try a pair of ear buds and see if that helps. You might also look for headphones with an inline battery powered amplifier.

Eric

[Ty Ford]

and IME, be prepared for more noise when using an inline headphone booster.

The inline amp only amplifies what it hears.

The Sony MDR7506 are (last time I checked) the most sensitive headphones out there.

Less sensitive headphones will reproduce in even lower volume.

Regards,

Ty Ford

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[Ben Edwards]

Ty,

Yes, that’s what I have heard also and they seem to be popular amongst broadcast camerapersons. I have also heard that the cheaper HDR v6 is as good, the dBw is also shown as 106.

I actually have a pair of Sensitizer HD 215 which are shown as 112 dB/w. They are around half the price so maybe they are not as good from a sound reproduction point of you but currently loudness is my issue so I don’t want to go backwards in this regards.

Regards,
Ben

[Mark Spano]

2¢ here: what you’re looking for (in a spec) is impedance. The lower the impedance, the louder the headphones will be at a given volume. The efficiency of the drivers is a factor, but not nearly as much as impedance. Impedance is a given value in Ohms (Ω) – the phones you currently have are 32 Ohm. That is a fairly low value, so I wouldn’t expect that the Sony MDR (63 Ω) would be any louder at the same volume level. I think in your case you may be better off looking at a more isolating headphone like the Sennheiser HD 280 Pro. Even though the impedance is around the same as the Sony pair, the isolation of these headphones is very good comparatively. That might block out enough outside noise so that at the same volume level you’ll be able to hear better.

[Ben Edwards]

Mark,

OK, Thanks for that.

The Sennheiser HD 215 I have is a full cup headphone and is 32 Ω.

The Sennheiser HD 280 Pro is also full cup but 64Ω.

Are you saying the HD 280 has something about its specific full cup design that makes it cut out background noise massively more then the HD 215?

Regards,
Ben

[Mark Spano]

I only have experience with the 280 Pro, not the 215, but I can tell you that they are the most isolated headphone I’ve ever used (outside of air traffic controller ear isolators). There’s a claim on Sennheiser’s site about 32dB ambient noise attenuation for the 280 Pro, and no claims for the 215 other than ‘excellent attenuation’. Not knowing much more about them, I think the 280 Pro is cheap enough (usually around $80) to borrow or buy to try. If it doesn’t help much, then it’s time to call Sony about their headphone output on the camera.

[Jordan Wolf]

SPL is a measure of intensity. See Rane’s definition for more detail.

Wolf
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[Ben Edwards]

OK, I just ordered a pair on these
AKG K 450 which are 32 Ohms and 126 dB SPL

To upgrade these
Senhhizer hd 215 which are also 32 Ohms and 112 dB SPL

As well as them looking a bit better on the SPL fromt they also have a non coiled cable (I hate coiled cables) and a detachable cord (actually they supply 2 cords of different lengths). Plus they are a lot smaller and fold up. The 215s are so big fitting them in the bag with my Sony Z1 is a real pain.

They are not totally full cup but a friend of mine has similar AKG headphones and they seem to offer very good noise protection. They seem to get favourable reviews and I got them for £30 which is a real bargain.

As for Rane’s definition I am afraid it only marginality helps, it seems to be mainly about Blue whales, while this is fascinating it does not really help me;).

Regards,
Ben