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Popular very low efficiency headphones?

amirm

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So I am getting worried about my hearing when it comes to testing headphone amp power. :) Most of the differences between amps shows up when they are pushed so I am thinking getting a much less efficient headphone than the ones I have. Is there a popular choice out there? I know of Hifiman HE-6. They are quite expensive but if needed, I may ask them for a sample and see if they donate it. :)
 

maverickronin

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The HE-6(SE) is pretty much the worst case.

The HE-5(Vanilla, LE, or SE) might be the next lest efficient. None of the 5s are in current production though.

Edit: actually the 5SE is still for sale on HiFiMan's site.

You can check Tyll's numbers to find their actual efficiency. HiFiMan always overstates them.
 
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bravomail

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Fostex T50 and T20. Your Sennheiser 650 reaches 600 Ohm at low freqs. I think, you should consider freq/impedance diagram of headphones when testing amps. One reason why I liked Schiit Magni (I have Magni 2 turns out), is that it drives those low sensitivity, but regular impedance headphones very good, and especially in the bass and subbass regions.
 

March Audio

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So I am getting worried about my hearing when it comes to testing headphone amp power. :) Most of the differences between amps shows up when they are pushed so I am thinking getting a much less efficient headphone than the ones I have. Is there a popular choice out there? I know of Hifiman HE-6. They are quite expensive but if needed, I may ask them for a sample and see if they donate it. :)
erm... ear plugs for the high volume testing? :)


Seriously, as I used to be a noise officer, hearing damage is a big concern to me. Once its gone its gone. Properly inserted plugs will typically reduce around 25 dB, but you can get lower class ones which reduce less. In industrial situations people can feel isolated with the high attenuation ones. I use some etymotic low attenuation plugs for concerts.

saw these just now.
https://earlabs.co/dbud/musicians-e...ZC80s-bUQ3AJg761WzVihCbSy0QrQsBhoCKx8QAvD_BwE

at least they seem to have decent data on actual performance

https://earlabs.co/dbud/the-tech-inside/


It may sound stupid but I think you can still discern relevant differences, amps being strained etc, with the plugs in.


1542072638832.png
 
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amirm

amirm

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erm... ear plugs for the high volume testing? :)
I have thought about that but want the testing to be representative. Saying something distorted with me wearing ear plugs will raise eyebrows out there.
 

March Audio

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Try it :) ASR says lots of things that raise eyebrows, doesnt mean its wrong :)

Obviously commenting on tonal balance would probably be inappropriate but things like audible distortion I dont see an issue. In fact at a reduced volume you may well find it easier to discern if you are not wincing in pain :)
 
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Blumlein 88

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I have thought about that but want the testing to be representative. Saying something distorted with me wearing ear plugs will raise eyebrows out there.
Alan has given you as superb suggestion.

Let me relay the following experience.

At one time I worked in an area that has several reciprocating engines. They were methane powered and ran low pressure high volume blowers. They were very, very similar to these pictured below in a building almost exactly like this. These appear to be running generators however. And are newer though the old ones were Cats this size.

A sound level meter on A-wtd would show 105 to 110 db SPL depending upon where you were. It was a cacophony. It assaulted your ears. You could stand it for a minute or three though it was a bad idea. Now these engines might need mixture adjustments, the valves might start to get noisy any number of things. Your ears are so heavily distorted at these levels and the loudest thing masked so much you could tell almost nothing about details of how an engine you were next to was operating from sound.

Put on some over the ear muffs...........oh what a difference. It knocked the sound down 25 db or so. You could easily hear all kinds of mechanical details in the sound that was just a cacophonous roar previously. You could hear the slightest ticking of valves getting out of adjustment. You could hear a wrist pin going bad, you would gauge very well with some experience by sound if the mixture needed trimming up, or timing tweaked. In audiophile terms you went from a smeared roar to a wealth of fine, fine detail you could hear.

So your ability to hear rubbing or distortion or other issues with the ear plugs in will be about an order of magnitude better. It may be weird, but you'll see instantly it works. If you have some clean cotton balls handy, I suppose you could check out the effect with those with a low level of attenuation.

The plugs above for musicians that claim a more even response would be a good idea I think. But while I've been reading of you testing limits of phones by listening at high volume I've winced at the idea. So I think once you give it a try with some hearing protection you'll instantly see the benefit of it. You'll hear more about what is going on, not less.
1542081770145.png
 

JJB70

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I spent quite a few years working in ships engine rooms with very high noise levels and it is indeed the case that you can hear an awful lot of subtle nuances even when wearing ear defenders. Just one reason I preferred steam turbine plant to diesels was the engine rooms were quiet.
 

restorer-john

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You could easily hear all kinds of mechanical details in the sound that was just a cacophonous roar previously. You could hear the slightest ticking of valves getting out of adjustment.

This is so true! I wear two sets (inner foam and outer muffs) when doing all my garden work. Only yesterday I could hear that my self propelled 4 stroke lawnmower needs an oil change (telltale clatter under load) and my leaf blower is getting a rattle in the conrod bearing. What you can hear in machinery when 50dB of noise is shaved off is amazing.

Amir, look after your ears!

You only get one set and damaging them for the sake of testing the latest headphone amplifier from China is foolhardy.

But then again, a whole new opportunity arises. Testing audiophile hearing aids down the track could be your calling... :)
 

solderdude

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Maybe use an attenuator between the output of the amp and the headphone ?

of course this alters the actual load of the amp and changes the output resistance the headphone 'sees'.

Another inefficient headphone is the K1000.
My vote would be the HE6 or the Susvara when you want to evaluate SQ at higher levels. (Susvara is a bit expensive)
As these are planars you can even use an attenuator without problems....

As you already have the HD650 (I thought) an attenuator would make sense.
 
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Zilfallion

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DT 880 600-ohm model takes a fair bit of power to drive. No HE-6 according to Innerfidelity measurements(HE-6 around 1 V RMS for 90dB, DT 880 at 0.5 V RMS), but a bit cheaper. Compared to HD 650 at 0.2 V RMS for 90dB, it's definitely a step less efficient.

Just as an option that hadn't been mentioned yet.
 

solderdude

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Just make sure the DT880 isn't the more common 250 Ohm version (0.3V = 90dB) or the 32 Ohm version (0.125)

Other inefficient ones: K240 Sextet (an old one) = 600 Ohm and 0.9V for 90dB, or the K240 DF (600 Ohm) 0.8V for 90dB.

However, I would suggest the attenuator instead. Most certainly for higher power amps.
The reason for this is that headphones also have increased distortion at higher levels and when listening to unattenuated with ear plugs it may be harder to discriminate which distortion is coming from the amp or headphone.
 

FrantzM

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Amir

I support Blumlein, DXD et al. Please protect your hearing. That some object to your findings is utterly irrelevant. Your subjective reviews were never of the "Statewide-soundstage-and-cosmic-blackness-of-the background "type anyway... they won't have too much to chew ... IOW F&$#k them!!
 

BurritoJustice

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So I am getting worried about my hearing when it comes to testing headphone amp power. :) Most of the differences between amps shows up when they are pushed so I am thinking getting a much less efficient headphone than the ones I have. Is there a popular choice out there? I know of Hifiman HE-6. They are quite expensive but if needed, I may ask them for a sample and see if they donate it. :)

I got my Hifiman HE6se and RME ADI-2 Pro today, and I can say that the HE6se definitely unearthed distortion that I didn't notice with any of my less efficient headphones using my Liquid Carbon X. I had to turn it up quite high with high gain and it had a very noticeable and loud hissing noise. Switching to the RME is a huge increase in performance.

So a vote towards HE6 for revealing faults in amplifier performance. You can find them second hand for significantly cheaper than the SE goes for.

Plus, added bonus, they are really lovely sounding headphones. I'm very much enjoying them.
 

momo7G

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isn't it they give you a pair in those ifi ear buddy?? maybe they are for this use. But will the earplug some what obstruct the fit of over ear phones?
 
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amirm

amirm

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Etymotics earplug is good. I have a pair of ER-20xs, use it some times sitting in the orchestra, when FFFs with all the wind/brass/choirs during rehearsal
I have these and will give them a try.
 
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amirm

amirm

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So a vote towards HE6 for revealing faults in amplifier performance.
Thanks. I dropped off an email to hifiman to see if they will send me one. Otherwise I will search for used ones.
 

graz_lag

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Thanks. I dropped off an email to hifiman to see if they will send me one. Otherwise I will search for used ones.

Alternatively, for a small budget, you can consider the AKG K92, they offer a level of sound quality that goes very much beyond their budget price tag of $50 ...
Ohh ... AKG offers the best comfortable headband and soft ear pads on the planet ...
 
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