Sennheiser HD650 Review (Headphone)

[solderdude]

Have you applied enough negative pre-amp to accomodate for the bass lift ?

 

[L5730]

Have you applied enough negative pre-amp to accomodate for the bass lift ?

This is what I am trying to say. Add, say 6dB of gain at 20 Hz, will mean having to put an overall gain to -6dB to prevent potential clipping distortion. Ideally in the same program/device that is providing the EQ as it will likely be handled neatly and won't mean the hassle of gain staging shenanigans.

 

[Jimbob54]

Did you try? Very buzzy bass.

If I don't know the track, how is me listening going to identify a "problem" in the chain as opposed to something on the recording?

 

[Deckard01]

Hello everyone can you suggest any budget balance 4.4mm cable for HD6+ cans?

Thanks a lot

 

[IAtaman]

Hello everyone can you suggest any budget balance 4.4mm cable for HD6+ cans?

Thanks a lot

FAAEAL cable. Cheap, well built, non microphonic. $16 delivered from amazon.

Amazon.com

 

[Deckard01]

FAAEAL cable. Cheap, well built, non microphonic. $16 delivered from amazon.

Amazon.com

Thanks a lot I was looking for that cable from Amazon but I see that is currently unavailable from my EU country! Too bad and can not find it anywhere else

 

[IAtaman]

Thanks a lot I was looking for that cable from Amazon but I see that is currently unavailable from my EU country! Too bad and can not find it anywhere else

Aliexpress also has it if that helps.

https://www.aliexpress.com/item/1005006016677379.html

 

[Deckard01]

Aliexpress also has it if that helps.

https://www.aliexpress.com/item/1005006016677379.html

Thanks I will give Aliexpress a try then!

 

[HoJ76]

Have you applied enough negative pre-amp to accomodate for the bass lift ?

I don't really understand.
I use Topping A30 on "h" an the clock (gain) around 12 (straight up) I gain on roon to decrease or increase the actual gain. I use around 50% gain on roon.

 

[solderdude]

Try to lower the overall gain (volume) in your software.
Gain of the amplifier is irrelevant.
I don't use Roon so have no idea if you use their EQ and if negative pre-amp is needed there and if it is if 50% (-6dB ?) is enough.

 

[Jimbob54]

Try to lower the overall gain (volume) in your software.
Gain of the amplifier is irrelevant.
I don't use Roon so have no idea if you use their EQ and if negative pre-amp is needed there and if it is if 50% (-6dB ?) is enough.

Yes, on roon you can either set a general headroom to apply to all eq profiles and /or a preamp reduction within the eq profile for each headphone /set up. Neither is a it automatic but @HoJ76 might want to also enable the red light clipping indicator to confirm or eliminate digital source clipping.

 

[HoJ76]

Red light clipping... In roon? Never heard of it before.

 

[IAtaman]

Red light clipping... In roon? Never heard of it before.

https://help.roonlabs.com/portal/en/kb/articles/dsp-engine-headroom-management#How_to_Manage_Headroom

 

[HoJ76]

That worked perfectly - Thanks. I have really struggled with this bass, now I am enjoying the sound. I am very happy!

 

[kestrel4]

This is a review and detailed measurements of the Sennheiser HD650 open back headphone. I purchase mine back in 2017. It costs US $400 with free shipping as of this writing from Amazon. My sample is near new because I don't use it everyday (due to high noise level, I have to wear closed back headphones).

The HD650 feels rather plastically although it has been robust in the face my rough handling at times:

View attachment 101558

Here is a close shot of the driver in mine just in case there are variations in production that are visible such:

View attachment 101559

My history with this class of Sennheiser headphones goes back to 1999 or so. We (my team at Microsoft) had just developed our audio codec and wanted the labels to use it for online music distribution. I was invited to a number of major music labels (Sony, Warner, Universal, etc.) for codec shootouts. I asked around and "the" headphones of the time at the labels was the Sennheiser HD series (560?) , Stax and Sony MDRV-6 (?). I promptly bought all and used them all the time in testing our codecs. Happy to say we did well with all the major labels and got our codec approved for distribution.

I donated my old Sennheiser to my son years ago and don't know where it is. But somehow I remember the velour pads to be softer and more luxurious than the current set which I find a bit stiff.

Anyway, being one of the most popular headphones out there, the HD650 has been reviewed to death. The purpose here then is to not provide yet another review but provide a good baseline for our measurements and testing of other headphones since so many people are familiar with it.

The measurements you are about to see are made using a standardized Gras 45C. Calibration level is 94 dBSPL @ 425 Hz.

Sennheiser HD650 Measurements
There is nothing more important than frequency response of the headphone as each is seemingly different and that difference leaves a very distinct character:

View attachment 101560

Focusing on 100 Hz to 7000 Hz, we see that the response of the HD650 comes very close to our reference curve in dashed blue. This is interesting since the HD650 predates the research that led to the blue preference curve. No wonder then that HD650 is so popular.

Below 100 Hz, we fall short and short a lot when it comes to bass and sub bass region. This is likely to make the headphone sound colder and perhaps brighter.

Showing the difference between the preference curve and left channel we get:

View attachment 101561

You can see the shortfall in bass and matching above that much better now. Note that above a few Kilohertz, there are reflections and other inaccuracies so care must be taken in interpreting that region. So don't be alarm about the large variations reaching 10 kHz and above.

We can take a quick look at the "Group delay" and see the warning signs of where to be careful about:

View attachment 101563

Those massive phase variations indicated by sharp dips or peaks indicate mixing of reflections usually which can create troughs in the frequency response.

There is some kind of resonance between 200 and 300 Hz which we can (barely) see in the frequency response as well.

Distortion measurement shows that there is excessive amount of compared to the (few) headphones we have measured in bass region:

View attachment 101564

Looking at this as absolute level we get:

View attachment 101565

The HD650 has variable and high impedance:

View attachment 101566

The high impedance means that it likes to have "high" drive voltage (at least 2 volts in my experience). The variable impedance means that if you drive it with a headphone amplifier with high impedance, e.g. a tube amplifier, it will modify its frequency response. That modification may be to your liking, or not. Better rely on equalization as I will show shortly instead of a haphazard one using a tube amp.

Sennheiser HD650 Listening Tests and Equalization
The HD650 sounds like it measures. That is, it has a very good sound and tonality out of the box -- better than any other headphone I have tested. No wonder that I am often surprised how good it is when I go back to testing it for a few seconds after using another for a long time. You can however do much, much better with just a bit of equalization:

View attachment 101567

Dual shelf filters work together to lift the bass up. There is a shortfall around 8 kHz. And some resonance peaking around 13 kHz that needed to be knocked off. I tried other filters but their effect was not conclusive. This set transforms the HD650 into a superb sounding headphone. I am listening to it right now and can't put it down! Try this wonderful clip from Nils Frahm for example (track #2):

The Tidal version is far better but even the youtube one sounds wonderful. Let it keep laying and it lays very good low frequency tones which the HD650 reproduces with little difficulty. Its reproduction with equalization is better than vast majority of speakers in rooms.

Where is not so good is the spatial qualities. There is a nice open circle that the sound sources emanate from. It starts from your ears and circles forward. There is no sensation of space beyond that. Nor that nice layering that the Sennheiser HD800S which I recently reviewed brings to the table. I always get a feeling of the sound closing up in space when I wear the HD650 after wearing others.

If you are wondering about effect of equalization on distortion, here it is:

Edit: the original measurement was in error. This is an updated one with slightly more optimization than distortion graph earlier. Will sync the two later.

View attachment 101746

As expected, my large increase in bass level naturally increases the distortion there. But listen to this: without EQ you hardly hear those notes down in 20 to 30 Hz. No sense in having a clean signal you can't perceive! With equalization, those notes now play as if you have 20 Hz to 20 kHz reference quality speaker over your head. Don't miss on this opportunity to hear the full spectrum of the recording.

As noted on the graph, extra distortion in bass is not always perceived as such. Instead, harmonics actually help fill out the bass region giving one the impression of more bass, not necessarily more distortion.

Conclusions
There are a lot of sexier headphones out there than this old design but the HD650 not only holds its own still but with equalization produces an excellent high fidelity experience. If you are anti-equalization, you can still enjoy a lot of what this headphone has to offer.

Happy to recommend the Sennheiser HD650 headphone.

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

I got my HD-650 headphones two days ago. With some music, it seems that a low very frequency boomy noise is triggered, which is quite annoying. Could it be because I am using only my laptop's standard audio-converter? It is the Dell USB-to-Audio dongle (3GVVD SA1023z). I would be quite relieved to find out it that was the cause.

 

[IAtaman]

I got my HD-650 headphones two days ago. With some music, it seems that a low very frequency boomy noise is triggered, which is quite annoying. Could it be because I am using only my laptop's standard audio-converter? It is the Dell USB-to-Audio dongle (3GVVD SA1023z). I would be quite relieved to find out it that was the cause.

There is not much info on the Dell USB dongle, so hard to say what's its capabilities and limitations. Do you have any chance to try it someplace else with some other headphone out?

 

[christaras]

Anyone paired the 650 with smsl c200?

 

[Robbo99999]

Anyone paired the 650 with smsl c200?

Who cares, this is all you need to know:

AOSHIDA SMSL C200 Review (DAC & Amp)

This is a review and detailed measurements of the AOSHIDA SMSL C200 balanced DAC and headphone amplifier. It costs US $210. The unit looks attractive enough for a desktop product. The LED is function but sadly displays the sample rate rather than volume (until you change that). Navigating the...

www.audiosciencereview.com

 

[isostasy]

AudioSanctuary have started stocking replacement contact springs ... not a repair I'd want to carry out myself given the delicacy of those wires

 

[solderdude]

You can succesfully repair the original springs by bending them back into original shape.
Those springs will last decades again.