Sennheiser HD 600/650. Still reference quality headphones

Freo-1 · « **on:** 26 Sep 2025, 12:55 am »

I've been a headphone enthusiast for many years. For what ever reason, I never had bought or listened to the Sennheiser HD 600 headphones.

I recently corrected this obvious oversight. Bought a pair of HD 650's recently. To say I was surprised is a understatement. I've had headphones costing up to 1500.00 that didn't sound this good. Easily one of the most neutral sounding headphone I've ever heard. The only knit against them is that the sub bass is low compared to other headphones. This is not a big deal for most music, unless you are a bass head, in which case, look else ware. Otherwise, these headphones may be all one needs to enjoy music for long listening sessions. They are very light, at 260 grams, and well built. Many people have owned them for 20 years or more.

I was so taken with the HD 650, when I saw a sale from Amazon for the HD 600, I had to get them. They are slightly different sounding, but share a very similar house sound. The HD 600 is a bit more analytical, whilst the HD 650 is a bit warmer and more forgiving. The differences are slight, but noticeable.

The sound can be further improved by using Sonarworks Sound Reference S/W for headphones. It provides a small amount of EQ for the 600 and the 650. Combine that with PGGB-RT via Foobar2000, and one can get very high quality sound from a reasonably priced set of headphones.

https://www.sonarworks.com/blog/reviews/sennheiser-hd650-review

Letitroll98 · « **Reply #1 on:** 26 Sep 2025, 11:41 am »

Although I've never owned a pair, I've always liked the 600 series Sennheiser phones. Between these two I agree that I slightly prefer the 650, but would be happy with either. What I haven't heard is the 660S2 which solely from reviews seems more in my wheelhouse. Any thoughts?

Freo-1 · « **Reply #2 on:** 26 Sep 2025, 02:59 pm »

Quote from: Letitroll98 on 26 Sep 2025, 11:41 am

Although I've never owned a pair, I've always liked the 600 series Sennheiser phones. Between these two I agree that I slightly prefer the 650, but would be happy with either. What I haven't heard is the 660S2 which solely from reviews seems more in my wheelhouse. Any thoughts?

Most of the reviews I've come across seem to not like the HD 660 S2 as much as the HD 650. I have been itching to try them out myself.

I like the 600 slightly more with Jazz/Classical, and the 650 more with rock music. The Sonarworks S/W does improve them both, making them almost identical.

FullRangeMan · « **Reply #3 on:** 26 Sep 2025, 03:23 pm »

Thankyou for your impressions.
How big is the soundstage?

Bodhi · « **Reply #4 on:** 26 Sep 2025, 03:25 pm »

+ 1. The Sennheiser HD 650 cans are sensational value, and will likely be the next headphones I buy.

Freo-1 · « **Reply #5 on:** 26 Sep 2025, 03:46 pm »

Quote from: FullRangeMan on 26 Sep 2025, 03:23 pm

Thankyou for your impressions.
How big is the soundstage?

The soundstage is good, but not overly expansive. It is very precise with placement. These headphones do need a quality headphone amp (section) to sound their best. At 300 ohms, they do require some power.

Freo-1 · « **Reply #6 on:** 30 Sep 2025, 03:48 pm »

Quote from: Letitroll98 on 26 Sep 2025, 11:41 am

Although I've never owned a pair, I've always liked the 600 series Sennheiser phones. Between these two I agree that I slightly prefer the 650, but would be happy with either. What I haven't heard is the 660S2 which solely from reviews seems more in my wheelhouse. Any thoughts?

Your post piqued my interest. Have the HD 660 S2 arriving this week. I'll post some impressions and let you know.

Bill Baker · « **Reply #7 on:** 1 Oct 2025, 03:10 pm »

I haven’t heard the 650’s but I have had the HD600’s for a couple years. I don’t get to use them often as they are for testing. I can say I have no desire to get anything else. I want to put together a small headphone setup so I can enjoy them more often. They do very well with both tube and solid state and are very clean and detailed.

Jon L · « **Reply #8 on:** 1 Oct 2025, 03:38 pm »

I have way too many $$ headphones but currently own zero "normal" dynamic headphones. If I had to buy one, I would buy the HD600 and use better headphone cables into a decent tube headphone amp and be done with it. I have always enjoyed that combo

FullRangeMan · « **Reply #9 on:** 1 Oct 2025, 07:00 pm »

IMO a balanced cable are very important.

Freo-1 · « **Reply #10 on:** 7 Oct 2025, 01:36 am »

Quote from: Letitroll98 on 26 Sep 2025, 11:41 am

Although I've never owned a pair, I've always liked the 600 series Sennheiser phones. Between these two I agree that I slightly prefer the 650, but would be happy with either. What I haven't heard is the 660S2 which solely from reviews seems more in my wheelhouse. Any thoughts?

Just got the 660 S2 in house. Very nice headphones. Seems to be a touch more detailed than the HD 650. They definitely share the Sennheiser house sound. They do have more bass than the HD 650. The midrange is similar to the HD 650, but the HD 650 may be just a tad more transparent. I think it depends on the recording. The treble has more energy and sparkle than the HD 650, but the difference is small.

Honestly, I like both a lot, and either one makes for excellent listening. The HD 660 S2 may be more to your liking, based on your comments.
I'm using Sonarworks for all my HD 600 series headphones, so that seems to make them sound more like one another, due to the EQ.

It's like having three different Single Malt Scotch from the same area. More alike than not, but each with it's own distinct flavor.

Letitroll98 · « **Reply #11 on:** 7 Oct 2025, 11:56 am »

Appreciate the comments Freo. But I have to ask did you listen without the Sonarworks EQ before making the evaluation? Judging from your comments compared to other reviews it's hard to tell. I checked out Sonarworks after your post on it and it seems to do a great job of making every headphone sound the same, at least that's what they advertise. However your assessment seems to match others non EQ'd impressions, same house sound, in between the 600 and 650 in transparency, but with more bass. That's what I'm reading.

Freo-1 · « **Reply #12 on:** 7 Oct 2025, 12:34 pm »

Quote from: Letitroll98 on 7 Oct 2025, 11:56 am

Appreciate the comments Freo. But I have to ask did you listen without the Sonarworks EQ before making the evaluation? Judging from your comments compared to other reviews it's hard to tell. I checked out Sonarworks after your post on it and it seems to do a great job of making every headphone sound the same, at least that's what they advertise. However your assessment seems to match others non EQ'd impressions, same house sound, in between the 600 and 650 in transparency, but with more bass. That's what I'm reading.

Your comment is accurate. I have tried all the 600 series with and without the Sonarworks. The 660 S2 definitely has more bass, and an extended treble. The midrange with 660 S2 is still very good, but just a shade less transparent than the 650 or 600. How much the differences are noticed depend on the source recording. There are some jazz recordings where I prefer the EQ off, but generally the EQ improves the sound.

The midrange is where I still prefer the HD 600 or HD 650 overall. EQ really helps the HD 660S2.

The EQ helps, but it doesn't make all the 600 series sound "exactly" the same. The flavor differences are still there, just not as pronounced.

Rocket · « **Reply #13 on:** 13 Oct 2025, 12:03 pm »

Hi,

I also have a pair of Sennheiser hd650's. I bought them years ago and I'm also happy with them.

Cheers Rod

Freo-1 · « **Reply #14 on:** 13 Oct 2025, 08:14 pm »

Quote from: Rocket on 13 Oct 2025, 12:03 pm

Hi,

I also have a pair of Sennheiser hd650's. I bought them years ago and I'm also happy with them.

Cheers Rod

Hard to go wrong with the Sennheiser HD 600 series. Headphones come and go, but the HD 600 series still holds its own.

Freo-1 · « **Reply #15 on:** 15 Oct 2025, 12:41 am »

If you really want to get the most of the headphones, use Foobar2000 with PGGB-RT, upscale to the max your DAC can handle, import the EQ settings from AutoEQ into PGGB-RT, and prepare to be amazed.

Early B. · « **Reply #16 on:** 15 Oct 2025, 12:59 am »

It's not the 600 series, but I just took delivery of a pair of Sennheiser RS 175 wireless headphones for Zoom calls and Internet browsing. I was looking for wireless headphones without Bluetooth connectivity so I could connect them directly to my headphone amp. They sound good, fit well, and serve the purpose. For the occasional music and movies, I'll switch to my planar magnetic headphones. This thread encouraged me to check out Sennheiser.

BobM · « **Reply #17 on:** 15 Oct 2025, 02:26 pm »

I have a pair of 600's that I've had for years. Still sound great.

About a year ago I needed some earbuds, so I bought a pair of Sennheiser Momentum 4's to take on a plane and vacation. I guess they are good, as far as earbuds go, but nowhere near the same sound you get from headphones (almost any headphones, including the Koss Porta-pro's which are still my traveling 'phones standard of excellence).

Bill Baker · « **Reply #18 on:** 15 Oct 2025, 04:46 pm »

I have a few pair of headphone I use for some testing.
A nice pair of AKG but still use the HD600 for serious listening.

Freo-1 · « **Reply #19 on:** 15 Oct 2025, 09:58 pm »

Quote from: BobM on 15 Oct 2025, 02:26 pm

I have a pair of 600's that I've had for years. Still sound great.

About a year ago I needed some earbuds, so I bought a pair of Sennheiser Momentum 4's to take on a plane and vacation. I guess they are good, as far as earbuds go, but nowhere near the same sound you get from headphones (almost any headphones, including the Koss Porta-pro's which are still my traveling 'phones standard of excellence).

I have the Momentum 4 headphones for travel. Using the Sonorworks Sound Reference S/W for Android (which provides EQ for supported headphones, including the Momentum 4), the sound is pretty good for travel.