Impressions & Thoughts on Open Back vs Closed Back Headphones – Sennheiser HD800/700 & Fostex TH-900


I’ve always been fascinated about audio and when I get the chance to hear new products, or even old products that have always been on my mind – I jump on the opportunity.
I recently was lucky enough to demo the Sennheiser HD800/700’s & the Fostex TH-900’s at P.J. Hi-Fi, a high-end audio shop located in Guildford. Before I get into my impressions, I would like to thank Andrew Holt for allowing me to spend as much time with these three headphones and more so being an extremely professional individual. I had a great chat with him both before and after my listening session; I found what he said really spot-on and honest. P.J. Hi-Fi is mainly a speaker/hi-fi shop, however they do store these three high-end headphones.

The headphones:
Sennheiser HD700 : £500-700
Sennheiser HD800 : £900-£1100
Fostex TH-900 : £1100-1500

Those are the three headphones that I was able to demo. Arguably the HD700 is the cheap-man’s HD800’s and the HD800’s is arguably the best open-back headphone in the market. Similarly the Fostex TH-900 is arguably the best closed-back headphones money can buy. The reason I use “arguably” in my sentences above, is because sound is very subjective but more so there are other headphones out there, that are also much cheaper. I will not go into the impressions of the headphones with consideration of the price, as I always do this when it comes to audio reviews. In this case, the high-end models will always be extremely expensive, for that niche market. I personally, couldn’t really justify spending that amount of money on those headphones, however could see myself spending £150 for a keyboard, whereas most people who buy £1000 headphones could never justify spending more than £30 on a keyboard. Because of this, I won’t comment on the prices of the headphones and the price/performance ratio – apart from comparing the HD700 and HD800’s price to performance ratio.

Furthermore, I used the Sennheiser HDVD 800 (£1500) to power the headphones. The amp was kindly provided by Andrew for my listening demo. I should also note that the amp had a really thick custom power cable attached to it, in order to reduce interference. Furthermore, in order for me to listen to the music I like and understand the difference between my personal headphones at home (like the D2000’s) I had my Samsung Galaxy S III (Wolfson DAC) connected to the amp via a RCA to 3.5mm adapter, which again was provided by Andrew and was a high quality cable.

Finally, the music I mainly listen to is between 256 & 320kbps MP3 files and R’n’B / dance music. I don’t consider having FLAC/lossless an inherent advantage over 256/320 MP3. People that often state: “You can’t listen to headphones of that quality with such rubbish tracks” really need to understand that people don’t have 1TB space for music. More so, when ABX’ing I could barely tell the difference between FLAC and 320/256. Sure there were extremely weak differences, but not ones that stick out.
I thought to explain the above, to avoid people complaining about my music choice, source and quality of music. Personally, if it doesn’t fit with my music and my files then I will never consider buying it – I honestly think that’s what people should do, but there’s always that one guy that will comment on that having higher quality music, in order to fulfil the headphones’ potential.

On a completely separate note, the pictures I took were with my S3, in low-light conditions, so I appologise in advance if they aren’t beautifully lit photos that have been taken with a proper camera and not a smartphone.

I will now take each of the headphones and list down my opinions on them.


Sennheiser HD800:

These were the first headphones I put on my head. I’ve always been intrigued about open-back headphones and what better place to start than the very best in the business. When I put them on my head, I felt as if the cups were so big and loose that with a little shake of my head, they would fall off. Despite that, they were extremely comfortable headphones, quite light considerably speaking and I could see myself wearing these for long listening periods. The cable was a little disappointing and even showed signs of wear and tear – that said, the cables can be taken out and replaced with either custom ones or new stock ones. The look of the headphones was very elegant, professional and sophisticated.
The sound, the best part of these headphones was what got me sitting there for over half an hour listening to them. The detail they had was extremely precise, but yet so vast; due to their open-back nature.
The HD800’s had a wide presentation of the sound and more so had a slower paced driver than the other two headphones I demo’ed. I found that due to the bigger driver on the HD800 over the HD700, music was a little “slower” but yet vast.
What I found intriguing about the HD800’s was their soundstage. This is to be expected with an open-back headphone, but when compared to the HD700’s, the HD800’s completely dominated them. The sound imaging, positioning, depth and width was for me the biggest quality of the HD800’s. The highs and lows were extremely accurate and felt extremely enjoyable. The feeling I had when listening to the HD800’s was: “I’ve never felt this type of detail, whilst being immersed in the sound” – It was how the HD800’s were designed, to give a flat, open-back and precise sound reporduction that really put a smile on my face.
However, there were some aspect of the sound that didn’t really engage me. Due to the open-back nature and its big driver, the HD800’s were a bit slow-paced in comparison with the HD700’s and the Fostex TH-900’s. Furthermore, due to it being open-back and being concentrated on mids and highs, the lows felt a bit dull. Don’t get me wrong, the lows were accurate and on-point, however they didn’t seem to really give me that “punchy” feeling I got with both the HD700’s and especially compared to the closed-back Fostex’s.
Its 300ohms drivers also didn’t help it, as it NEEDED to be driven quite a bit by the HDVD 800 amp, the HD700’s still needed to be driven, but not as far as the HD800’s needed to. In all honesty the Fostex could easily be powered by my S3’s Wolfson DAC. Of course someone with a Fostex wouldn’t naturally be listening to it without an amp nor have a nice setup, but the fact that I don’t NEED an amp was something that quite attracted me to the TH900’s over the HD800’s.

Overall the HD800’s were extremely detailed, precise and more than anything very open sounding headphones. They revealed a lot of detail and flaws in my music, but the thing that would make me buy the HD800’s wouldn’t be its capability of producing detailed highs and mids, but the fact that it “feels” so open that it makes me intrigued about the music around me. I can imagine the HD800’s being the king (out of the three headphones) for gaming. Due to its width and depth, the headphones will be able to pick up sounds that the other headphones wouldn’t be able to produce as accurately. I thus enjoyed the HD800’s, however didn’t really feel that they were headphones I would buy for my own personal use. They suited trance, classical and wide-sounding music files (such as gaming), but for my music taste which is mainly R’n’B and dance, I never really felt “on my toes” whilst listening to my music. Whereas, even with my modded D2000’s I always seem to have a smile on my face when listening to my music genre.

Sennheiser HD700:

The Sennheiser HD700’s as one would expect are the smaller brothers of the HD800’s in price, sound and even size. The HD700’s had a lot of the similar traits to the HD800’s, however I felt the HD700’s didn’t quite hit the nail on the head when it came to trance, electronic or classical music. If I hadn’t the HD800’s there, I wouldn’t have been stating that, but by directly comparing the HD800’s and the HD700’s together I felt as if Sennheiser had just tuned down the HD700’s in order to be the cheap-man’s HD800’s. The highs weren’t that engaging as the HD800’s, the mids felt a little veiled at times and more than anything it didn’t feel like a fully open-back headphone. This is not critiquing the HD700’s ability, but more so comparing it against its bigger brother the HD800’s. The biggest factor for me of the HD800’s was its open-back sound. The HD700’s when compared to the HD800’s felt like a semi open-back headphone. It was quite astonishing the differences I was able to pick out, by simply listening to dance music. Thus, when listening to trance and electro, the differences were much more apparent.
It sounds like I’m bashing the HD700’s, but I really don’t want to as out of the three headphones, it was the best price to performance ratio headphone there. For the amount of money spent you were getting a close-to HD800 sound, and for that it was well worth investing that amount of money. However one could argue, if you are going to spend HD700-type money, then why not just spend that extra little bit and get the better HD800 headphones (at least that’s what I would do if I were in that situation).
I should note, as previously mentioned in the HD800 section, the HD700’s were faster paced headphones and in fact had a better capability of producing those mid-bass tones than the HD800’s. As I felt that the HD700’s felt more like a semi open-back headphone, the HD700’s thus felt that they were giving out a bit more in the lows.

Overall, the HD700’s are exactly what I perceived them to be in previous demo sessions, and now I can confirm my beliefs in that respect: “the cheap-man’s HD800’s”. If I were going down the open-back route, I wouldn’t personally buy the HD700’s, simply because they aren’t “that much cheaper” than the HD800’s If I want a high-end open-back headphone, I wouldn’t really consider the HD700’s knowing that their older brothers the HD800’s provide a better overall reproduction.

Fostex TH-900:

The Fostex TH-900’s were incredible. Now before going into this, I should again state that I own the Denon AH-D2000’s (D2K) at home. I have modified the D2000’s with the D5000 wooden cups, that have also been dampened, I have changed the annoying cable to a shorter and re-terminated version of the D7000’s and finally included the Lawton Audio pads, that give me increased comfort and a wider soundstage due to the driver being further away from my ear. The drivers produced for the old Denon AH-Dxxx line was produced by Fostex, whereas the new range is built in-house at Denon. The reason I stated that is because the sound, construction of the headphones really resembled by D2K’s.
First of all the aesthetics and construction:
I was greatly disappointed by Fostex’s choice of materials and design. Don’t get me wrong the D2K’s have a great construction for a £180 headphone, but for a £1200 headphone, one would expect something a little better. Everything from the horrid cable (that twists and tangles itself) to the extremely weak hinges on the headband, all reminded me of the D2K’s. I expected something superior for 10x the price from the TH-900’s, but that was no where to be seen. The biggest complaint I had was the headband – as I have experienced with my D2K’s they seem a little fragile – if they were to be twisted or dropped, I would not be surprised if the headband assembly would fall-apart. The TH-900’s had exactly the same feel to them, and that’s not a feeling I want to have around a set of £1200 headphones. What were they thinking when designing or porting-across the design from the old Denon range? That’s beyond me, only Fostex knows that answer.
The ear pads on the TH-900’s reminded me of a Lawton Audio type pad. Which definitely is an improvement over the old Denon line.

So what about the sound?
Well, “sensational” from a Denon-user point of view. It had quite a lot of the same sound that the D2/5K’s had, but was more refined. I can’t comment on the D7K’s as I haven’t heard them properly for an extended period of time, but the sound was definitely close to the D2/5K’s. With the refined sound, the soundstage was better, the noise separation was a little better and more than anything the mids were not as hindered by the lows. This is something I noticed with my own D2K’s in comparison to other headphones (such as the AKG K551’s, which focus more on mids). Thus if I had to describe the Fostex TH-900’s I would state that they are the old Denon line on steroids. Now in comparison to the HD700’s and HD800’s the difference was apparent before even putting on the headphones. By that I mean, the power the Fostex TH-900’s needed via the HDVD 800 was much lower than the other two headphones. As soon as I put on the TH-900’s I straight away felt a lack of space, separation and width in the sound. That came down directly to the closed-back design that the TH-900’s have. Thus the TH-900’s were severely disadvantaged over the HD700’s and the HD800’s when it came to classical music and trance. I didn’t prefer the colouring of the sound that the TH-900’s had over the Sennheiser’s and it was something extremely apparent. There wasn’t really any competition for the Fostex in that area, the Sennheiser not only did a better job but outdid the Fostex’s by a considerable margin.
However, there’s always a flip side: The bass that I was craving from the Sennheiser’s was not only present but booming in the TH-900’s; it got me stomping my feet, nodding my head and enjoying my music, whereas with the HD800’s for example, I was just sat there with my eyes closed and quite bored in some respects.

Overall, the TH-900’s were sensational for the music I was listening. I found that out of the three headphones demo’ed that day, if I had to ever spend £1500 on a headphone, it would go towards the Fostex without a shadow of a doubt.

Observations and Conclusions:
Hopefully you can now see a pattern emerging from the above three descriptions and impressions I had of the headphones. I’m definitely no audiophile, but one that enjoys music. In order for me to enjoy my music, the TH-900’s ticked all the boxes and resembled a sound that I quite enjoyed (from my D2K’s). Note how I used “enjoys music” – the music type I listen to as stated above isn’t classical, nor mainly trance, electro etc. The closed-back vs open-back debate for me has been put into a coffin, after hearing these three headphones. They are all three of them extremely good headphones, however taking the HD800’s as a benchmark for open-back and the TH-900’s as a benchmark for closed-back, the closed-back headphones are better suited for music that has more bass. That’s my humble opinion. I felt that the open-back headphones didn’t really give me that warmth, impact and “fullness” in the music I was listening to. Of course they gave me depth, width and separation, but that’s not what gets me up and dancing. The Fostex TH-900’s in that respect would be my headphones that I would go for, however for my mother, I would buy her the HD800’s rather than the TH-900’s, simply because she loves her classical music and she would enjoy listening to the HD800’s more than the TH-900’s.

Now would I buy these headphones?
Well if I ever had £1500 to spare, sure why not. Would I save-up to buy the headphones? Personally, I would never do so. I had this same impression after a headphone meet in September 2012. I came back to my audio rig and said: “My headphones might not be worth £1200, nor do I have an extremely expensive amp, but in comparison to the price I paid for my audio rig, I think it does an extremely good job in competing with the high-end audio gear that can be had”. My now-discontinued modded D2K’s, with my DigiZoid ZO2 and EHP-O2D provide me with a very good audio setup. MY headphones were around £270 (after mods), O2D around £100 and ZO2 around £40 – I’m looking at around £410, just about half price of the HD700’s, let alone the TH-900’s. Again, don’t get me wrong the three headphones I demo’ed were extremely good in their own categories, but when I look at the price I would have to pay for them and see if I could justify that purchase – I would never be able to. I couldn’t be happier with my headphones, especially listening to arguably the “very best” in headphones. Maybe one day, when I have a lot of money to spend and have nothing else to spend it on, will I spend that amount of money on the TH-900’s.

That said, if you DO HAVE the money, then by all means go and try them out yourself and enjoy the experience. I’m sure if you have the money, you’ll buy the headphones and won’t ever find headphones that quite compete with them (the HD800’s or TH-900’s) – again there are a FEW other headphones that COULD be bought, but they are extremely hard to come by.

I should also mention, after demo’ing the headphones, I chose to double amp them with my DigiZoid ZO2 amp – the experience I had after that was sensational. I had a huge smile on my face after listening to the TH-900’s going through my phone > ZO2 + custom cable > RCA to 3.5mm > HDVD 800 and to the headphones. I’ve said it many times – the ZO2 brings me something that I don’t know how to explain. Adds something new to the sound and something more – it does veil and change the sound a little, but it does it so right for me, that I can’t go without it.

I hope this post has given you an insight towards high-end headphones and more so allowed you to see my honest opinions of the headphones.
I’m sure people could comment and say that I’m bias towards my own audio gear, or towards closed-back headphones – and by all means do those people have a point. But when it comes to audio, I always try and take a neutral point of view and review them based on other headphones or earphones I have heard, not based on subjectivity. More so, looking at the headphones objectively (by using graphical representations of frequency response) is completely and utterly ridiculous. I never look at my audio gear as I look at my graphics card in my PC. It doesn’t need to be benchmarked with graphs nor be proved that it has spikes in certain parts of its audio frequency. Audio is and always will be subjective, and because of that one has to formulate an opinion and a review based upon previous experience. You can’t have an opinion or debate with objective data. I’ve seen it a few times and now choose to ignore it.

Honourable mentions in this post:
Denon AH-D2000
Recabling D2000
Wooden cups on the D2000
Epiphany Acoustics EHP-O2D
DigiZoid ZO2


4 thoughts on “Impressions & Thoughts on Open Back vs Closed Back Headphones – Sennheiser HD800/700 & Fostex TH-900

  1. abhishek

    Hey hi. Your videos and tutorials are of a great help man..thanks a lot! Can you help me with this please..
    I took a backup of stock 4.1.2 on my gt i9300 via clockwork mod. I then installed d supernexus rom. I wanted to know..if I flash the back up ie stock will it reset my flash counter so that i can recieve official updates?


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