Headphones, Slee Novo and AKG K550 continued ......


New member
Aug 10, 2019

I have recently bought a pair of AKG K550's to go with my Graham Slee Novo.

It sounds mostly good although the headphones are not run in yet having only 4 hours of use. But there is a distinct lack of bass depth and some leaness to the sound in genral which is realy spoiling it for me.

I read somewhere that the Novo could sound lean if used into low impedances. Weather or not this plays a part I do not know, maybe the Novo just isn't a good match!

Perhaps you good what hifi reviewers could suggest a better amp or headphone choice

So before I ran out and bought a new headphone amp or backed the headphones them selves I though I would seek advice from you good people.

The rest of my system is a Cyrus DACX+ & power supply running from my pc from the asus xonar essence st sound card via a wireworld starlight 6 rca digital inter connect.

Any help or comments much appreciated

TopReply Quote[/list]#1quadpatch OfflineJoined: 28/03/2011Posts: 282RE: AKG K550 Graham Slee Novo
I gave the K550s a go and found the exactly the same thing. The bass is non existant on everything I plug it in to, even the Fiio E17 on +10 bass is not enough, I am very disappointed! Even less tollerable than the K/Q701 which is ridiculous! I have tried it on a bunch of the DACs (listed below) and all the same. I have recently tried the Audio Technica ATH-M50 and I think that has most of what I like about the K550 but also has amazing bass! Also circumaural and better isolation all for less money too. The Q701 was a keeper for me despite the lack of bass but K550 is most definitely not! Shame as they look so pretty!

DAC/amps: Fiio E7 ● Fiio E17 ● Audinst MX1 ● iBasso D7 ● Yulong D100II ● Epiphany EHP-02D

Headphones: Denon D7000 ● AKG Q701 ● VModa M80 ● AKG K550

TopReply Flag As Offensive Quote[/list]#2Gedfan OfflineJoined: 08/05/2012Posts: 26RE: AKG K550 Graham Slee Novo
They are inherently lean on bass. Try Audio Technica ATH-50S if you want some excellent bass.
TopReply Flag As Offensive Quote[/list]#3shafesk OfflineJoined: 18/09/2010Posts: 405RE: AKG K550 Graham Slee Novo
I've heard the slee and voyager with my k702s and they sound brilliant and also add a little bass to the headphones. However, I reckon the k550s being more efficient causes an impedance mismatch which causes the bass to disappear. My x-cans when connected to a lot of relatively efficient headphones sound very bloated. I guess some headphone amps are meant to be driven by power hungry headphones. I second the Audio Technica suggestion if you want more bass, AKG isn't a company known for its bombastically bassy headphones....even their in ears lack bass


Mordaunt Short Mezzo 6, Cayin A-55 T, Technics-SLQ210, CA-340a, 540p, Dac-magic, Marantz 5004CD and 6025 Turntable, Mac and Pure AV interconnects


Akg K702, Grado SR60i, UE Triple-fi, Musical Fidelity X-cans, HRT Music Streamer 2+

TopReply Flag As Offensive Quote[/list]#4idc OfflineJoined: 02/01/2008Posts: 7613RE: AKG K550 Graham Slee Novo
An interesting review and comments

Can this thread be moved to the headphone section of the forum? I suspect it will come in useful as a reference.

Internet - laptop - DAC - amp - lots of headphones.


"A music lover will stop what he's doing and stay glued to a favorite piece of music even if it's coming over a 3" speaker or a public-address system..." - Ken Rockwell

TopReply Flag As Offensive Quote[/list]#5jamesym OnlineJoined: 26/02/2009Posts: 27RE: AKG K550 Graham Slee Novo
Thanks very much everbody for all your input.

It's looking like it's the AKG K550's that's the source of my problem, that's what you get for not trying before you buy I guess.

Do you think I will get decent bass from the Slee with the Audio Technica ATH-M50 and are there any other suggestions for headphones and there charectoristics?

I was also considering buying a Musical Fidelity Headphone Amp the M1-HPA and may still.

Has anyone compared this with the Slee Novo? Is it worth the extra outlay?
Thanks again
TopEdit Reply Quote[/list]#6jamesym OnlineJoined: 26/02/2009Posts: 27RE: AKG K550 Graham Slee Novo
PS would the psu1 be a worth upgrade to the novo in regards dynamics and bass weight

TopEdit Reply Quote[/list]#7jamesym OnlineJoined: 26/02/2009Posts: 27RE: AKG K550 Graham Slee Novo

Will the the Audio Technica ATH-M50 being studio monitors still be hifi quality probably a silly question after the above comments!
TopEdit Reply Quote[/list]#8Gedfan OfflineJoined: 08/05/2012Posts: 26RE: AKG K550 Graham Slee Novo
James, absolutely. They are, in my opinion, the best value I've heard. The cheapest I found is Pro Audio Systems where I bought mine from. Top service. No affiliation by the way.

I do like bass, not overbearing but tight and controlled. I've put 30+ hours on these babies now and am very happy with them. I've got AKG K450s, Sennheiser HD202s, had Grado SR125s and Senn 600s in the past and these top them all, in my humble opinion.
I'd be very interested to know what more expensive Audio Technica ones are like in anyone has any experience?
TopReply Flag As Offensive Quote[/list]#9jamesym OnlineJoined: 26/02/2009Posts: 27RE: AKG K550 Graham Slee Novo
I'm sold lol.

I have just sold my grado 125i's as they sounded bass lite to me also but the sound was good.

When I read the whathifi review and saw the size of the akg's cups I thought I would be on a winner but Alsa!!!

So i'll go for these I think as the price is good yes!

And before I go mad and buy a set of Audio Technica ATH WX1000x's I've been eyeing up :/Thanks again for your time and advice......
TopReply Quote[/list]#10jamesym OnlineJoined: 26/02/2009Posts: 27RE: AKG K550 Graham Slee Novo

Is there any difference between the ATH-M50 and the ATH-M50s besides the colour do you know

TopEdit Reply Quote[/list]#11quadpatch OfflineJoined: 28/03/2011Posts: 282RE: AKG K550 Graham Slee Novo
I would be careful about the W1000/X. Although I loved the M50 I thought the W5000 was absolutely boring as hell. I don't hate all reference headphones either since I absolutely loved the Sennheiser HD800. I think the moral of the story is try before you buy if you can. I am taking my K550's back this weekend - I also bought without testing thoroughly enough.

Oh and as far as I know there isn't much difference between the M50 and M50s, possibly just the cable?

I think the M50 is a solid choice, what is it.. £130? you certainly can't go wrong for that. I will be hunting a pair down as soon as possible and will save myself £50. I am assuming that like me you want something that is large so it doesn't touch your ears and is comfortable for long periods. If not then I highly recommend the VModa M80! I have those and will certainly never sell them but I need something more comfy for the office.

DAC/amps: Fiio E7 ● Fiio E17 ● Audinst MX1 ● iBasso D7 ● Yulong D100II ● Epiphany EHP-02D

Headphones: Denon D7000 ● AKG Q701 ● VModa M80 ● AKG K550

TopReply Flag As Offensive Quote[/list]#12Gedfan OfflineJoined: 08/05/2012Posts: 26RE: AKG K550 Graham Slee Novo
50S has the straight cable - AFAIK that is the only difference. I actually quite like the coiled cable as it suits my listening position (not all of it is coiled).

TopReply Flag As Offensive Quote[/list]#13jamesym OnlineJoined: 26/02/2009Posts: 27RE: AKG K550 Graham Slee Novo
Thanks again for all the comments.

I've bought the
Audio Technica ATH-M50s
with the straight cable.

Looking forward to receiving them now they should come tomorrow.

Backing the akg's.

I have to say for me, WHAT A LET DOWN!!!!!

Let you know what I think when they turn up,

TopReply Quote[/list]#14quadpatch OfflineJoined: 28/03/2011Posts: 282RE: AKG K550 Graham Slee Novo
Awesome! I think you will be happy but am eager to hear what you think so please do write back. I am going for the same thing as soon as I can but I think I may have to eBay my K550s as the shop probably will not take them back.

DAC/amps: Fiio E7 ● Fiio E17 ● Audinst MX1 ● iBasso D7 ● Yulong D100II ● Epiphany EHP-02D

Headphones: Denon D7000 ● AKG Q701 ● VModa M80 ● AKG K550

TopReply Flag As Offensive Quote[/list]#15jamesym OnlineJoined: 26/02/2009Posts: 27RE: AKG K550 Graham Slee Novo

I've had the Audio-Technica ATH-M50s for 3 weeks now.

But it's been a busy month so I’ve put only 15 hours on them so far but only 5 hours of listening.

Out of the box they sounded a little bland, bass was much better than the AKG K550's though but also unexciting.

With 15 hours on them so far though they have started settled down.

The Bass has deepened and become much more tuneful and controlled.

The midrange has sweetened and most of the brashness/hardness has gone and is also much more articulate I’m hearing things in the upper mids and bottom trebles amazingly that were not there with the AKG’s!

The AKG’s are very clear, and clean though but I think for that part it’s going to be more sitting back and looking at the overall balance which I feel when run in the Audio T’s for me will have the best of that department.

The AKG’s main fault for me was the lack in the mid and upper bass region and even low Bass was lacking depth and extension almost like it was curtailed just before it got going if that makes any sense.

I’m still not certain if they will make the best of my Slee Novo though!

Once they’ve run in fully (I'm thinking another 20 to 30 hours to be sure I’ll be able to add more thoughts.

I must confess though I want more already oh will I ever be satisfied!!!

Wanting closed backs I'm thinking now about the Denon ADH7000's and the Musical Fidelity H1 MPA Headphone Amplifier.

Does anyone have experience of these?

Would they make a good combination?

Or would my slee be perfectly adequate?

I must add that I am very impressed with the little Novo and I'm wondering is the Graham Slee PSU 1 a worthwhile upgrade for it.

Any thoughts always much appreciated



New member
Mar 28, 2011
Hey James, Since writing that stuff about the K550 I have tried several more times to get on with it's sound signature. I have tried many different DAC/amp combos and I have felt a tiny bit of improvement at times but mostly they still feel really hollow and veiled from a complete lack of low end. I am sat here with the Denon AH-D7000 right now and absolutely loving the sound! I am using them with the Epiphany Acoustics EHP-02D which is so warm its on the edge of being overpowering with the Denon's bass but, everything else about this combo is really amazing! If you wanted a bit less emphasis from the bass but beautiful detail I can highly recommend the Yulong D100 mkII. I did try the M1 HPA with the Denons once in a shop and I was not blown away by it but I am still of the impression that shop testing is no very useful.

The Denon D7000s seem to show up the source quite a lot (read: they like expensive DAC/amps). They sound rather dull with the Fiios and even the Audinst, which are lovely budget DACs. I think your Slee Novo could be fine with the Denons, especially running off that Cyrus DACX so worth trying that first.

Oh and another word of warning: None of the high-end headphone isolate well. The Denon keeps sound in quite well but you can hear everything around you pretty well so they are not good for an office and they certainly don't feel like they want to be taken outside.


Thanks for all the info quadpatch that's all been very helpful and i'll have a look at your suggestions cheers.

Quick update on the m50s's. I've got 10 more hours on them now and they are realy starting to come in to there own!.

The harshness at volume is nearly all but gone, another few hours I think should see that off.

The over all balnce is realy great, quite phenominal infact for the price.

That Bass weight and Dynamics are great and so is the detail, although first of all your not realy aware of it strangely but when you've listened for a few tracks towards the end of the running in period you realy notice everything gels so well over the whole dynamic range anf I could even hear things the AKG K550 didn't relay.

I would not hesitate in buying these again especially for the money, they are such a bargin it's a joke.

And if I was personaly going the closed back route wouldn't bother with any thing else in between these and the Denon AHD7000's.

The Audio Technica M50s's also work realy well with the grahman Slee Novo I have. That is another product I couldn't recommended enough and I think with the PSU1 bupgrade I might get away with it with the Denons too.....


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