Does anyone know what Impedance headphones I should be looking at to connect into the AXR4T?
Looking at the specs, the output from the AXR appears to be 40ohms. I’ve tried a set of Sennheiser HD 660S (150ohm), and also AKG K550mkII (32ohm). Neither of them sound great.
I read an article somewhere that mentioned there should be an 8x ratio on the output/input impedances. Does this mean I need something in the 320ohm range? Or have I totally misunderstood?
Cheers, Paul.
Paul - I have the same experience.
Not sure regarding ideal impedance for headphones through the AXR4 but I assumed the engineers would have designed for a wide range.
After hearing so much about the stellar sound quality of the interface, I honestly felt very underwhelmed when listening through the headphone outs for the first time.
The main outs (line outs 1 & 2) seem to sound a little smoother and better balanced than both of the headphone outs which sound a little harsh in the mids to me, with bass that isn’t as full or punchy.
Could it be that Yamaha cut a few corners regarding the quality of the D/A converters for the headphone outs on the AXR4?
If you have the cabling to test your headphones through the line outs, you could try and then let us know if you hear any difference.
Not sure whether it’s just more accurate, or me being too used to the sound of my old interface, but the AXR4 headphone outs definitely sound less pleasant and more fatiguing to listen to in general.
That said, I have no complaints regarding the preamps and A/D conversion. In general, everything recorded has sounded superb.
My biggest gripe with the interface has been the lack of support and features that I assumed would be standard on such a device.
I’m tempted to buy something like this and see if it makes a noticable difference 
I could presumably connect one of the spare line out pairs into this.
Or you could just get the cabling first (if you don’t already have it) and simply try your headphones directly connected to the line outs.
I realise that the impedance matching might not be ideal but there may be other factors that play a bigger part in the end result besides that. From the manual the line out impedance is 75 Ohm. As you’ve mentioned the headphone out impedance is 40 Ohm (at the maximum output level).
Your Sennheisers will likely be a better match than your AKGs but still, I would try first and see what difference you hear before buying a headphone amp. Different headphones may react differently to source impedance changes.
Alternatively, if you have access, you might want to borrow a pair of 600 Ohm Headphones (to try with the line outs) and 300 Ohm Headphones (to try with the headphone outs) to see if that much of a difference is made.
Currently I have line outs 1 & 2 connected to a half normalled patchbay with signal flowing to both my monitors and headphones for testing.
I assume you would just use the following cabling to directly connect to the line outs.
Headphone amps are no line outs, and line outs are not designed to drive headphones.
Agreed - but it is possible for line outs on interfaces to drive headphones and the reverse also (ie. headphone outs can provide decent line level signal).
The whole point is that the actual AXR4 headphone outs don’t seem to be providing a very good sound for the OP. This ofcourse is very subjective, but I’ve found that to be the case myself (underwhelming being the word used).
For whatever reason - I’m getting better results testing direct through the AXR4 line outs vs the headphone outs themselves. I don’t get the bass rolloff and the overall sound & balance seem to be smoother as well. What’s more - I’m able to drive my cans with more than enough volume. Can you explain why I’m getting better results?
Assuming you are an AXR4 user yourself, how do the headphone outs sound for you? Would be good to know from other users, what their experience has been with the headphone outs.
Harshness in the mids is my main complaint regarding the AXR4 headphone outs. The sound just isn’t as smooth and balanced as expected. The bass representation also seems to be a little lacking, and my usual preference is not to have too much of it. Just thought it would be more premium sounding overall.
Ofcourse alot of this is subjective, and could be due to personal taste, but I’m keen to hear what other users honestly think.
I’ve ordered the ifi Audio Zen Can from richersounds.com in the UK. They have said that they will give me a full refund if it doesn’t do what I need.
Plan is to connect OUT 7+8 from the AXR using 2x unbalanced 6.35mm jack → RCA cables, to the Zen Can RCA input. I’ll then connect my headphones to the front panel of the ZenCan. I’ve actually got a balanced heaphone cable with my Sennheiser 660S which might connect into the balanced out if it’s the correct type (4.4mm Pentaconn)
I’ll let you know how I get on. If the worst comes to the worst, I get my money back, so it’s worth a try