Raal Ribbon Headphones - SRH1A
Jan 22, 2020 at 4:20 PM Post #1,788 of 7,847
Well, Schiit will be at Canjam. I can’t see how they won’t bring one with the RAAL. This is in my top 5 most anticipated listens.

Jason -

Will there be a Raal/Requisite headphones w/ Jotunheim R setup at AXPONA 2020?
I don't think that is an ideal setting to hear headphones well, but it would be interesting to see.

"Jason Stoddard, post: 15430943

Yes, we'll have that setup at shows going forward, starting in New York.
 
Jan 22, 2020 at 10:15 PM Post #1,791 of 7,847
I had been listening to Raal Sr1a last two weeks enjoying its open and fast sound.

I am back to Stax 009s driven by Kgsshv Carbon for comparison.

009s is not a slouch in speed with more bass impact than Sr1a while Sr1a give tighter bass



009s sound more analog with round and liquid texture.

Sr1a sounds more digital with lively and open signature but without harsh edge.

Soundstage width are on par, but edge on depth for Sr1a.


If I have to choose one, I will go for Sr1a.

But I will keep both since I also enjoy relaxed sound out of 009s.

Purist Audio Design balanced cable connected between Dave and amplifier help 009s and Sr1a sound smooth.

This comparison was done using Crown XLS 2502.

After I get Jot R, I will do comparison again.
 
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Jan 23, 2020 at 3:15 PM Post #1,792 of 7,847
Listening to the Jot R and Bifrost 2; it sounds clearer than going off my Parasound Halo Integrated sourced by the ADI-2 DAC. Between the Bifrost 2 and the ADI-2 DAC, I preferred the ADI-2 DAC when hooked up with the Jot R. Still testing, so I'll update this thread with some more thoughts later.

EDIT: The Bifrost 2 sounds a little more analog, I'm guessing that's what others were saying they like about it? But I do like the way it looks with the Jot R.
 
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Jan 23, 2020 at 8:01 PM Post #1,794 of 7,847
I’ve got a little over 24 hours on the JotR running continuously. I’m not going to say this makes the SR1a “a completely different headphone that’s better than anything.” No, the SR1a is the same headphone, but it is audibly different and, to my ears, markedly better. I’ve been listening to the SR1a/Buffer/Vidar combo for over a month. I’ve come to the conclusion that, while this is competitive with my Stax009/T2 combo, it’s not better, and probably not quite as good. But the JotR changes that. As I have noted in another post, and additional hours of break-in continue to confirm, this is an improved experience compared to the Buffer Box/Vidar. The JotR sounds:
1. More open, in the sense that higher frequencies have more air around them;
2. Conversely, those same high frequencies are smoother, less sibilant;
3. Bass is significantly better-controlled and mid-bass is very tight and authoritative; piano in this range sounds superb;
4. Mids have a depth and resonance, that makes the Vidar sound thin, though “thin” is not how I would have described it before today (maybe “less full” is better);
5. Percussion is amazing. Transients, attack and decay, are significantly improved.
In addition to the JotR, I also moved the SR1a into the MSB signal path. The Lumin A1 that was previously feeding the SR1a is a very good, musical DAC, but it is a bit veiled, less detailed, and two-dimensional even, compared to the MSB. So in fairness to the Vidar, this DAC switch has probably helped to improve the sound of the SR1a.

I should be receiving a Stax 009S before too long, and it will be interesting to see how it compares. Right now, the SR1a sounds amazing and, while I find the Stax more comfortable to wear, and its imaging and F-B depth more familiar and realistic to me, the RAAL night just sound better overall. It’s going to take some more careful level-matching and extended comparisons to have confidence in that assessment (or its rejection), though. BTW, that’s a 13x cost differential in the amps.
 
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Jan 23, 2020 at 10:34 PM Post #1,796 of 7,847
One thing that's a little disheartening about the SR1a is, at least with the JOT R set to the 12 o'clock position, anything really bass heavy causes the sound to distort. Setting the dial back to the ~10 o'clock position prevents this (same scenario occurred when I had it hooked up with my speaker amplifier). Reminds me back when I had the KSE1200 IEMs and had to adjust the chain where the sound was sufficiently loud enough and it didn't distort.

I have a bad habit of turning the volume dial up when a song gets energetic and you can move some serious air with these ribbon drivers. Gotta control myself and save my hearing.
 
Jan 24, 2020 at 5:11 AM Post #1,797 of 7,847
Hi,

About these SR1a, that's a point I would ask regarding ribbons: is it possible to get real bass (under 60Hz) with this technology even with a small surface (30cm2) remembering the Apogee with their "Trapezoidal Bass Panel" going down to 25Hz but showing a lot of surface ?
The Apogee panels were an Aluminium/Kapton combo.
 
Jan 24, 2020 at 8:13 AM Post #1,798 of 7,847
The ribbon obtains good bass extension since it has a lot of excursion and a very low resonance frequency due to the stiffness (or lack thereof) of the driver. The problem with a ribbon playing this low is that it will encounter compression above a certain amplitude depending on frequency. This means that while the SR1A can play good bass while right next to your ears (since SPL drops over distance) it physically cannot excurse enough to reach the same SPL at a longer distance (but for higher frequencies it still has enough excursion for this not to be an issue). Another issue with this type of driver is that the magnetic field linearity is not as good when the driver has to excurse a lot, and so it distorts. A larger ribbon would more likely lead to a higher max SPL/lower distortion rather than any significant increase in bass extension (since the resonance frequency is already so low) and I am sure RAAL had their reasons for going with this specific kind of ribbon, whether it be the practicality of integrating a larger ribbon into the design or that the smaller ribbons have beneficial properties. That would be a good question for Aleksandar I suppose.

I would argue the SR1A has real bass under 60hz, but the bass characteristics of the SR1A is much more akin to that of a loudspeaker (significantly higher distortion than most headphones, but unlikely to be an audible issue).
 
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Jan 24, 2020 at 9:58 AM Post #1,799 of 7,847
Holy Moses Pale Rider..........crazy great gear! What espresso machine do you use? I have a humble Rocket Appartamento.
Thanks! I’ve got a Slayer and a Speedster. Love them both, but the Slayer makes better espresso.
 
Jan 24, 2020 at 10:29 AM Post #1,800 of 7,847
The ribbon obtains good bass extension since it has a lot of excursion and a very low resonance frequency due to the stiffness (or lack thereof) of the driver. The problem with a ribbon playing this low is that it will encounter compression above a certain amplitude depending on frequency. This means that while the SR1A can play good bass while right next to your ears (since SPL drops over distance) it physically cannot excurse enough to reach the same SPL at a longer distance (but for higher frequencies it still has enough excursion for this not to be an issue). Another issue with this type of driver is that the magnetic field linearity is not as good when the driver has to excurse a lot, and so it distorts. A larger ribbon would more likely lead to a higher max SPL/lower distortion rather than any significant increase in bass extension (since the resonance frequency is already so low) and I am sure RAAL had their reasons for going with this specific kind of ribbon, whether it be the practicality of integrating a larger ribbon into the design or that the smaller ribbons have beneficial properties. That would be a good question for Aleksandar I suppose.

I would argue the SR1A has real bass under 60hz, but the bass characteristics of the SR1A is much more akin to that of a loudspeaker (significantly higher distortion than most headphones, but unlikely to be an audible issue).

Actually, great effort was made to make the magnetic filed as homogenous as possible, without having excessive mass of magnets.

Here is the plot of the magnetic flux lines throughout the cross section of the magnetic gap volume withing which the ribbon travels.
Flux 2.jpg


The width of this graph is the width of the ribbon and height is the total excursion back and forth.
The ribbon rests horizontally in the middle.

Here is the plot of magnetic field induction magnitude across the ribbon width, at 3 positions:
Mag B.jpg


Red: the rest position
Black: -3dB until max excursion
Green: the moment at which the ribbon hits the cage (physical clipping, ribbon flapping against the bars)

Once we integrate the total sum of mag. filed. strength across the width of the ribbon, we get very little variation throughout the excursion range.

Basically, the field sum is fairly constant across the excursion, so B x L product is a not a major issue as a distortion contributor.

The distortion in this ribbon hides in nonlinearity of suspension compliance.

This here is the key, because it matters very much how distortion is generated.

I won't try to form a nice explanation of this, when everything is superbly explained in this article by Morten Halvorsen:
Low frequency harmonic distortion is almost inaudible. So what’s the point of low distortion drivers?
Here: https://purifi-audio.com/tech/

As for the ribbon size, I went for the smallest size that fits the bill for desired SPL, distortion spectrum distribution and weight. We didn't want 700 grams of headphones.

Cheers,

Alex
 
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