[Aleksandar R.]

I had not seen that discussion, exactly the same answer I am looking for, but I have no idea how to create that curve in digital domain, I will send a message...thanks genefruit.


hmmm, bad news. I will try it out, since you used the term "potentially", there is still hope. Thanks ThanatosVI.

We also have on offer passive analog SR1 compensation barrels, in RCA and XLR types.
You plug them in the input of the amp, then plug the interconnecting cables in them.

 

[Sandro Sena]

We also have on offer passive analog SR1 compensation barrels, in RCA and XLR types.
You plug them in the input of the amp, then plug the interconnecting cables in them.

I was aware of this option. How can I purchase them separately (I have no immediate interest in the new interface), Aleksandar?

 

[Aleksandar R.]

And do you have the new pads?

Still a bit too early for the new pads.
We're working right now on the final version(s).
The foam won't hold well in the long-term to the adhesive substrate we used initially (foam tape with acrylic glue) over the supporting ring.
It tacks great, initially, but after wearing for a while, the foam tends to detach itself easily.
Testing the epoxy now, so we'll see how that goes, while waiting for even smoother and more "velvety" feelig memory foam samples.
We worked with it before, really feels great on the skin, but sucking-in the midrange a bit too much, so the shape of the pad is not final just yet, as I want to adapt it (if possible) to this smoother foam, without the acoustical penalty.
They will be ready in a week and sent to all that got the pilot-run of the CA's.

 

[Aleksandar R.]

I was aware of this option. How can I purchase them separately (I have no immediate interest in the new interface), Aleksandar?

Danny is the man, send him an email to danny(AT)raalrequisite.com, tell him what you would prefer...

 

[yyzSB]

Led Zeppelin - When the Leveee Breaks on the CA is unreal. Crap I love this headphone for this type of music. So much power coming out of the CA.

VM-1a (Pentode) + CA could be better than the SR1a on this type of music. Or it could be like Chocolate and Vanilla, I like them both.

 

[eboleyn]

Implementation matters. A digital compensation will never sound the same, as an analog implementation and not even two (different) analog correction circuit will sound the same. Implementation can break the case.

As someone who regularly uses digital correction, they are more flexible than the analog implementation in general, and I personally like them. You can both implement near-exact copies of the analog filters and new types of filters not possible in analog.

There are 2 basic "best" digital filter forms to use for those uninitiated:

1. "Minimum phase" filters - This is very similar to the way it happens in analog if using enough resolution. It delays the phase of the input based on the frequency, but takes only a tiny fixed amount of time to process. This is almost always the way "SW equalization" is implemented, and works a LOT like a HW equalizer, and sounds like them too. The exact form of the filter will determine how much phase delay you get on which frequencies. Humans are notoriously bad at detecting phase differences, so most people find this more than adequate.
   • To be clear, all standard analog filters are some variation of this, and the digital processing is just reproducing those filters.
2. "Linear phase" filter - This category of filter is something that you can basically only do digitally, and it produces a variable delay based on the filter configuration, but your output can then have frequency-specific level shifting with phase preserved or even "corrected" to some other phase profile in the more sophisticated variants. I.e. for any particular configuration, you get a fixed delay for the whole signal, but changing the configuration can change the delay.
   • I have noted that using linear phase filters makes the "stereo image" seem a bit more natural/real with speakers (using a DEQX HDP-5 box for correction), but tonality-wise I can not tell any difference whatsoever. In headphones where the stereo image is already partially defeated then I'm not sure the advantage of linear phase filters will matter in a human-perceivable manner.

So, the analog OB correction, be it in the RI box, the various "ribbon headphone" amps, or in the OB correction line signal filters Raal has built recently, are the analog "phase delay" sort, and usually a simple version that ends up with say a 90 degree phase delay in the upper frequencies.

Having said the above, I have 3 sets of digital filters that I'm using on a DEQ2496 box, which has 31-band digital equalization built in using 96 Khz sampling rate using minimum-phase style EQ with 0.5 DB resolution. I.e. I can layer them and they just add together.

• OB correction:
  • 315 -0.5
  • 400 -0.5
  • 500 -0.5
  • 630 -1
  • 800 -1.5
  • 1000 -2
  • 1250 -2
  • 1600 -2.5
  • 2000 -3
  • 2500 -3
  • 3150 -3.5
  • 4000 -4
  • ... -4
• Bass correction to match "typical headphone bass profile":
  • 160 +1
  • 125 +2
  • 100 +3
  • 80 +4
  • 63 +5
  • 50 +5.5
  • 40 +6
  • ... +6
• Compliance correction outside of bass zone to match "typical headphone profile":
  • 1600 -3
  • 4000 +3
  • 8000 -2

With the standard RI box, I have been appling the 2 "correction to match typical headphone profile" items. After modding my RI box with a switch to allow removal of the analog OB compensation, adding in the OB compensation digitally as a decrease in response in upper frequencies matched my mod.

To be clear, any difference between doing the OB compensation in analog in the RI box or in digital in the DEQ2496 equalizer is so small (or human ears don't care) so I cannot detect it, and they sound literally the same to me. I like doing it all in the digital domain, so I tend to prefer that, but I'm sure that's just my bias.

Sometime soon(-ish) I'm probably going to set up an experiment to do the same filters as my DEQ2496 does but in linear phase, probably via using BruteFIR or similar on a text linux box. This way I could see if the linear phase vs minimum phase sounds identical to my ear or if there is some "naturalness" improvement. As mentioned above, I suspect the answer might be "maybe a bit" on the SR-1a due to the hybrid stereo image effects (i.e. partway between headphone and speaker kind of results), but that with the CA I suspect the results will be even more minor or not detectable, at least to me. We'll see.

 

[Litlgi74]

Last night I tested out the reason for me getting the new CA headphone. That was listening to the headphones with my head on a pillow. That worked out great and so comfortable. I will be spending less time in front of the computer now.

I may be the oddball.. but have you not tried the SR1a on a pillow? I enjoy it very much.. adds a bit of bass as well.

 

[SageM]

TI-1b : Will it ship with inputs/output on the same front face, or will it be setup like the TI-1a, inputs back, RAAL output front?

Also it doesn't matter it says 6W max? I can just run a power amp into it?

TI-1b has all connectors on the same side (front). TI-1b is standard for CA unless your get the "Naked" version (headphone only).

 

[paradoxper]

I may be the oddball.. but have you not tried the SR1a on a pillow? I enjoy it very much.. adds a bit of bass as well.

You are all about the pillow talk.

 

[SageM]

I was aware of this option. How can I purchase them separately (I have no immediate interest in the new interface), Aleksandar?

The OB Compensation barrels are available separately. Balanced pair is $80 and Single-Ended pair is $50. We're working on a new site so, for now, just send us an email if you decide to order.

 

[yyzSB]

I may be the oddball.. but have you not tried the SR1a on a pillow? I enjoy it very much.. adds a bit of bass as well.

I had KRELL K-300i integrated amp previously in my bedroom, which is great with the SR1a. I tried to listen to the SR1a while lying down with my head on a pillow. I just could not find a comfort zone with that position. I was always thinking about the headphones and not relaxing with the music. Infact, I sold the KRELL and got rid of my bedroom gear.

Last night I brought a zero-gravity chair into my office and listened to the RUSH album. It was so comfortable (I have arthritis) that I fell asleep for a few minutes. When I woke the music was playing perfectly without the headphone flopping around.

I am on a Led Zeppelin bender today with the CA and VM-1a. I cannot really get any work done, but luckily my colleagues know me to be unproductive.

 

[Sandro Sena]

The OB Compensation barrels are available separately. Balanced pair is $80 and Single-Ended pair is $50. We're working on a new site so, for now, just send us an email if you decide to order.

I sent email a few hours ago, thank you.

 

[SageM]

I sent email a few hours ago, thank you.

Hi Sandro, I just replied.

 

[SageM]

Led Zeppelin - When the Leveee Breaks on the CA is unreal. Crap I love this headphone for this type of music. So much power coming out of the CA.

VM-1a (Pentode) + CA could be better than the SR1a on this type of music. Or it could be like Chocolate and Vanilla, I like them both.

I was going to suggest "When The Levee Breaks" on CA. With VM in Pentode, it's pretty much the definitive playback of that track, that genre.

 

[yyzSB]

I was going to suggest "When The Levee Breaks" on CA. With VM in Pentode, it's pretty much the definitive playback of that track, that genre.

I did listen to it 3 times now.

Going through the catalog starting from the first album. I go on these Zeppelin benders occasionally, but the CA + VM-1a is the best experience so far.

BTW - most importantly, ZERO FATIGUE.