Article: Taking the RAAL-requisite SR1a Headphones To Another Level

[mitchco]

Thanks Chris, that was a lot of fun!

 

The website will take a bit of time to get setup. In the meantime, people can contact me at [email protected] and purchase the RAAL requisite convolution filters for US $250.00 via PayPal. Each filterset includes sample rates from 44.1 kHz to 384 kHz as stereo .wav files. As Chris described, there are 3 filtersets in this package. One neutral, one with bass extension and one with both bass and treble extension.

 

Kind regards,

Mitch

 

[mitchco]

Hi @AudioDoctor please send an email to [email protected] and we can work out the logistics.

 

Kind regards,

Mitch

[mitchco]

15 hours ago, ted_b said:

I don’t understand enough about the filters and HQP to understand why separate ones for each sample rate, etc. 

 

Hi Ted, when the source sample rate changes, the convolver would automatically load the filter with the matching sample rate. This is the traditional approach. But if using a resampler, than most folks will choose the highest sample rate filter and leave it at that.

[mitchco]

6 hours ago, Confused said:

With speakers, the "preferred" in room frequency response curve would drop by maybe -10dB from 20Hz to 20kHz. 

 

The correction for the RAAL's is ruler flat, which is incredibly impressive I have to say, but is this at odds with the above?

 

I'm not sure if I have missed something here?

 

Hi @Confused Agree with the preferred in room response. Consider a loudspeaker that measures flat in an anechoic chamber and then placed in a room. When measuring loudspeakers in typically reflective listening rooms the resulting steady-state room curves exhibit a smooth downward tilt. It is caused by the frequency dependent directivity of loudspeakers (i.e. cones and domes) - they are omnidirectional at low bass frequencies, becoming progressively more directional as frequency rises. More energy is radiated at low than at high frequencies. This is the cause of the downward tilt.

 

With headphones, there is no room or frequency dependent directivity (relatively speaking).

[mitchco]

Hi @skatbelt Chris and a few others tried out the filters and I asked if anyone could hear a shift of the centre image when engaging the filter. The reports back are the that the centre image did not shift. So it would seem from a practical standpoint any driver matching differences are not audible.

 

I listened to and measured fairly extensively while shifting the SR1a's in different positions on my head, including varying the angles. The SR1a is amazingly consistent through the range that fits comfortably. In Chris's article, I show a set of measurements where one was centered and the other two at the ends of up and down on the ears from a headphone wearing perspective and you can see the frequency response is very consistent. Given that they are open baffle type headphones, there is no concern about the bass response varying depending on the seal. One can see that in the measurements and I noted that while listening.

[mitchco]

On 7/30/2021 at 5:36 PM, ajay556 said:

Yes sounds like listening with filters is key. Wonder if mitch provides a trial version :-)

 

Sorry, it is on my todo list but I don't have an ETA.