Crossfeed with phones

ryno · « **on:** 9 Jun 2005, 05:04 am »

I'm looking at a couple portable headphone amps. One is simple, in/out on/off volume, in a very nice case. The second has bells and whistles, DC in jack timer off gain jumpers and variable crossfeed, in a cheap altoids tin. "They say" crossfeed helps because for speakers, your right ear hears some of the left speaker and vice-versa. In headphones this doesn't happen, so adding some left to right and right to left sounds better. Is this something that really sounds better, or just a gimmick.
Thanks, Ryan

ooheadsoo · « **Reply #1 on:** 9 Jun 2005, 05:41 am »

It's a matter of taste. It does do what it claims but maybe not in the way you would expect. If you have foobar on your computer, there's a simple crossfeed plugin that you can play with to get a feel of it. Most crossfeed implementations change the balance of the sound, however.

csero · « **Reply #2 on:** 9 Jun 2005, 11:21 am »

Quote from: ooheadsoo

Most crossfeed implementations change the balance of the sound, however.

Headphone listening change the balance of the sound, however

Crossfedd try to fix a problem with a very-very crude approximation of the missing HRTF caused by bypassing the torso/pinna related filtering. Wether you like it or not is up to you.
You can try real "extrenalization" processing, like the toltec or modern surround headphones, but because the HRTF is individual for each listener, the generalized filtering may or may not work for you. Even then the changes caused by small head movements are issing, and the externalization is not working well.

Davey · « **Reply #3 on:** 9 Jun 2005, 01:32 pm »

"Crossfeeding" with headphones goes back many many years. I first saw this from Siegfried Linkwitz in the early seventies but efforts date before that. If you want to do some reading on this subject and look at a variety of projects check some of the headphone forums like Headwize.

http://www.headwize.com/projects/cmoy1_prj.htm

Davey.

onemalt · « **Reply #4 on:** 19 Jun 2005, 10:23 am »

I use a Headroom Cosmic Reference. The guys at headroom are the "Kings of Crossfeed". What I'm saying is that they do it right on their amps. I used the crossfeed for a couple of months when I first got the amp and found it OK but ultimately decided it was at the expense of detail. I stopped using it then and have never looked back. YMMV.

The Meier Corda HP amp line also employs a slightly different crossfeed circuit than the one used by Headroom which many find very enjoyable, if you're interested.

EMM801 · « **Reply #5 on:** 27 Jul 2005, 05:16 am »

HeadRoom's products enjoy a well-deserved positive reputation.

There are software implementations that allow finer control than is possible in the analog hardware domain. On Windows, WinDVD 5 had Dolby Headphone which worked well. There is a VST plugin for Macs called "Canz3D" (midnightwalrus.com). Both these work pretty well, more convincing than the somewhat unnatural line-between-the-ears image of conventional headphone sound. Dolby Headphone gives you a few options as to room size and type, but Canz3D allows user control of the following parameters:

Master
Master gain adjustment applied to all sources

Speaker
Relative gain adjustment for sound directly from the simulated speakers

Live
Relative gain adjustment for all reflections except the back wall

Dead
Relative gain adjustment for the back wall reflections

Balance
The balance between the simulated speakers

Blend
Parameter which controls the channel crossfeed (0=none, 1=full simulation)

Shape
Parameter which controls the frequency shaping (0=none, 1=full simulation)

Delay
Parameter which controls the left-right relative delays (0=none, 1=full simulation)

Spkr Tap
(Speaker Tap) The time width of the tap for sound directly from the simulated speakers

Live Tap
The time width of the tap for all reflections except the back wall

Dead Tap
The time width of the tap for the back wall reflections

Live ACL
Low frequency absorption coefficient for all reflections except the back wall

Dead ACL
Low frequency absorption coefficient for the back wall reflections

Live ACH
High frequency absorption coefficient for all reflections except the back wall

Dead ACH
High frequency absorption coefficient for the back wall reflections

Live ATF
Absorption transition frequency for all reflections except the back wall

Dead ATF
Absorption transition frequency for the back wall reflections

Head Siz
(Head Size) Approximate circumference of the listener's head

Spkr Ang
(Speaker Angle) The angle between the speakers from the listener's perspective

Spkr Spc
(Speaker Space) Distance between the listener and the speaker plane

Frnt Spc
(Front Space) Distance between the speakers and the front wall

Side Spc
(Side Space) Distance between the speakers and the adjacent side walls

Back Spc
(Back Space) Distance between the listener and the back wall

Flor Spc
(Floor Space) Distance between the speakers/listener and the floor

Ceil Spc
(Ceiling Space) Distance between the speakers/listener and the ceiling

Snd Sped
(Sound Speed) The speed of sound used in the simulation

Try getting that type of control in the analog domain![/b]

Jon L · « **Reply #6 on:** 27 Jul 2005, 06:01 am »

Forget crossfeed. It's good for one thing only: taming horribly bright recording as a psedo-EQ to shave off treble/detail.

For $250, you could buy a very nice-sounding portable amp, the SuperMacro v.3 Lite (light in features but not sound).

http://www.fixup.net/products/macro/

Aman · « **Reply #7 on:** 27 Jul 2005, 08:05 pm »

Actually, crossfeed has one very good characteristic, which is that it will make your bright, crappy, channel-separated 60's rock recordings (like The Beatles and The Doors) sound like new mixes.

Crossfeed really helps when you take this into consideration. If you're still spinning your Beatles vinyl or are listening to MP3s of Strange Days on your MP3 player, Crossfeed may be a good feature to have.

EMM801 · « **Reply #8 on:** 11 Aug 2005, 06:18 pm »

Is crossfeed a gimmick?

Well, yes, but if you think about it, so is stereo. And moving pictures. And Dolby Noise Reduction.

When well done, as in Dolby Headphone or Canz3D, it can help the all-inside-your-head stereo image. I confess have not heard any of the analog implementations like the HeadRoom amps but suspect they are crude approximations of what can be done in the digital domain.

EMM801 · « **Reply #9 on:** 18 Sep 2005, 10:29 pm »

Might want to check the samples on the website (just google Canz3D). there are comparison samples there you can listen to, as long as you have a player that can handle Ogg Vorbis). Is it perfect? No, but what is? If you keep an open mind, you might find something worthwhile. Heck, it's only 10 bucks. There's even a bypass switch. As long as I can turn it off, I'm OK with it.

My time is done and I thank you for yours.

CSMR · « **Reply #10 on:** 22 Oct 2005, 08:44 am »

To those who don't like crossfeed, if crossfeed doesn't work, what does?

EMM801 · « **Reply #11 on:** 10 Mar 2006, 05:53 pm »

Peyote

Dusty Chalk · « **Reply #12 on:** 11 Mar 2006, 01:46 am »

Quote from: CSMR

To those who don't like crossfeed, if crossfeed doesn't work, what does?

To accomplish what?

jlo · « **Reply #13 on:** 18 Mar 2006, 12:54 pm »

I also did a VST plugin but for Windows with some parameters to adapt to your ears/headphones and with the goal "not" to change the sound quality.

Download and try it at http://www.ohl.to/crossfeed-and-eq-for-headphones/.
Use the signal generator included to do your own setup.
I think that most of CD's really benefit from crossfeed and with some, it's "night and day"

Thanks to let me know your results.

EMM801 · « **Reply #14 on:** 27 Mar 2006, 03:58 pm »

Done right, crossfeed is a subtle effect that mainly alleviates the sensation of sound coming only from a straight line between your ears. I don't have a Windows machine to test your plugin but wish you luck with it. I hope some will try it and provide feedback. To repeat a point I made earlier, remember, stereo can be considered a "gimmick" too.