To crossfeed or not to crossfeed? That is the question...

[bigshot]

Ah! So they aren't typical dipoles or bipoles. What is the effect of more refections off the front wall? Does that create coupling, or does the out of phase info cancel that? I would imagine speakers like that do best in the middle of the floor of an open room where the back side can't reflect off the front wall. I had a friend with those Magnipans once. He had to divorce his wife to clear out the living room so his speakers worked properly! They sounded OK but the bass was very thin. Bass is the one thing that sounds full in headphones and isn't anchored between the ears.

Which are the ones that fire in phase front and back? I remember back in the 70s, there was a fad to put rear facing tweeters in studio monitors. I have a set that have that. I turned them off because it messed with the high frequencies. I tend to prefer higher frequencies directional, and lower ones not as directional. I like non directionality and wide dispersion in the rear where there is no center channel to bridge the gap, and horn loaded in the center channel up front to anchor the vocals naturally. That sounds more like the singer is in the room with me. It seems to me that if you are going to fill in, it's better to do that on the sides and rear and not mess with the precise imaging of the soundstage. Spread out sound would ruin a Culshaw opera.

 

[Mink]

I have always been interested in those Mirage speakers. The convenience that they don't have/need a sweet spot for creating a believable soundstage, but rather sound the same no matter at what listening position you are. The downside would be less precise imaging.
How do they compare to the BOSE 901's? Which are kinda similar in their approach, although technically very different. Maybe the difference is that the BOSE have a large sweet spot and the Miraga's none?

http://www.audiopolitan.com/blog/mirage-speakers-the-omnipolar-sound-approach/

 

[sander99]

Before @bigshot gets confused:
In the past Mirage used to make speakers with drivers on front and back like this:

And nowdays they make speakers with the "reflecting cones" to achieve 360 degrees dispersion:

The goal is the same: all around dispersion.

 

[bigshot]

Precise imaging is what is needed to accurately reproduce soundstage, no?

I have KEF speakers in the rear with a radial design that may be similar to reflecting cones. They’re good for rear channels, but I wouldn’t use them for mains myself. I like a precise layout from left to right.

I guess some people like widely dispersed sound. Maybe they don’t like a precise soundstage.

Do you have to set the mirage speakers out freestanding in the middle of a large room too? They sure would dominate the living room!

 

[hakunamakaka]

For accurate soundstage notes have to blend with each other. Listen to certain multidriver IEM's with crossovers, even with razor sharp precision they are unable to reproduce accurate staging and music can sound artificial and detached

 

[jamesjames]

I have always been interested in those Mirage speakers. The convenience that they don't have/need a sweet spot for creating a believable soundstage, but rather sound the same no matter at what listening position you are. The downside would be less precise imaging.
How do they compare to the BOSE 901's? Which are kinda similar in their approach, although technically very different. Maybe the difference is that the BOSE have a large sweet spot and the Miraga's none?

http://www.audiopolitan.com/blog/mirage-speakers-the-omnipolar-sound-approach/

The Mirage speakers were my personal favourites. I owned several versions, but found the passive 7si to work best in a standard room. They are/were very inefficient - requiring lots of power - I bi-amped two Marantz PM11 integrated amps, which I found to be enough (just). As you say, they can deliver a believable soundstage from a range of listening positions. They can also deliver prodigious bottom end power - I guess in the case of the 7si down to around 35Hz. Unlike some other models, they weren't symmetrical (more speakers firing forward). But I liked all the Mirage speakers, including their active hybrids and omnis. The Quads are striking - like Stax headphones - but not really convincing for me - and they certainly don't shake the room with bass! I'm afraid I find all planars a little synthetic in character - something about dynamic shading I think. I prefer dynamic speakers (loudspeakers and headphones). The Bose (which I also owned many years ago) were less sophisticated in all respects - a bit crude in comparison. But they certainly delivered something of the realism of 'reflective' speakers - I actually had the integrated amp made for the 901s, with 'wide' and 'narrow' settings. I've listened at length to the current Duevel omni speakers, and like them too. I should say I've never liked front firing box speakers. I think they are never convincing - always artificial and often glaring. And, generally, I find the compromises necessary for headphones preferable to those of loudspeakers - and I prefer them as recording monitors.

 

[bigshot]

The sound system in my listening room doubles with a projection video screen. It's 5.1 with about a 14-15 foot spread from left to right. The front soundstage is very precise and defined, and it is perfectly scaled to the screen, so when a character crosses the screen, the sound follows the image perfectly. Multichannel music takes all kinds of approaches to soundstage, from a fixed front soundstage with reverb behind, to an immersive sound field where you are sitting in the middle of the soundstage. You can't really make any generalization about that. For stereo, I often use a DSP called Yamaha Stereo to 7.1. It spreads the sound of stereo music all around the room. That is probably the equivalent of crossfeed for speakers, although I wouldn't say it increases depth at all... just fills the room with sound without messing up the front soundstage too much.

I haven't found any way of listening to headphones that comes close to the spatial depth of multichannel speakers. Not even close. And even stereo with speakers is capable of better depth than headphones. But that depends mostly on the mix.

 

[jamesjames]

I remember finding the advent of multi-channel arrangements, and multi-channel SACDs very impressive. Unlike the older reflected sound approach (a la omni speakers), which almost ignores the recording, and relies on harnessing in-room delay, multi-channel relies on the recording, and tries to reproduce accurately a recorded fascimile of the sound event (complete with reflected sound from the recording venue). And I can't really explain why I find di/bi/omni polar speakers more satisfying than multi-channel. I find it even harder to explain why I prefer headphones, given that reflected sound is arguably less relevant here. All I can say is that the relatively low-tech strategy of seeming to push the performance space away from the listener seems to be disproportionately important in allowing some blending of sound that I find captures the feeling of a live performance. And I find crossfeed on the right phones the most convincing effort yet to achieve this - or perhaps I should say the least problematic ...

 

[bigshot]

Distance is directly related to scale. Nearfield speakers can present a miniature soundstage, but that isn’t natural. In my listening room I spent a lot of time experimenting to get the soundstage to a human scale. Bands sound like they’re standing in front of my fireplace arrayed out from one side of the room to the other, like a small club. Orchestras can sound like hearing them from a good seat in the 15th row. That depends a lot on secondary depth cues though. Headphones give me no sense of distance or scale. It’s all inside or around my head. That can sound nice, but it isn’t realistic.

 

[jamesjames]

Distance is directly related to scale. Nearfield speakers can present a miniature soundstage, but that isn’t natural. In my listening room I spent a lot of time experimenting to get the soundstage to a human scale. Bands sound like they’re standing in front of my fireplace arrayed out from one side of the room to the other, like a small club. Orchestras can sound like hearing them from a good seat in the 15th row. That depends a lot on secondary depth cues though. Headphones give me no sense of distance or scale. It’s all inside or around my head. That can sound nice, but it isn’t realistic.

... perhaps you should try better crossfeed ...

 

[bigshot]

The two things that determine scale are physical distance and height. You don’t get either of those things with headphones unless you’re operating some complex processing t simulate height or distance. Just fuzzing everything up into a diffuse field isn’t the same.

I’ve tried Apple’s Spatial Audio and Dolby’s virtual surround too, and they just make everything sound like it’s indistinctly distant. Not pinpoint.

 

[jamesjames]

The two things that determine scale are physical distance and height. You don’t get either of those things with headphones unless you’re operating some complex processing t simulate height or distance. Just fuzzing everything up into a diffuse field isn’t the same.

I’ve tried Apple’s Spatial Audio and Dolby’s virtual surround too, and they just make everything sound like it’s indistinctly distant. Not pinpoint.

Seriously, I'm not trying to convince anyone of anything. I'm just trying to explain my own experience of crossfeed, in a way that might be interesting to others if they are interested in this topic. This is a thread about crossfeed, after all. It's abundantly clear that you're not a big fan. I get that. What I don't get is why you find it necessary to respond to every post as if this were some sort of debate. You don't need to read my posts, or respond to them.

 

[bigshot]

The two poles are crossfeed blending on one side, and channel separation. When you lean towards the crossfeed end, the soundstage suffers. When you lean towards the channel separation side, it can sound like a dog's breakfast because most commercial music isn't mixed to be listened to in headphones. It's monitored on speakers in a typical triangulation.

One of the reasons you really liked those two types of speakers is their height. Height and distance create scale. Bookshelf or stereo box speakers don't have that. That's why I brought up scale. Of course neither distance nor scale apply to headphone listening because that is all in your head.

 

[jamesjames]

The two poles are crossfeed blending on one side, and channel separation. When you lean towards the crossfeed end, the soundstage suffers. When you lean towards the channel separation side, it can sound like a dog's breakfast because most commercial music isn't mixed to be listened to in headphones. It's monitored on speakers in a typical triangulation.

One of the reasons you really liked those two types of speakers is their height. Height and distance create scale. Bookshelf or stereo box speakers don't have that. That's why I brought up scale. Of course neither distance nor scale apply to headphone listening because that is all in your head.

Understood. Many thanks.

 

[71 dB]

The two things that determine scale are physical distance and height. You don’t get either of those things with headphones unless you’re operating some complex processing t simulate height or distance. Just fuzzing everything up into a diffuse field isn’t the same.

I’ve tried Apple’s Spatial Audio and Dolby’s virtual surround too, and they just make everything sound like it’s indistinctly distant. Not pinpoint.

How does the ears know how far the sound came from and how large the sound source was? Spatial cues! If you can generate such spatial cues well enough, the spatial hearing can be fooled. Normal crossfeed is very simplistic way of mimicking those spatial cues, but it is something and for me it changes the spatiality a bit toward speaker spatiality. We don't really experience large ILDs at low frequences* in our everyday lives and that's why at least some people including me experience these large ILDs headphones often generate unnatural and annoying. Crossfeed fixes this problem for me.

* Headphones are pretty much the ONLY method to generate large ILDs at low frequencies. Normally low frequencies arrive at both ears at ILD of no more than a few decibels. Spatial hearing expects the ILD to be very small at low frequencies. Binaural recordings can be analysed to see how much ILD, ITD and ISD there is in normal listening of environmental sounds. At low frequences the sound is quite monophonic. Only at higher frequencies do we have significant ILD-values. There is a sweet pot for ILD that is a function of frequency. Going below this sweet spot makes the sound mono-like and going above it make the sound super-stereo-like. I want to do my listening at the sweet pot. With speakers it happens "automatically", because room acoustics regulate the spatiality. With headphones I need crossfeed to limit ILD, because there is no room.