narrow and wide baffles and imaging


According to all the "professional" audio reviews that I've read over the last several years, narrow baffles are crucial to creating that so-desired pin-point imaging.

However, over the last few weeks, I've had the opportunity to audition Harbeth 40.2, Spendor Classic 100, Audio Note AN-E, and Devore O/93.  None of these had deficient imaging; indeed I would go so far as to say that it was good to very good.

So, what gives?  I'm forced to conclude that modern designs, 95% of which espouse the narrow baffle, are driven by aesthetic/cosmetic considerations, rather than acoustical ones, and the baffle~imaging canard is just an ex post facto justification.

I can understand the desire to build speakers that fit into small rooms, are relatively unobtrusive, and might pass the SAF test, but it seems a bit much to add on the idea that they're essentially the only ones that will do imaging correctly.



128x128twoleftears
it is more than imaging....
try this simpleexperiment

make 2 8.5 x 11 baffles out of cardboard, hold on either side of mouth while speaking, record voice from a distance of 6’ in middle of room , repeat with no baffle.....


you can of course also duplicate the simple horn shapes for fun also......
of course if your designer is trashing time and phase information, all bets are off on imaging anyway....
 I think that's a bunch of BS. Some of the best imaging speakers I've had have had hugely wide baffles. Of course I'm sure it helped that they were point source but still if the baffle was that important they would've been a lot worse 
you missed my point about it is more than about imaging....did you try the simple experiment and hear the change in sound ?
you can also take any small narrow point or even line source speaker and enlarge the baffle with a sheet of MDF, back your speakers up against the rear wall and get same effect plus more bass.... just basic math and physics...
also the large baffle will generate positive and negative cancellation which shows up as frequency response anomaly.....

these simple experiments in what and how younhear are agnostic to brand and speaker religion...and IMO help to further educate the avid listener...

I am deeply sorry IF my post offended any...

back to hearing Richard Thompsen sing about some redheaded girl...
I don’t know the answer here, but simply on some personal experience:
The wider-baffle speakers that I’ve become acquainted with and auditioned - I’m thinking the larger Harbeth models, Devore and to some degree Audio Note - all have impressed me by "disappearing" and soundstaging much more than I would have expected given their looks, and given the usual audiophile ideas that narrow profile speakers image well/wide speakers don’t.

That said....

It’s also the case that while those speakers did surprising imaging/soundstaging/disappearing, they also weren’t near head of the class for those qualities. In each case I have found soundstage depth somewhat flattened, and a sense I can hear the speaker contributing to the sound (which as a hunch could be due to the thinner-cabinet-working-with-resonances approach also taken by those speakers).  Many narrow baffle speakers seem to disappear much "more" and with greater depth to the imaging.

narrow and wide baffles and imaging

narrow baffles are crucial to creating that so-desired pin-point imaging.

Yes the narrower the baffle the better, but also a similar thing to image destroying wide baffles is, so many "audiophiles" love to put all their equipment on racks in between their speakers. Just so they can gaze them it in wonderment while listening.

This is one of the biggest image and depth destroyers there is. Stop the "glitz gazing" and put that stuff over to the side/s and have nothing in between your speakers and beside them and behind them as far back as you can as well.

The late Neville Thiel (T/S speaker speaker design laws) told me to do this once many moons ago he called it the 3 x B’s, and I have never looked back and never had anything "between, beside and behind" the speakers. I have an image and depth heard and seen that makes you think you can get up and walk into it

Cheers George
Room acoustics matter a great deal, but I’ve read, and listened and I truly believe this:

Extra-wide baffle speakers are better able to convey a sense of the recording space compared to "normal" and "skinny" speakers in most rooms. My favorite example of this is the Sonus Faber Stradivari.

You can get more insight reading Troels Gravesen’s article on a "poor man’s strad" here:

http://www.troelsgravesen.dk/PMS.htm

Besides that, one thing that bedevils a lot of speakers is baffle diffraction. This is not just the baffle width, but the height and the driver placement. For whatever reason, wide baffle speakers seem to cure a lot of it. 
@prof  Hmmm.  In my auditioning of the 40.2's in a big room in which they could well and truly breathe, they both imaged and sound-staged extraordinarily well.  The Classic 100's in another set-up also did very well on both scores, to my mind.

@analogluvr I agree.  I mean, if it were as simple as narrow good, wide bad, why would these modern wide speakers perform as well as they do, even if they are not perhaps the equal of the absolute imaging champs.

@mindlessminion I think I'd have to say the 40.2's, though the Classic 100's were at a different place, in a different room, with totally different equipment.  Both very good indeed.  The Audio Note's had perhaps the greatest purity of sound, the highest truth-to-timbre, more like the live acoustic instruments than perhaps anything else I've ever heard.  But despite their claims to the contrary, I did think their positioning close to the front wall, as is traditional with them, did tend to foreshorten a little the soundstaging, and reduce a little the general airiness.  Of the four mentioned, I liked the Devore least, though they were fine. 
So, what gives? I’m forced to conclude that modern designs, 95% of which espouse the narrow baffle, are driven by aesthetic/cosmetic considerations, rather than acoustical ones, and the baffle~imaging canard is just an ex post facto justification.
That is certainly most of it. Those who claim otherwise haven’t heard a properly setup pair of SP100s that can completely disappear, unlike numerous "high end" towers. As for time and phase alignment being critical, that’s total hogwash - it's important for decay, not imaging.
Yes but shape of the baffle is just as important - rounded smooth edges are best.

Very Narrow baffles will image second best.

Very wide baffles (like mine) will image third best.

Speakers flush mounted into a wall with essentially an infinite baffle image the very best.

 Intermediate size baffles tend to be the worst (about 1 foot to 2 foot).

Wilson triangular angler Watt puppy design is a very good example of a small effective unobtrusive baffle.

summary 

Excellent < 1 foot (think small two way and audio physic narrow designs)
1 foot < mediocre < 2 feet
very good > 3 feet
perfect > 10 feet

but remember the shape of baffle edges can be just as critical.


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@shadorne Interesting.  If I understand correctly, those parameters would put both the Harbeth and the Spendor into your "worst" category.

@kosst_amojan How wide is wide in your reckoning?  Also wondering how proper radiusing of corners mitigates other problems.

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Rack in corner would be bad because of excessive bass frequencies causing vibration to the components. You do want to get the rack in equipment out between the speakers, that's for sure! Preferably in another room
Of all the speakers I've heard and read about that are touted as having truly outstanding holographic 3D imaging and soundstaging, ALL have narrow baffles (at least as far as the mids and highs are concerned).  It's not that wide baffle speakers can't have these properties -- they most certainly can and do.  It's just that they don't inherently excel in this particular area as well as their narrower counterparts, and to be sure wide baffle designs have inherent strengths and advantages of their own.  I'll leave the science to others, but my experience and reading seem pretty darn conclusive on this point. 

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@twoleftears

Yes you are correct. Also mid sized ATC like the ATC 100, JBL and other big boxey three ways tend not to image (or disappear) as well. It all has to do with mid range and tweeter frequencies because the LF sound wraps around the entire speaker (wavelength is much larger than the woofer)

I did not mention but a waveguide around the mid range or tweeter can create directivity and reduce the baffle issue too. ATC mid range has a waveguide and so does the tweeter but nevertheless the smallest models image best. A horn works well too like Avantgarde.

Audiophysics really do the disappearing trick and so did Bose Acoustimass although the audiophysics are a fantastic speaker and Bose is average but you get the idea....

It is more the disappearing act than imaging that is most immediately noticeable...

Genelec have done a lot of work on this

https://www.genelec.com/key-technologies/minimum-diffraction-enclosure-mde-technology




see Jim Smiths excellent book on getting your gear off to the side
pretty much every competent designer is doing the radius trick with the grilles
also as mentioned the massive baffle causes frequency response issues....just basic physics... yes you get more output but most of it is distortion...and finally, true to internet where we argue w words, nobody has two small sheets of cardboard to do the physical experiment
and as an Infinity dealer, I was very aware of the plus and minus effects of the large wood baffles as one moved up the line, louder...yes
better? not so much.....
@wolf_garcia .....I hurl at spelling......and typing with ipad...

IMO imaging is way more than speakers disappear, it is 3 D depection of the soundfield and the acoustical space ( what there might be of it ) by the system...
massed chorale in church, environment not severable from performance..
multitrack studio..not so much....most of the depth is relative volume and reverb

for those who might care see Youngs slit experiments, nice utube videos, U Conn physics has some decent stuff, not hard to see what the bigger baffle does....

perhaps Alon knows of math where the edge discontinuity matters not? 

wolf back to Cowboy Junkies......ambisonic....

In the wider baffle speakers I'm familiar with, a consistent impression has been a bigger, more full sound especially in the midrange, vs the typical narrow profile speaker.   That's certainly a big aspect of what attracts me to the Harbeth and Devore speakers.

(Though, at least in my case, when I bought the Harbeth Super HL5 plus speakers to try at home,  I couldn't get them to image with the believable depth that I'm generally accustomed to).
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So what about the SF Elipsa series, which if memory serves is a good deal wider than any other SF models?  Did SF ever provide a rationale for why they did the Elipsa's that way?

@prof  Exactly!  That's precisely what struck me--and impressed me--auditioning the 40.2s and Classic 100's.  The "sound launch", for want of a better term, seemed more substantial, had more body, than just about anything else I've heard.  Besides narrow/wide baffles, made me wonder too about woofers located on the sides or back of the box, rather than on the front.

the Stradivari presented a more weighty, unusually solid picture that seemed to be a three-dimensional curtain wrapped behind the baffles and extending well back into virtual space.
A friend had the SF Amati’s which were really nice and had a great believable image/depth presentation, then his dealer persuaded him to trade up to the SF Stradivari same system same everything, ask me around to have a listen a to give my opinion as he wasn’t happy.

As soon as he put on a Diana Krall cd that I’d heard on the Amati’s just a week before, I turned as said to him "my god, why has she's suddenly got a 10ft wide mouth" he said "exactly" no amount of re-positioning fixed it, next day he had his Amati’s back.

Cheers George
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There's kind of a continuum of room to speaker matching.

<narrow directivity> ----------------------------- < wide directivity >
<narrow sweet spot> ----------------------------< wide sweet spot >
<less room dependent > ------------------------< more room dependent>

It's not _just_ the room or _just_ the speakers. However, well treated rooms are, by and large, accomodate a wider range of speakers and have better, bigger sounding bass. 
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@kosst_amojan OK, I'll bite.  By imaging I understand individual sound sources (voice, instrument) being well defined and easily localizable within the overall sound stage.  Ideally, the listener should be able to map, more or less precisely, where each "instrument" is on the left to right axis and, at least to some extent, on the front to back and high/low axes.  Also, importantly, the instrument should not appear to be substantially larger or smaller than the other instruments in the soundstage than it is in real life.  Example: a three foot wide clarinet.
@twoleftears  there are clear explanation  how width of baffle
make sound or sound stage different , The problem coming from 
different diffraction lost from low frequency and mid freg. 
the call baffle step , you can read more on google
http://diyaudioprojects.com/Technical/Baffle-Step-Correction-Circuit-Calculator/ https://www.trueaudio.com/st_diff1.htm and much more.
Good design 3 way Loudspeakers usually dont have this issue. 
but one way crossoverless and some 2 way get this problem
result -pure soundstage, lack midbass, voices and piano sound  thin   
Also, Voxative  made one nice Loudspeakers with huge baffle
try to avoid this issue. The Good Horn design  also is good for
this reason and make  good  soundstage
The width of the baffle really only affects the baffle step. If the crossover designer knows what they are doing, there is very little difference. Having chamfered edges or a curved face (like the LS50’s) have a bigger impact than the width of the baffle (assuming equal efforts of dealing with the baffle step).
I've heard from a speaker manufacturer that the main reason we're seeing so many ultra-narrow baffles is WAF -- narrow speakers can be shoehorned between the furniture.

Otherwise, I think it's a tradeoff. As Alon Wolf said, a larger baffle reduces the baffle step effect, something that can never be completely corrected. On the other hand, a large baffle causes diffraction issues that are known to interfere with imaging and can also block room reflections that add to the sense of space. In any speaker, these issues can be minimized by for example curving the edges of the baffle and using felt.

Interestingly, though, the most holographic imaging I've ever heard was from the IRS V, at Lyric. Which of course had a huge baffle, curved to minimize diffraction effects. As I recall, the room was also quite dead, which tends to give you pinpoint imaging at the expense of spatiality (width and depth) and a sense of ambiance. And it was being used with tube electronics (CJ) that were known for enhancing depth (out of phase second harmonic distortion).

Otherwise agree with those who say to get the electronics out from in behind the speaker -- the rack will cause a reflection and create a virtual speaker that confuses imaging.

One of the most important factors in imaging seems to be the distance from the speaker to the walls -- you want ideally to have no early reflections greater than -20 dB for the first 25 ms or so, because the ear uses first reflections to judge the size of a space and early reflections from the room mask the recorded ambiance of the original venue. In all but very large rooms, some acoustical treatment (absorption or diffusion) at the early reflection points is needed to do this.

You also have to consider your distance to the rear wall. I've found that if you're too close to the rear wall, rear wall reflections interfere with the imaging. Since in my own undersized listening room I have to sit a few feet in front of a wall, I put some Owens Corning 703 on it and the imaging problems disappeared.

Another imaging rule that I've found useful is that good mono makes good stereo. If you listen to a mono recording or pink noise it should be pinpoint centered between the speakers. That will give you palpable, pinpoint stereo imaging. Asymmetries in the listening room and setup can cause the sound to wander with frequency. I recently put a sheet of plexiglass in front of a window behind my right speaker to flush it out with the wall, and I was astounded by the improvement in imaging. I didn't think a couple of inches would make such a difference, but it did.

It's amazing how much of a difference small changes to the room can make. For example, I have a computer monitor off to the side, and when I angle it so that it faces the rear wall and doesn't reflect the sound from the speakers to my ear the imaging improves. A Umik-1 measurement mic and the impulse response display in Room EQ Wizard are great tools for catching early reflections.
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There is more to the mater then the size of the front baffle. The speaker will not appear to have good imaging if the cabinet is noise ( has a lot of resonance ) . Many wide baffle speakers " very wisely " opt not to attempt to go in the bass. This makes for a cleaner sound and one where you can appreciate the imaging. 
They were amazing, weren't they? I remember having the sense that I could go into the soundstage and walk between the instruments.

Soundsrealaudio, that's an interesting point and one I'd never heard.
My wider baffled 1977 DLK model 1, not so high end by today's standards, conveyed a wonderful sense of immediacy and realism, like I'm in the bar and the band is 20 feet away, while likely lacking the ultimate  in 'resolution' and  'clarity'. My  recently auditioned narrow- baffled Chane 2.4  MTM s presented a deep, holographic ambience, but some percussion, transients sounded off and artificial to my ears, a certain hollowness in part of the midrange. I don't think baffled width is any kind of determinant.
The best imagining Infinity ever, was the IRS Beta’s with midrange, tweeter, and super tweeter baffle’less.
http://product-images.highwire.com/12510183/1772-14.jpg

But as far as highs having a 3 dimensional image, nothing touches my 360’ MP-02 Plasma Flame tweeters
https://i.ebayimg.com/images/g/V5sAAOSwCJxZ6PXy/s-l1600.jpg.

Cheers George
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I could be mistaken, but the IRS-V’s midrange/tweeter panel was also baffle’less, no?

Yes line array, but that sure looks like a baffle to me, even though it curves away. 
http://www.infinity-classics.de/models/IRS-series+Beta+Gamma-Delta-Sigma-Epsilon-1988-95-98/IRS/IRS8...

Cheers George
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