A question for Richard Allen/EB Ricky, AEJim, Ketan (or any other loudspeaker designers/manufacturers lurking here).

[chebby]

Why are most loudspeakers nowadays deeper than they are wide?

When I first started buying loudspeakers (and for many years after) they were all wider than they were deep.

Is this a cosmetic thing? (Moden designs give the impression of being slimmer when looked at face on.)

Is it a physics thing? (In which case, why were all those great manufacturers/designers getting it wrong before the 1980s/1990s when the relative width/depth proportions starting changing?)

Is it just fashion? (ie it doesn't really matter.)

 

[Andrew Everard]

I think it's quite possibly to do with the fact that in the past speakers were more likely to be used on bookshelves, which kinda dictated they should be relatively shallow front to back, while height and width offered more flexibility.

 

[Frank Harvey]

Narrower speaker generally have better imaging.

Over the years, people have demanded less intrusive speakers, so manufacturers have made them narrower. This loses cabinet volume, so some manufacturers have made their speakers deeper to make up the lost cabinet volume.

 

[AEJim]

It's a good question and I tend to think it's a mixture of many of those things you've mentioned.

Fashion is certainly a factor and slim appearance from the seating position is generally preferable - though in many rooms the amount of depth taken up borders on intrusive when you factor in clearance from a wall, even with a small stand-mount speaker.

Technically the general trend towards smaller drive units has meant the speaker can be made very slim but often require ports for bass reinforcement which are 6" long or so and also need some internal clearance, making shallow cabinets tricky unless using side porting (the Royd Minstrel was a very good example of this implementation). Some speakers utilise slot porting and transmission line internals which again need depth to work properly.

The smaller drive units have probably come into fashion as they are a lot more efficient than they were in the 70's (due to modern materials, glues etc) when large, shallow speakers were the norm. The smaller drive unit can be faster in response than the old 12" ones though there is still a trade-off in the amount of air they can shift, hence the use of multiple drivers being another trend - this tends to look better in a narrow column as well as benefiting from the imaging aspects mentioned by David.

Overall I think it's probably the fashion aspect that has dictated the majority of manufacturers direction in this, you can make most styles work given enough development time but I don't think the public would like the old style 15" wide and 6" deep speakers simply because they would be "different than the norm". The Ford Focus looked very odd when it came out and smaller car manufacturers would no doubt have suffered sales hits from such a design, Ford were popular enough to get past this and as the Focus got seen on the road more regularly people accepted it more - now it's seen as pretty dull. I'm sure someone could bring out a different "old style" speaker and start a new trend if it was good enough (the style itself is pretty practical, especially as it is usually large enough to allow a sealed box for wall placement). Now I'll leave it to one of the big boys to get that particular ball rolling...

 

[chebby]

Thanks James. Lots to ponder on there.

 

[Richard Allen]

chebby:

Why are most loudspeakers nowadays deeper than they are wide?

When I first started buying loudspeakers (and for many years after) they were all wider than they were deep.

Is this a cosmetic thing? (Moden designs give the impression of being slimmer when looked at face on.)

Is it a physics thing? (In which case, why were all those great manufacturers/designers getting it wrong before the 1980s/1990s when the relative width/depth proportions starting changing?)

Is it just fashion? (ie it doesn't really matter.)

There is an equation, although the exact maths escape me at the moment, as to the width and the depth of a loudseaker. The ratio, I believe, is the diameter of the driver vs the width of the cabinet. Ideally, the cabinet should be wider than it is deep. This is to allow for ' diffraction'. Unfortunately, 'Er Indoors' dictated that loudspeakers should have a slimmer profile so, because of market forces, we went there. As was previously posted, these became reflex designs (with all the shortcomings), but the ideal is wider than depth.

 

[Anonymous]

I agree, although not sure about the diffraction issue. In an ideal world, I think the width of the baffle is the driver diameter multiplied by 3.1415, or is it the square root of that??

 

[chebby]

Richard Allen:Ideally, the cabinet should be wider than it is deep. This is to allow for ' diffraction'. Unfortunately, 'Er Indoors' dictated that loudspeakers should have a slimmer profile so, because of market forces, we went there. As was previously posted, these became reflex designs (with all the shortcomings), but the ideal is wider than depth.

Thanks Richard and EB Ricky.

I suspected that aesthetics/fashion/domestic acceptability were prime, rather than secondary, considerations in this trend.

Interesting about the 'ideal' being a speaker that is wider than it is deep.

My (enclosed cabinet) N-Sats are about 20cm wide and 20cm deep - without the grilles - and have a very slightly convex front baffle that is much wider than the bass/mid driver.

If I divide 20cm by 1.77 (square root of 3.14159) then I get 11cm which is the exact diameter of the cone material of my N-Sats. (The rubber surround and chassis make them look a bit bigger obviously.)

I must start looking up dimensions of some of those old (and wider) favourites like MS Festival 2s and AR18s and your near namesake's Richard Allan RA-8s. (And Peter Comeau's original Heybrook HB1s). All sealed enclosure designs. See if they conform to that cone diameter x square root of pi ratio

Thanks.

 

[chebby]

EB Ricky:I agree, although not sure about the diffraction issue. In an ideal world, I think the width of the baffle is the driver diameter multiplied by 3.1415, or is it the square root of that??

Seems more likely to be the square root, otherwise all those 'old school' speakers would have looked very strange.

 

[chebby]

I have been researching the Neat Petite SX speakers - online - and just noticed, when checking their dimensions, that (unusual nowadays) they are wider than they are deep.

Colossally boring I know, but this seems to go right against the last 20 years of trends in 'speaker dimensions.

I wish that Neat's designer chap was a member here (like AEJim) to explain why they made the decision.

Just noticed that all the Neat 'Classic' models have cabinets that are wider than their depth. So maybe this trait is a historical thing and they have always been like this.

 

[the record spot]

Tannoy ressurected a line of older speakers which I think were the Glenairs a few years ago which fitted this description. Of course they also did their famous Yorkminster and Westminster Royals which were true behemoths!

 

[chebby]

I guess my on/off interest in this subject is because users of modern, 'compact' speakers may be listening to designs that are slightly compromised due to fashion (see AEJim and Richard Allen's updates above) and are not as compact as they might seem.

I have read/heard arguments from speaker designers and others that both support the 'ideal' of a wider/shallower cabinet and support the concept of cabinets that are as narrow as possible but deeper. Arguments for both claim it aids diffraction.

Their visual impact on a room makes no difference (given a constant volume) because the shallower (wider) design sits less far into a room and the deeper (narrower) cabinet will only look smaller when looking directly face on, seated between them (and only if they are toed-in to the extent that the sides are not visible). Viewed from anywhere else in a room the 'bulk' of the speaker will look pretty much the same whatever the ratio of width to depth.

I would rather manufacturers design the proportions according to what sounds best rather than trying to 'divert' the eye or play visual tricks that only work viewed head-on or at angles where the depth is not apparent. (Thinking of what they look like in ads too.)

 

[oldric_naubhoff]

I guess my on/off interest in this subject is because users of modern, 'compact' speakers may be listening to designs that are slightly compromised due to fashion (see AEJim and Richard Allen's updates above) and are not as compact as they might seem.

I don't want to argue with what AEJim says but if this statement is true there should be abundance of wide-shallow speakers on the market. you know, there are loads of speaker manufacturers out there who don't give a dime about fashion and whose designs follow function. and yet you'll be hard pressed to find wider than deeper designs even in high-end end of the market. the only such designs being manufactured now that I'm aware of are those uber sensitive boxes intended to be used on the end of flea power tube SET amps. other than that you get narrow-deep designs so there has to be another reason working here, not just fashion. there are even modular designs where big woofers (some 12" or 15" drivers) are housed in seperate enclosure and midrange and HF drivers in another, which is much narrower. as far as I'm aware narrow designs help with imaging.

BTW, I find narrow-deep designs more aesthetically appealing so if it's only a matter of fashion it's fine with me

 

[manicm]

I agree with you Chebby, but it's rich coming from someone who thinks his little Marantz is already too big

Oldric - as Chebby said, Neat are going against the grain, and till the late 80s a wide-narrow design was common - so are you saying speakers back then were rubbish? In fact a lot of the great speakers were a wide design, as are some very high-end ones today.

 

[Diamond Joe]

BTW, I find narrow-deep designs more aesthetically appealing so if it's only a matter of fashion it's fine with me

FWIW I'm of the same opinion, I prefer to look at a narrower speaker - not that I sit here staring at them! :O

 

[oldric_naubhoff]

Oldric - as Chebby said, Neat are going against the grain, and till the late 80s a wide-narrow design was common

doh, maybe you should check out Neat's contemporary designs (especially flagship Ultimatum range) if you're saying that Neat's going against the grain. Neat Petites, the ones Chebby was mentioning, come from the Classic range, so no wonder they're wider than deep.

so are you saying speakers back then were rubbish?

that's not what I'm saying. that's what you're saying I'm saying

look, I'm not an expert in speaker design but I know one thing. in order to get deep bass you have to move certain amount of air (volume) in certain amount of time (frequency). there are basicaly two ways to return at certain frequency; use large area diaphragms with low excurtion or the other way round - smaller diaphragms with bigger excurtions. 30 years ago you were basically getting paper cone woofers. paper is good material for a woofer because it's light so you don't need a lot power to shake it but it's not too rigid so it can't move too much or you risk distorion. hence large cones were a norm if you wanted to reach some seriously low frequency (40 Hz or below). but now we have a variety of new, exotic, artificial materials that are light but also much more rigid (MSP in Dynaudio, CCAM in MA, polymer reinforced paper, aluminium or glass fibre in Scanspeak, kevlar in B&W or Wharfedale, or polymer in Spendor to name a few). so now you can easily go deeper with smaller cones and less distortion. it's not uncommon to get 45 - 50 Hz from one 6.5" woofer. with a good 8" woofer you might get as low as 30 Hz and 10" is all you need to reach 25 Hz. I don't think it was possible to build so compact subwoofers that went so deep in the early 80-ties or before. if you wanted to have some decent bass you had to have two extra wardrobes in your living, am I wrong about this?

In fact a lot of the great speakers were a wide design as are some very high-end ones today.

can you name some wide face high-end speakers manufactured today, that are NOT designed to work with SET amps (as I already mentioned in my previous post)? I'd like to know which speakers you have in mind.

 

[manicm]

oldric - you're throwing around many irrelevant specs and generalisations - may I refer you to the Acoustic Energy AE22 reviewed here on WHF? Admittedly they're not flattering in the company of designer furniture.

Irrespective of materials used, a narrow-wide design does not dictate at all the quality or amount of bass produced. Have you also noted Rega's side firing woofers?

 

[John Duncan]

I have been researching the Neat Petite SX speakers - online - and just noticed, when checking their dimensions, that (unusual nowadays) they are wider than they are deep.

Yes they are, which is why I don't own a pair. If they'd been the other way round, I'd have been on 'em like a rat up a drainpipe (provided they could make me the grilles I asked for, and they come in something other than maple). But then the bass drivers wouldn't have been so big and they'd have been, well, totally different speakers. But apart from that...