Evidence-based Speaker Designs

[Kal Rubinson]

Absurdly expensive bookshelf speakers run without subs. Has baffled me for years.

It's a cult.

 

[MattHooper]

Absurdly expensive bookshelf speakers run without subs. Has baffled me for years.

I get your point, I believe, but to understand why someone would buy expensive bookshelf speakers without adding a sub, we have to remember that other people have other experiences and priorities - time, money, desire, ergonomic, aesthetic, etc - that might make their choices perfectly rational within that context.

So, correct me if I'm wrong, but I interpret your point to be roughly: If you care that much about sound quality that you'll put tons of money in to an expensive bookshelf speaker, why in the world would you leave your sound crippled, cut off at the knees, rather than add a good sub to get the rest of what you are missing?"

I have some very expensive stand mounted speakers (MBL) and never added a sub, so I think I'm in touch with some of the rational, not to mention what I've seen from others in a similar position.

Answer: Not everyone wants a sub in their system. Why not?

First, they simply may not care anywhere near as much as you do about hearing full range sound. There are many audiophiles who absolutely love two-way stand mounted speakers - it's their preference. Why? Well...they just do. They find it easy to get great sound, integrate them in to their room, and they find the sound fulfilling with no desire to do more. Also, remember personal experience is a strong driver for all of us to one degree or another, and plenty of audiophiles have experienced "bad sub set ups" to the extent they become allergic to the idea of adding a sub. Frankly, that was the case with me too. I've lost count of how many times I've heard "Oh, you don't like subs because you haven't heard them set up right...check out my system." And then...I always seem to 'hear' the sub; I don't find the sound seamless. If you've had these experiences, it's not irrational to conclude that subwoofers are hard to integrate properly.

And they ARE very hard to integrate properly. I've only really delved in to adding subs again recently and in consulting all the sub experts (e.g. those who sell subs like JL Audio, or all the subwoofer fanatics in places like AVSforum)...it is DAMNED tricky and demanding to do the subwoofer thing right. I was constantly told that if I really was serious about getting good sound I was going to have to buy microphones, room acoustics/calibration software, crossover, and go through all sorts of maneuvers to find the right sub placement....which in many rooms can be quite limited. So you find out that one sub often isn't good enough, the usual recomendation now is multiple subs - 2 at the least, 4 if you can do it. So now you need to find a place to put multiple subs, they all need power, it involves a host of new cabling, and plenty of time to spend tweaking and perfecting. If the thinking is "if you are going to do high quality sound right you are going to add a subwoofer" then it follows the thinking will be "and therefore you ought to be doing everything advised to do subwoofers right!"

Plenty of people just don't want to go through all this and that is reason enough not to bother, especially if they are satisfied with a very high level of sound quality they are already getting from their stand mounted speaker.

In my case I mostly bought my 2 JL Audio subwoofers, their crossover, and an anti-mode room correction for the subs, to add to my floor standing Thiel 2.7s which aren't quite full range. But it's been such a long learning curve, and involves so much hassle, that frankly it's been months and months and I haven't got around to it, as I can simply walk in, turn on my system and enjoy how great it sounds already without subs. (And frankly I hate the look of subwoofers. Never seen what I consider a nice looking sub in a room, where I truly enjoy the look of a good floor standing speakers like the ones I own. So even on aesthetic grounds, not to mention ergonomic, there is friction in the case of adding subs in to the room).

I hope this helps explain the reasons *other people* may have for not immediately going the subwoofer route.

 

[andreasmaaan]

So, correct me if I'm wrong, but I interpret your point to be roughly: If you care that much about sound quality that you'll put tons of money in to an expensive bookshelf speaker, why in the world would you leave your sound crippled, cut off at the knees, rather than add a good sub to get the rest of what you are missing?"

Actually, that's not really my issue. The absurdity for me is that a 5" or 6" woofer in a small box, no matter how expensive, is going to be distorting massively playing even upper- and mid-bass at moderate levels.

If you're going to spend a huge amount on speakers, I would avoid bookshelf speakers (without subs) not because they don't extend low enough in frequency (that's fine for many), but because they will necessarily, simply as a matter of physics, perform worse than any competently designed floorstander costing much less - even if that floorstander doesn't even have lower bass extension.

They won't necessarily save you any floorspace vs floorstanders either.

I hear what you're saying about the difficulties of sub integration. But again, if you're going to spend many thousands on a stereo system and don't know how to set it up and are not willing to learn how to do so, paying someone to do so would be a wiser investment than throwing more money at a pair of bookshelf speakers.

On a tight budget, however, I think bookshelf speakers aren't necessarily a bad investment at all btw.

 

[MattHooper]

Actually, that's not really my issue. The absurdity for me is that a 5" or 6" woofer in a small box, no matter how expensive, is going to be distorting massively playing even upper- and mid-bass at moderate levels.

Ok, that's clearer, thanks.

If you're going to spend a huge amount on speakers, I would avoid bookshelf speakers (without subs) not because they don't extend low enough in frequency (that's fine for many), but because they will necessarily, simply as a matter of physics, perform worse than any competently designed floorstander costing much less - even if that floorstander doesn't even have lower bass extension.

Sure, I get that when you yourself thinking through this, and considering your own experience and aims, this makes sense. And it would make sense for some other people too. But, again, we have the issue of people with different experience, desires, aims.

If someone isn't putting floor-stander-like demands on their stand mounted speaker, then it seems to me there isn't the rational to get the floor stander. If a stand mounted speaker already suites their needs and desires - aesthetically, sonically etc - why introduce more bass in to the equation that will only make room integration more of a challenge?

I agree that floor standers often don't take up more space than a smaller speaker and it's stand. But some people find floor standing speakers more dominating then they want. I go back and forth in my room between floor standing and stand mounted speakers. The stand mounted speakers definitely lend a more open, airy presence, less imposing. Though, for me, I actually prefer the looks of a good floor stander.

I hear what you're saying about the difficulties of sub integration. But again, if you're going to spend many thousands on a stereo system and don't know how to set it up and are not willing to learn how to do so, paying someone to do so would be a wiser investment than throwing more money at a pair of bookshelf speakers.

Again...that assumes one would want to add a sub...where many are satisfied without a sub.

If someone *was* motivated to add a sub, that presumes they weren't satisfied with only the stand mounted speaker in the first place. Even if one considered the option of paying a professional to add subwoofers, that person can still look at the added expense, complexity and aesthetics of adding a sub - multiple subs if "done right" - and reasoably decide they are satisfied enough not to bother.

Like I acknowledge, you give perfectly good reasons for adding subwoofers, that would make sense in any number of cases. But there will remain cases where someone's decision to remain only with an expensive stand mounted speaker with no sub is entirely reasonable, given their own needs and aims.

Sorry if I'm being somewhat pedantic on this.

 

[Ron Texas]

While this is aesthetics and not SQ, a floor standing speaker looks a log bigger than a stand mount, even if floor space is the same. Luxury finishes make the visual impact better, but add to the cost.

As for setting up a sub woofer, it is difficult, especially if it is your first try. I just completed the process. Perhaps some of the new ones with built in EQ work better. If a sub woofer is working the way it should, the improvement on small stand mount monitors is dramatic on music and incredible on movies.

Some go overboard on subs. They might want the room to shake more than when the same movie is viewed in a theater.

 

[andreasmaaan]

If someone *was* motivated to add a sub, that presumes they weren't satisfied with only the stand mounted speaker in the first place. Even if one considered the option of paying a professional to add subwoofers, that person can still look at the added expense, complexity and aesthetics of adding a sub - multiple subs if "done right" - and reasoably decide they are satisfied enough not to bother.

Like I acknowledge, you give perfectly good reasons for adding subwoofers, that would make sense in any number of cases. But there will remain cases where someone's decision to remain only with an expensive stand mounted speaker with no sub is entirely reasonable, given their own needs and aims.

Sorry if I'm being somewhat pedantic on this

No problem about being pedantic. But I'm going to be pedantic back

I'm not suggesting people should buy outrageously expensively standmounts and then spend extra on subs and on setting them up. I'm suggesting that if someone intends to blow a huge amount of money on a sound system, they should not buy only standmount speakers, they should reallocate some of that money to subs/setup, or buy floorstanders.

Unless they're only interested in the aesthetics of course.

I'm also not even suggesting necessarily people should introduce more bass into the equation. I'm just pointing out that due to the laws of physics, a 5" or 6" woofer in a small box can't reproduce any amount of bass (I'm not even talking about loud SPLs or sub-bass here) without a fair whack of distortion. Subs don't have to increase the amount of bass in the room, although of course they can. More importantly though, they take the stress off small drivers being asked to reproduce frequencies they shouldn't be reproducing.

 

[Ron Texas]

I'm also not even suggesting necessarily people should introduce more bass into the equation. I'm just pointing out that due to the laws of physics, a 5" or 6" woofer in a small box can't reproduce any amount of bass (I'm not even talking about loud SPLs or sub-bass here) without a fair whack of distortion. Subs don't have to increase the amount of bass in the room, although of course they can. More importantly though, they take the stress off small drivers being asked to reproduce frequencies they shouldn't be reproducing.

Trying to get bass out of a small driver in a small box is as much fun as pulling teeth. It isn't only distortion. My understanding is ported enclosures fall off @ 24 db/octave. One may equalize, but a point is easily reached where the power is more than the voice coil can take. Fried drivers, anyone?

 

[andreasmaaan]

Trying to get bass out of a small driver in a small box is as much fun as pulling teeth. It isn't only distortion. It is my understanding that ported enclosures fall off @ 24 db/octave. One may equalize, but a point is soon reached where the power is more than the voice coil can take.

Yeh, and it's particularly fruitless trying to EQ up the bass below the port tuning frequency in a ported box. The woofer's motion is uncontrolled and it will flap around and distort like crazy. Cutting the bass below the port resonance is likely to be a better move in most cases.

 

[Ron Texas]

Cutting the bass below the port resonance keeps the voice coils cooler.

 

[Floyd Toole]

While this is aesthetics and not SQ, a floor standing speaker looks a log bigger than a stand mount, even if floor space is the same. Luxury finishes make the visual impact better, but add to the cost.

As for setting up a sub woofer, it is difficult, especially if it is your first try. I just completed the process. Perhaps some of the new ones with built in EQ work better. If a sub woofer is working the way it should, the improvement on small stand mount monitors is dramatic on music and incredible on movies.

Some go overboard on subs. They might want the room to shake more than when the same movie is viewed in a theater.

It is possible to do better in a home theater (small room) than in a typical cinema (large room, small budget). My system is not boosted, just flattish, but whole body bass in some movies is addictive, and some new studio music creations use low bass like organ pedals. Nice, if you can hear it!

 

[MattHooper]

It is possible to do better in a home theater (small room) than in a typical cinema (large room, small budget). My system is not boosted, just flattish, but whole body bass in some movies is addictive, and some new studio music creations use low bass like organ pedals. Nice, if you can hear it!

Floyd,

May I ask: Given it seems you employed numerous subwoofers in your system, what is the reasoning for having the full range Salon 2 speakers in your system? If you are crossing over at 80 Hz anyway, is this not sort of "throwing away" much of the work that went in to the design to achieve the bass in that speaker and wouldn't smaller speakers have worked without the added expense and taking up more space?

Thanks.

 

[Ron Texas]

It is possible to do better in a home theater (small room) than in a typical cinema (large room, small budget). My system is not boosted, just flattish, but whole body bass in some movies is addictive, and some new studio music creations use low bass like organ pedals. Nice, if you can hear it!

My sub was firing down on a plywood floor over frame on the third story of my house. The floor would go crazy at 32 hz. Lucky for me it could be used as a front firing sub too. Things got back to reality once in the front firing mode. It was beyond full body bass. I have been through less intense earthquakes.

I am very much into live music and natural sound. The sound (and shakes) of a passing freight train can be a source of enjoyment as well as the musicians in bars on 6th street in Austin, TX.

Your recent post in this forum about some 1985 research overwhelmed a few of us. It's profound. Thank you for participating here.

 

[Krunok]

Uh Oh, I better cut the legs off the bed.

Sure, science has confirmed that is the only way to be safe.

 

[Halcyon]

Most of the Finnish loudspeaker scene is pretty much dominated by Uniform Directivity (i.e. fairly linearly downward sloping on+off-axis power spectrum).

Examples of these, in addition to Jorma Salmi's (RIP) Gradient are:

Amphion Krypton series (hypercardiod diffusion pattern horizontally and vertically fairly directive)
https://amphion.fi/enjoy/products-home-audio/krypton-floorstanding-loudspeaker/

You'll find a lot of similarities with Krypton on Aurelia's Graphica-series loudspeakers (designed by the same engineer who designed Krypton for Amphion):

Aurelia Graphica XL
http://www.aurelia.fi/en/xo/graphica-xl/

Taipuu Loudspeakers usese similar ideas, but with a different approach (doesn't try to make minimum front facing surface, but uses coaxial loudspeaker elements along with DSP corrections and shifting the crossover filter to a proper frequency for uniform diffusion:

Taipuu Speakers
https://taipuuspeakers.fi/en/taipuu-speakers-loudspeakers/

And of course, Genelec who (among a few others) pioneered the use of custom-molded and precision aligned wave-guides in their active monitors to ensure proper uniform directivity and diffusion of spectral power and trying to eliminate the front baffle diffractions (S360 SAM being the latest incarnation of these design principles):

Genelec SAM 360
https://www.genelec.com/studio-monitors/sam-master-studio-monitors/s360-sam-studio-monitor

I have heard the first two and seen professional (University level anechoic chamber) measurements for most (in Finnish, in a printed magazine at the local library, don't have them here, don't ask).

They all have their failings (what doesn't), but the for me the general design principles are sound (just like with Klein+Hummel).

Are these state of the art? I don't know. I haven't heard the most expensive or over-engineered loudspeakers in the world, so I cannot vote on this. Do they adhere to the principles of objective measurements and subjective listening test neutrality? Yes, they try to.

In general, they are much more forgiving about placement and room reflections (of course, nowhere near immune to those, as no loudspeaker is, but just more forgiving due to uniform directivity and fairly high directivity). The sound is of course, subjective preference. I've found that Brits tend to like British loudspeakers more, the Germans the German loudspeakers and the Finns, well they like everything, but also Finnish loudspeakers. The hearing is very adaptive and gets used to most colourations.

 

[Cosmik]

To what extent can we be sure that speaker designs aren't based on tradition or obsession rather than evidence?

Most hi-fi speaker designers seem to be a certain sort of person; the sort that has 'obsessions' about things; the sort that is maybe elevating a hobby into a garage business. Being nothing like that sort of person myself, of course, I could imagine that they start with an idea e.g. the BMR transducer, and they *really* want to play with it. Even if the evidence goes against it, they'll persevere, and they'll selectively put together words that justify their delusion against the rest of the world.

One example springs to mind, where the designer of very expensive speakers based on a 'unique' driver said something like "These speakers are so good that you don't need to play them loud". When of course the reality was that they fell apart when played loud.

 

[Ron Texas]

To what extent can we be sure that speaker designs aren't based on tradition or obsession rather than evidence?

Most hi-fi speaker designers seem to be a certain sort of person; the sort that has 'obsessions' about things; the sort that is maybe elevating a hobby into a garage business.

Manufacturing speakers requires a relatively small investment. Tons of off the shelf drivers are available. Passive crossovers are fairly basic electronics. There is a lot of cookbook information on how to build a ported enclosure. The rest is woodwork. I recall someone is selling a Seas coaxial driver with a reference crossover in a ported box for $6000.

 

[Floyd Toole]

Floyd,

May I ask: Given it seems you employed numerous subwoofers in your system, what is the reasoning for having the full range Salon 2 speakers in your system? If you are crossing over at 80 Hz anyway, is this not sort of "throwing away" much of the work that went in to the design to achieve the bass in that speaker and wouldn't smaller speakers have worked without the added expense and taking up more space?

Thanks.

The Salon2s are four-way systems; other options were three way. The differences are potentially better dispersion from the 3-inch midrange and the ability to play louder with less power compression - for movies, not music. As full range systems the Salon2s are fine for music. My multiple subs not only provide what I call "whole body" bass when needed, but employed in a Sound Field Management scheme they do it for multiple listeners - I rarely watch movies alone. But, as I said, once you have such a system one finds impressive examples of powerful low bass in modern recordings. Was it there deliberately? We may never know, because most recording studios, especially of the home variety, probably cannot reproduce those frequencies as I can.

 

[Ron Texas]

The Salon2s are four-way systems; other options were three way. The differences are potentially better dispersion from the 3-inch midrange and the ability to play louder with less power compression - for movies, not music. As full range systems the Salon2s are fine for music. My multiple subs not only provide what I call "whole body" bass when needed, but employed in a Sound Field Management scheme they do it for multiple listeners - I rarely watch movies alone. But, as I said, once you have such a system one finds impressive examples of powerful low bass in modern recordings. Was it there deliberately? We may never know, because most recording studios, especially of the home variety, probably cannot reproduce those frequencies as I can.

I found the description of your system to be just amazing. It's definitely not a DIY project unless the owner is a professional in the field.

 

[andreasmaaan]

The Salon2s are four-way systems; other options were three way. The differences are potentially better dispersion from the 3-inch midrange and the ability to play louder with less power compression - for movies, not music. As full range systems the Salon2s are fine for music. My multiple subs not only provide what I call "whole body" bass when needed, but employed in a Sound Field Management scheme they do it for multiple listeners - I rarely watch movies alone. But, as I said, once you have such a system one finds impressive examples of powerful low bass in modern recordings. Was it there deliberately? We may never know, because most recording studios, especially of the home variety, probably cannot reproduce those frequencies as I can.

Sorry to piece apart your words here @Floyd Toole I'm just curious as to whether by "better" dispersion you mean better-matched to the tweeter, or you mean to say wider is better generally in your view?

 

[Floyd Toole]

Sorry to piece apart your words here @Floyd Toole I'm just curious as to whether by "better" dispersion you mean better-matched to the tweeter, or you mean to say wider is better generally in your view?

Yes. Ideally the directivity of a woofer should match that of the midrange to which it is transitioning, and likewise the midrange directivity should match that of the tweeter - you will note the use of custom designed waveguides on some tweeters to improve this transition. Thinking about it, one of the most challenging designs is the very popular 8-inch two way, especially those with no tweeter waveguide. A midrange speaker improves the design. Adding more subdivisions, up to a point, can also be beneficial. Obviously, three- and four-way designs require significant engineering effort to live up to their potential. The goal is a smooth DI.

If you read my book and/or papers it will be found that most people listening for recreation have a preference for wide dispersion, as a way to attenuate the basic limitations of conventional stereo.