bookshelf v.s floorstandings

[fmw]

I've been disappointed with way more floorstanding louspeakers than I ever have with bookshelves. There's magic in a bookshelf, ego in the floorstander.

Mark

I got thinking about this statement and I think there is some validity to it. Here's why. One of the most negative factors in louspeaker performance is enclosure resonance (sound from the vibration of the cabinet itself rather than from the drivers.) The things that generate the most resonance are the amount of air movement (woofer size) and the size of the enclosure itself. Bookshelf speakers have smaller woofers (move less air) and smaller enclosures and, by definition, will be less subject to the negative effects of enclosure resonance.

Even separating the mids and highs from the bass by integrating a subwoofer helps because is keeps the mids and highs away from enclosure resonance. That should result in cleaner, tighter mids and highs.

Full range speakers without noticeable enclosure resonance are very, very expensive. Subwoofers with well controlled resonance, on the other hand, are pretty affordable. Add a sub to a bookshelf pair and you have full range speakers in three cabinets instead of two. And you have a better chance of reproducing the mids and highs with more clarity and cleanliness.

After noodling it out in my head, I'm drawn even more to the concept of subwoofer/satellites than ever before.

 

[Davemcc]

I know what you mean. I've been troubled by this resonance in some of the floorstanders I've listened to, notably in the Paradigm S8 and to a lesser degree in some equally expensive speakers.

 

[fmw]

I know what you mean. I've been troubled by this resonance in some of the floorstanders I've listened to, notably in the Paradigm S8 and to a lesser degree in some equally expensive speakers.

I meant VERY expensive. Full range speakers without audible enclosure resonance are typically 5 figures or close to it. The high end B&W units with the matrix enclosures would meet this spec but they are all in the 5 figure price area per pair and weigh around 200 lbs per cabinet or even more. Anything under, say, $5000 per pair is most likely going to have audible enclosure resonance. A lot of speakers over $5000 per pair will also have audible resonance.

Understand, it is all a matter of degree. Some enclosure resonance, obviously, is acceptable to most listeners. My point was that I think it is possible to reduce resonance a lot for a lot less money using the sub/sat concept.

 

[3db]

I got thinking about this statement and I think there is some validity to it. Here's why. One of the most negative factors in louspeaker performance is enclosure resonance (sound from the vibration of the cabinet itself rather than from the drivers.) The things that generate the most resonance are the amount of air movement (woofer size) and the size of the enclosure itself. Bookshelf speakers have smaller woofers (move less air) and smaller enclosures and, by definition, will be less subject to the negative effects of enclosure resonance.

Even separating the mids and highs from the bass by integrating a subwoofer helps because is keeps the mids and highs away from enclosure resonance. That should result in cleaner, tighter mids and highs.

Full range speakers without noticeable enclosure resonance are very, very expensive. Subwoofers with well controlled resonance, on the other hand, are pretty affordable. Add a sub to a bookshelf pair and you have full range speakers in three cabinets instead of two. And you have a better chance of reproducing the mids and highs with more clarity and cleanliness.

After noodling it out in my head, I'm drawn even more to the concept of subwoofer/satellites than ever before.

Alot of speaker manufacturers that employ woofers in their bookshelves use the same woofer from their tower speakers. Also these manufacturers go the extra mile to reduce cabinet resonances. If you look at the design of PSB's new Synchrony 1, each 6.5" woofer is enclosed in its own cavity.

Paradigms older Titans which are bookshelves suffered alot from cabinet resonances. I think you are generalizing a little bit to support your own arguement.

 

[3db]

I know what you mean. I've been troubled by this resonance in some of the floorstanders I've listened to, notably in the Paradigm S8 and to a lesser degree in some equally expensive speakers.

Are you sure it was cabinet resonance? Did you have accelerometers attached to the cabinets to verify this? You don't think poor placement or room acoustics had an effect?

 

[avaserfi]

I think you are generalizing a little bit to support your own arguement.

Actually fmw is pretty spot on with this - there are very few commercial speakers with audibly inert cabinets. The high end B&Ws are some of the few that do. A quick look at Stereophile reviews [they use accelerometers] shows that nearly all mass produced (DIY mostly are too) speakers are resonant machines coloring sound everywhere they go. Simply put having bracing isn't good enough - you need to have a well braced cabinet (XYZ is often ideal) using proper material that will push the cabinets resonant band out of those being played. Simple bracing found in 99% of speakers out there is just not good enough.

Substantial amounts of work needs to be put into completely removing resonance from any speakers, but due to surface area constraints of towers it is more common to see them resonate. Towers would have to weigh hundreds of pounds and be extremely expensive to not only develop but build as well.

The easiest quick test for hearing resonance without a control is turning up the speaker a bit and placing your ear on the cabinet. Not only will you feel the cabinet move, but you will likely be able to hear the cabinet resonate at certain frequencies. This generally works best with well recorded classical music.

 

[3db]

Actually fmw is pretty spot on with this - there are very few commercial speakers with audibly inert cabinets. The high end B&Ws are some of the few that do. A quick look at Stereophile reviews [they use accelerometers] shows that nearly all mass produced (DIY mostly are too) speakers are resonant machines coloring sound everywhere they go. Simply put having bracing isn't good enough - you need to have a well braced cabinet (XYZ is often ideal) using proper material that will push the cabinets resonant band out of those being played. Simple bracing found in 99% of speakers out there is just not good enough.

Substantial amounts of work needs to be put into completely removing resonance from any speakers, but due to surface area constraints of towers it is more common to see them resonate. Towers would have to weigh hundreds of pounds and be extremely expensive to not only develop but build as well.

The easiest quick test for hearing resonance without a control is turning up the speaker a bit and placing your ear on the cabinet. Not only will you feel the cabinet move, but you will likely be able to hear the cabinet resonate at certain frequencies. This generally works best with well recorded classical music.

Will try that. I've placed my hand on the cabinets before during loud bass passages but haven't felt anything. I'll try the ear method to see if I can hear that.

But at what point does cabinet resonance come audable? I'm drawing the analogy to THD in amplifiers. Below a certain value, I think its .1%, THD becomes inaudable. If don't hear the resonance affect whem SPL is at the high 80s, but I hear it at when SPL reaches well into the 90s, then I'm not going to be bothered by it too much. I rather save my hearing and max out in the 80s never getting the affects if resonance. Know what I mean?

 

[avaserfi]

Will try that. I've placed my hand on the cabinets before during loud bass passages but haven't felt anything. I'll try the ear method to see if I can hear that.

Don't due it during a bass passage, try using a mid-bass one. I also strongly recommend using a natural recording with acoustic instruments (opera and classical are great for this). A while ago TLS Guy posted a link to a CD he recorded for free download that should do a fine job of exciting your speakers resonant bands.

But at what point does cabinet resonance come audable? I'm drawing the analogy to THD in amplifiers. Below a certain value, I think its .1%, THD becomes inaudable.

This is actually a very complicated topic that depends on room interaction as well as the type of sources being played. It cannot really be simplified, but I can direct you to a great research article on the subject.

The Modification of Timbre by Resonances: Perception and Measurements. J. Audio Eng. Soc. 36, 122-142, 1988 by Toole, Floyd E. and Olive, Sean E.

 

[fmw]

Alot of speaker manufacturers that employ woofers in their bookshelves use the same woofer from their tower speakers. Also these manufacturers go the extra mile to reduce cabinet resonances. If you look at the design of PSB's new Synchrony 1, each 6.5" woofer is enclosed in its own cavity.

Paradigms older Titans which are bookshelves suffered alot from cabinet resonances. I think you are generalizing a little bit to support your own arguement.

Not generalizing at all. Any manufacturer can take the same drivers and put them in a smaller enclosure with the same bracing and materials and there will be less enclosure resonance every single time. The size of the enclosures is one of the two factors most affecting resonance. Less enclosure, less surface, less resonance. It's just the laws of physics.

I didn't make any comments about any brand or model of speaker except for the B&W's that have the matrix enclosure. I mentioned them just as an example of full range speakers that do not have audible resonance. They certainly have resonance but not very much. Almost every bookshelf speaker ever made will have more cabinet resonance than the B&W's with the matrix enclosure. I didn't say all bookshelf speakers have less resonance than full range speakers. What I said was it would be cheaper to achieve less resonance with a pair of bookshelf speakers and a sub than with full range speakers. If you want to debate that then fire away.

I have no idea how much resonance the speakers you mention generate. I'm not criticizing your speakers. I don't even know what they are. I'm trying to explain to myself and others why the poster's comments make sense. I pay little attention to subjective opinons about sound. If I can put some common sense and physics into the mix, then I have what is an acceptable explanation for the statement - at least to me. That's all I did.

 

[Soundman]

Alot of speaker manufacturers that employ woofers in their bookshelves use the same woofer from their tower speakers. Also these manufacturers go the extra mile to reduce cabinet resonances. If you look at the design of PSB's new Synchrony 1, each 6.5" woofer is enclosed in its own cavity.

Paradigms older Titans which are bookshelves suffered alot from cabinet resonances. I think you are generalizing a little bit to support your own arguement.

I have to agree to some degree mainly b/c each speaker is designed differently so you can't lump them all together. I've found it easier to integrate a sub more easily with towers. The problem with some sub/sat combos is the lack of midrange response even though you 've integrated the sub correctly. This issue is nonexistent with a good tower speaker. I think both types of setups can sound excellent though. There are pros and cons to both.

 

[3db]

Not generalizing at all. Any manufacturer can take the same drivers and put them in a smaller enclosure with the same bracing and materials and there will be less enclosure resonance every single time. The size of the enclosures is one of the two factors most affecting resonance. Less enclosure, less surface, less resonance. It's just the laws of physics.

I didn't make any comments about any brand or model of speaker except for the B&W's that have the matrix enclosure. I mentioned them just as an example of full range speakers that do not have audible resonance. They certainly have resonance but not very much. Almost every bookshelf speaker ever made will have more cabinet resonance than the B&W's with the matrix enclosure. I didn't say all bookshelf speakers have less resonance than full range speakers. What I said was it would be cheaper to achieve less resonance with a pair of bookshelf speakers and a sub than with full range speakers. If you want to debate that then fire away.

I have no idea how much resonance the speakers you mention generate. I'm not criticizing your speakers. I don't even know what they are. I'm trying to explain to myself and others why the poster's comments make sense. I pay little attention to subjective opinons about sound. If I can put some common sense and physics into the mix, then I have what is an acceptable explanation for the statement - at least to me. That's all I did.

I'm not taking this as a critique of my speakers. So all is good with me
I also can't dispute the law of physics either and you have clarified what you said from your earlier post.

At what point (SPL) does resonance color the sound of a speaker? If a speaker's resonance starts at such a high SPL thats it dangerous to one's hearing, isn't that kind of a mute point? Like going after .0001% THD on an amp?

 

[AcuDefTechGuy]

I am in search of new speakers. Should I buy bookshelfs or floorstandings? Also, I currently have JBL's and I was wondering if I should keep them or upgrade???? Any ideas?

I originally owned bookshelf/monitor speakers for 10 years. But after owning full-range tower speakers, I would not go back to bookshelfs. There is no substitute for cubic inch. Larger speakers will give you fuller range sounds without the use of subwoofers. It's just that if you listen in Pure Direct Modes, the LFE/Subwoofer channel is turned off.

I think if you have the room, then get tower speakers. If your space is limited, than get bookshelfs.

 

[fmw]

This issue is nonexistent with a good tower speaker. I think both types of setups can sound excellent though. There are pros and cons to both.

In my experience the "issue" isn't any more existent or non existent because of the number of woofers in the enclosures. The sub replaces the woofers in a sub/sat system. As long as it is adjustable for crossover frequency and level, making it integrate with the other drivers is not any different than using woofers in the same cabinet with a different crossover. Any difference in mids and highs would relate mostly to how the well the sub is adjusted or any of the million other factors affecting speaker performance.

I can use my own speakers as an example. My home theater mains are tiny towers - just like bookshelfs except the enclosures are longer and they sit on the floor. They have 6" woofers (really midrange drivers to be honest.) When my sub is properly adjusted using an SPL meter, I have no frequencies that vary more than 6 db from flat in that listening room from 25-20khz. On the other hand, I have some full range 3 way speakers in my upstairs stereo system. There are two 10" woofers per enclosure. That system has a bulge of 8 db at 200 hz and is down 10 db at 35 hz. Why is this? Who knows? different quality? Different design? Different listening room? Take your pick. But the number and size of the woofers isn't one of the factors, to be sure.

I undertand that the frequency response of speakers depends on many factors. I agree that it is possible to get the job done either way and I also agree that the individual units involved would affect the outcome of either approach.

 

[fmw]

I'm not taking this as a critique of my speakers. So all is good with me
I also can't dispute the law of physics either and you have clarified what you said from your earlier post.

At what point (SPL) does resonance color the sound of a speaker? If a speaker's resonance starts at such a high SPL thats it dangerous to one's hearing, isn't that kind of a mute point? Like going after .0001% THD on an amp?

It's a good question and I don't know the answer. Certainly resonance would increase as volume increases. No doubt about that. Does it require deafening volume levels to hear the effects of resonance? I don't think so. I don't think it is a matter so much of hearing some extraneous frequencies that beat with the resonant frequencies of the cabinets. It is more a matter of the resonances beating with the music and coloring the sound. I think resonance can affect sound even at normal listening levels. How much resonance is acceptable? I don't know that either and it would obviously be a subjective issue.

It appears to be subject worthy of more exploration doesn't it?

 

[3db]

It's a good question and I don't know the answer. Certainly resonance would increase as volume increases. No doubt about that. Does it require deafening volume levels to hear the effects of resonance? I don't think so. I don't think it is a matter so much of hearing some extraneous frequencies that beat with the resonant frequencies of the cabinets. It is more a matter of the resonances beating with the music and coloring the sound. I think resonance can affect sound even at normal listening levels. How much resonance is acceptable? I don't know that either and it would obviously be a subjective issue.

It appears to be subject worthy of more exploration doesn't it?

This is beginning to interfere with my full time job

 

[avaserfi]

How much resonance is acceptable? I don't know that either and it would obviously be a subjective issue.

It appears to be subject worthy of more exploration doesn't it?

This is actually a very complicated topic that depends on room interaction as well as the type of sources being played. It cannot really be simplified, but I can direct you to a great research article on the subject.

The Modification of Timbre by Resonances: Perception and Measurements. J. Audio Eng. Soc. 36, 122-142, 1988 by Toole, Floyd E. and Olive, Sean E.

There has been quite a bit of research on the subject involving thresholds and preferences of resonance. Audibility of resonance depends on the the room itself as well as the media being used.

For example it has been shown the audibility of resonance increases in an actual room as compared to headphones or an anechoic environment.

It has also been shown that coloration due to resonance is generally not preferred over a resonance free source. Look into Toole's articles for more information on these subjects.

As it seems part of the problem with recognizing resonance is that many people seem to attribute the coloration to other parts of the system (the speakers sound) rather than realizing that this coloration in fact resonance.

 

[TLS Guy]

Don't due it during a bass passage, try using a mid-bass one. I also strongly recommend using a natural recording with acoustic instruments (opera and classical are great for this). A while ago TLS Guy posted a link to a CD he recorded for free download that should do a fine job of exciting your speakers resonant bands.

Glad you liked that CD. It's an audio workout alright, especially the Magnificat. I took great care in the matter of phase in my recordings among other things. It all helps to produce an expansive 3D image with a good set up.

If I might be so bold as to ask, but were the instructions clear? I'm thinking of adding more of my archives for download.

 

[3db]

There has been quite a bit of research on the subject involving thresholds and preferences of resonance. Audibility of resonance depends on the the room itself as well as the media being used.

For example it has been shown the audibility of resonance increases in an actual room as compared to headphones or an anechoic environment.
.

Reflected waves striking against the enclosure?

It has also been shown that coloration due to resonance is generally not preferred over a resonance free source. Look into Toole's articles for more information on these subjects.

As it seems part of the problem with recognizing resonance is that many people seem to attribute the coloration to other parts of the system (the speakers sound) rather than realizing that this coloration in fact resonance.

Will I need to brush up on my math or is this a fairly straight forward read?

 

[avaserfi]

If I might be so bold as to ask, but were the instructions clear? I'm thinking of adding more of my archives for download.

To be honest I didn't follow the instructions I am a computer guy . More would be interesting the recording quality was good, but the coughing drove me nuts just pulled me out of the moment every time.

Reflected waves striking against the enclosure?

Actually, the room/wave interaction seemed to amplify the audibility of the resonance. It wasn't necessarily the enclosure having waves reflected off of it just the room itself.

Will I need to brush up on my math or is this a fairly straight forward read?

There is some math, but not much. Be ready to read many graphs though. I would say this article is essential for anyone who wants to really understand cabinet resonance and its affect on loudspeakers.

Also, this is just the first part to understanding resonance and its affect on the system. There is other perceptual research that should be read to gain the full understand. I always recommend aes.org and look for Toole, Floyd. Yeah its expensive to buy all the articles so hopefully your library has them or can get them, mine did .

 

[fmw]

For example it has been shown the audibility of resonance increases in an actual room as compared to headphones or an anechoic environment.

Headphones wouldn't have any enclosure resonance but I'm sure you're right that resonance would be more audible in a listening room than in an anechoic chamber. I don't think the resonance itself is as big an issue as the coloration it induces in the music. Beat frequencies can cause all sorts of cancellations and enhancements.