Bookshelf VS Tower - mid-range SPL

K

Kwiercyski

Enthusiast
I'm sure this topic has been covered ad nauseam. Although, I can't find the exact answer to my question.

I'm looking to upgrade my "home theater in a box" and take the buy once cry once route. I'm looking for a 60% stereo music, 40% streaming 5.1 system. I'm more concerned with clean detailed forward mids and present but not harsh highs. Lows are definitely nice but I'll have that covered with the SVS pb3000 that's currently on the way. My room is, well... My whole house. It's open floor plan design, with two story open cathedral ceilings. As of now it will be powered off a simple Yamaha RX-V485. Will upgrade in the slightly distant future with an added power amp. Due to current power constraints, high sensitivity is preferred.

There... Got that out of the way. I was actually talking to a SVS rep and he pointed out that if budget is a concern and that I have the PB3000 coming then I should just get bookshelves of a higher quality vs a lower quality tower. He showed how bookshelves of the same "class" tend to have the exact same mid-range driver and the additional speakers are used for lows. I'm thinking fine, I like this idea. Now i'm sure it's just psychological but the physical size of the towers just says to me cleaner, louder... Mids included.

Does anyone have any experience on this? Should I expect the same SPL from a bookshelf as I would a tower in regards to mids and highs? If I EQ out the lows would I "gain an additional mid-range driver" with the towers?? (Seem impractical but worth an ask) If not would the low range woofers just not play? But a deep powefull male voice I would assume is within their crossover. Aswell a cello or bass guitar. I wouldn't want to loose the potential depth of these bands with a bookshelf, but I'm honestly not sure. I've just have not had the option to sit back and listen to them side by side at any reasonable volume. Especially not in a room of my size.
 
Jon AA

Jon AA

Audioholic
Big, open room, get towers. (Short answer)

(Longer answer): There are some generalizations that need to be made when generalizing...and there are always exceptions to the rule, but here are some problems with the above thinking that are often true:

Even when using the same mid-driver, most bookshelves in a given line will be two-way. So that mid driver is playing bass as well. Even after crossing to a sub it's playing a lot of upper bass/lower midrange that it wouldn't be in a three or even 2 1/2 way tower. So it may play the mids less cleanly and won't handle as much power.

Most bookshelves are tuned lower than they should be if you are going to use subs (so they'll sound better for people who don't). This reduces sensitivity.

Along with lower sensitivity, they'll usually handle less total power. Not what you want for a big open room.

Stands needed.

Floor bounce.

Those are some of the general things that are often (but not always, of course) true when comparing bookshelves to towers from a given line from a given company that you'll want to look out for before spending the money. Yes, bookshelf/sub systems can sound fantastic. But I sometimes think they're pushed a little harder than they should be, especially for customers with large rooms they're trying to fill with sound.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Well, like everything in this hobby, it depends. It depends on the tower, and the bookshelf.

Imo, and Ime, even if the bookshelf reaches the same SPL, the tower will do so in a more effortless fashion. This of course depends on listening volume, distance from the speaker and of course content. Many “towers” are not much more than a BS speaker with a built in stand and have no advantage. But quality towers usually have larger, and/or more drivers. This usually makes them more sensitive and easier to drive while adding to midrange impact, and thermal load is also shared by the multiple drivers. Despite what the SVS rep said, the extra drivers are NOT just for extension. This is sometimes the case but it depends on the number of drivers and how they’re purposed in the speaker. One to hopefully chime in is @Pogre. He had a very nice SVS ultra BS setup. With some prompting(lol) and a natural curiosity he upgraded to the towers as mains. In recent postings, he mentioned that his towers had much more impact, and better imaging than any of his bookshelf speakers. There is no replacement for displacement, and especially in a larger space, and longer seating distance is this more important.
Speaking of large spaces. How big is your space? Sounds like another pb3k might be in order. This will certainly help with smooth response, but will add headroom.

Edit: yes, also what Jon AA said.
 
TLS Guy

TLS Guy

Seriously, I have no life.
I'm sure this topic has been covered ad nauseam. Although, I can't find the exact answer to my question.

I'm looking to upgrade my "home theater in a box" and take the buy once cry once route. I'm looking for a 60% stereo music, 40% streaming 5.1 system. I'm more concerned with clean detailed forward mids and present but not harsh highs. Lows are definitely nice but I'll have that covered with the SVS pb3000 that's currently on the way. My room is, well... My whole house. It's open floor plan design, with two story open cathedral ceilings. As of now it will be powered off a simple Yamaha RX-V485. Will upgrade in the slightly distant future with an added power amp. Due to current power constraints, high sensitivity is preferred.

There... Got that out of the way. I was actually talking to a SVS rep and he pointed out that if budget is a concern and that I have the PB3000 coming then I should just get bookshelves of a higher quality vs a lower quality tower. He showed how bookshelves of the same "class" tend to have the exact same mid-range driver and the additional speakers are used for lows. I'm thinking fine, I like this idea. Now i'm sure it's just psychological but the physical size of the towers just says to me cleaner, louder... Mids included.

Does anyone have any experience on this? Should I expect the same SPL from a bookshelf as I would a tower in regards to mids and highs? If I EQ out the lows would I "gain an additional mid-range driver" with the towers?? (Seem impractical but worth an ask) If not would the low range woofers just not play? But a deep powefull male voice I would assume is within their crossover. Aswell a cello or bass guitar. I wouldn't want to loose the potential depth of these bands with a bookshelf, but I'm honestly not sure. I've just have not had the option to sit back and listen to them side by side at any reasonable volume. Especially not in a room of my size.
You have asked a really pertinent and important question, seldom asked and even less understood by even professional designers.

The place to start is understanding this chart.



This shows the frequency range of common musical instruments and speech.

It also shows the the fundamentals in black and the harmonics in yellow.

Now there is more power generated by the fundamental than the overtones. Most instruments radiate even harmonics. That is to say if the fundamental is 400 Hz the second harmonic will be 800 Hz. Generally the power output goes down as the order of harmonics increases.

Now if you look you will see a heavy clustering of fundamentals from 60 Hz to 600 Hz, but going out to the 2.5 to 3 Khz range, after that range we are largely dealing with harmonic content. The big exception is pipe organs that have powerful fundamentals throughout pretty much the whole audio range. This makes them ideal for burning out tweeters.

The big point is that most power is required in that 60/80 Hz range to the 600 to 1000 Hz range, but significant power also required to the 2.5 to 3 KHz range.

But it is worse for speakers then it looks. Most speakers have forward facing speakers. Now for every speaker like that there is a point where it transitions from being a forward (half space) monopole radiator to a omni directional (full space) omnipole radiator. This occurs at a frequency depending on the front baffle width. The narrower the front of the speaker the higher this transition frequency. This is known as the baffle step frequency as at that transition the forward radiation goes down 6 db. For most speakers this occurs between 400 and 600 Hz. So unless the range below this frequency is boosted the speaker sounds thin. So this requires more then doubling the power output below this transition. That frequency unfortunately corresponds to the area where fundamental frequencies of instruments are concentrated.

So you are correct in your concern about lack of power bandwidth in this frequency range. I personally believe that most speakers are deficient in the required power band response in this region, especially since small bass mids have become the rule.

There are very few small bass mids that do have sufficient power response in this band, but there are some.

In practice it means that more than one driver to cover this band is actually required.

If you really understand what I have just explained you will see why the notion that bookshelf speakers and a sub have you covered is nonsense.

One last issue is that properly compensating for the baffle step results in an impedance drop below the baffle step frequency. So to drive a properly designed speaker with correct baffle step compensation really requires amplification that is comfortable with 4 ohm loads. This is a downside of more channels being added to receivers, as there seems to be a universal backing away of late from specifying performance at 4 ohm.
 
K

Kwiercyski

Enthusiast
You have asked a really pertinent and important question, seldom asked and even less understood by even professional designers.

The place to start is understanding this chart.



This shows the frequency range of common musical instruments and speech.

It also shows the the fundamentals in black and the harmonics in yellow.

Now there is more power generated by the fundamental than the overtones. Most instruments radiate even harmonics. That is to say if the fundamental is 400 Hz the second harmonic will be 800 Hz. Generally the power output goes down as the order of harmonics increases.

Now if you look you will see a heavy clustering of fundamentals from 60 Hz to 600 Hz, but going out to the 2.5 to 3 Khz range, after that range we are largely dealing with harmonic content. The big exception is pipe organs that have powerful fundamentals throughout pretty much the whole audio range. This makes them ideal for burning out tweeters.

The big point is that most power is required in that 60/80 Hz range to the 600 to 1000 Hz range, but significant power also required to the 2.5 to 3 KHz range.

But it is worse for speakers then it looks. Most speakers have forward facing speakers. Now for every speaker like that there is a point where it transitions from being a forward (half space) monopole radiator to a omni directional (full space) omnipole radiator. This occurs at a frequency depending on the front baffle width. The narrower the front of the speaker the higher this transition frequency. This is known as the baffle step frequency as at that transition the forward radiation goes down 6 db. For most speakers this occurs between 400 and 600 Hz. So unless the range below this frequency is boosted the speaker sounds thin. So this requires more then doubling the power output below this transition. That frequency unfortunately corresponds to the area where fundamental frequencies of instruments are concentrated.

So you are correct in your concern about lack of power bandwidth in this frequency range. I personally believe that most speakers are deficient in the required power band response in this region, especially since small bass mids have become the rule.

There are very few small bass mids that do have sufficient power response in this band, but there are some.

In practice it means that more than one driver to cover this band is actually required.

If you really understand what I have just explained you will see why the notion that bookshelf speakers and a sub have you covered is nonsense.

One last issue is that properly compensating for the baffle step results in an impedance drop below the baffle step frequency. So to drive a properly designed speaker with correct baffle step compensation really requires amplification that is comfortable with 4 ohm loads. This is a downside of more channels being added to receivers, as there seems to be a universal backing away of late from specifying performance at 4 ohm.
Right! Ok I wasn't able to put it in them terms due to ignorance. Buts i just couldn't imagine a single 6.5in or smaller driver could handle the fullness required for the 60-600 range while simultaneously being "light and airy" enough for accurate detail and imaging up to 2.4k or wherever they crossover the tweeter. The physics just dont seem to be there. I would estimate my room size (whole house) to be close the 30kcuft. (Weird shapes, with hard to measure areas) I had a feeling but, wasn't sure, that the bookshelf route would just simply be irresponsible. I wasn't sure if these speaker companies were able to figure out some sort of magic potion to fill a room with a single woofer. At the end of the day I guess physics are still physics. I'm thinking I'll probably scrap that idea and continue my search for the perfect tower!

I want to thank everyone else who replied, I was looking for the nitty-gritty and you guys provided! I knew I came to the right forum!
 
Pogre

Pogre

Audioholic Slumlord
I have been playing around and swapping out different speakers lately and my towers absolutely have something the others don't, tho to be fair I haven't done any critical listening between my Ultra towers and Ultra bookshelves for a more apples to apples comparison. Placebo? Maybe. I could definitely detect more presence in the mid-lower range compared to my TP160S, 7T Mini towers and my Infinity Overtures.
 
K

kini

Full Audioholic
Right! Ok I wasn't able to put it in them terms due to ignorance. Buts i just couldn't imagine a single 6.5in or smaller driver could handle the fullness required for the 60-600 range while simultaneously being "light and airy" enough for accurate detail and imaging up to 2.4k or wherever they crossover the tweeter. The physics just dont seem to be there. I would estimate my room size (whole house) to be close the 30kcuft. (Weird shapes, with hard to measure areas) I had a feeling but, wasn't sure, that the bookshelf route would just simply be irresponsible. I wasn't sure if these speaker companies were able to figure out some sort of magic potion to fill a room with a single woofer. At the end of the day I guess physics are still physics. I'm thinking I'll probably scrap that idea and continue my search for the perfect tower!

I want to thank everyone else who replied, I was looking for the nitty-gritty and you guys provided! I knew I came to the right forum!
I'm curious as to why you feel you need to "fill" the whole room and not just to the listening position? If you want to really fill a space that large you're going to need large venue pro audio components.

You really should just be concerned with getting enough SPL at or near your primary listening position.

That said, IMO I would go for towers regardless. I think they almost always look better and they're almost always a little more efficient within the same line/manufacturer.

Why not add a pair of SVS Pinnacle towers to you sub order?
 
lovinthehd

lovinthehd

Audioholic Jedi
When I switched from a bookshelf/sub setup to towers I was happier in my big room (and the biggest room I've had to deal with to date), but in smaller rooms the bookshelf/subs (same ones) work great, too. I liked it even more when I replaced the bookshelf surrounds with towers as well. They're completely different speakers on the other hand. Now subs in a big space like you've got, one may be sufficient nearfield....
 
K

Kwiercyski

Enthusiast
I'm curious as to why you feel you need to "fill" the whole room and not just to the listening position? If you want to really fill a space that large you're going to need large venue pro audio components.

You really should just be concerned with getting enough SPL at or near your primary listening position.

That said, IMO I would go for towers regardless. I think they almost always look better and they're almost always a little more efficient within the same line/manufacturer.

Why not add a pair of SVS Pinnacle towers to you sub order?
A pair of pinnacle's to go with the sub is definitely an option that I have considered. I've noticed that SVS seems slightly low where sensitivity is concerned. I'm really trying to squeeze what I can out of the low-power AVR I'm currently working with. Im really just looking for a step up to tide me over for a little while until I got a little extra cash to throw around. $1,600 a pair I know isn't outrageous, and you tend to get more then what you pay for with svs. But I blew a quite substantial chunk of my change on that sub (lol couldn't help myself). I'm not necessarily sure if "fill the entire room" with sound is truly my ultimate goal. But we tend to listen to music as we move about and entertain. I would like something to keep up with whatever the conditions demand. Although understand I'm not necessarily looking for a nightclub in my living room. Lol
 
K

Kwiercyski

Enthusiast
When I switched from a bookshelf/sub setup to towers I was happier in my big room (and the biggest room I've had to deal with to date), but in smaller rooms the bookshelf/subs (same ones) work great, too. I liked it even more when I replaced the bookshelf surrounds with towers as well. They're completely different speakers on the other hand. Now subs in a big space like you've got, one may be sufficient nearfield....
Thanks for the input! I do truly think my space is simply too large for bookshelves. I'm worried about losing the "mid-low". Especially because a lot of my concern is not necessarily near-field. My "home theater in a box" satellite speakers actually have... well, acceptable.... performance, near field when watching movies. But back up a few feet and they really fall apart. This is truly what I am trying to fix. So I do believe towers are likely my prescription.... With the added benefit of near-er field slam! (8ft listening position)
 
lovinthehd

lovinthehd

Audioholic Jedi
Some prefer to be at least 8 ft from a tower, you might be able to back up a bit now :) I don't know about 88dB sensitivity being all that low, tho the towers I went with are 92 and 90 (JBL 590 for L/R, 580 for surrounds).
 
Pogre

Pogre

Audioholic Slumlord
Thanks for the input! I do truly think my space is simply too large for bookshelves. I'm worried about losing the "mid-low". Especially because a lot of my concern is not necessarily near-field. My "home theater in a box" satellite speakers actually have... well, acceptable.... performance, near field when watching movies. But back up a few feet and they really fall apart. This is truly what I am trying to fix. So I do believe towers are likely my prescription.... With the added benefit of near-er field slam! (8ft listening position)
I have a fairly large space and went with Ultra bookshelves on my front stage at first and they really did the job well. I bought the towers more out of want than need and I love them but I can't say it was a night and day difference if there's a sub or 2 in the mix.

If you have the budget and like the form factor/makes you feel better I say go for it. I did and they're awesome. If money is a factor I do believe bookshelf speakers with properly integrated subwoofage can get you most of the way there. At least close enough that it's gonna be hard to tell without instant a/b comparison.
 
K

Kwiercyski

Enthusiast
Some prefer to be at least 8 ft from a tower, you might be able to back up a bit now :) I don't know about 88dB sensitivity being all that low, tho the towers I went with are 92 and 90 (JBL 590 for L/R, 580 for surrounds).
Yeah, I guess you're right 90 just looks a lot bigger than 88 right!? I shamed the SVS guy for not having any towers for me to demo, Id hate to buy something without hearing them first. I've heard only good things of the pinnacles, so hopefully I'll get my chance to hear them soon. I'm definitely a buy once cry once kind of guy. I just can't swing for the nutty stuff like to 702 s2's regardless of how they sound ☹
 
Pogre

Pogre

Audioholic Slumlord
Yeah, I guess you're right 90 just looks a lot bigger than 88 right!? I shamed the SVS guy for not having any towers for me to demo, Id hate to buy something without hearing them first. I've heard only good things of the pinnacles, so hopefully I'll get my chance to hear them soon. I'm definitely a buy once cry once kind of guy. I just can't swing for the nutty stuff like to 702 s2's regardless of how they sound ☹
This is the beauty of SVS. If you don't like what you hear for any reason, they'll refund you a hundred percent and pay the return shipping even. You have 45 days of in home demo time to make up your mind so it's really risk free. Outstanding customer service. Once you're in the family they try to keep you there. I've been sent a $50 replacement grille (that I damaged), pin cups and one time a replacement amp for a sub. All shipping paid, free of charge. They have awesome support.

That's my experience ordering direct from their site but I can't imagine a dealer wouldn't offer the same.
 
davidscott

davidscott

Audioholic Ninja
I much prefer the sound of my infinity primus 363 towers to my infinity 163 bookshelf speakers. No sub with the 163s to be fair but the 363s don't really need one in an apt. Much fuller and deeper as can be expected. Maybe when I move I'll add a sub to the 163s for a more fair comparison.
 
K

Kwiercyski

Enthusiast
I have a fairly large space and went with Ultra bookshelves on my front stage at first and they really did the job well. I bought the towers more out of want than need and I love them but I can't say it was a night and day difference if there's a sub or 2 in the mix.

If you have the budget and like the form factor/makes you feel better I say go for it. I did and they're awesome. If money is a factor I do believe bookshelf speakers with properly integrated subwoofage can get you most of the way there. At least close enough that it's gonna be hard to tell without instant a/b comparison.
This is the beauty of SVS. If you don't like what you hear for any reason, they'll refund you a hundred percent and pay the return shipping even. You have 45 days of in home demo time to make up your mind so it's really risk free. Outstanding customer service. Once you're in the family they try to keep you there. I've been sent a $50 replacement grille (that I damaged), pin cups and one time a replacement amp for a sub. All shipping paid, free of charge. They have awesome support.

That's my experience ordering direct from their site but I can't imagine a dealer wouldn't offer the same.
You see.... I shouldn't know these things
 
ryanosaur

ryanosaur

Audioholic Overlord
Akin to what TLS said earlier, I had been thinking a great deal on the efficacy of Standmounts and subs. I've seen many designs now that are two-part speakers, say, using an upper cabinet for the Mids and Tweet, along with a bass cabinet. The extension of the bass cabinet varies of course, by design. My Phil 3s are supposed to be F3 at 25 Hz; The old Salk SS10 is F3 @22 Hz; the SS12 is F3 at 18 Hz... Then if you look at the Troels Gravensen speakers, he has several designs based on stacked cabinets; RBH does this...
What stands out here, is that these are not instances of two very disparate items, such as where the sub is limited to ~200Hz on the upper end along with a Standmount that might struggle below 60.
The Two-Part Floor Standing designs may still want a sub added in some circumstances (I do with my Phils), but the Bass cabinets are working to a higher threshold before rolling off to the Mid-Woofer(s) much as they would in a fully integrated traditional 3-way Tower.
Of course, there are still trade offs in how the designer handles the details TLS brought up earlier, such as power handling, as well as other aspects of the XO and such. (There are two Gravesen designs I am aware of where he includes a Hypex Plate Amp to power 1-2 woofers crossing at various frequencies before passing to the Mid, they are active power with DSP, but utilize a passive XO).
At the end of the day, I know I prefer either large 3-Way Standmounts or (much more so) good Floor Standing speakers. As I learn more about the design aspects, I will hopefully have a better enough base to fully grok the implications of combining drivers into an integral unit capable of delivering high quality full range sound.
Of course, I'm still only at the beginning of this journey. :)
 
Jon AA

Jon AA

Audioholic
I've seen many designs now that are two-part speakers, say, using an upper cabinet for the Mids and Tweet, along with a bass cabinet. The extension of the bass cabinet varies of course, by design.
The ones I'm going to build certainly resemble that remark. ;) In their case the 15" woofer doesn't cross over until 350 Hz, a couple octaves higher than you'd ever want to try and run a sub. Think of them as built-in midbass modules. :D
 
K

Kwiercyski

Enthusiast
Akin to what TLS said earlier, I had been thinking a great deal on the efficacy of Standmounts and subs. I've seen many designs now that are two-part speakers, say, using an upper cabinet for the Mids and Tweet, along with a bass cabinet. The extension of the bass cabinet varies of course, by design. My Phil 3s are supposed to be F3 at 25 Hz; The old Salk SS10 is F3 @22 Hz; the SS12 is F3 at 18 Hz... Then if you look at the Troels Gravensen speakers, he has several designs based on stacked cabinets; RBH does this...
What stands out here, is that these are not instances of two very disparate items, such as where the sub is limited to ~200Hz on the upper end along with a Standmount that might struggle below 60.
The Two-Part Floor Standing designs may still want a sub added in some circumstances (I do with my Phils), but the Bass cabinets are working to a higher threshold before rolling off to the Mid-Woofer(s) much as they would in a fully integrated traditional 3-way Tower.
Of course, there are still trade offs in how the designer handles the details TLS brought up earlier, such as power handling, as well as other aspects of the XO and such. (There are two Gravesen designs I am aware of where he includes a Hypex Plate Amp to power 1-2 woofers crossing at various frequencies before passing to the Mid, they are active power with DSP, but utilize a passive XO).
At the end of the day, I know I prefer either large 3-Way Standmounts or (much more so) good Floor Standing speakers. As I learn more about the design aspects, I will hopefully have a better enough base to fully grok the implications of combining drivers into an integral unit capable of delivering high quality full range sound.
Of course, I'm still only at the beginning of this journey. :)
Wow! I love the nitty gritty I'm getting from you guys! Honestly this is going to take me a sec to decipher (still learning the language) but I love it non-the-less! Thanks for the details, now I'll do some homework.
 
K

Kwiercyski

Enthusiast
The ones I'm going to build certainly resemble that remark. ;) In their case the 15" woofer doesn't cross over until 350 Hz, a couple octaves higher than you'd ever want to try and run a sub. Think of them as built-in midbass modules. :D
Hey quick newbie question regarding this, it may be a little naive but this is the way I see it in my head. (backed up with no experience or broader knowledge)

Wouldnt crossings over a 15in woofer at such high frequency cause an unnatural sounding spike in SPL above say, 120Hz? Given the assumption you plan on driving this woofer down to say ~20Hz. My thought process is the power required to create the desired SPL and to accurately drive that woofer down in the 20-35Hz range would be excessive over 200Hz.....

But I guess you could make that same argument for any woofer size....

Idk, now I feel like I'm just confusing myself.
 
newsletter

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top