why big woofers?

[greyhound]

the trend in audioland seems to bee smaller cabinets, almost dissapearing in the background of the livingroom.
most speaker manufacturers use smaal woofers , somethimes 2 ore three.
but what is the advantage of using one big one?

[timc]

Big woofers couple better with the air. At least thats how i see it. You just "feel" the big woofers better. Even if you have the same cone area with many small woofers. This may be technical inaccurate.


To replace a, lets say a 18" woofer, you need four 9" woofers. To get theese to work as one, is next to impossible, (plese correct me if im wrong on this) due to tollerances and slight difference in distance from the listening position.


-Tim

[hjames]

the trend in audioland seems to be smaller cabinets, almost disappearing in the background of the living room. Most speaker manufacturers use small woofers , sometimes 2 or three.
but what is the advantage of using one big one?

No no - the trend in living room design is smaller, invisible speakers.
The laws of physics haven't really changed.

Of course, I have 15s in both of my listening systems - with an extra 15 for the sub, so maybe I'm prejudiced ...
:)

[pelly3s]

simplest answer is because its cooler to have big woofers :applaud:

[Maron Horonzakz]

I can piss louder than little woofers.:D

[BigT]

To replace a, lets say a 18" woofer, you need four 9" woofers. To get theese to work as one, is next to impossible, (plese correct me if im wrong on this) due to tollerances and slight difference in distance from the listening position.


Is it really that hard? The wavelengths are pretty long and our ears are not all that sensitive to differences at woofer frequencies. I should think there wouldn't be much of a problem at all. If multiple woofers are a problem, what could be done about it?

[AltecLansingFan]

Big woofers say "woof" - small woofers say "waf"
The only nice small "things" are girls, everything else must be big, like big houses, big cars, big cigars, big hamburgers, big woofers and so on.....:nanana:

[toddalin]

Probably because we were "bottle babies." ;)

Actually, two smaller woofers could have half the cone area of a bigger woofer and still produce the same/near the same level of bass if they are acoustically coupled where they pick up a 3 dB advantage. Obviously this wouldn't happen at all frequencies.

[timc]

Obviously this wouldn't happen at all frequencies.


Wich means you would get a weird response?



-Tim

[Gary L]

Sounds like an age old question but we all know the real answer, Bigger is Better!

Gary

[subwoof]

Here's the story of a man named jed.

Air molecule jed and his drinking buddies get slapped upside the head from the big bad computer's 2" subwoofer and rush to tell their buddies at the corner store. Which takes a small amount of time and energy since they live SO far away ( in the relative sense ).

Now these molecules run and run and get a little tired along the way so one of them sits down for a break leaving the other 2 to carry on.

By the time they get to the convenience store the sole survivor is too tired to say anything.

Now the owner of the corner store only sees a single molecule show up and wonders what the big deal is. He knows it is a woofer's message but it is too faint to hear...

A little while later, in a living room far far away, a 2245 woofer smacks a few billion air molecules at the same time with a 4X4. They ALL run out and tell their buddies and they ALL run and tell their buddies, ad infinitum.

Even though only some of them make it to the store, the store owner KNOWS it's "another brick in the wall, part 2" not just another "thump" and calls the police about the loud music down the street.

The moral is it takes a substantial amount of power and surface area to re-create ACCURATELY the sound that is on the CD you are playing. A bass drum on stage is 24" - do you really expect that little pair of cubes on the veranda to make the same sound??

It's all physics and tiny is a marketing hype.

sub

[cooky1257]

Yup, I've always understood it to be down to the size of the wavefront approaching that from real instruments too(see 24" bass drum, double bass, bass amp cab etc).

[Maron Horonzakz]

I heard four 24" hartley woofers whomping away in a system,,,,,It peeled the green off my teeth. These multible woosey woofers dont cut it.:D

[Mr. Widget]

the trend in audioland seems to bee smaller cabinets, almost dissapearing in the background of the livingroom.The trend in audio land is such a complete disappearing act that there almost is no more audio land. Smaller speakers are more popular than larger ones. No speakers at all are even more popular. Don't forget even Bose used to make much larger speakers. Old Dr. Amar may have some whacky ideas about what good sound is, but he certainly has had a sound mind when it comes to making money. :D

All that aside, a smaller woofer can do well in a home environment as long as you are not trying to play music at stupid SPLs. There are many excellent speakers out there that have managed to do quite well with 2-3 6.5" or 8" woofers. Typically you do need multiples if you are after sub 40Hz bass.


Widget

[edgewound]

Actually....

In a well designed system, multiple small woofers are quicker, more accurate and can handle more power than say, a single 15". Why? Because they can start and stop faster, and the multiple motors/voice coils can handle more power with less power compression. Given high quality drivers of course. Four 8" woofers have roughly 15% more cone area than a single 15", excluding the the motor topology and voice coil excursion

But accuracy and the visceral "ooomph" that many listeners prefer are many times mutually exclusive. That's where the 15" or 18" can win the game.

Is the mic'd kick drum at a monster concert an accurate reproduction of the kick drum by itself acoustically?....I think not. It's a major synthesizer that's tuned by the house engineer based on the system he has at his fingertips.

Check out the Revel line by Harman. Woofers are multiple 8"s or smaller.

[Gary L]

:D I have friends who really think their Bose wave radios sound just as good as my Altec 19s!

They too need their heads examined!:banghead:

Music for me has to both sound and feel good!

Gary

[Allanvh5150]

I find large woofers are more appealing visualy. I have built my whole system in New Zealand native timber to match the rest of the furniture in my house. The large cabinets, 4 x L150, 1 x 4355 style and 2 x L86 where made to be "peices of furniture". I dont run my system at horendous levels but if I do, the clarity is phenominal. Of course the major drawback with large speakers is that you need and over abundence of power to keep it clean. My amplifiers consist of 7 x 150W, 2 x 200W, 2 x 500W and 2 x 1000W. Most people will call this insanity, I just look at them and smile and say "its just a hobby".:) So are my speakers too big for home use? YUP. Are my amplifiers too big for home use? YOU BETCHA. But who cares..... You will find that most of the members of this site own or want to own, either the top end home use JBL's, or, large format studio monitors. We like em because they sound great and they also have a lot of the "holy crap" factor. And, what I think is the most important factor, we generaly dont follow current trends.:)

[edgewound]

So are my speakers too big for home use? YUP. Are my amplifiers too big for home use? YOU BETCHA.

Says who?

It's your house and your system. Until the "Speaker Gestapo" shows up to confiscate them, and you're not bothering your neighbors, that's right....

Who cares?

[Gary L]

"So are my speakers too big for home use? YUP. Are my amplifiers too big for home use? YOU BETCHA".

You forgot to ask the next question in this progression, Do I love the way my system sounds????????

My wife already knows there needs to be room for my speakers and system or I am a very unhappy camper!

Gary

[Mr. Widget]

Check out the Revel line by Harman. Woofers are multiple 8"s or smaller.The Revel F52 only has (3) 6.5" woofers yet I'd rather listen to them than a pair of L300s. It has tight articualate bass down to a -10dB point of 21Hz! The rated (in room) frequency response is +/- 0.5dB 33Hz to 18KHz. (Yeah, I know... which room!) However I have heard these wee beasties and their smaller brothers in many rooms and they just sound great. They do require a big amp (at least 150wpc) but they are dynamic, image holographically, and are virtually coloration free.

My biggest gripe with them is that Harman didn't have the balls to badge them as JBLs and dump all of those cheesy vinyl clad boxes that do have the JBL name on them.


Widget

[cooky1257]

Actually....

In a well designed system, multiple small woofers are quicker, more accurate and can handle more power than say, a single 15". Why? Because they can start and stop faster, and the multiple motors/voice coils can handle more power with less power compression. Given high quality drivers of course. Four 8" woofers have roughly 15% more cone area than a single 15", excluding the the motor topology and voice coil excursion

But accuracy and the visceral "ooomph" that many listeners prefer are many times mutually exclusive. That's where the 15" or 18" can win the game.

Is the mic'd kick drum at a monster concert an accurate reproduction of the kick drum by itself acoustically?....I think not. It's a major synthesizer that's tuned by the house engineer based on the system he has at his fingertips.

Check out the Revel line by Harman. Woofers are multiple 8"s or smaller.
That's actually only 5% larger assuming we're talking flat circles, but wont 8" cones be more shallow, have smaller dia voicecoils/lower thermal power handling? Therefore power compression will set in earlier for a given LF output? To say nothing of rising distortion with excursion.
Either way you get there you still need cone realestate regardless of level IMO.

[edgewound]

My biggest gripe with them is that Harman didn't have the balls to badge them as JBLs and dump all of those cheesy vinyl clad boxes that do have the JBL name on them.


Widget

That is a statement that I wholeheartedly endorse, also.

Check out the JBL "LS Series" in Japan. Makes you scratch your head and ask why not here? Some JBL insiders wonder the same thing.

[edgewound]

That's actually only 5% larger assuming we're talking flat circles, but wont 8" cones be more shallow, have smaller dia voicecoils/lower thermal power handling? Therefore power compression will set in earlier for a given LF output? To say nothing of rising distortion with excursion.
Either way you get there you still need cone realestate regardless of level IMO.


Well, I did qualify that by stating "high qualility" drivers. There are some mighty killer 8's on the market with 3" voice coils that can go to 20-30Hz and take several hundred watts to kilowatt peaks.

I'd love to hear what multliple JBL 218F's could do in an verticle line array with a small enclosure footprint.

[greyhound]

i always wondered why a few drivers that together have the exact same surface area as one biggie would do any worse.
fact is when i listen to bass drums and electricbasses the sound comes more natural with a big diameter woofer. problem is i dont understand why!
is it just in my head?
whats important for a woofer is the control the voice coil has on the cone.
the bigger the coil the more control its got on the driver right?
jbl uses big voice coils but when you compare them with the small drivers and do the math, the small ones should have more control.
large coils means that the amount of windings from the wire's are smaller. because the circel is bigger. so that means that the gap of the voice coil is smaller.

also when you hear a bass drum a lot of info is comming from the (how you call them) squakers ? ore midrangers,waffers?
and also the tweeters.

[Gary L]

I think a smaller dia. cone has a better chance of being faster and more accurate then a larger woofer.

Don't know the math but I'd say 2 10s should be able to outperform 1 15.

Coupeling the sound and matching the woffers would be very important if my thoughts are correct.

I always questioned Bose and the 901 series speakers because I think it is possible to get 2 or three speakers performing close enough in spec to sound great together but I had my doubts about 9 of them doing it.

I do appreciate the bass response from old Altecs that contain 2 12s over those that have 1 15 in them.

Gary

[Mr. Widget]

i always wondered why a few drivers that together have the exact same surface area as one biggie would do any worse.
...I think it is possible to get 2 or three speakers performing close enough in spec to sound great together but I had my doubts about 9 of them doing it.The problem isn't that the drivers are closely matched or not. The problems arise when you get above a few hundred Hz. As the frequencies get higher you get cancellations and lobing due to the comb filtering that occurs due to the shorter wavelengths having different arrival times. For lower frequencies the wavelengths are so long that they blend seamlessly and you can use two 12s or 10s or three 8s and so on. This is why the Revel pictured above must have a mid that can go down fairly low to the crossover between it and the three woofers.

As for control, as Edge said, with "high quality" drivers you can get exceptional control out of smaller drivers. For them to do deep bass justice they still must have respectable xmax and a low enough Fs etc. The main thing you do lose is sensitivity. None of these multi-driver systems can match a 15" or 18" system for sensitivity.


Widget

[CONVERGENCE]

It has to do with cabinet size, I've tried column PA speakers and they don't come near anything a 15 " woofer in a large cab will give you in terms of performance.

........................

[Gary L]

It has to do with cabinet size, I've tried column PA speakers and they don't come near anything a 15 " woofer in a large cab will give you in terms of performance.

........................

My own personal tastes agree with this Convergence but I think an Altec 9844 with 2, 12" 414s has alot nicer bass then other Altecs with a single 15" 416.

I have a fond appreciation for large woofers that can excite alot of air in a room and I've just never felt that with any multiple woofed towers.

Gary

[Mr. Widget]

It has to do with cabinet size, I've tried column PA speakers and they don't come near anything a 15 " woofer in a large cab will give you in terms of performance.I believe we were discussing home audio. For pro-audio the requirements are quite different.

Speaking of columns of smaller drivers remember the Shure Vocal Master speakers? :barf: This JBL was better, but hell yeah, give me some big ass woofers any day... as long as someone else is doing the hauling. :D



Widget

[Maron Horonzakz]

Just got my latest issue of Voice Coil Mag. In it is a Ad from TB speakers... Touting a 2" SUBWOOFER speaker... Yeh right !!!:D

[toddalin]

Just got my latest issue of Voice Coil Mag. In it is a Ad from TB speakers... Touting a 2" SUBWOOFER speaker... Yeh right !!!:D

A 2" subwoofer! Boy have I got a use for those! :bouncy:

http://michelleswebkids.com/02.CRW_9333.jpg

http://www.trainweb.org/girr/todds_site/nov_98/sp_gp9.jpg

http://www.trainweb.org/girr/todds_site/nov_98/shays_taking_water.jpg

[Maron Horonzakz]

Hey I looked just like that kid,,, Only cute,r...Wow what a train set ,,,Great detail.... I,m into steam locos. (need more woof in the bass for effect)..:applaud:

[Mr. Widget]

Hey I looked just like that kid,,,I guess that was before your teeth turned green.


Widget

[Maron Horonzakz]

But my breath is minty.:D

[4313B]

but what is the advantage of using one big one?The name of the game is to move as much air as possible with minimal effort. Always has been, always will be. Ask Steve Schell if you can listen to his subwoofer. You'll get the picture real quick.

If you see a ten or twelve inch woofer fighting to get out of its enclosure just dump it over on its face and let it blow itself up. Put it out of its misery, and ours.

My biggest gripe with them is that Harman didn't have the balls to badge them as JBLs and dump all of those cheesy vinyl clad boxes that do have the JBL name on them.Yeah, that's a really funny one. Use the same brand name for the best Pro sound in the world on trinkets sold at Best Buy or Circuit City. Oh well, go figure.

[1audiohack]

i always wondered why a few drivers that together have the exact same surface area as one biggie would do any worse.
fact is when i listen to bass drums and electricbasses the sound comes more natural with a big diameter woofer. problem is i dont understand why!
is it just in my head?

Do you think it is because that is what we are used to hearing these things reproduced on? There are no small woofers at a concert, or even at the clubs.

also when you hear a bass drum a lot of info is comming from the (how you call them) squakers ? ore midrangers,waffers?
and also the tweeters.

If you take a "scope" measurement with something like TEF, the slew rate of a kick drum is much faster than most would think, fast enough to get a click into the HF portion of your speakers with ease.

When looking at a kick drum trace, I became certain that you had to be polarity correct, meaning mic diaphragm moving inward = speakers moving outward if its going to sound dynamic, and the speaker system phase corrected if its going to sound right,,, thats another topic however.;)

[Don McRitchie]

As always, any loudspeaker design is a compromise since no one approach is perfect. It comes down to the designers' choice on what attributes they choose to prioritize and then what compromizes they are willing to make. Each approach has its own intrinisc advantages and disadvantages. That said, here are some of the intrinsic advantages of JBL's design of large bass transducers:

1) Large drivers can displace more air with less excursion. This makes it easier to design a low distortion driver since the smaller movements can be more easily kept within the linear operation of the motor and suspension.

2) Large drivers more easily lend themselves to high efficiency operation with a suitably designed motor. This means less energy waste in heat generation which is one of the leading causes of distortion and power limitation in a dynamic driver.

3) Large drivers more easily lend themselves to high power handling given the ability to utilize large diameter coils that dissipate heat more effectively and allow more wire in a given depth gap.

4) The combination of high power handling and high efficiency results in high dynamic range that cannot be matched by a single small diameter driver.

None of these attributes are absolute and it is possible to design smaller diameter drivers (sometimes requiring multiples) with similar levels of performance in any given criteria. The trick is to gain all of the attributes of the large diameter driver in a small diameter alternative which is extremely difficult if not impossible depending on the application.

Obviously, there are intrinsic disadvantages with large diameter drivers:

1) It is more difficult to mitigate cone breakup in a large diameter driver which is a source of distortion.

2) It is easier to design multiple small diameter drivers to be linear over narrow bandwidths than to design a large diameter driver that is linear over a wide bandwidth, as in many JBL designs.

3) Large drivers equal large enclosures which are becomming less and less attractive to the buying public's lifestyle.

Again, none of these disadvantages are absolute as evidenced by many successful JBL large driver designs.

My personal preference is towards the large driver designs. That is because I place greater importance on dynamic realism than most other design attributes and nothing matches a big drivered JBL for dynamic realism.

[greyhound]

yep, thats what i mean when i call the lower regions of the sonic expririence "more natural".
bass seems smoother and capable of delovering true dynamics. especially when listening to a live concert.

te only systems over here that can do that with small drivers cost many times more then a decent pair of jbl's.

filters are always very important. jbl seems to be on the safe side with flitering a 12"woofer at 600hz. and thats good

also a lot of electro and magneto static listeners here. took a "strapping young lad" album and those things totally drowned. there so much bass drum rolls on there that the statics simly gave up.

But in the mid and higher region it can sound beautifull.

did lansing or jbl ever experiment with things like ribbon,electro ore magnetostats?

[Mr. Widget]

filters are always very important. jbl seems to be on the safe side with flitering a 12"woofer at 600hz. and thats goodDepends on the model. The classic L100 has no filter on the woofer at all. In fact, I'd say that the filters used in JBLs before the '80s were frequently not up to the level of the rest of the system.



did lansing or jbl ever experiment with things like ribbon,electro ore magnetostats?I don't think so. They are still refining the 1940's compression drivers. :D

As for the planar speakers. They do have appeal, but having owned and listened to a variety of Electrostats, Maggies, and ribbons, they too have their problems. Dynamic range being only one of them.


Back on the topic of this thread, I do agree with Don's post that it seems the best way to achieve dynamic realism is with big woofers, though I have heard systems with multiple 10" or 12" woofers that were also quite capable in this area.


Widget

[duaneage]

FWIW large drivers have a lower FS than smaller drivers, provided the suspension is loose enough. The lower FS makes for better bass by keeping driver resonance lower than the musical notes. Vented systems can go pretty low with big woofers, with smaller woofers you need to use non flat alignments and they don't sound nearly as good.


I think you an go too big as well. EV made a 30" and I've seen 24" drivers from C-V, they needed many yards of cabinet and were not usable above 100Hz.

I think 12 and 15 inch drivers are the most practical for bass reproduction.

[sonofagun]

Yu doaneed biggur woofers- jus smallur eardrums!

Put Prep H in yor ears!