Why does polk not make bigger drivers???

thesurfer

Ive been looking for some rt7,s Got to thinking, they have the 7,1/2 mid bass, Why is it, polk lives, and dies by the 6,1/2 drivers??????

toucanet

I'm sure that it may have something to do with displacement (possibly getting very similar sound with less materials), price points and consumer demand.

just my .02

Conradicles

Not sure why. But my LSi9's have 5 1/4" drivers and sound amazing!!! Incredible bass for such a small speaker.

shack

Aesthetics. Polk has determined the majority of buyers do not want a speaker cabinet as wide as the 7.5" or 8" inch driver would require. It's not displacement. If you notice on the new LSiM floorstanders, Polk has designed them with 5"x7" and 6"x9" subwoofers to keep the cabinet as slim as possible.

mdaudioguy

^ +1. Have you noticed that it's not just Polk? There are trends in this industry, you know?

Face

Smaller drivers have better off axis dispersion.

madmax

Smaller drivers usually have better definition.

sda2mike

and less slop in the low end..less of the 'cabinet' sound, too

nguyendot

Better punch.

Fongolio

Smaller drivers have less mass and are easier to move giving more accurate bass/mid bass. Also, less distortion because of reduced surface area of cone(s).

Face

Fongolio wrote: »

Smaller drivers have less mass and are easier to move giving more accurate bass/mid bass. Also, less distortion because of reduced surface area of cone(s).

Not true. A large driver that is well designed will play lower with less distortion than a smaller driver of the same build quality.

danger boy

small drivers respond faster than large ones. i don't know of any speaker maker today that uses the huge 12 or 15" drivers of the 70's.

Face

madmax wrote: »

Smaller drivers usually have better definition.

You are probably getting this from the better off axis of smaller drivers. Plus, smaller drivers generally can play higher without breakups/distortion.

skrol

No driver envy at Polk.

TECHNOKID

Face wrote: »

Smaller drivers have better off axis dispersion.

madmax wrote: »

Smaller drivers usually have better definition.

sda2mike wrote: »

and less slop in the low end..less of the 'cabinet' sound, too

IMO, it has more to do with trends, aesthetics and larger profits (due to lower costs and justification for adding external subs) however, I am notdebating the above comments...

nguyendot wrote: »

Better punch.

I don't think so see below;

Not true. A large driver that is well designed will play lower with less distortion than a smaller driver of the same build quality.

Agreed, this is simple physic! You can not defeat physic, larger drivers are ideal for bass.

thesurfer

TECHNOKID wrote: »

IMO, it has more to do with trends, aesthetics and larger profits (due to lower costs and justification for adding external subs) however, I am notdebating the above comments...

I don't think so see below;
Agreed, this is simple physic! You can not defeat physic, larger drivers are ideal for bass.

I think what he means is, that the smaller driver has less air mass to move,, there for, well responed faster, quicker, as opposed to a larger one,, that takes more air volume, to do the same thing,,,

TECHNOKID

danger boy wrote: »

small drivers respond faster than large ones. i don't know of any speaker maker today that uses the huge 12 or 15" drivers of the 70's.

Really? Don't all companies use large drivers for subwoofers? When you go up their line, doesn't their better subwoofers all use larger drivers which are in the area of 12 - 15"? Again for bass physics calls for larger drivers to be used. In the older days, many speakers were full range (which you can not accomplish with smaller drivers) and did not require the use of external subs. Smaller drivers in speakers = incomplete frequency spectrum = external subwoofers required = more sale = more money.

While the bass was not going any lower 40 hz in most full range of the speakers of the 70s era this would definitely be improved greatly with todays technology with the addition of modern Xos and proper isolation chambers design in the cabinets. Just look what Polk has done with the new LsiM towers. I am not sure of the lower end spec for the LsiM towers but I am convinced it will be an improve to any of the modern Polk speakers and yet the bass driver is just slightly bigger than the usual Polk speakers.

thesurfer

TECHNOKID wrote: »

Really? Don't all companies use large drivers for subwoofers? When you go up their line, doesn't their better subwoofers all use larger drivers which are in the area of 12 - 15"? Again for bass physics calls for larger drivers to be used. In the older days, many speakers were full range (which you can not accomplish with smaller drivers) and did not require the use of external subs. Smaller drivers in speakers = incomplete frequency spectrum = external subwoofers required = more sale = more money.

While the bass was not going any lower 40 hz in most full range of the speakers of the 70s era this would definitely be improved greatly with todays technology with the addition of modern Xos and proper isolation chambers design in the cabinets. Just look what Polk has done with the new LsiM towers. I am not sure of the lower end spec for the LsiM towers but I am convinced it will be an improve to any of the modern Polk speakers and yet the bass driver is just slightly bigger than the usual Polk speakers.

Subs got big on the scene because of home theater, Put a rtia3, next to a cerwin vega, 3 way that has a 15 inch woofer, the cerwin vega, well sound boomy muddy, and simply loud,, no imageing, no detail, and certanily wont be accurate,

danger boy

TECHNOKID wrote: »

Really? Don't all companies use large drivers for subwoofers? When you go up their line, doesn't their better subwoofers all use larger drivers which are in the area of 12 - 15"? Again for bass physics calls for larger drivers to be used. In the older days, many speakers were full range (which you can not accomplish with smaller drivers) and did not require the use of external subs. Smaller drivers in speakers = incomplete frequency spectrum = external subwoofers required = more sale = more money.

While the bass was not going any lower 40 hz in most full range of the speakers of the 70s era this would definitely be improved greatly with todays technology with the addition of modern Xos and proper isolation chambers design in the cabinets. Just look what Polk has done with the new LsiM towers. I am not sure of the lower end spec for the LsiM towers but I am convinced it will be an improve to any of the modern Polk speakers and yet the bass driver is just slightly bigger than the usual Polk speakers.

but in a tower.. I don't know of any speaker maker using the 12" or 15" subwoofers anymore. since as someone mentioned... a stand alone subwoofer has replaced the needed low end in most towers now.

newrival

danger boy wrote: »

but in a tower.. I don't know of any speaker maker using the 12" or 15" subwoofers anymore. since as someone mentioned... a stand alone subwoofer has replaced the needed low end in most towers now.

I can think of a few off the top of my head:

Emerald Physics 2.3 uses 2 open baffle 15" drivers
Def Tech BP8080 uses a 12 side firing woofer
Salk has a model or two with 12" woofers.

Anyways, there are a lot out there, just not as many as there used to be.

I've also been seeing a lot of those oblong bass drivers similar to the ones in the LSiM's. Never heard any though.

ben62670

Larger drivers are heavier, and need to be stiffer. This added mass slows them down.

TECHNOKID

thesurfer wrote: »

Subs got big on the scene because of home theater, Put a rtia3, next to a cerwin vega, 3 way that has a 15 inch woofer, the cerwin vega, well sound boomy muddy, and simply loud,, no imageing, no detail, and certanily wont be accurate,

Agreed however, you are not taking the best example as there much better to compare than cerwin vega. Cerwin vega were considered the big thing at the time by people looking for loud and powerfull not by people concerned with good SQ.

I also agree with you on your HT comment. That some I wanted to mention, when used for HT full range speakers are a waste/not necessary nor wanted since an external sub is used for the bass. However, for music I still believe a full range speaker is ideal.

danger boy wrote: »

but in a tower.. I don't know of any speaker maker using the 12" or 15" subwoofers anymore. since as someone mentioned... a stand alone subwoofer has replaced the needed low end in most towers now.

Agreed, pretty rare nowadays. External subs, aesthetics (WAF) and trends are all part of the picture along with the extra $$ made on providing an external subwoofer.

ben62670 wrote: »

Larger drivers are heavier, and need to be stiffer. This added mass slows them down.

Agreed! Is a trade off but when properly engineered a full range speaker is ideal for music IMO.

I've also been seeing a lot of those oblong bass drivers similar to the ones in the LSiM's. Never heard any though.

I never had a chance to audition any of them either but in my opinion this is a good way to cover the gap between the old and new ways to built speakers.

I think Polk has done is homework and used good engineering technique for the LsiM (I can't comment on other brands since I am not knowledgeable of their work).

I don't know/remember if in all the threads about the LsiM if it was ever mentioned if the tower could be "tri-amped"? I believe (IMO) today's technologies be Xos, isolated speaker chambers along with using high, mid and bass isolated external amplification would provide for a fabulous full range speaker tower.

polkfarmboy

ben62670 wrote: »

Larger drivers are heavier, and need to be stiffer. This added mass slows them down.

I think my 8 inch paper cones on source se add a thunder that sounds incredibly fast and punchy for music and gives a nice weight to the low frequency

newrival

TECHNOKID wrote: »

I believe (IMO) today's technologies be Xos, isolated speaker chambers along with using high, mid and bass isolated external amplification would provide for a fabulous full range speaker tower.

Are you familiar with the Linkwitz Labs Orion? A fine example of what you describe. Some have argued that it's one of the best sounding speakers ever designed. Although take that with a grain of salt. It is, nevertheless, a very fine speaker. Unfortunately I only heard it at very low levels.

cnh

As far as smaller drivers, even Polk's SDAs use the smaller woofers and depend on a large PR for BASS. So can't we say that even Polk's large speakers use the smaller mid-drivers and that's not because of aesthetics?

cnh

TECHNOKID

newrival wrote: »

Are you familiar with the Linkwitz Labs Orion? A fine example of what you describe. Some have argued that it's one of the best sounding speakers ever designed. Although take that with a grain of salt. It is, nevertheless, a very fine speaker. Unfortunately I only heard it at very low levels.

I've read about them (I think they were discussed on here too in the past?). Kits are also available for DIYers I believe. What is the frequency spectrum on them? It seems their weakness is actually in the bass range but apparently very good for music. As I can recall IMO they look huglt as hell (however my comment is definitely subjective... or isn't it?).

TECHNOKID

OK, here they are;

ORION System Specifications
Full-range open-baffle loudspeaker
Outside dimensions: Height 46" x Width 13" x Depth 16" max
Weight 60 lb each
3-way active Crossover/Equalizer
LR4 crossover filters (24 dB/oct acoustic)
Tweeter - Seas T25CF002 - 1.4 kHz to 20 kHz
Midrange - Seas W22EX001 - 120 Hz to 1.4 kHz
Woofer - 2 x Peerless 10" XLS, 830452 - 20 Hz to 120 Hz
8 x 60 W power amplifiers - AT6012, weight 73 lbs, 2 kVA transformer
Room size: >180 ft2 area, >8 ft ceiling
Speaker placement measured from tweeter:
>4 ft from wall behind it, >2 ft from side walls,
speaker separation >8 ft
Listening distance 8 ft to 18 ft
Room acoustics: Fairly live with RT60 of 400 ms to 700 ms

Goes down to 20hz, definitely very/more than decent for music.

Two open-baffle loudspeaker cabinets of 46"H x 13"W x 16"D,
each with two 10" woofers, one 8" midrange and one 1" tweeter,
and with a Speakon connector. Revision 0.1 is included. Each speaker weighs 60 lb

2 10" woofers would definitely do the trick for decent music bass while 8" should suffice for mid bass... All they need is a decent cabinet.

http://www.linkwitzlab.com/orion_us_specs.htm

Fongolio

Face wrote: »

Not true. A large driver that is well designed will play lower with less distortion than a smaller driver of the same build quality.

I understand your point but it's not quite so black and white. Yes, a larger driver can give lower response but I don't necessarily agree on the distortion end. Extreme slow motion video has shown that as larger drivers reach break up they do so much more dramatically than do smaller drivers. AND, I should have said smaller driver array. One of the big draws of the whole SDA line (SDA effect aside right now) is how the extremely effective and accurate array (combined with passive radiator) produces very good bass with little distortion and excellent accuracy. Polk Audio understood this a long time ago and their products have reflected it since. So did Bose and several more modern speaker companies but we won't go there right now.

PrazVT

My Dad's classic JBL L166s have 12in woofers, but I don't think he's ever had enough power going to them to really test 'em. Maybe the next time he's out of the country...

Amongst the misconceptions I had before coming here, I used to think the bigger the driver the better. But my RTi A7s do a damn good job w/ bass. My sub is only used for TV

But all the reasons I see sound logical. I can see having more of 'em (ie. RTi A9) helping.

And yes, smaller drivers are cuter lol

tonyb

danger boy wrote: »

small drivers respond faster than large ones. i don't know of any speaker maker today that uses the huge 12 or 15" drivers of the 70's.

Alot of upper end speaker makers do. Look at Legacy and PBN Montana just to name a few. Not the same material as the 70's grant you, but 12 and 15 inch drivers are still out there by many speaker makers.

organ

Very interesting thread.
It also depends on the application of the driver. A mid-range driver in a 3-way speaker can be small because it's only doing a smaller portion of the mid band compared to a larger driver in a 2-way set up.

Also, there will be a lot more restriction in dynamics when comparing, say, a 4.5" driver and a 6.5" one in a two way design from the same manufacturer.

Take a look at Fostex drivers. Super efficient and made to run in single driver designs. They're lightning fast. One of the "fastest" sounding speaker I've heard is a single driver using an 8" Fostex. Their drivers are so light that even the 8" model probably weigh less than most 4" drivers (not counting the basket and magnet).