Does a sub HAVE to have a 20hz ext to be a SUB?

yepimonfire

5 people from various AV forums have said polk makes crap subs and that they are nothing more then mid-bass speakers. firstly, someone is obviously forgetting mid-bass octaves begin past 100hz, secondly, what's wrong with polks subs? people keep telling me that a subwoofer is only a subwoofer if it can go all the way down to 20hz. well i went on some audio dealer sites and found out not even half of them can do that, most stop at around 30hz, the super expensive ones make it down to about 25hz. only about 5 actually made it down to 23hz, none went all the way down to 20.

so are polks subs really that bad and why are they being bashed by everyone?

cnh

Polk's new line of DSW and MicroPro subs are 'good' subs and lots of those people have NEVER heard one of those. They are basing their opinions on previous lines which are, let's say, not quite up to the more RECENT standards.

A lot of R&D went into the new Polk subs. And I would argue that it 'worked'. These new subs, especially the Micropro lines are some of the most musical subs you will find in their price range. And the DSWs can pound with some of the best in their price class. Such statements are woefully ignorant.

Of course Polk does NOT make the world's best subs. But they are pretty darned good..and a LOT better than they used to be.

And you are right. It is almost physically impossible to get a sub to play LOUD below 20hz unless you have some IMPRESSIVE SIZE and wattage and cabinet volume. Few subs ACTUALLY play much below 25hz, i.e., can hit 25hz at 100 db or louder. A spec woefully missing in many manufacturers brochures!

Sure they can play 18hz but at WHAT VOLUME?

Now if most of the people you are referring to are running something like THOR's HAMMER....the size of a small refrigerator and about the same weight. Then sure...Polk's won't compete with that. But that's thousands and thousands and thousands of dollars there!!

cnh

danger boy

everyone here and on every other forum has their fan boys... we are polk fan boys.. there are all the hundreds of other fan boys of all the many different kinds of subs out there.

TNRabbit

.....

mystik610

yepimonfire wrote: »

5 people from various AV forums have said polk makes crap subs and that they are nothing more then mid-bass speakers. firstly, someone is obviously forgetting mid-bass octaves begin past 100hz, secondly, what's wrong with polks subs? people keep telling me that a subwoofer is only a subwoofer if it can go all the way down to 20hz. well i went on some audio dealer sites and found out not even half of them can do that, most stop at around 30hz, the super expensive ones make it down to about 25hz. only about 5 actually made it down to 23hz, none went all the way down to 20.

so are polks subs really that bad and why are they being bashed by everyone?

A subwoofer, by technical definition, is a speaker designed to play subsonic/sub-bass low frequency material that extends below the limits of human hearing (30hz and below). Very few subwoofers sold in traditional retail markets meet that criteria these days....because the subwoofers that do meet that criteria would probably be difficult to market on a mass-market scale.

This has been fine for a long while now, as realistically, there hasn't been much material that plays down in the subsonic frequencies. With the coming of Blu-ray and lossless audio tracks, however, we're pretty regularly seeing a lot of material dipping down into the subsonic frequencies that a lot of retail subs flat-out aren't designed to handle.

It has less to do with price IMO, than it does with aesthetics. There are plenty of 'true subwoofers' available that sell considerably less than the Polk DSW series subs, the velodynes, the martin logan grotto subs etc etc, but most of these subs are comparably huge in size. Most of them weigh around 100lbs, and are about the size of an end-table. There are smaller, sealed, 'true subwoofer' offerings out there that are more WAF friendly, but those tend to cost quite a bit more than anything you would find in a retail store.

As such, 'true subwoofers' are appealing to a very small niche market, which makes them difficult for retail brands like Polk, Velodyne, Martin Logan (yes they're a retail brand now), to market using a traditional brick and mortar marketing/distribution system.....it also presents a great opportunity for companies like SVS, HSU, EPIK, E/D etc to leverage the efficiencies of internet direct selling to compete in the niche market that the retail brands are neglecting.

Honestly, it doesn't take a whole lot of engineering ingenuity to build a high quality sub-woofer and Polk has both the experience and the resources to build a very good 'true subwoofer'. But that isn't the market that Polk plays in. That being said, I've played with the DSW subs, and Polk has done some great things with these subs given their size and feature-sets.....but from a price/performance standpoint (and that's what's more important to audio enthusisats) the Polk subs really aren't competitive. They might be great for most consumers, but don't expect them to get a lot of respect on audio enthusiast forums.

VR3

There are tons of subs that can play down to 20hz and below at a reasonable price point.

SVS, HSU, Epik, VMPS, ACI Audio

cnh

You're right. But how LOUD can those subs play a 20hz or an 18hz tone? 85db, 95db, 105db, higher. Because a lot of specs NEVER list the output at the limit of human hearing...which is really 20hz for most of us.

Many manufacturers will tell you their output at 50hz or 30hz, for example?

cnh

VR3

I owned a PCi 25-31 (600 dollars)

It outputted in my room 16hz at 105db (10x10x8)

Most of those subs are -3db drop at 20hz from the above manufactures and can usually play at 95db or higher at 20hz.

My old VMPS - 1200 with an amp - could output 20hz at 114db

tonyb

Polk makes good subs for the right application. Will they compete with SVS and their likes ? No,but thats not the intention. Room size plays a big role in loading it up with bass, Polk subs are ment for small to midsize rooms imho. Sure you could throw 2 or more 505's or micropro's into each corner, but then what are you spending? Most people don't have a 30 by 30 foot room dedicated to HT and the ones with smaller rooms,don't want a sub the size of a compact car sitting in there either. Polk subs fill the gap. Not everyone wants the nails in the walls to pop out from explosions in movie soundtracks. There are alot of variables to getting a good low end in any given room, but when you compare apples to apples,Polk subs can stand on their own.

mystik610

cnh wrote: »

You're right. But how LOUD can those subs play a 20hz or an 18hz tone? 85db, 95db, 105db, higher. Because a lot of specs NEVER list the output at the limit of human hearing...which is really 20hz for most of us.

Many manufacturers will tell you their output at 50hz or 30hz, for example?

cnh

A lot of these have been independently tested if you hunt online (craigssub for instance)...many play over 100db at 18hz.

kuntasensei

cnh wrote: »

You're right. But how LOUD can those subs play a 20hz or an 18hz tone? 85db, 95db, 105db, higher. Because a lot of specs NEVER list the output at the limit of human hearing...which is really 20hz for most of us.

Many manufacturers will tell you their output at 50hz or 30hz, for example?

cnh

My SVS 20-39CS+, which is over 4 years old, is flat to 18Hz (-3dB) in my room with the native 20Hz tuning, no ports plugged. I use a Buttkicker LFE to subtly enhance anything below that, with a subsonic filter on the SVS to prevent the driver from bottoming (which it never has). As to how loud they can play a 20Hz tone... I can't say specifically for a 20Hz tone because I would never throw a sine wave near that range at any subwoofer with significant level for fear of frying the voice coil. But I can say that The Haunting DTS registered over 115dB on my SPL meter during the "Coming Mother" scene with my original db12.1 driver, and it's one of the only times I've seen the clip light flicker on the Samson 1000 that drives my SVS. That scene has bass down near 8Hz... and you can feel it, even without the Buttkicker. It made my storm windows flex. Since then, I've upgraded my sub to the dB12.3 driver, which supposedly has better extension. I fear for the safety of my windows if I ever pushed it that hard.

I used to run a Polk PSW-350 when I first got into home theater and I was fairly happy with it 'cause I didn't know any better. It sounded fantastic at the time... and then I got the SVS, and it paled by comparison. Polk makes great consumer-grade subs, and that's their milieu. But realistically, for modern digital soundtracks, if it doesn't extend down to 20Hz with significant energy, it's not suitable for home theater. Polk has come a long way with their subs since I had my PSW-350, and I hear their newer offerings are far more solid... but not enough for enthusiasts to even consider them suitable in most cases.

All that said, the co-worker I sold my PSW-350 to is perfectly happy with it and would never consider needing more sub than that. Ignorance is bliss.

thsmith

Although I do not own a PA sub the new subs look pretty good.

I find most people do not have their subs setup right and rely on brute power where if they set up a decent sub correctely matched for their room size they would be better off.

I do have a brute SVS sub but it is setup correctly and and does not over power my system but blends nicely. My room is large with a large opening into another room and PB13 was the only sub I tried that could give the experience I was looking for otherwise I would have settled a smaller sub.

Conradicles

Vr3MxStyler2k3 wrote: »

My old VMPS - 1200 with an amp - could output 20hz at 114db

That is what I'm talkin' about. 114db at 20Hz...:cool::cool::cool:

And musical too!:eek:

dorokusai

Polk finally started to make a good subwoofer, beginning with the new DSW MicroPro and DSW Pro series lineup. Before then the subwoofers were marginal performers. That being said, hundreds of thousands of them were sold to people who don't need a subwoofer to hit 114db @ 20hz.

Mark Susskind is the reason they finally started to pay attention to the subwoofer as a real tool and performer. He is the mind behind the SR car audio series....along with others of course.

I read that all the time, Polk subs suck....and they used to....not anymore. Most of the experience that those folks have is based on something from 10 years ago....or they are putting a PSW10 against a SVS PB12 Ultra/2. You can't make everyone happy and the bigger picture is that it's a couple comments out of a million others.

yepimonfire

musically speaking, a sub does not need to go past about 30hz because there is no real musical data below 30hz, home theater speaking, alot of LFE tracks have harmonics down to 4hz, this is what makes that rumbling sound. also, i am young enough to clearly and easily hear 10hz just as good as 40hz. getting a sub to go down to 10hz would take an extremely large driver that is atleast 15 inches if not more with a very large cabinet volume and a very large port. and as a correction to mystik, a sub was not created to play subsonic frequencies. the subwoofer was originally designed when customers buying electrostatic speakers complained they could not reproduce bass very well.

mystik610

yepimonfire wrote: »

musically speaking, a sub does not need to go past about 30hz because there is no real musical data below 30hz, home theater speaking, alot of LFE tracks have harmonics down to 4hz, this is what makes that rumbling sound. also, i am young enough to clearly and easily hear 10hz just as good as 40hz. getting a sub to go down to 10hz would take an extremely large driver that is atleast 15 inches if not more with a very large cabinet volume and a very large port. and as a correction to mystik, a sub was not created to play subsonic frequencies. the subwoofer was originally designed when customers buying electrostatic speakers complained they could not reproduce bass very well.

The first separate powered woofers were used in conjunction with electrostatic speakers to reproduce the bass frequencies that electrostatic speakers have trouble conveying. These were used in lieu of the woofers you would see in a traditional full-range speaker. These were not, but definition, sub-woofers. Sub-woofers, by definition, are speakers designed to play frequencies below that of what a woofer would play. On the other end of the frequency spectrum, super-tweeters are designed to play frequencies above that of what a traditional tweeter would play.

Musically speaking you're right, there is no musical data below 30hz and a subwoofer is not only unnecessary, it also won't integrate as seamlessly as a full-range tower equipped with tweeters, mids, and woofers would. As home theater and hi/fi systems have become more commercialized, however, full-range towers have become a rarity, as speakers are designed these days to accomodate consumer aesthetic appetites for compact speakers. Most speakers today (even tower speakers) do away with woofers, and much like the electrostatic speakers in the 60's, aren't able to properly convey bass frequencies.

Most of the subwoofers you see in retail stores are simply powered woofers designed to play the bass frequencies that modern day speakers (which lack integrated woofers) are lacking.

A True Subwoofer, on the other hand, is designed to play frequencies below that of a woofer (30hz and below). Modern day home theater sound-tracks are growing increasingly more active in the sub-bass frequencies, and frankly, a lot of the speakers being passed off as sub-woofers these aren't equipped to handle this material.

True Subwoofers don't necessarily don't need to be huge, though most of them are. There are quite a few compact, sealed sub-woofers out there (HSU ULS-15 and Sunfire True Subs come to mind).

BeefJerky

mystik610 wrote: »

Musically speaking you're right, there is no musical data below 30hz and a subwoofer is not only unnecessary

That's not completely true, as it depends on the type of music. For instance, music that incorporates a pipe organ (i.e. Nelly Furtado - Childhood Dreams) can go as low as 16hz. I know that my prior subs could not hit notes that low, however my current 15" Paradigm certainly can (albeit at lower decibels). After playing that song with the new sub, I realized just how much I was missing.

yepimonfire

actually, look at a Plot Spectrum of your favorite music, and it has harmonics all the way down to 4hz. Most of my music has harmonics down to 15hz and down to 4hz. many subs have no issue dealing with those low harmonics because they are only needed to form the shape of the waveform and they are not at a loud level. just like if you were to go on a tone generator and generate a 50hz tone, then add a 5hz tone at -12dB, totally different sound. most of the time, musical base frequencies for notes do not go lower then 28hz (the lowest C) also not to mention some harmonics are sawtooth and square (more sawtooth then square) shaped and are much easier to generate then a sine wave. if you were to remove all frequencies above 15 hz on a bass guitar playing open E (43hz base frequency) you would see a rounded off version of a saw tooth shaped harmonic.

halo71

yepimonfire wrote: »

also, i am young enough to clearly and easily hear 10hz just as good as 40hz.

So do you howl at the moon as well? Can you hear elephants communicating with each other at the zoo? lol Sorry.

If you can hear in the infrasound range of 10hz you are a rarity I would think!

yepimonfire

then i am a rarity, i can hear 10hz, not as easily as 20 and i certainly have to crank the volume about twice as loud as the threshold for 20 but its there, i can also faintly hear 25khz i dont know if i can hear higher because with a 48khz sampling sound card i can't build tones higher then 25khz. so maybe, maybe not. i doubt it though because its very hard to hear 25khz.

and whos to say i dont howl at the moon? you might actually be suprised that you can hear it as well. if you have audacity or some program that will create sine waves put in a 15hz sine and use some good full size headphones and crank it up.

ViperZ

yepimonfire wrote: »

actually, look at a Plot Spectrum of your favorite music, and it has harmonics all the way down to 4hz. Most of my music has harmonics down to 15hz and down to 4hz. many subs have no issue dealing with those low harmonics because they are only needed to form the shape of the waveform and they are not at a loud level. just like if you were to go on a tone generator and generate a 50hz tone, then add a 5hz tone at -12dB, totally different sound. most of the time, musical base frequencies for notes do not go lower then 28hz (the lowest C) also not to mention some harmonics are sawtooth and square (more sawtooth then square) shaped and are much easier to generate then a sine wave. if you were to remove all frequencies above 15 hz on a bass guitar playing open E (43hz base frequency) you would see a rounded off version of a saw tooth shaped harmonic.

Did you check with the doctor, mr. impossible? Human ear cannot hear below 20 Hz. There is a difference between perceiving / feeling a sound and actually hearing it.

ViperZ

yepimonfire wrote: »

. if you have audacity or some program that will create sine waves put in a 15hz sine and use some good full size headphones and crank it up.

Oh yeah, please show me the headphones that output down to 15 Hz (hopefully within -3dB). (edit: I did find Sennheiser on-ear headphones on amazon, which state that they go down to 10 Hz, but did not say the gain at that frequency...).

thsmith

From wikipedia "Specifically in humans, we have a maximum aural range of 12 Hz under ideal laboratory conditions[1] to 20,000 Hz in some individuals, but the range shrinks during our lifetime, usually beginning at around the age of 8 with the higher frequencies fading."

kuntasensei

ViperZ wrote: »

Did you check with the doctor, mr. impossible? Human ear cannot hear below 20 Hz. There is a difference between perceiving / feeling a sound and actually hearing it.

Okay... 20Hz isn't a hard scientific "you can't hear below that" point. It's a guideline based on a statistical average. The limits of hearing are different for each individual. It's kinda' like how people say you can't localize sound lower than 80Hz. They actually mean MOST PEOPLE can't, based on a statistical average. A lot of people can actually localize sub-80Hz sound; just not MOST people. Same goes for sound below 20Hz.

ViperZ

thsmith wrote: »

From wikipedia "Specifically in humans, we have a maximum aural range of 12 Hz under ideal laboratory conditions[1] to 20,000 Hz in some individuals, but the range shrinks during our lifetime, usually beginning at around the age of 8 with the higher frequencies fading."

Have you seen those 'ideal laboratory conditions'? I have (doing testing on antennas in close to ideal anechoic chambers). I'd be seriously amazed to see the person who truly can hear that low, even in those rooms.

kuntasensei, I just seriously doubt that the person can hear such low notes in the sound output, especially using headphones.
I guess, of course, as he said, if you output just 15 Hz and crank it as high as you can, you will hear something... Oh well.

thsmith

ViperZ wrote: »

Have you seen those 'ideal laboratory conditions'? I have (doing testing on antennas in close to ideal anechoic chambers). I'd be seriously amazed to see the person who truly can hear that low, even in those rooms.

Agree and yes I have. I think what people hear below 20 hz are vribrations from the sub or other things in the room.

I have test tones CD for calibrating subs and find this to be the case, YMMV.

ViperZ

thsmith wrote: »

Agree and yes I have. I think what people hear below 20 hz are vribrations from the sub or other things in the room.

I have test tones CD for calibrating subs and find this to be the case, YMMV.

Sorry, but again to clarify - do you *hear* or do you *feel* those vibrations?

thsmith

feel but hear stuff in the room vibrating

kuntasensei

ViperZ wrote: »

Sorry, but again to clarify - do you *hear* or do you *feel* those vibrations?

Y'know, this is really a silly argument... because outside of a strictly controlled environment, you can't be sure if you're hearing the 20Hz tone itself or feeling it in conjunction with hearing the harmonics in the audible range that lend it its tone. I can band-limit the hell out of a tone and hear 20Hz in my room at a very low level... but does it matter for actual content? Nope. Can I hear a difference with pipe organ music between my current sub-20Hz sub and my old "dies around 35Hz" one? ABSOLUTELY. Harmonics matter.

Regardless, you can't make a blanket statement that no one can hear below 20Hz. There are certainly people who can... just as much as there are people who can't hear below 30Hz too. We all have different sensitivities and tolerances. But despite all of that nonsense, the original point remains: If your subwoofer doesn't play down to at least 20Hz, you can't properly reproduce modern digital soundtracks in your home.

yepimonfire

ViperZ wrote: »

Have you seen those 'ideal laboratory conditions'? I have (doing testing on antennas in close to ideal anechoic chambers). I'd be seriously amazed to see the person who truly can hear that low, even in those rooms.

kuntasensei, I just seriously doubt that the person can hear such low notes in the sound output, especially using headphones.
I guess, of course, as he said, if you output just 15 Hz and crank it as high as you can, you will hear something... Oh well.

most full size full range headphones will put out sound that low, no certainly not -3 dB but they will, i don't need to argue my point if i can hear them i can hear them. and no not crank it as high as you can, not unless you want to go deaf.

ShinAce

kuntasensei wrote: »

But despite all of that nonsense, the original point remains: If your subwoofer doesn't play down to at least 20Hz, you can't properly reproduce modern digital soundtracks in your home.

CDs are flat to 0Hz(DC)! Unless your sub plays flat to 0Hz and you live in an airtight cabinet, you aren't getting the full CD experience!

There are pieces of classical music with cannon shots producing sound under 10 Hz. I guess I should upgrade my sub, again.