# Is a sub required?



## azgreenb (Nov 19, 2007)

Newbie here, please forgive my ignorance. I am not new to the idea of a home theater, but I am unsure what a sub would for my listening experience. Here's my setup: HK AVR-645, CV VS-120's, Yamaha in-ceiling mounted surrounds and a Sony Center channel. It is really a hodge-podge of a system, but I like how it sounds. 
I read quite a few of the post regarding the SVS subs and honestly I drool alot with some of the reviews, my question is how will a sub make my experience any better? I feel that I get a pretty good response from the CV's and movies like Lord of the Rings/Transformers can create quite a rumble. How would a sub change that? Thanks.


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## FlashJim (May 6, 2006)

Go to any home theater store (maybe even Best Buy's Magnolia Room) and listen to one of their setups. A sub really sucks you into the movie, in my opinion. You feel it as well as hear it.


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## Sonnie (Apr 11, 2006)

Where do you live? It would be nice if you could find a fellow enthusiast who owned a nice sub and have a listen to something like Transformers on his/her system.

I'm pretty sure you are going to realize you are missing the lowest octaves with those CV's, which are most likely only rated down to about 30Hz or so.


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## tonyvdb (Sep 5, 2007)

azgreenb said:


> my question is how will a sub make my experience any better? I feel that I get a pretty good response from the CV's and movies like Lord of the Rings/Transformers can create quite a rumble. How would a sub change that? Thanks.


Hi and Welcome to the Shack.

A sub is recommended for any system no matter what speakers you are using. Subs are designed to reproduce frequencies down in to the single digits some as low as 5hz. I would say that about 90% of speakers built out there for the general consumer do not go much below 30hz and bookshelves not much below 60Hz so a sub fills out the missing dynamics of the movie soundtrack. 
There was a time where VHS movies were the only media available to us and the audio recorded on them was not digital so 20hz was about as far down as was necessary but now with audio being digital subsonic frequencies do exist and play a large part of the movie listening experience.
Frequencies in the 40 to 15Hz range are the ones that really shake your chest and most speakers don't have the high output level in that range to accomplish that.
Another plus to having a sub is that it can then releave the load on the receivers amps as you wont need to drive your main speakers as hard to get the same effect.


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## jerome (Apr 24, 2007)

Ever been to a movie theater to watch an action movie ? Well, subwoofers are the speakers that make your heart shake and give you the complete movie _experience_.
Once your try at home, you will never want to watch a movie without a sub :bigsmile:.


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## Sonnie (Apr 11, 2006)

And if you setup your home theater right... you won't want to go back to the public theater. :whistling:


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## JCD (Apr 20, 2006)

Reasons why a sub is a good idea..

Even if a speaker is rated to go down fairly low (e.g., 60hz or lower), they'll do a better job in the upper octaves if they don't have to because the sub is taking the burden of reproducing the lower octaves.

You're just gonna get more oomph down low -- they're designed to go lower and they have their own power source (amp) usually.

For music, there is USUALLY not too much in the lower octaves.. but movies, especially action movies, there is more and more coming in the lower reaches that you're just not going to appreciate unless you have a sub of some sort.

JCD


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## alexadams77 (Aug 4, 2007)

I went years without having a sub in my HT, as I thought my mains were giving me the Bass and LFE that I was looking for. I had a set of Bose 701s w/2 x 8" subs in each speaker. They would shake my house and rattle things from time to time when pushed to reference levels. When I did hit reference levels though, the rest of the speaker started to sound very bad. The highs were tinny and the mids were low and the bass would get a bit distorted.

A subwoofer will take a lot of strain out of your mains and sound incredible doing it as well. Instead of hearing explosions, I now feel them with authority. The subwoofer really opened up my system and I wish that I would've bought one years ago.


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## azgreenb (Nov 19, 2007)

Thanks for the replies! 
I do recall the AC-10 gunship in Transformers having a deeper sound at the local theater when it was firing upon the scorpion decepticon. Kind of like it was punching you in the chest. I have also watched the pod race scene in Episode I and from what others have said, I must be missing quite a bit of low end, because I don't feel much. 
I think I will take the advice and head to a HT store and demo a few setups, with and without subs.


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## MatrixDweller (Jul 24, 2007)

Correct me if I'm wrong but isn't the LFE track a discrete channel? 

Given that point, do the receivers take that discrete track and combine it into the fronts if a sub is not present? 

If not then you'd be missing the LFE the director had put into the original.

Even if it did, fronts normally drop off in the mid 30Hz range like others have stated. 

Everyone else is right about the sub taking some of the burden off the receiver. Low bass takes a lot of energy and can strain even the best AVRs. Your AVR-645 is rated at 75W all channels driven or 90W in 2-channel. If you were to listen at modestly loud levels a lot of that power would be going into driving the woofers. Pass the bass under 80Hz to the sub and that means less power required and lower theoretical distortion.

A byproduct of power output in an amplifier is distortion (less amplification = less distortion). That's why good receivers will state their power ratings at a certain level with a distortion of .07% or less. The lower quality amps might state 140W/channel to wow the uneducated but it's at 10% THD, which is super high distortion (it might other wise rate at 20W @ .05% THD which doesn't sound very appealing).


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## azgreenb (Nov 19, 2007)

MatrixDweller: Just checked the specs again on my receiver. It claims 75 watts @ <0.07% THD. I believe this means it should be one of the better receivers.
I will check the LFE settings. When I initially set up the AVR, it detected whether or not a sub is present and sets everything accordingly. Don't remember those settings.


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## azgreenb (Nov 19, 2007)

A bit of an update: I went to Circuit City yesterday and demo'd the velodyne subs. Although the salesman was extremely helpful, he didn't seem to know how to setup there demo's properly. The powered DPS 10" was not able to add the depth that I was looking for, without sounding distorted. When not overdriven it did sound nice.
We then watched WOTW at home. After reading some of the replies here, I noticed (and so did my wife) that it did not sound very good. Like I said Transformers sound great, but from what people have written here, there should have be some noticable bass when the tripods emerges. My setup was definately lacking on this movie. Thanks again for the help.


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## MatrixDweller (Jul 24, 2007)

My old Cerwin Vega front speakers were rated at around 32Hz on the low end. I used them for about 6 months before I got a 10" CV sub. It wasn't a great sub, but I could definitely hear a difference. This was almost 10 years ago but I remember the scene from the Matrix where Neo is firing the mini gun from the helicopter was much much deeper. Almost like getting slapped in the chest.

I was messing around with my new stuff a while back and turned the power switch on the sub off. The next time I started to watch a movie I forgot to turn it back on and my first reaction was, "What the **** is wrong with my system?". My bookshelves are only rated at 46Hz and they still sounded great but there was something big missing from the sound.

In a nutshell a subwoofer makes explosions, gunfire, crashing, thunder, rumbling (eg: earthquakes), spaceship rockets, jet engines, etc sound much deeper, more realistic and possibly louder so long as the soundtrack accommodates the lower frequencies. 

Next time you go audition a subwoofer, it's best that you bing your own movie (or have them put in one you know) so that you can get a more accurate feel of what's going on. LOTR The Fellowship of the Rings, has some good scenes. I like the Bridge of Kazaa Doom when the ceiling starts falling apart and the steps Frodo and Aragon are on falls. The Balrog and Gandalf confrontation shortly after is great as well. A good subwoofer will shake your whole house (and possibly your neighbor's too) during that scene.


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## azgreenb (Nov 19, 2007)

Visited another HT store. This one actually "designs" HT's. I asked to demo their subs. Klipsch is their brand of choice. First impression, was this is not any better than my setup. The first sub was a RW-10d. It seemed over driven. I want to hear/feel the bass but I don't want to hear the sub. (Does that make sense?) Plus there setup seemed to rattle. I then asked to hear their best sub. He showed me a scene from King Kong, where Kong breaks out of the theater. Other than being truly impressed by the 7.1 surround, once again the sub (this time a RT-10d) really didn't "do it" for me. Am I expecting too much?
I was expecting that if I demo'd a "top of the line" sub, it would be night and day from my own. I wasn't getting that impression.
Got to get back to work....


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## tonyvdb (Sep 5, 2007)

azgreenb said:


> The first sub was a RW-10d. It seemed over driven. I want to hear/feel the bass but I don't want to hear the sub. (Does that make sense?) Plus there setup seemed to rattle.......(this time a RT-10d) really didn't "do it" for me. Am I expecting too much?
> I was expecting that if I demo'd a "top of the line" sub, it would be night and day from my own. I wasn't getting that impression.
> Got to get back to work....


Although I would say that either sub you heard are not bad by any means they are not the best out there, SVS makes far better ones for the money.
The statement that you want to feel not hear your sub is more an issue of the frequency response of the sub. Almost all frequencies below 20hz are "felt" not so much heard other than the reaction of the "subsonic" frequencies on walls and other objects in the room. If the crossover is set to high allowing frequencies above 60hz to go to the sub you will defiantly hear it more than feel it.
Your speakers will not go into the subsonic zone so you are missing that area of the frequency range.
The next time your in a audio store ask them what the frequency response is of the sub you are listening to. If it wont go below about 25Hz at a decent volume (at least 90db) then don't even bother. Because then yes you wont hear much difference between what your mains do and having a sub.


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## MatrixDweller (Jul 24, 2007)

The RW-10d is Klipsch's smallest sub in the reference line-up. The RT10d is a pretty good sub though. It plays low and accurate (low 20's). They probably had it mixed in with RF63 fronts so you would not have heard a huge difference since those also go down pretty low for floorstanders (~30Hz). 

What were the other factors in the setups you auditioned (ie: speakers, amps, AVRs, room size, etc)?

It is all about personal preference though. You might find it more appealing (for you) to put the money you would spend on a sub towards better front speakers, or a better receiver.


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## bobgpsr (Apr 20, 2006)

azgreenb said:


> once again the sub (this time a RT-10d) really didn't "do it" for me. Am I expecting too much?
> I was expecting that if I demo'd a "top of the line" sub, it would be night and day from my own. I wasn't getting that impression.


A 10" driver with two 10" passive radiators with a spec of -3 dB down @ 22 Hz in "1/8 space". Just what is 1/8 space anyway? A room? :huh:

Best would be to visit someone's home setup with a better (bigger drivers) subwoofer(s) that is properly integrated. SVS used to have such a user experience program. I once had a guy come visit and go away afterwards fully aware of what a sub "*feels*" like when the room's floor vibrates. :yes: That was with a PC-Ultra in a room open on one side to the rest of the house.


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## azgreenb (Nov 19, 2007)

Not sure what the entire setup was? I was mainly there to hear a sub. The entire 7.1 speaker package was something around ~7k. Not sure why the salesman told me that? Anyway like I said it was a nice setup. Just wasn't what I have been expecting.
I think my receiver is as good as I will be getting for the next few years. (Just purchased it 3 months ago) I think it is pretty good overall. I know my CV's are not optimal but with my HT I plan on taking the approach of filling in what I don't have. A sub is something I am missing, but I am trying to understand its effects and get a bit more knowledge. There are other peices that I will need but I am focusing on the sub for now.


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## thxgoon (Feb 23, 2007)

Ya a 10" sub is pretty small for getting down deep. I'm not sure I'd buy the 22hz at -3 spec. If I were you I would listen to the biggest woofer you can find to give you an idea of what a sub is for and then look at used woofers or look into building something of your own to keep costs down.

Another reason for a separate subwoofer is that you can place it optimally in the room, ie it's not locked to the front L/R positions so you can position it for the best performance.


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## ISLAND1000 (May 2, 2007)

Yes, a sub IS required. All of us are not fooling ourselves into thinking a sub is just a cool thing to have. If you've noticed, many DIYers go to great lengths to reproduce the lowest octaves of music and in addition be able to rumble the sounds from movies down to the 10 cycles per section region.


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## OvalNut (Jul 18, 2006)

> ... I have also watched the pod race scene in Episode I and from what others have said, I must be missing quite a bit of low end, because I don't feel much.





> ... but from what people have written here, there should have be some noticable bass when the tripods emerges.


Yea, you definitely need a sub. :rubeyes: 


Tim
:drive:


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## azgreenb (Nov 19, 2007)

ISLAND1000 said:


> All of us are not fooling ourselves into thinking a sub is just a cool thing to have.


As I posted earlier, I am a newb. None of my friends have a 5.1/7.1 setup. So I am just trying to get an idea on what a sub is gonna do. I don't think anyone is delusional. I wouldn't have purchased a new receiver if I thought otherwise

I do believe that from what I have heard the 10" subs are not gonna give me what I am looking for. I will try to get out a demo a nice 12" sometime.

Another reason for this post is to have some facts to show the "better half" when I potentially spring the idea of a $1300 sub on her. Right now she has heard what I have heard and there isn't a huge difference from my current setup, although I know I am missing the really low stuff.


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## ISLAND1000 (May 2, 2007)

azgreenb said:


> Another reason for this post is to have some facts to show the "better half" when I potentially spring the idea of a $1300 sub on her.


 Never mind showing her the facts . . . . that never works with a woman. Challenge her to make the 16 inch cutout for the 18" subwoofer you're gonna (build). Tell her all the other DIY wives do it allll the time. Then buy her a real nice shiny coping saw and a sheet of 3/4 inch MDF and tell her to get busy!
I oughta know about wives, I've had three of them already and working on a forth . . . . :cunning:


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## salvasol (Oct 31, 2006)

azgreenb said:


> .... None of my friends have a 5.1/7.1 setup. So I am just trying to get an idea on what a sub is gonna do. ...


onder: ... What about a member from the forum near you??? or A friend of your friends??? :huh::huh:

I don't have the best set up of the world, but I enjoy the movies (I have two 10" subs, one in the front and one in the back) ... if you were close to me I invited you to come and see the set up, but were to far away...


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## SQBubble (Nov 12, 2007)

Sonnie said:


> And if you setup your home theater right... you won't want to go back to the public theater. :whistling:


haha, thats so true.

I actually watch transformer not too long ago with the subs on, and it was amazing, theres a part that goes in slow motion near the end of the movie, where they fighting in the city, man o man the deep low bass were simply incredible, it really makes you feel your in the movie.

Although good speakers are very important, good sub-bass gives the movie a whole new experience


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