Do I really "need" a subwoofer?

[mjzraz]

I think the answer is yes, but I am getting conflicting information...

I have a 16' x 22' room with two 5' openings to other rooms. I am using a Pioneer Elite vsx-43-tx 100Wx7 receiver with B&W 604s3 fronts and 601s3 rears and a KEF Q9c CC I bought from my neighbor.
At first, I had just the receiver and the Front speakers and was listening to everything in Stereo and I though that was great since I was new to Home Theater/Audio. Then I got the rears and the CC and switched to listening in Surround 5.1 and The sound was phenomenal compared to just the two speakers, especially the bass in movies, which leads me to my current pondering of how much bass my speakers already put out and how much better, if at all it will sound with a sub.
The 604's have two 7" woofers each. Here are the specs from the manufacturer page:
Freq. Response 39Hz - 22kHz ± 3dB on reference axis
Freq. Range -6dB at 30Hz and 42kHz
Sensitivity 90dB spl (2.83V 1m)
Nominal Impedance 8 ohms (minimum 3 ohms)

The VTF-3 MKII is the sub I am interested in - How do the above specs compare with this sub. Is that a pretty low frequency for front speakers?

When I demo the system to friends, etc.. I like to use Chapter 30 from Lord of the rings: Fellowship of the Ring. This sounds great, but I have to wonder what I am missing and feeling from 20/25Hz to 39Hz in the case of the VTF-3 MKII. I also wonder if there will be much of an increase in perceived loudness. I am hoping a sub will make a big difference, I just don't want to be disappointed and find out that my four 7" woofers were putting out the same loudness and low frequencies. One of the things I read somewhere was that DVD's often have a lot more upper frequency bass because most HT systems can't reproduce the lowest sounds. Not sure how true this is, but that has me thinking it's the reason why my system sounds good without a sub even.

I guess I am maybe looking for testimonials from people that maybe added a sub for the first time after being without one for so long.

[BeFree]

You're missing a lot. There's plenty of deep bass that you're not hearing because your speakers don't have the capacity to produce them. That's why people buy subs.

Just order the VTF-3 MKII. You'll be amazed at the sound.

[smartbot]

Need is a very subjective word. But in my oppinion, yes you 'need' one.

[Dudley]

For a long time I was very impressed with my main speakers and did not think I needed a sub. They had enough punch to make it seem like you were kicked in the gut during certain scenes (gladiator - catapults). They are bp-8's and are claimed to do 22 hz (obviously a lie, but they were supposed to get near 30 hz). Finally I broke out my spl-meter, and found that I was flat to 50 hz and -20 db by 40 hz (at which point it stayed -20 to a little below 30 hz). I had no idea I was missing that much.

Test your speakers to see if they meet spec. They may only be flat to 45 Hz or so in your room (manufactureres can use ideal positioning to extend the bass) in which case you are missing a lot.

[mjzraz]

Originally posted by Dudley
For a long time I was very impressed with my main speakers and did not think I needed a sub. They had enough punch to make it seem like you were kicked in the gut during certain scenes ..[snip].. Finally I broke out my spl-meter, and found that I was flat to 50 hz and -20 db by 40 hz (at which point it stayed -20 to a little below 30 hz). I had no idea I was missing that much.

Thanks for the replies.
Dudley, this is exactly the perception I have. My first question is (I assume you have a sub now) How are those same movie scenes now with the sub and which one did you get?

The other question is to understand the testing terminology:
Flat to 50 Hz means that at a fixed volume the SPL (loudness?) stayed at the same level down to 50Hz - Right?
Then from 40-30Hz, the SPL dropped by 20db from the the fixed volume that was measured above 50 Hz. If this is right, I think I understand, but how does a 20 bd drop affect the sound? Can you just not really hear those frequencies over the rest of the sound because every other frequency is still at the original fixed level?

[Dudley]

Actually this is all fairly recent, and I do not have a sub yet, but have listened to many. I am very interested in the STF's, and think I will get the STF-2 (I would prefer the 3, but it will not fit under an end table, and me spouse will probably not go for it.

You are correct on your assumptions on the SPL levels. I hear people talk about scenes in movies that have huge bass, and I don't even know what they mean - I basically hear almost nothing when the sock gets exploded in monsters inc. Gunshots and explosions are fine, but the really low rumbles just are not there.

[Retread]

Originally posted by mjzraz
Thanks for the replies.
Dudley, this is exactly the perception I have. My first question is (I assume you have a sub now) How are those same movie scenes now with the sub and which one did you get?

The other question is to understand the testing terminology:
Flat to 50 Hz means that at a fixed volume the SPL (loudness?) stayed at the same level down to 50Hz - Right?
Then from 40-30Hz, the SPL dropped by 20db from the the fixed volume that was measured above 50 Hz. If this is right, I think I understand, but how does a 20 bd drop affect the sound? Can you just not really hear those frequencies over the rest of the sound because every other frequency is still at the original fixed level?

"Flat" means a constant sound level. There is no such thing as "flat." What they mean is that the sound level is within certain sound level bounds over the frequency range specified.

The generally understood minimally perceptable change in sound level is 3dB. 20dB is a LOT. If your speakers are "down" by 20 dB, that means you simply aren't hearing sounds at those frequencies as strongly as the rest of the program material.

I'm basically one phase ahead of you. For maybe 20 years I've been listening to stereo over a pretty good pair of Polk bookshelf units -- specs down 3 dB at 32 Hz and falling rapidly below that. I've listened to VHS videos over that for years and felt pretty good about them. In November I decided to do home theater, which necessitates new receiver, new surround speakers, etc. My golden-ear audiophile son (a pair of large Klipshes -- next size down from corner horns) told me I had to have a sub, and said that the Hsu VTF-3 had the best price-performance on the market. So I bought one, along with the Ventriloquist system, and a receiver, and a progressive DVD player, and a front projector, and 100" screen. The difference in bass sound is nothing short of startling. The soul of many movies is in the low bass.

Being an engineer, I don't expect ever to finish setting up my system. There are too many things to measure and too many things to tinker with. By measurement, I know that I'm getting strong output below 20 Hz, and can hear the bass strongly above 20 Hz. I'm extremely pleased I got a sub, and am convinced the reviews saying the VTF-3 are tops in price-performance are correct.

[sputnikv8]

"need"... hmmmm. Only in the US do people "need" home theaters. :)

But yes. You will not believe that you were watching movies before without one. It will completely change your experience. Guaranteed.

So yes... if you want to fully enjoy the home theater experience you "need" one.

[joema]

My room is about your size, and my main speakers are Axiom M60s (dual 6.5" woofers), with a 37-22khz (+/- 3db) response. I had a Hsu STF-2 and now have a VTF-3R. The sub makes a huge improvement in HT, but also (to my ear) even for music. You're definitely missing a lot without a sub.

I'm sure the VTF-3 Mk2 is great, but don't sell short the STF-2. It's quite compact, and has great sound. It was just very impressive. My VTF-3 can shake the room a little more, but if space or cost issues constrain you to an STF-2, that's still great.

Despite main speakers like ours having pretty good bass response, the difference (esp for HT) in adding a sub is vast. Get the sub! You won't regret it.