Why Do I NEED a Subwoofer for My Speakers?

[HiFiCanada]

It's the music for me, The big European and U.S pipe organs, to try and get the lower 32ft stop, is what I built my sub for. But I think the 32ft stop's lowest note C is 15hz, don't think my sub will do that, but it sure does add a lot to the lower frequency's, in hearing and feeling the music.

[Yamahalic]

My sub is real noticable if I leave it set at my HT setting (80hz XO, slightly elevated volume), but I set it to blend seemlessly for music at a 40hz XO with lower volume. I have a 100% "I need it" conversion rate with friends when I get them to listen to a few interesting tunes, then I will turn the sub off abruptly...WOW, HOLY S@&T!!!...What happened??? Well it seems my large towers with 12" woofers can reproduce some low frequencies (to about 50hz somewhat competently, but the lows are reproduced at a lower SPL compared to the middle frequencies, so the sub helps to straiten out the overall "system freq response". Wonderful overall system freq response once the sub was tuned in.

BTW everyone should get on the case of their speaker manufacturer(s) that publish frequency responses without a corresponding SPL range. A freq response without SPL info is "worthless"!!! To say that a speaker (rating) can go down to 50hz is meaningless without knowing at what SPL it is relative to the avg freq response. 50hz at -3db is a whole lot different than 50hz at -20db.

[HiFiCanada]

Originally Posted by Yamahalic

My sub is real noticable if I leave it set at my HT setting (80hz XO, slightly elevated volume), but I set it to blend seemlessly for music at a 40hz XO with lower volume. I have a 100% "I need it" conversion rate with friends when I get them to listen to a few interesting tunes, then I will turn the sub off abruptly...WOW, HOLY S@&T!!!...What happened??? Well it seems my large towers with 12" woofers can reproduce some low frequencies (to about 50hz somewhat competently, but the lows are reproduced at a lower SPL compared to the middle frequencies, so the sub helps to straiten out the overall "system freq response". Wonderful overall system freq response once the sub was tuned in.

BTW everyone should get on the case of their speaker manufacturer(s) that publish frequency responses without a corresponding SPL range. A freq response without SPL info is "worthless"!!! To say that a speaker (rating) can go down to 50hz is meaningless without knowing at what SPL it is relative to the avg freq response. 50hz at -3db is a whole lot different than 50hz at -20db.

Could,nt Agree more, that was even a problem back in the 1980's, claims that smaller speakers can produce the low frequencies just as well. The specs claims that low frequency responce, most people would believe that, not there fault, because that is what they are told. But at what SPL levels, that was never in the spec's.

[dkelley]

of course most significant speaker manufacturers do spec their responses fairly well, traditionally with -3db points.

[cwall99]

I read the first two pages of this thread and this last page (page 12 so far), so if this has already been discussed, sorry. I'm just too lazy to read the additional 9 pages of posts.

Anyhow, one of the things a subwoofer can do for you, provided this is the way you listen to music, is offload a big chunk of stress on your amps. This is provided, of course, you can configure the crossover point in your amp or receiver and can set your speakers to small or large.

In the HT world, FWIW, most modern AVRs and pre/pros allow you to configure your speakers as either small or large. If large, your receiver feeds the full audio spectrum to the speaker. If small, only the frequencies above the XO point go to the speaker. THX recommends that even if your speakers can go full range that you set them to small.

This offloads the stress of pushing those lower frequencies from the shoulders of your amp or AVR. This gives everything above the XO a lot more power to play with, and can, when done right, result in a greatly improved sound.

It all depends on getting your gear set up correctly.

[dkelley]

yes, true. however that's the "modern" term for a subwoofer, not the original definition that we're discussing here, where a subwoofer only adds to the lower frequency output which your regular full range speakers simply can't hit (such as below 40Hz).

The THX concept etc is of course correct and excellent, but it doesn't actually setup a powered subwoofer as a subwoofer, it sets up a powered subwoofer as the speaker(s) that create ALL of the low bass in the system, like the bottom third of what a traditional woofer might do, rather than only doing the stuff that no traditional woofers can do at all (like getting down to 18Hz).

So most "subwoofers" in home theatre systems don't really behave like true subwoofers or extend the response down as low as a true subwoofer, although there are of course expensive exceptions that do get right down there :-)

Anyway, in the modern HT or sub/sat concept that you're talking about, yes, definitely you're right.

it's really more of a bi-amplificatied multiway speaker system by definition though, and as we noted a couple of pages back, has been mis-marketed as having a subwoofer when, in fact, most home theatre's powered low frequency bass modules don't do any better than a well designed multiway full range pair of loudspeakers.

anyway, I just wanted to explain that since you skipped a few pages :-), now you're up to speed with our discussion controversy on the topic.

But yes again, you're right of course, subwoofer definition permitting.

[mrt2]

Originally Posted by dkelley

yes, true. however that's the "modern" term for a subwoofer, not the original definition that we're discussing here, where a subwoofer only adds to the lower frequency output which your regular full range speakers simply can't hit (such as below 40Hz).

The THX concept etc is of course correct and excellent, but it doesn't actually setup a powered subwoofer as a subwoofer, it sets up a powered subwoofer as the speaker(s) that create ALL of the low bass in the system, like the bottom third of what a traditional woofer might do, rather than only doing the stuff that no traditional woofers can do at all (like getting down to 18Hz).

So most "subwoofers" in home theatre systems don't really behave like true subwoofers or extend the response down as low as a true subwoofer, although there are of course expensive exceptions that do get right down there :-)

Anyway, in the modern HT or sub/sat concept that you're talking about, yes, definitely you're right.

it's really more of a bi-amplificatied multiway speaker system by definition though, and as we noted a couple of pages back, has been mis-marketed as having a subwoofer when, in fact, most home theatre's powered low frequency bass modules don't do any better than a well designed multiway full range pair of loudspeakers.

anyway, I just wanted to explain that since you skipped a few pages :-), now you're up to speed with our discussion controversy on the topic.

But yes again, you're right of course, subwoofer definition permitting.

Well put.

[MAC ED]

my main speakers consist of b&w n805's. nice sounding speakers w/o much low end. to cure that problem i employ a velodyne hgs-15.
the sub and the mains synergize excellently.
i would never play music w/o a great sub in the system.

btw, i found the whole system sounded much better by running the mains w/o the sub's electronics in the mix. in other words, i hook the sub up to the #2 preamp out and than blend it to the lowest frequency of the main speakers.

a great test cd for exploring the low end of your system is "20 mothers" by
julian cope. this is a fabulously produced cd, and has excellent bottom.
the 1st track especially.

one last thought; i'm very fortunate that my system is in a location with a concrete floor. through my own experience, i believe a sub speaker performs better on concrete than wood.
less resonance.

[Yamahalic]

Originally Posted by dkelley

of course most significant speaker manufacturers do spec their responses fairly well, traditionally with -3db points.

I think that a -3db is a good spec to which all manufacturers "should" abide. Although I am "Yamahalic", I am saddened to look at the current Yamaha website and see that they no longer provide an SPL spec on the frequency response rating of their subs (shameful IMHO). In the past, Yamaha at least provided a -10db spec with their subs, which although not perfect is better then no SPL spec at all.

Sadly, too many folks quote a non-SPL freq response spec for their speakers and/or sub, which is really not very useful. I prefer to see a graphical freq response curve with speakers so that I can see the rate of decline of the lower frequencies as measured by the manufacturer.

[Fred Sanford]

Originally Posted by BMWCCA

That's me. I just don't do turbos or sub-woofers, and I admit to being a Luddite.

Oh- so this wasn't you, then?

[qboneus]

Originally Posted by Fred Sanford

Oh- so this wasn't you, then?

oh my god, think i just threw up a little!
nice job on the hood they did with their dremel tool huh?
yikes!
tal