Sound quality and driver size... Opinions?

StopherJJ1980

Recently while auditioning speakers for my setup I came across a common dilemma.... do I really need the bigger speaker? i.e. CSi3 vs. CSi5... FXi3 vs. FXi5... RTi8 vs 10 or 12... etc. You get the picture.

While listening to all of these most of the time these speakers all have no problem hitting the 80Hz that theyre usually crossed over to the sub at, and have identical upper limits freq. resp.-wise. But there just seems to be SOMETHING that always made them different even though they technically are reproducing the exact same range and are from the same series and voice matched an all that... So I came up with three options

1) Is there just something about the timbre of the larger driver that makes for a better (or just different) sound quality. Guitar players may understand the analogy that you can play a note on a string, but if you go up or down a string you can play the exact same note technically, but there will be an ever so slight difference if you play the two back to back.

2) The crossover frequency of the speaker from the driver to the tweeter is different resulting in a different sound.

3) I am just nuts and there is no difference.

Is it a little bit of all of the above, or something Im not thinking about? Im interested if this is obvious to other people and your opinions on the cause. Thanx

F1nut

There is no substitute for large radiating surfaces.

McLoki

I am guessing that it has something to do with running multiple drivers and the fact that distortion is kept lower since the drivers have to move less to produce the same volume. (since there are more of them)

Multiple drivers can start to get into issues with cancellations as well (this is why Polk is using the 2.5 and 3.5 way crossovers in thier LSi line when multiple drivers are used).

I am sure that towers and bookshelves sound different but better is left up to the person listening to them. (I will be able to expound on this more next week. Pick up my LSi15's on Monday... )

Michael

steveinaz

As much as I liked the Lsi9, they just didn't have the depth, size and scope of the soundstage that my Energy towers achieve. If you want "big" sound, go with a big speaker. If you listen at moderately loud and below levels, bookshelves will probably fill the bill.

bpadget

Don't forget your harmonics. This is where the real listening qualities of sound come from. Pure tones are usually pretty nasty to listen to. Using your guitar analogy, the difference in tone comes from 2nd and higher order harmonics. The shorter string has a shorter natural frequency than the long string and provides higher frequency overtones. I could go on about box size, etc. but you get the picture. It's all about the harmonics.

aaharvel

it's Quality not Quantity.

StopherJJ1980

Thanks guys, intersting to hear your comments

markmarc

Just as large cones have more area to radiate, small cones are faster. It comes down to a combination of execution and personal hearing/taste.

adam2434

With proper amplification, larger speakers with numerous or larger drivers can play louder with less strain and distortion, especially if you have a large room to fill.

As others mentioned, larger speakers can sound larger (more dynamic).

Another large speaker dude here. I've played with bookshelf/sub combos, but I could never get the integrated sound and slam that come with good full range speakers. Other folks love their bookshelf/sub combos, so this is subjective.

Adam

VR3

The small cone = better is annoying.

Why? Because its not 1980 anymore.

A 8" midbass can produce the same kind of mids a 5.25" midbass can, IMO. A quality driver is a quality driver regardless. Its either quick or its not.

As for more = better, nah... Id take a 2-way over a 4 way anyday!

MacLeod

Im wth Sid. I prefer a good 2 way for pure SQ.

I also prefer a good size driver at least a 6.5".

Early B.

I hear lots of talk about driver speed, but how the hell can you tell? What does it mean for a driver to move "faster" than another one?

VR3

I find speed to be...

How fast a driver can do one thing and do something entirely different and do it while not muddying up the thing it is doing currently or before...

or doing multiple things at one time without sacrificing quality...

For instance, some say an 18" woofer is to slow to be accurate, that it cant hit a note, return to the position and hit another note without muddying it up.

Obviously these people have never heard the DD18.

Speed is just how fast a driver can move to keep reproducing notes faithfully.

Early B.

OK, so it sounds like speed is just another expression of clarity. For instance, if a driver is considered "slow," it will be muddy, i.e. lack detail. Conversely, a "fast" driver has the ability to capture greater levels of detail because it can pick up more of the subtle nuances of the music. Is this correct?

I'm simply trying to gain an understanding of audio terminology because most of these terms seem to convey the same principle.
(I'll start another thread on this topic.)

unc2701

Yeah, when comparing drivers, look for the Moving mass in the specs. Smaller is better, but it's always a trade off. You can get a Vifa 8" driver with an Fs of 21 hz and a moving mass of 29grams... It'll hit hard, it'll hit low, it'll hit fast. And it'll only handle 125 watts. Compare to the dayton titanic 12". Fs is 22.2 hz, moving mass is 188 grams- it'll handle 500 watts, but it has to get that 160 additional grams started and stopped just as fast- which is just can't do.

Now, your enclosure will play into this too. A sealed enclosure acts as a spring, pushing the driver back into position, so you get faster, tighter bass, but you're going to get less db's.

Anyhow, I'm convinced that unless you're going to drop a ton of cash, you need two subs. A light musical sub that you use at moderate volumes and cross over at the rolloff of your mains (say 40 hz) and a heavy duty theater sub that you use loud and roll off at the THX 80hz.

Early B.

unc2701 wrote:

Anyhow, I'm convinced that unless you're going to drop a ton of cash, you need two subs. A light musical sub that you use at moderate volumes and cross over at the rolloff of your mains (say 40 hz) and a heavy duty theater sub that you use loud and roll off at the THX 80hz.

Agreed. Use the right sub for the application, if it's possible and practical to do so. The "one size fits all" concept doesn't work here.

Doc99

unc2701 wrote:

Yeah, when comparing drivers, look for the Moving mass in the specs. Smaller is better, but it's always a trade off. You can get a Vifa 8" driver with an Fs of 21 hz and a moving mass of 29grams... It'll hit hard, it'll hit low, it'll hit fast. And it'll only handle 125 watts. Compare to the dayton titanic 12". Fs is 22.2 hz, moving mass is 188 grams- it'll handle 500 watts, but it has to get that 160 additional grams started and stopped just as fast- which is just can't do.
This I think is one of the main reasons why speaker designs have changed to multiple smaller drivers. A larger driver can not attack and decay as quickly as a small cone. Size and mass.

VR3

Not nessicarially.

Subwoofers and woofers are a bit different.

Subwoofers move around 1-4" linear... (good ones)

Thats is alot of traveling, most "woofers" move no more than 3-5 MM like a regular midbass. Like what was mentioned before, a quality driver is a quality driver...

StopherJJ1980

Velodyne actually discusses this issue on their site. They mention how the "speed" of a driver most people talk about is just another word for distortion. Since a larger driver is more likely to bend and curve slightly when moving it is easier to not get a nice tight bass sound out of it. But if you are using quality products (like they claim to), they should be able to have a nice rigid driver that does not flex, and granted you have a nice size piston and enough power, you should be able to get the same tight low distortion sound out of larger size drivers as well.

Tour2ma

unc2701 wrote:

Yeah, when comparing drivers, look for the Moving mass in the specs. Smaller is better, but it's always a trade off. You can get a Vifa 8" driver with an Fs of 21 hz and a moving mass of 29grams... It'll hit hard, it'll hit low, it'll hit fast. And it'll only handle 125 watts. Compare to the dayton titanic 12". Fs is 22.2 hz, moving mass is 188 grams- it'll handle 500 watts, but it has to get that 160 additional grams started and stopped just as fast- which is just can't do.

Correct it takes 610 watts... I really do not have a clue what your are trying to say here unless it is that it takes more power to start and stop a greater mass.... and that is axiomatic.

unc2701 wrote:

Anyhow, I'm convinced that unless you're going to drop a ton of cash, you need two subs. A light musical sub that you use at moderate volumes and cross over at the rolloff of your mains (say 40 hz) and a heavy duty theater sub that you use loud and roll off at the THX 80hz.

First, who crosses over at their main's roll off point? That's inviting a hole in your system FR. Second why would you cross a "heavy duty" sub higher than a "musical" sub? It makes no sense to me to ask the sloppy, old HT sub to handle higher frequencies.

The whole musical sub thing has been hashed out here before, and it really doesn't float. A bad music sub is going to be a bad HT sub and vice versa.

unc2701

Tour2ma wrote:

Correct it takes 610 watts... I really do not have a clue what your are trying to say here unless it is that it takes more power to start and stop a greater mass.... and that is axiomatic.

Car metphors are bad, but lets say you're trying to dodge a truck between a line of cones. An empty truck will always do this better than a full truck (ignoring distribution considerations... ehhh, car metaphors are bad).

Tour2ma wrote:

First, who crosses over at their main's roll off point? That's inviting a hole in your system FR.

Depending on the roll off slope of the two (assuming correct phase), this would typically result in boost at the crossover point, but that's not my point. I'm of the pursuasion that for music that you should let your mains handle everything that they can (no high pass filter on them), then pull in the sub ONLY for notes out of the range of the mains... This is going to be a lower crossover point than the THX standard. Also, with a proper crossover, it's easier to get a flat response across this narrower range.

Tour2ma wrote:

Second why would you cross a "heavy duty" sub higher than a "musical" sub? It makes no sense to me to ask the sloppy, old HT sub to handle higher frequencies.

DVD's are mastered with a 80hz crossover in mind. However, I could go either way on this one. The main thing is that you're going to want more db's in the HT setting and this requires more higher engineered enclosures to get from a small driver. So without laying out the cash for a Rel, ML, etc. you'll need a bigger, heavier driver to get what you want.

Tour2ma wrote:

The whole musical sub thing has been hashed out here before, and it really doesn't float. A bad music sub is going to be a bad HT sub and vice versa.

Depends on what you want to spend. HT and music have two different ideal specs and with limited funding, I think I can get more from two subs than any single one at the combined cost.