S.Q.- Larger subwoofer drivers vs. smaller drivers

[rjrauso]

Ok, I'm not swamped with client projects today and I'm bored... I was having a fun little argument w/my father the other night on which of our subwoofers sounded better. He has an M&K mx-200 which has two 12" drivers in a push-pull configuration (one facing forward, the others magnet facing downward) and a 200 watt amp. Mine is a custom 18" Ascendant Audio Avalanche (with xbl^2 motor) in a 4.6 c.ft. sealed enclosure w/a 1000 PE plate amp.

I've listened to both plenty of times and honestly think mine sounds more natural and life like... Drums sound like drums not booms. His is a little more punchier. Both sound great on music. While he does have a lot more experience in audio, he has really never sat down and listened to my sub. Right now mine is hooked up to my movie setup so I do have it turned up a little more then if I was listening to music.

He basic argument is that it's an 18, and all 18's sound like 18's. They aren't as articulate as a 12. Also the fact that my amp could be a little bit more powerful and my box vibrates more then it should (at extreme levels) only helps is argument.

We aren't talking apples to apples here, in fact if his M&K had drivers built as well as my 18, I could see it making sense, but they aren't even close... They look to be the quality of the DVC's or the old Adire shivas(at best) used to make. And not dogging those drivers, but they just don't sound as good. I've built a lot of other subs and I've never heard one that sounded better then my 18. For comparison's sake his sub sounds as good as the original titanic 1200 in a 2c.ft. sealed box... at best, and I mean at best.

In general, I always hear that smaller drivers are better for sound quality then larger drivers. In all honestly, if they are designed correctly, it's my personal belief that this is false.

[cjd]

> In general, I always hear that smaller
> drivers are better for sound quality then
> larger drivers.

Everyone should be using in-ear monitors. Smallest drivers around, they MUST sound better.

As usual, it's about so very many things and size is only one small part of the equation. Mostly, that plays into how high it can play before beaming (dictated directly by the relationship of diameter to wavelength). Smaller drivers don't play as low either (usually) which tends to "tighten" bass (when the reality is, it's simply leaning out)

So, you're right. Size has nothin to do with performance. It's ALL about how you use it.



C

[robert]

> Everyone should be using in-ear monitors.
> Smallest drivers around, they MUST sound
> better.

> As usual, it's about so very many things and
> size is only one small part of the equation.
> Mostly, that plays into how high it can play
> before beaming (dictated directly by the
> relationship of diameter to wavelength).
> Smaller drivers don't play as low either
> (usually) which tends to "tighten"
> bass (when the reality is, it's simply
> leaning out)

> So, you're right. Size has nothin to do with
> performance. It's ALL about how you use it.

>

> C

I think it has to do with cone mass, motor structure, and how high you are running the sub. Back in the Day (lol) 15's and 18's often had small motors to the fairly high cone mass and could sound thuddy/muddy/dull. I'm guessing a very sloppy Bl curve there from the high cone mass / small motor combo. A small magnet and voice coil aren't enough for something that huge. That's probably where that opinion comes from.
An XBL obviously has that problem licked, though you can get into opinions on the sound of high excursion subs too.

Robert

[philiparcario]

> I think it has to do with cone mass, motor
> structure, and how high you are running the
> sub. Back in the Day (lol) 15's and 18's
> often had small motors to the fairly high
> cone mass and could sound thuddy/muddy/dull.
> I'm guessing a very sloppy Bl curve there
> from the high cone mass / small motor combo.
> A small magnet and voice coil aren't enough
> for something that huge. That's probably
> where that opinion comes from.
> An XBL obviously has that problem licked,
> though you can get into opinions on the
> sound of high excursion subs too.

> Robert
I don't think 12 inch subs can do the deepest home theater properly. I love 12 inch subs for the 35hz to 80hz range. I think high quality 15 or 18 inch subs are needed to get that 16hz to 40hz sound from special effects. When you go higher 70hz 80hz most large subs don't blend right with the mains. I have 3 subs a 15 inch to run from 50hz down and a pair of 12 inch subs from 40hz to 80hz. This is the best sub sound I have managed to get so far.To be fair if i had a pair of 15 inch aurasound subs at 700 a driver new in a good box. I might feel differently.

[---k---]

> I've listened to both plenty of times and
> honestly think mine sounds more natural and
> life like... Drums sound like drums not
> booms. His is a little more punchier. Both
> sound great on music. While he does have a
> lot more experience in audio, he has really
> never sat down and listened to my sub. Right
> now mine is hooked up to my movie setup so I
> do have it turned up a little more then if I
> was listening to music.

I'm sure his sounds better also because he paid a lot more for it than you did.

This topic of smaller drivers sounding better is a whole source of internet lore and flame wars. It is sad that you're father would rather parrot something he read than have you bring your sub over for a show down.

A crappy 12" may sound better than a crappy 15". But with today's high quality drivers, in designs optimized for them, I don't think it holds any water.

[rjrauso]

> I don't think 12 inch subs can do the
> deepest home theater properly. I love 12
> inch subs for the 35hz to 80hz range. I
> think high quality 15 or 18 inch subs are
> needed to get that 16hz to 40hz sound from
> special effects. When you go higher 70hz
> 80hz most large subs don't blend right with
> the mains. I have 3 subs a 15 inch to run
> from 50hz down and a pair of 12 inch subs
> from 40hz to 80hz. This is the best sub
> sound I have managed to get so far.To be
> fair if i had a pair of 15 inch aurasound
> subs at 700 a driver new in a good box. I
> might feel differently.

I agree 100%. There really is no comparison in output between the two subs, it's not even close.

Are there any good articles explaining driver sizes versus their sound quality? I'm having a hard time convincing this old fart - I mean old school audiophile that the newer 15" - 18" subs with a lot of xmax don't have the bad/boomy sound quality tied to them that they used too back in the day.

[rjrauso]

> I'm sure his sounds better also because he
> paid a lot more for it than you did.

> This topic of smaller drivers sounding
> better is a whole source of internet lore
> and flame wars. It is sad that you're father
> would rather parrot something he read than
> have you bring your sub over for a show
> down.

> A crappy 12" may sound better than a
> crappy 15". But with today's high
> quality drivers, in designs optimized for
> them, I don't think it holds any water.

Well he's the old school audiophile type that has to hear it to believe it. He also can't come to grips that with computer technology it's fairly simple to develop and build a subwoofer compared to the old days...

Although those M&K subs are vastly out of date technology wise, they still do produce very nice sound. I'm guessing it's this sound he expects and anything that sounds different isn't as good.

The only time he heard my sub is when we had it sitting in the middle of the room and I was testing it's limits and trying to break the driver in at the same time. At extreme levels it didn't sound that great because the amp couldn't keep up. But now that it's setup correctly, broken in, you really have to have it turned up to hear any type of stress.

[billfitzmaurice]

> In general, I always hear that smaller
> drivers are better for sound quality then
> larger drivers. In all honestly, if they are
> designed correctly, it's my personal belief
> that this is false.

As is the case in other endeavors as well the size of a tool is not what counts, it's how well one employs it. The folded horn sub I use for my HT is loaded with one eight, and leaves nothing more to be desired.

[romanbednarek]

> Ok, I'm not swamped with client projects
> today and I'm bored... I was having a fun
> little argument w/my father the other night
> on which of our subwoofers sounded better.
> He has an M&K mx-200 which has two 12"
> drivers in a push-pull configuration (one
> facing forward, the others magnet facing
> downward) and a 200 watt amp. Mine is a
> custom 18" Ascendant Audio Avalanche
> (with xbl^2 motor) in a 4.6 c.ft. sealed
> enclosure w/a 1000 PE plate amp.

> I've listened to both plenty of times and
> honestly think mine sounds more natural and
> life like... Drums sound like drums not
> booms. His is a little more punchier. Both
> sound great on music. While he does have a
> lot more experience in audio, he has really
> never sat down and listened to my sub. Right
> now mine is hooked up to my movie setup so I
> do have it turned up a little more then if I
> was listening to music.

> He basic argument is that it's an 18, and
> all 18's sound like 18's. They aren't as
> articulate as a 12. Also the fact that my
> amp could be a little bit more powerful and
> my box vibrates more then it should (at
> extreme levels) only helps is argument.

> We aren't talking apples to apples here, in
> fact if his M&K had drivers built as well as
> my 18, I could see it making sense, but they
> aren't even close... They look to be the
> quality of the DVC's or the old Adire
> shivas(at best) used to make. And not
> dogging those drivers, but they just don't
> sound as good. I've built a lot of other
> subs and I've never heard one that sounded
> better then my 18. For comparison's sake his
> sub sounds as good as the original titanic
> 1200 in a 2c.ft. sealed box... at best, and
> I mean at best.

> In general, I always hear that smaller
> drivers are better for sound quality then
> larger drivers. In all honestly, if they are
> designed correctly, it's my personal belief
> that this is false.

Putting the mountain of other factors aside, in general a larger coned driver will have less distortion. This is mainly because the larger cone can move more air when compared to the same motor with a smaller cone. So in order to get the same output level from a smaller cone, a greater excursion is required and the voice coil begins to enter a region where its operation is less linear.

Now using dual drivers is a way to reduce the distortion from a smaller cone driver because only half of the power is required to produce the same spl level as a single driver. It gets very tricky to compare things evenly but in general you usually compare the total Sd (radiating area) of the drivers used in the designs.

Aside from enclosure differences, I think that most of the differences with subs can be traced back to non-linear distortion. Cone materials can be critical as well because certain cones have a tendency to flex more. Like I said above, there are just too many factors to consider to make a strong argument.

[natediggidy]

Your pop's used to the sound of his sub and it sounds good to him. You may get him to agree that your sub sounds good, but it's not going to sound the same as his. Subjectively, I bet he'll still prefers his.

I have a big 15" sealed HT sub (DIY thank you) that's so clean sounding, the "Meeting Darla" scene (Finding Nemo) sounds like drum hits and you hear the decay from each hit.