What makes big speakers sound "big"and smaller ones sound "small"?

[ahofer]

Ime there are perceptual thresholds which are not conveyed by frequency response curves, especially if those response curves are in-room curves which do not differentiate between direct and reflected sound.

Thanks. Now I see the distinction you are making.

And yes, within SPL I would include peaks/dynamic range. Something like the compression test Erin usually runs.

 

[Duke]

Thanks. Now I see the distinction you are making.

And yes, within SPL I would include peaks/dynamic range. Something like the compression test Erin usually runs.

Thank you.

One thing don't know how to correlate with measured response is the perceptual difference that motor strength seems to make.

I manufacture bass guitar cabs, and two (now discontinued) cabs had 18" woofers. Both cabs were -3 dB at 46 Hz, the first overtone of F#0. One cab was noticeably bigger than the other because its parameters called for a larger enclosure to hit that 46 Hz target.

I brought both cabs to a bass player get-together and numerous bass players played through both cabs. The bigger cab had a little over 1 dB higher voltage sensitivity, so it was a little bit louder. Both woofers had more than enough linear excursion considering the amp they were being used with (same amp for both cabs). There were no visual cues indicating anything about the motor strength, but the one woofer's motor was significantly stronger than the other's.

Subjectively, one of them "hit like a pillow" and the other "hit hard", according to bass players who played both cabs side-by-side. I presume the cab that had subjectively more impact is the one that would have been described as sounding "bigger". It was the smaller cab, the one with the more powerful motor. Imo the difference was not subtle, but of course I cannot prove any of these subjective impressions. (The editor of Bass Gear Magazine owns and loves one of the smaller 18" cabs).

My attribution of the subjective difference to motor strength may be mistaken, but to my ears the same trend has held up across other bass cabs. That bass player get-together was the only instance where I had a whole room full of people making an "apples to apples" comparison of visually similar cabs having similar low-end responses and visually similar woofers but with significantly different motor strengths.

If I knew exactly which measured (or better yet modelled) response characteristics correlate with the perception of "impact", I would attempt to optimize for it. I have only imprecise "rules of thumb" to go by, which is less than optimal.

If you have any suggestions of what to look for in measured or modelled response, I'm all ears!

(And I readily concede that I have no "scientifically impeccable evidence" for what you may deem to be my "scientifically improbable claim" of an audible difference that seems to correlate with motor strength.)

 

[Kvalsvoll]

My attribution of the subjective difference to motor strength may be mistaken,

You are not mistaken. While it may not be motor strength (Bl^2/Rdc) directly, motors with higher Bl tend to have better non-linear behavior, with less dynamic compression when reproducing signal with wide frequency bandwidth and short in time interval.

This is also the main reason most typical subwoofers sound very sluggish, with no real impact.

 

[benanders]

…

I presume the cab that had subjectively more impact is the one that would have been described as sounding "bigger". It was the smaller cab, the one with the more powerful motor.

…

I’m not sure if a speaker’s dynamic slap/slam/whatever is synonymous with sense of “bigness”. Can a “big” sounding speaker be soft, or does a speaker have to hit hard to seem big? I find these conundrums of subjective (but important) descriptors a challenge.
Does it also stick with an assumption of lower bass frequencies being all-important for sense of size, vs. the previously mentioned role of frequencies up to an beyond ~500 Hz?

The comments in this thread regarding total driver surface area (@AdamG , @DonR ),

... While it may not be motor strength (Bl^2/Rdc) directly, motors with higher Bl tend to have better non-linear behavior, with less dynamic compression when reproducing signal with wide frequency bandwidth and short in time interval.
...

excursion behavior (motor strength goes here Y/N?), directivity (…and also here?), and the perceived interaction effects from reflections. The interaction part is what should make it a real challenge for conventional measurements to elucidate, no? It shouldn’t be impossible, but it’s also probably not something that available software is ready for. Probably why Toole’s comments in this area were largely drawn on behavioral tests.

 

[riker1384]

My theory is that bookshelves always sound small because of the floor-bounce cancellation in the upper bass.

I've never been able to get bookshelves with a sub to sound quite as good as a floorstanding tower with a big woofer near the floor, or multiple woofers. Even if I turn up the subs it always ends up sounding thin-with-boomy-bass. I don't have the measurement equipment to confirm my theory, though.

 

[beagleman]

IMHO Speakers are Air pumps. Big pumps (speakers) move more air and create more tactile room energy which your body/ears sense. Engines are air pumps as well.

Not sure I agree.......

When talking at the same sound levels, would not all speakers if reproducing the same level AND frequency move the same exact amount of air??

A small driver would simply move further, and large woofer less movement.

Now if you are talking about ultimate ability to play loudly, yes a larger speaker, all else being equal would do that....

 

[beagleman]

I think we need to define "Bigger" first off.

If as the OP asked, "At the same SPL", we are not talking louder per se, but more what size area the sound eminates from maybe.

I have found speakers with pinpoint imagining on narrow baffles, tend to sound more concentrated and not cover a whole wall with sound, and also the Bose 901 to sound quite huge, but have poor imaging.

Old console stereo I was given several years ago, sounded ungodly huge sound wise, but had utterly horrible imaging and so on.

 

[Barrelhouse Solly]

I'm not sure that size is the only relevant variable. I remember when I first heard the Advent sub/satellite speaker and was amazed by the "size" I heard. Before that the biggest sounding speakers I'd heard were a friend's Voice of the Theater speakers in a small living room. My experience is limited and subjective but I hear "big" from a decent pair of small speakers paired with a decent active subwoofer.

 

[egellings]

On an all pass it will be less noticeable because the effect will change all drivers to be just as out of phase as eachother. It's variations between driver's in crossover that can be problematic or two different speakers with different phase characteristics, although that's rare unless mixing and matching. In theory though, two speakers despite being different should provide good sound still given a well designed integration of the driver's in each speaker. And then there's placement as well, I used to run 4 speakers at one point, 2 in front and 2 behind, and to make that work correctly regarding phase you needed to wire the speakers behind with polarity reversed.

Speaking of which, that's something that's always baffled me about home theatre set-ups. Does the receiver change the polarity internally so the consumer matches the correct + and -? I'm guessing so, unless it tells people to reverse polarity for speakers behind them. I don't know mutch about home theatre.

I don't do home theater, so I can't comment on that.

 

[Deleted member 48726]

My theory is that bookshelves always sound small because of the floor-bounce cancellation in the upper bass.

I've never been able to get bookshelves with a sub to sound quite as good as a floorstanding tower with a big woofer near the floor, or multiple woofers. Even if I turn up the subs it always ends up sounding thin-with-boomy-bass. I don't have the measurement equipment to confirm my theory, though.

I'd say that's close to my experience as well.

 

[Multicore]

What makes big speakers sound "big"and smaller ones sound "small"?

Size?

Just guessing.

 

[ahofer]

Size?

Just guessing.

Well, and motor strength, as posited above. But it seems sort of like ‘what makes watts’ to me. Isn’t peak SPL essentially a product of movement and surface area?

 

[Waxx]

Big speakers are mostly high sensitive and/or high power capable. Which makes them sound effortless on low volume and very low in distortion compared to smaller speakers. What they says "there is no replacement for displacement" does not only fit subwoofers, higher up it's also valid.

Dispertion is also a part, just like baffle step diffraction on a lower frequency (so more midbass), but i think the main thing is that they go louder, and so play lower distortion on lower volume than small speakers. At least that is my experience.

 

[Jaxjax]

Isn't it just simply that the large speakers potentially can pummel you in a larger type room & hold without strain.. In one of my old large dedicated rooms with large JBL horns it was a startling thing to go thru with the right music. HIgh spl without strain in big rooms means something...
I been to concerts albeit rare,, that are so loud its beyond stupid but also clean at the same time & this is indoors...
Joe

 

[thewas]

I've never been able to get bookshelves with a sub to sound quite as good as a floorstanding tower with a big woofer near the floor, or multiple woofers. Even if I turn up the subs it always ends up sounding thin-with-boomy-bass. I don't have the measurement equipment to confirm my theory, though.

You can have subs with one or two woofers directly under the bookshelf instead of a stand which make them from configuration point of view and with some suitable EQ like a similar floorstander as I have done here:

KEF R Series with MAT white paper

I know this is r thread but seeing as the Kef guys are here... Any plans for a centre version of the ls60w and/or adding wysa support? The thinness of the ls60w is really useful for slotting under a TV horizontally. I'm guessing the market is too small to justify but I can dream right? Also...

www.audiosciencereview.com

 

[dfuller]

The speakers that have sounded the biggest to me always have three things in common:

1, lots of woofer area (at least ~10" nominal, or equivalent)
2, the sheer size to be directive down below 300ish hz (or use some other fancy tricks to do that).
3, lack of audible compression.

 

[Sokel]

I've said it again while I have no explanation why,all the old studio guys I have met said the same,big sound = big Voice coils and with that,big cabinets and strong motors.
And another.
What i do as an experiment is to use my small desktop Fostex's at different heights with only a woman voice as content,(blind of course,with help and care to always be tilted to me)
I can absolutely localize that height,Is that maybe a clue?As bigger speakers tend to be taller?

Not clear thought,as even when I put them beside my big ones with the same content (so no bass clues but some midbass,all voices contain it) the big ones surely sound bigger as if the sound comes from a bigger space.

All that with the same SPL of course.

 

[Sokel]

You can have subs with one or two woofers directly under the bookshelf instead of a stand which make them from configuration point of view and with some suitable EQ like a similar floorstander as I have done here:

KEF R Series with MAT white paper

I know this is r thread but seeing as the Kef guys are here... Any plans for a centre version of the ls60w and/or adding wysa support? The thinness of the ls60w is really useful for slotting under a TV horizontally. I'm guessing the market is too small to justify but I can dream right? Also...

www.audiosciencereview.com

You can but there are some rules about the distance between mid and woofer which is not standard depending x-over freq and driver's-cab characteristics of course.
It takes a lot to optimize that distance when the x-over goes higher than 200-300Hz which is what makes a true 3-way different than sat+sub.

 

[Ron Texas]

Size matters.

 

[thewas]

You can but there are some rules about the distance between mid and woofer which is not standard depending x-over freq and driver's-cab characteristics of course.
It takes a lot to optimize that distance when the x-over goes higher than 200-300Hz which is what makes a true 3-way different than sat+sub.

I agree on the first but not on the second, a true 3-way can have (be doesn't have to) also its x-over at 200-300 Hz, actually some of the 3-ways I like most are like this.