Low-sensitivity speakers — What's special about them?

That advice — get a more efficient speaker — makes sense to me, but before I just twist with every opinion I come across (I'm a newbie, so I'm pathetically suggestible), I'd like to hear the other side. Viz.,

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Look the reason you seem to be a  bit skeptical about going towards the high sensitity speakers, is all due to 50 years of marketing ploys from The Industry.
Likea carrot ona stick we were all led down that path,, 
Look at homw many xover designs came out in the past 50 years, 
Hundreds. 
The odds of us ever comming across a  good quality high sensitivity speaker were  slim to none. 
All the audio shops jhad the box xover designs.
It too me 20 yrs to figure out that maybe xover low efficiency was not voicing my clasdsical music the wauy I REALLY wantedd to hear it. 
And so after some hesitations, I FINALLY began ordering several cheap chinese wide band speakers. 
After 4 months experiementations, pay off was nice.
It occured to me to jump  the xover ship forever.
Its takes some curiosity and guts to make this ship jumping.

I'm glad I do not ever again have to hear my classical througha  xover./low efficient speaker ever again. Its like my music is playing for the very 1st time via a  higher (91db) full range 4 inch cheapo chinese speaker. $20/pair, And you get what you pay for, = Not worth 1 cent more than $200 = Avoid all chinese full range = trash. 

QUESTION: What is the value in low sensitivity speakers? What do they do for your system or listening experience which make them worth the cost and effort to drive them? Has anyone run the gamut from high to low and wound up with low for a reason?

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I sure wish I had UNDERSTOOD 
These Q's way back when
And after grasping this high sensitivity vs low sensitivity issue, 
Made some honest answers to MYSELF IN all honesty. 
Its kind of like Jimi Hendrix's 
*Have you EVER been experienced?
WEll I have*

Most audiophiles do not understand what a  higher sensitity wide band driver is, does/how it works/how it sounds.
Second, they have noo interest to understand, NOR ask any Q's. 

Your Q's  show your ~~puzzle-ment~~ over how folks can continue down the xover/lower sensitivity path to musical reproduction. 
No doubt over the comming decades as new audiophiles enter this hobby, they will be asking more Q's , wider interest in whats avaliable Before they make a  purchase. 
Xover/lower sensitivity designs  sales will take a  hit, Most  labs will not survive the economic downturn. 

hilde45 OP2,229 posts02-13-2020 5:55pm

I’ve not bought any power yet. Thanks for the replies. I understand the technical trade offs better, now. If one had the bass covered by a subwoofer, it seems there’s no positive, specifiable, aesthetic reason to prefer low sensitivity speakers. I think that captured every remark so far, no?


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Yes EXACTLY

If one has a Scanspeak super woofer (retails at $500-$1500 EACH!!!) then you already have all the bass your dreams could ever dream.
There 100% pure rock solid bass, Done
Now we move on to 800hz-15k hz range
Here is where higher sensitivity speakers shine in all the glory over the muddling lower sensitivity speakers,
This is the range where the battle gets gutsy.
Higher sensitivity wide bansd will out shoot xover designs every time. well lets limit the highs, to say 10k, Although if you ck AER’s web site, they claim
80khz. top end, which we all know the ultimate top end is 15khz, and really there is not much above 10khz.
My tech geek mentioned we want a certain **ambience** to be present in the 12k-15k range, sort of like a sparkle and shimmering on cymbols and other percussion. , Piano’ high notes and such.
But I have no idea on how the new wide band’s voice the 12k=15k range.
The earlier designs had roll offs.
I am waiting to order a pair as i type. the newer wide bands that is,

So back to your point
Exactly, If one has a Scanspeak Super Woofer acting as sub,
There really is not need to use a  xover design traditional speaker for the 1k-10k range.
This range under lower sensivity speakers sound like a  wet blanket has been thrown over the front. 
vs the live soundstage of a newhigh tech wide band.
If you purchase a  wide band and you feel the low bass is a  bit thin, well go ahead and get a  super Scanspeak Woofer for extra bass. 
Bass that will beat out Wilsons' higher end  speakers.

mrdecibel2,476 posts02-13-2020 8:01pmEvery speaker, to some extent, makes some trade offs, and, at all price points, imo. The thing is, as a listener, we need to determine, what musical parameters of recorded music, are most desirable to each of us. And as explained above, the speaker / amp / room combination, should be matched as close as possible, to work together. Someone above, although appreciating the efficiency of horns, prefers other things. I, on the other hand, prefer horns, and the efficiency, is simply, icing on the cake. Advice : Take you time, and listen to as much gear as you can. Also, go listen to some live, " un-amplified " music, as this will give you an indication, as what to listen for, in audio gear ( speakers, specifically ). My best, and Enjoy ! MrD.


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Great insight, assessment.
Price point/budget constraints.
Going to live musica events, then go back  lsiten to ones speakers,
= Higher sensitivity = near as live as you are going to get. 
I madea  experiement
One channel Seas Thors, with Mundorf Silver Gold caps
Other channel
cheap chinese full range 6 inch. 
The winner, cheap single chinese 1/2 full range (lows/highs rolled off)
Judging midrange only as thats all this cheap chinese 1/2 full range could pull off, Specs claim 91db, about right.
Seas Thors 87db. sounded likea  wet blanket was thrown over them. 
Next minute ripped the brand new Millennium's out the Thors , placed them on Ebay at 60% off my debt of $700 sold in 2 hours. Free shipping.
Never will ever consider low sens drivers for my 1khz-10khz range.
can't, My classical music demands at least 92db. 
For low bass 30hz-800hz, yeah OK midwoofer/Mundorf caps, = doable. 
But I'm expecting the new high tech wide band to take care of the lower fq's. 
Won;'t know til I order a  pair. 

timlub1,887 posts02-13-2020 7:59pmWhat it comes down to is... really good mids with any type of top end extension without cone break up is hard to find in true high sensitivity speakers


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I think AER and Voxativ has made some  advances in these issues  vs the earlier labs, attempts in high sens wide band drivers,  Lowther/Fostex. 

basically now its a contest between the best of xover traditional designs , Wilsons and the hih end wide band designs, AER and Voxativ. 

If we list the +'s/-'s of each speaker.
You'll find the xover traditional full range style will end up with more -'s in the tally of  specs/practicality/audiophile happiness.

I have very specific design parameters that I'd like to achieve.  

Hey, @timlub --

Not sure what we’re doing here, but I’ll bite. I assume that you are simply saying that it can be achieved with horns.

A combined effort perhaps of incorporating a horn/waveguide and letting an extra cross-over point come into play (downwards), hereby letting the two "main" driver elements better meet (like better power response at the cross-over point) as well as to achieve higher sensitivity and better control of directivity. Hybrid designs of both a direct radiator and an acoustic impedance transformer have their own set of challenges, but carefully implemented it appears good results can be had.

The Lamar driver is very good for sure. Its top end extension lacks, but its nice sounding, fairly linear (plus or minus 5db from 200 to 2500) and can cross as low as 80 hz. Yes, add a tweeter and you’re good to go. So, thank you for posting 1 horn driver that is capable The 12a horn is huge and you are correct, this has not been the target in my designs.Something a little more compact.

The 12a’s are behemoths for sure, and won’t cater to WAF/spouse factor or interior decoration aspirations, unless one for some reason fancies big horns. Have yet to listen to the Lamar-fitted 12a’s in question, but on my next trip to Brighton will.

I’ve been looking for a couple of parts... a 12 to 15 inch that is closer to plus or minus 2 from 40 to 1500. I’ve contacted 3 manufacturers, I’m told that it can be built for me, but as of now is not out there. The AudioTechnology Flex 15 is close but its only 93db. and its only getting 93db because of its very low QTS of .22. Another factor is trying to get a woofer. I’d really like to have more like 97db and I need some xmax. Most every driver that comes close to what I’m try to achieve has a very low xmax. Again, I’m told that I can have it manufactured, we’ll see.

Coming back to my first paragraph I’m wondering why you’re adamant in regards to 40Hz extension from a 12 or 15 inch that extends up high as well, while maintaining a sensitivity goal around 97dB’s - is it to avoid the use of subs and keep simplicity? 1.5kHz extension for this size of driver is a stretch as well (beaming, break-up). My first thought would be to give up extension down low to achieve the desired sensitivity (and then augment with subs), and next I’d think in the direction of a fitting waveguide perhaps (OSWG?) with a compression driver, for a variety of reasons really, but also to lower the cross-over point more comfortably to about 1kHz. I’m sure you’ve heard of Earl Geddes’ Summa and Abbey speakers (now apparently NS15 and NA12 respectively) - just to give an idea of a 2-way design, in the need of subs augmentation, and a sensitivity in the higher 90’s. Actually the first Summa iteration of Geddes used the B&C 15TBX100 - crossed at approx. 900Hz, if I’m not incorrect - the same driver I’m using in my pair of tapped horn subs.

EDIT: giving up extension down low from a suitable, say, 15 inch would not only raise sensitivity, but high-passing it at about 80-100Hz (for subs to take over) would make it even more agile/clean sounding up to its cut-off point.  

Hi @phusis

Not sure what we’re doing here, but I’ll bite. I assume that you are simply saying that it can be achieved with horns. The Lamar driver is very good for sure. Its top end extension lacks, but its nice sounding, fairly linear (plus or minus 5db from 200 to 2500) and can cross as low as 80 hz. Yes, add a tweeter and you’re good to go. So, thank you for posting 1 horn driver that is capable The 12a horn is huge and you are correct, this has not been the target in my designs.Something a little more compact. I’ve been looking for a couple of parts... a 12 to 15 inch that is closer to plus or minus 2 from 40 to 1500. I’ve contacted 3 manufacturers, I’m told that it can be built for me, but as of now is not out there. The AudioTechnology Flex 15 is close but its only 93db. and its only getting 93db because of its very low QTS of .22. Another factor is trying to get a woofer.  I'd really like to have more like 97db and I need some xmax. Most every driver that comes close to what I’m try to achieve has a very low xmax. Again, I’m told that I can have it manufactured, we’ll see.

@timlub --

Somehow I got around to base my first post only on the quoted passage by you, and not the whole post (I quoted the passage early the day before yesterday to reply, but didn’t get around to actually write it until later on, and so blissfully forgot about the rest of it).

Now taking that into account I better understand where you’re coming from, though I fail to comprehend how you apply a "true high efficiency" design with direct radiators. It appears however that this is what you believe to be the best outset to work from as opposed to horn-loading, and so presents the specific challenges laid out by you - i.e.: if a sealed bass principle is preferred (less efficient compared to a ported alignment, not to mention horn-loading) and you seek to minimize cross-over points as well, then the challenges you find yourself placed in the midst of are certainly present and understandable in the context of aiming at high efficiency.

For what it’s worth: a friend of mine has build a pair of wood replicas of the Western Electric 12a’s (fitted with a Lamar driver), and they in themselves cover from ~100Hz to a few kilohertz (sorry, can’t remember the upper frequency cut-off). Add in a horn tweeter hung down in the midst of the 12a horn and a pair of horn subs beneath them, and you have yourself a very(!) high efficiency all-horn set-up, 3-way at that, with a range potentially from 25Hz on up. Apparently several who’ve heard this setup (though with twin 15" AE units in open baffles per side for the lower range) regard it as the best they’ve ever heard, not doubt in large part due the specific frequency range of the big 12a horn driven from a relatively small and very lightweight diaphragm.

@phusis
My original post towards this subject was dealing with what it takes to design a true high sensitivity design that is capable of audiophile use. That is why I posted a few driver spec's in that post to make sure knowledgeable people knew that I was referring to drivers. 
Yes, in general,  I was speaking of cone speakers and woofers in general.  Many may not realize that MOST cone mid range drivers are woofers that have very good top and bottom extension.  The higher in sensitivity that you shoot for,  In general, the worst the top and bottom end extension gets. 

@timlub --

So you say "Percieved" and that these mid and bass drivers with good extension and little cone break up are readily available.... recently I’ve shopped a few hundred drivers looking for such. Please list the model numbers.

Perhaps we’re addressing this matter differently by now. Initially you wrote "really good mids with any type of top end extension without cone break up is hard to find in true high sensitivity speakers," so I set out to express my impressions from a complete speaker system - not focus on a single driver. Cone break-ups can be more or less challenging depending on your design goal and overall requirements, and nothing yet has been specified into the nature of a given design to illuminate your context.

Where "true high sensitivity" goes horns seem to be dictated, and with midrange compression drivers I’d wager their upper range (clean) extension isn’t a bigger issue, if as much as their lower end limitation in a given horn. Knowing what one is dealing with here would dictate what to work around rather than against, and with horns in particular it’s not exceeding the bandwidth of each horn element to main good power response etc., so a full-range all-horn system would typically require a 4 or 5-way approach.

With true high sensitivity speakers an excellent midrange can be had via a range of designs, so why would cone break-ups be a particular issue here if the design accommodates inherent challenges? You’re addressing and calls for the existence of specific midrange (and now bass) drivers with good extension, so what’s your context, specific use and related issue?

@phusis 
So you say "Percieved" and that these mid and bass drivers with good extension and little cone break up are readily available.... recently I've shopped a few hundred drivers looking for such.  Please list the model numbers.  

That aspect @phusis "a live sound imprinting" is significant. Thanks for putting it that way. Another, good metric to judge speakers by; very useful.

@timlub --

What it comes down to is... really good mids with any type of top end extension without cone break up is hard to find in true high sensitivity speakers.

Perceived really good mids and upper range extension (i.e.: "any type of top end extension" leaves room for quite a lot) is readily available with true high sensitivity speakers - without necessarily requiring exotic cone materials. Being so I gather cone break-up, in whatever shape it may present itself (or not), isn't an issue. 

@unsound --

One will be hard pressed to find high sensitivity speakers that can produce respectable step response or square wave response.

Question is whether it holds significant correlation in regards to perceived sound quality, not least depending on who you're asking. There's hardly consensus here, but transient behavior in (time aligned) all-horn set-ups, representing the best efficiency, are hardly the ones to fault the most in this regard. Even so, relevance/correlation is required. 

There's a lot more to speakers than sensitivity alone.

Sure, but I'll definitely side with poster @alexberger's above posts on the significance of high sensitivity (and headroom) as an aspect highly overlooked by the audiophile community at large, and that it's an essential ingredient in achieving a live sound imprinting. Those who've heard a well-implemented all-horn system covering most of the audible range will know this kind of sonic ignition, scale, presence and ease simply doesn't exist in low to moderately sensitive speakers; they just sound restrained and malnourished by comparison, not that they can't be highly capable in other areas. Yes, high efficiency and full-range requires BIG size, but you want to eat your cake too that's the pill to swallow. Personally I find it's definitely worth it. 

Thanks, unsound. That helps me make a bit more sense of the measurement which the page for the speakers I ordered list. I bought them for the reputation and reviews --and the notion they'd be sized well for my listening room, which was confirmed by the maker. It was only later on that I realized the sensitivity was low. Here are the stats/landing page for that speaker. http://www.salksound.com/model.php?model=WOW1

With the vast majority of typical speakers one can make a speaker's impedance more linear by lowering it's impedance, which can allow amplifiers to provide a more linear frequency response through those speakers. But doing so will decrease the speakers sensitivity.

One will be hard pressed to find high sensitivity speakers that can produce respectable step response or square wave response.


There's a lot more to speakers than sensitivity alone.

@larry5729  I will. I’m glad you think the Salks will be good. I went listening today to some amps... and heard some Spendor A4s and some Elacs S61. They didn’t do much for me, though they sounded good. Looking forward to getting the Salks, someday. I ordered them Jan 9. 

A phd in a post, out for beachside valentine lunch. Our path similar!
will write more later!!!

I would go with the SALK speakers.  When you talk to Jim Salk tell him Larry Edwards from Denver sent you,  His speakers are just incredible.  You will love Jim.

@tomic601 , Happy Valentines Day to you too, sir ! LOL. We all have a story, so I hope my story is interesting, and not too long, so, I apologize. I have stated in many posts, that personal taste, is what this hobby is all about. The arguments between SQ differences folks have, have been ridiculous, as far as I am concerned. The earlier someone finds their cup of tea, the easier it will be to build a system around that, tweak it, get it closer to their ideal. During my childhood ( before 10 ), my dad had a Fisher 500C, Dual 1229 with Shure cartridge, feeding AR3a speakers ( all of which I had acquired after his passing, and just recently sold, very reasonably, to a listener who would enjoy them much more then I ). My dad, wanted to move away from the Fisher, with the onslaught on these ss Japanese receivers, and replaced it with a Sansui 881 Deluxe. At that same time, I had just received my pair of Klipsch Cornwall Verticals from my singing coach / music teacher ( he upgraded to Khorns ), and I used the Fisher, along with an AR table. That was the time, when my ears became " tuned " to the horn sound. I found the AR3’s amazing, do not get me wrong. I became a tweaker, sold and managed at a few audio stores, became a rep for a short time, and then became an independent audio consultant, helping people spend their money on systems. Not everyone liked Klipsch, Altecs, JBL’s, etc, as much as I. I understood the varied differences between all of the speaker designs, and at the same time, I understood the weaknesses. I owned multiple systems, having owned Vandies, Maggies, MLs, DQ10s, Gale 401s ( a wonderfully musical, yet very inefficient speaker ), and so many others, and heard a plethora of others during my travels. Same with the front end gear. Before, and during the intro of digital, I was enamored with open reel tape, which was fabulous, in every sense of the word. I also realized and understood, at an early age, that recorded music, will never sound like real, unamplified music. Once the instrument, or voice, reaches the microphone, it is a done deal. Those listeners who keep changing equipment, like I, underwear, fall under several categories. ( 1 ) Have not found their flavor, ( 2 ) Are looking for a " sound that does not exist ", meaning, very high expectations, ( 3 ) Does not have the auditory expertise in system matching and development, ( 4 ) Have not spent enough money on the equipment, ( 5 ) Have spent too much money on equipment, to the point, they are hearing every weakness of the recordings, which are many, and is why, what they listen to, are only the best mastered, and not necessarily, the most musical, ( 6 ) Does not have a " reference " of music reproduction, to guide them, ( 7 ) Have a serious, neurotic personality, ( 7 ), Can simply, never find happiness in a system / room........There are more, and of course, a combination, of many above. I am not trying to sound like, or appear to be, a know it all ( although to some extent, I do know a few things, lol ). Again, I apologize to all. Enjoy ! MrD.

Thanks. I'll try to watch the video. Extended auditions are in order. 

All transistor amplifiers (except class A) have thermal distortions (similar to low sensitivity box speakers). The transistors parameters change with changing of temperature.  
This distortions have inertia. As result you can't fix these distortions by feedback.
Our brain is very sensitive to these kind of distortions. These distortions cause tiresome and decrease enjoyment from listening music.
So, if you use combination of low sensitive  sensitivity box speakers with powerful  transistor amplifiers you get thermal distortions in a square.
As a result, you have a tiring, depressed, suffocating, annoying sound.
I think this combination is the worst delusion of audio industry.
Sadly, most of audiophiles don't understand it. 

What it comes down to is... really good mids with any type of top end extension without cone break up is hard to find in true high sensitivity speakers.

The Classic Audio Loudspeakers use a beryllium diaphragm with Kapton surround in their compression drivers; the first breakup is at 35KHz. The model T3 which I have at home is 97dB and 16 ohms, flat to 20Hz owing to dual TAD 15" woofers.

I listen to music using Magnepan 20.1s, which are a 4 ohm and 85 db sensitivity speaker. Yes, they require some power to drive, especially if you don't want your amp to overheat. But you don't have to pay a fortune for an amp that can drive them. Emotiva has the A-300 amp for $400 right now and it has 150 wpc at 8 ohms and 300 wpc at 4 ohms. The 300 wpc is enough to make the Maggies sing.

I think it’s a common misperception that smaller speakers mean you can have a lesser amp to drive them. The exact opposite is case if the speakers are good quality and you want to get the most out of them. 

More and better bass out of a smaller package with the right beefy amp capable of delivering it. 

@mrdecibel as always I so enjoy our measured and reasonable exchanges based on mutual respect for different tastes :-)

OP did you watch the video ? Red cone movement is out of phase to the input and 100% distortion....

@aewarren Can't argue with your logic. For me, the key factor is the most revealing order-of-discovery, if you will.
I get a better sense of speakers by swapping them in and out and keeping the amp constant.
I am not sure if the experienced change would be nearly as great if I kept the speakers constant and swapped out the amps.
This latter factor is difficult because I am not sure which speakers to get yet! I need to choose them first. Then, I'll choose among a few amps for the best component fit/match.
Down the road, I can upgrade/change speakers as long as I have enough power or a fairly flexible kind of power.

It's really about component matching. If have decided upon a speaker system you like, then you need to match them with an amp that will drive them adequately. Conversely, if you have found an amp you like, match it with a speaker system. In other words you don't want a low powered amp driving inefficient speakers nor waste a high powered amp on high sensitivity speakers.

1++ Almarge and Atmasphere:)

@andrew -- I looked long and hard at Ascend Acoustics. They have great deals and what seems like amazing speakers.

@melvinjames The goal for me would be to avoid exactly what you describe by buying enough power. My understanding was that if there’s enough "headroom" then one does *not* have to crank things up to get the response needed for engaging sound. Perhaps I had that wrong, but that’s what I thought I learned in this video: https://www.youtube.com/watch?v=th8CxTk22pY

For the past couple of years I’ve been happy running a SET/high-efficiency system but previous systems were all of the higher-power/low-efficiency type. Obviously, there are compelling reasons for setting up a system either way. One thing about the low-efficiency approach I don’t care for is the need to crank the volume for the speakers to come alive. Low level listening just sounds anemic otherwise. Of course, some people get around this using EQ or headphones. Something to consider nonetheless.

I have a bedroom system w Sierra2ex 89db sensitivity. I run a pair of 80w class a monoblocks and a pair of REL t-zero. I can rock the entire house from that little system. I was worried about the same thing, but I gambled on this and won. 

The advice to get speakers that I enjoy and then find the amps to match is how I was initially going forward.  It was the warning that I might be boxing myself in that caused me to reconsider the speakers that I had heard and enjoyed. But there are more speakers out there and some of them might be higher efficiency...so there’s no harm in just doing more listening! Of course if some delightful and expensive tube amplifiers really make a big difference to the sound, well, then, it might not hurt to consider that as a potential orienting factor for the speakers! You see how I get turned around and around! Still, it makes sense to start with the speakers. 

I’ve always gravitated to lower sensitivity speakers mainly because they were the speakers I enjoyed the most. Pluses and minuses either way I suppose. Dynaudio makes excellent speakers if you buy the Evokes I bet you would be quite happy. Down the road you could consider the opposite and drive a highly sensitive speaker with a low wattage tube amp, that is what makes this hobby fun.
Right now I am enjoying Magnepan LRS speakers that are quite different from box speakers. Could I go back to Dynaudio or Totem someday - probably. Anyway my point is buy what sounds good to you, no matter what you buy you’ll have to match it up with proper amps / stands / Dac anyway so don’t sweat it. 

Every speaker, to some extent, makes some trade offs, and, at all price points, imo. The thing is, as a listener, we need to determine, what musical parameters of recorded music, are most desirable to each of us. And as explained above, the speaker / amp / room combination, should be matched as close as possible, to work together. Someone above, although appreciating the efficiency of horns, prefers other things. I, on the other hand, prefer horns, and the efficiency, is simply, icing on the cake. Advice : Take you time, and listen to as much gear as you can. Also, go listen to some live, " un-amplified " music, as this will give you an indication, as what to listen for, in audio gear ( speakers, specifically ). My best, and Enjoy ! MrD.

What it comes down to is... really good mids with any type of top end extension without cone break up is hard to find in true high sensitivity speakers.  It has already been mentioned about bass.... The bigger the magnet/motor structure of a woofer, the more sensitivity and the more mass it needs to produce low fs/Qts.... these are attributes that lead to deep bass.  As you as you ad mass fs goes down and qts goes up,  but the trade off is that sensitivity goes down.  
Its not a perfect world.  I try to find the sum of parts as a whole to start the design process. Not being able to find any single part can kill an entire speaker project.  
Alot of people really like sealed box speakers for bass, I am one of them, but woofers that work well in a sealed box need a qts of a minimum of .4 and preferably .5 or even a bit higher.... Look at spec's on high sensitivity woofers,  you'll see .2 to .35.  This is just too low to produce bass in a sealed box system,  Although .35 can produce very satisfying bass in a ported or vented design.  You also have to consider that most good designers prefer to keep the crossover out of the vocal range,  so again,  it requires drivers with a fair amount of extension on the top end or bottom to pair with other drivers. 
There are plenty of excellent parts to design high quality low to medium sensitivity 2 or 3 way systems with great results. 

+1 tomic601.  I have installed a  pair of Vandersteen Model 3 Subwoofers.  They are sublime.

I've not bought any power yet. Thanks for the replies. I understand the technical trade offs better, now. If one had the bass covered by a subwoofer, it seems there’s no positive, specifiable, aesthetic reason to prefer low sensitivity speakers. I think that captured every remark so far, no?

IMO a fantastic speaker for you would be Vandersteen VLR signature on Sound Anchor stands with a Vandersteen Model 3 subwoofer with 11 bands of analog EQ for perfect bass at the listening position and a built in amp that takes load off your main amp yet preserves transfer function of the main amp

It’s not just about bass, one needs to consider the source the root causal reason for higher output.

one form of higher output is achieved with a mechanical device to focus energy - imo at cost to fidelity. Horns are not everyone cup of tea. Since to appear focused on dynamic drivers, I will comment more about those..

for dynamic driver speakers, non pistonic motion creates higher output thru constructive and destructive interference. Check out the Utube video on the comparison of two 5” midrange, for a dramatic and easy to understand visual representation of in and out of phase behavior. That video is linked on the Vandersteen website. For a non pistonic driver ( most of them frankly ) A great deal of output is just in and out of phase trash. When a pistonic cone assy is fitted to the driver with equal mass, output drops. The bottom line is trash counts in the efficiency measures. Another reason to listen and not get too wrapped up in less than critical specification. Pay attention to impulse response tho!