Enough SET Power for Rock and Roll

I'm still trying to figure out what SET amp would sound best for Rock and Roll (and other music but especially Rock) on Klipsch Cornwall II speakers (101dB efficiency) in a room about 18x13 (with kind of medium acoustics - not live, not totally dead.) On a Marantz 2230 (which sounds very good, surprisingly good for being ~35 years old and 30 watts of solid state) I found that when I crank up the Rock and Roll on the Cornwalls I'm listening from about 89dB to 97db, but frankly if I wasn't worried about clipping or blowing out the speakers or receiver I could probably enjoy an occassional 100 dB :) - but if I have to live at 97 dB and below I could. (Measurements made with a Radio Shack meter set on fast, C weighting - taken from 1 meter away from the speakers, and also at the main seating position which is about 10-11 feet from the speaker plane.)

From many posts here and over on AudioAsylum it sounds like a 45 SET amp would sound great but might not have enough oomph - although that isn't 100% certain. It seems that a 2A3 SET amp would have a better chance of handling the loud music and the "complexities?" of Rock (and orchestra music) vs. say simple instrumentals and vocals. Next up would be a 300B SET, more power but some people seem to think it gives away some of the "magic" of the 2A3 and especially the 45. It isn't so clear to me from reading the various posts how any of these tube types do on the low end; I think low end (reasonably deep and tight) is needed to do Rock and Roll well - but so is good midrange and highs, so it's a balance, of course.

What do you think, more power and listen loud with ease, ie go with a 300B, or can a 2A3 or possibly a 45 do it all? Or is it possible that SET just can't do Rock and Roll seriously with 101db speakers in a 18x13 rom? In which case, next up is what kind of tube amp? If SET makes sense, I'd like to give it a try but I don't want to push physics or the budget too hard with experiments that aren't likely to work.

We just had a four hour listening session last night that included the MFSL of Queen's "The Game", and Robin Trower's "Bridge of Sigh", with Coincident Frankensteins shining brightly through Coincident Total Victory IV's. I love the Franks on hard rock. The bass is insane! Tight, organic, articulate and totally satisfying.
Some guy's selling a pair of original Franks with KR Balloons and two other pairs of 300B's for $2600.00. That's pretty close to a price you could safely "audition" them with your Klipsch pair. Make sure you have good power cords with these amps, though. A lot of current for eight watts!
I personally like the KT-88 type tube for having authoritative bass with beautiful mids and highs. This tube was invented for audio, and is readily available for reasonable prices. A parallel single ended integrated amplifier (using 2 KT88s per speaker) offers 30 watts. But, in reality, w/ spkrs that have 101db of sensitivity, "how many" watts should not be the concern but rather "how good" of a watt can you get. Your spkrs actually do the work in this case. 3 watts should knock sheetrock off your walls. I still like the sound of the KT88 type tubes though and even a single ended amp using (1) kt88 per spkr. will offer 15 watts. Also, don't overlook the importance of the output transformer (not in OTL amps of course). The best sounding amps will only come from the best, musically driven manufacturers. I also credit the CD player with providing the quality of sound that the rest of the system gets to work with. Once your music leaves the CD player, it will not get better. It will get worse, but not better. Actually, to get the best sound per dollar spent, make sure everything in your system has similar quality. (spkrs, cabling, electronics & especially the source) Just my opinion. Hope this helps.
I also use the Coincident Frankenstein MK2 amplifier and their 8 watts per channel(300b) will be surplus power for your needs. My room is 14x26x8 feet and opens into an ajoining 17x 24 room. My speakers are 94db efficient, yet if desired the amp can easily drive to sound levels of 95 to 100db with ease and no hint of strain. Given your speakers and smaller space you should`nt have any problems. I can`t speak to other 300b tube amps given the differences in transformer quaility, driver tube choice and part selection. Best of luck.
I haven't had the pleasure of hearing the Franks, but I'm consdering them. It's hard to fathom 8 watts having a lot of bass....I'm not doubting anyone's claims it's just hard to wrap my head around that statement. Which is why I thougth about going to the dragons, but now not sure again....
To answer your concern honestly, yes the Frankenstein amps can do 'very' good bass. It depends on your speaker(load characteristics,efficiency,crossover type etc...) this is really the key. It ultimately won`t match the more powerful Dragon(211 tubes in push-pull). There`re always some degree of trade offs. The choice of 300b tube makes a significant difference in the bass quality also.

The Frankenstein has a superb power supply, over speced transformers and uses the very potent,high current 6em7 as the input/driver tube. It`s a exceptionally capable amp'if' matched to the appropriate speaker. I`m using the marvelous Takatsuki 300b tube and it drives my Coincident speakers(94db and 14 ohm load)with utter ease and control. I hope you get the chance to hear the amp with a proper speaker.
IMO 300B would probably be your best and safest bet given the levels you wish to attain at the distance from the speaker you listen at. The 300B will supply more headroom for the peaks.

Not that a 45 or 2A3 wouldn't work, but we manufacturer both a 45 amp and 300B amp and in our listening tests with 98 DB speaker at around 10 ft. the 45 does strain a bit when SPLs hit 100 dB (our test tracks include rock, big band, and large scale classical). It is still plenty load though for our tastes.

I use both a 12 watt 13EM7 and our own 10 watt 300B SET amp and play loud rock with no problems at all.
Interesting thread.

I'd like to try a SET based setup someday but right or wrong I tend to associate SETs more with Jazz and chamber music than rock and pop, which constitutes a fair portion of my listening.
It is really hard to say what volume level you are actually trying to achieve, and therefore, whether a particular amp or kind of amp is capable of delivering adequate power. Generally speaking, I would not expect power to be an issue with any 300b, 211/845 or tetrode/pentode used in single ended fashion (e.g., KT88, El34, etc. The 45 might be marginal and even the 2a3 might be marginal.

Aside from power, you need to first determine if single-ended sound is what will fit your sonic preference. Certain pushpull tetrode/pentode amps and many solid state amps deliver a harder edged attack to notes. This can be experienced as greater "slam" to the sound and might be preferred for rock music. Also, pushpull and solid state amps tend to have tighter sounding bass which adds "punch" to the sound. You need to hear a good SET amp (one with good output transformers is the key, and that generally means not a cheap amp), to decide if the sound is right for you.

As to the characteristic sound of particular tubes, there is considerable variation with brands and sound is also affected by the particular amps. Generally speaking, the 2a3 is the leanest sounding of the types you mentioned. It does not have as much upper bass/lower midrange as the other two and bas tends to be tight; the treble on a 2a3 is wide open and airy. The 300b is just the opposite-- it is warm in the upper bass and lower bass tends toward the loose side and there is less extension on top than a 2a3. The 45 is sort of in between. It has quite punchy, tight and deep bass and is warmer than a 2a3; it is also quite open on top like a 2a3 (for my taste, the only downside to a 45 is its lower power output). Properly implemented, ALL of these tubes can produce terrific sound, and it is a matter of taste and power requirement that will ultimately determine what kind of amp is right for you.

I personally think SET amps can do rock music extremely well. I don't listen at ear splitting levels, and at lower levels I really like what SET amps do with all types of music. At lower levels a good SET amp will sound more lively and vivid than a solid state amp or most pushpull tube amps.

One more thing, do not overlook output transformerless tube amps. This type of amp sounds VERY dynamic, lively and exciting. A 30 watt OTL would make a great "rock" amp coupled to high efficiency speakers.
I have certainly been able to get some strong bass and rock levels with both of the value-priced amp options from MiniWatt (S1 and N3). Great way to try out a SET for not too much cash. Remarkably quiet tube amps, especially considering the cost.
I wonder what pairings of SET and speaker might do rock/pop best?

Klipsch Cornwall seems like a good match. Are there better ones? What kind of cost should one expect between amp and speakers to really do it well along the lines Larryi described? Any good smaller speaker options?
I had a set (pardon the pun) of SET 45s. My speakers are 98 db. There was no-where near enough power...

So I built up a set of type 45 push-pull amps just for fun. Instead of about 3/4 watt, now I get something more like 5. So about double what I got out of my 2A3 SETs that I also had. One thing is for sure: the P-P 45s sound a lot better than either SET did before, regardless of volume- deeper bass, more extended highs, far more neutral and engaging in the midrange (nevertheless my 30-watt OTL took it to task immediately but that is another story).

DHT (Directly Heated Triodes) have a lot of linearity, but I don't see people comparing P-P to SET much in this realm, mostly because P-P DHT amps are somewhat rare. But I would consider it- you always want the amp to have essentially unlimited power regardless of the speaker for best result. With the Klipsch (depending on the room) that might mean 15-30 watts to really never be pushing the amp hard.

The problem with SETs is if you need power, the more power the amp can make the more the bandwidth is limited. By the time you get to 7 watts, most of them don't have much bandwidth below 30Hz (if they do then there will be no really high frequency extension...). This means that there will be colorations translating to lack of impact up to about 300Hz. But getting well below 15 or 20 Hz is no problem for a P-P amp, even if it makes 60 watts (and you can still have the HF bandwidth).

Now usually SETs are more transparent than many P-P amps, but if we are to compare apples to apples that P-P amp really should be using DHTs. If its a pentode amp *of course* the triode amp is going to be more linear...

The nice thing here is that with the Klipsch you pretty well can run whatever you want- its friendly to all known amplifiers.
My Audio Mirror SET monoblocks are rated at 45w - plenty 'o power for you. He also makes them at 20w.
I own a DHT pushpull amp that uses the 45 tube. It is a terrific amp--bass is tight and punchy, harmonic structure of instruments is fully saturated and realistic, and attack and decay of notes is very natural. These are all the qualities one would expect of DHT tubes. The biggest difference with SET amps is in soundstaging. SET amps tend to be better at presenting a big, enveloping soundstage in which the listener feels fully emersed rather than looking from outside in.

I mentioned high quality SET amp in my earlier post because there is a general impression that SET amps are lower in cost because of their simplicity. The problem with that assumption is that it is quite challenging to make decent output transformers for SET amps because of the high DC current saturating the core. The transformer is the key to a great SET amp, and good ones are not cheap.
The Audio Mirror stuff is very nice looking and appears reasonably priced.
I have a 2A3 SET amp @ 3 or 4 watts. It will rock with my 98db speakers.
But - Even when I had Klipschorns @ 104 db, and in a small 12' x 13' room, I always thought there were better options for rock. If loud is 20% or so of your listening, sure go for it.
But from your post it sounds as if loud rock is a majority of your listening. I would not recommend a 2A3 SET, I would skip the 300b SET and go right to a 211 or a parallel SET or PP DHT.
Flea power SET amps can do loud rock, but it ain't what they do best. Other topologies do loud rock best.
I wonder how some of the Zu speaker offerings compare to Klipsch in terms of performance and value for rock music off a SET type amp?
Here is what Steve Guttenberg had to say about Zus with a number of amps, including the MiniWatt:

I've heard the Jolida fx10 mentioned in that article do a surprisingly good job with a pair of Nola monitors. I could see it doing very well with Zu's. THe author seemed to like the Miniwatt as well. Will have to check those out.

How about Zu versus Klipsch in general for rock/pop music using a flea powered tube amp?
845 SET is the ticket. On 101db/w/m Zu Definitions, I can cave in my skull on clean heavy rock with 25w of 845 SET drive. You can also try PSET 300B at similar power, or 211 SET at about 16/16w with surprising drive. But unless you go for exotic big glass like the KR T-1610 or the Audio Mirror 6c33c SET monoblocks, 845 is the only SET for rock'n'roll. You can even find a few options for PSET 845, but you don't need it with 101db speakers.

I've listened to Klipsch Cornwall IIs with 45 SET Welborne monoblocks. I like to listen to rock and reasonably loud in a room about 18x14 or so. I think the 45s drive enough volume to just about get there. Would a little more volume be nice? Yes, but it's not that far from being enough. The 45s and the Cornwall IIs do very well together from top to midrange to bottom, but if there is one of the three that could go a little more it would be the bottom. I've tried other amps (more to get some deeper low end than to get more volume), including tube amps up to about 100 watts but the 45s are still the winner overall. I've also tried a Marantz 2230 and it's a very good receiver, but the 45s do a better job. Over course, the whole thing is somewhat system and room synergy dependent, and YMMV, but I think if you try 45s you might be happy to very happy, you will have a good frame of reference, and if you find something you like better you will probably be able to sell your 45s (I think 45s are becoming increasingly popular as more people learn about them). Let us know what you do and how it goes.

PS, the real answer is this whole think can be a trip/journey; so be prepared to have two of everything (amps, preamps, turntables, cartridges, speaker cables, ICs, etc. You will be able to A-B, settle on a winner, sell the loser, buy a new contender, and repeat; wash, rinse, dry, and repeat :)
this is an old thread but worth reviving- if you get an SET amp, and your speakers are truly that efficient, you won't need no damned 100 decibels to hear and enjoy the music.  you'll find yourself turning it down to 50-60 decibels and about 2-3 watts per channel, and you'll be hearing ALL the music, all the detail, with no ear fatigue- and you will listen longer to your recordings, and enjoy them more, and will be hearing details and vibes that you never knew were there.  when I first stumbled upon single ended sound, I was on the high power solid state trip- which is like some druggie chasing their first high, but never achieving it again.  solid state is all about bass hit and volume, not detail and smoothness.  what I found was a 12ad7 driving a 6bq5, per channel, is all you really need, if the PST, OPT, chokes, caps are all high quality, and my speakers are run of the mill consumer grade Technics 97 db/w/m rating from the 1980's.  what I did find was the 15" woofers are a must have for decent bass.  going down to a 12" or 10" just sacrifices too much.  still every nice sound but not quite enough for rock music.  I went the single ended PENTODE route.  simply because they are plentiful, cheap, and sound very good for a tiny investment.  the 300b is the top of the heap in SE sound.  it has that thick, syrupy sound that makes you want to close your eyes and fall asleep listening to it, which is what I like. I did tests with voltmeter and decibel meter in my 28' x 14' listening room, with speakers in upper corners of one long wall, and the sound is AMAZING.  the soundstage is UNBELIEVEABLE. I'd never go back to solid state except for maybe an outdoor party where volume was needed.  and what I found with the dB meter was, it only needed 50-60 dB sound level- not 100 dB.  and with the voltmeter, I took measurements and found out I only needed 2-3 watts per channel to achieve this.  realize your 101 dB rated speakers, only need ONE WATT to achieves 101 dB, 3 feet away from the speakers.   if you had 3 watts that would be plenty and your wife would be bitching to turn it down.  the great perk of these tube stereos is, you can listen all day and a relatively high level, and after 12 hours of listening, your ears are no phased at all.  no ringing or muffled hearing.  it saves your ears. 
ps- let me add, if you can see both your speakers in a picture of video view, they are too close together. the speakers have to be at least 20-25 feet apart to get the soundstage to emerge- the farther apart they are, the BIGGER THE SOUNDSTAGE. this is a simple but well kept secret amongst experienced veteran tube-stereo audiophiles. having speakers 10’ apart creates a tiny soundstage in miniature. mine are 28’ apart and the soundstage is HUGE, like a real concert, with depth that sounds like it’s 30 feet away in the front yard, and forward towards me only a foot away, while the speakers are in fact 14’ in front of me, to each side. yet the 28’ space between the speakers, creates a realistic soundstage with individual singers, instruments, etc. with drums to the background, just like sitting in the front row of watching a real band on stage. or, what you get is the effect of exactly where the mics were placed at the live recording, for instance the live Zeppelin double LP, it sounds like the stage is maybe 30’-50’ away, because that’s about where they had the mics to record it.
Rock music is loud and that's the way most fans want to hear it.  If you are an audiophile you want it loud with all the other good stuff audiophiles listen for.   

The opinions appear to be mixed whether a SET amp can truly do rock well.   I think most SET owners are willing to compromise in this area which is fine.  Some may have big large high quality speakers capable of the task, but those are not for everyone.  

Also I have yet to hear a SET do rock music loud and real at shows.   Most vendors naturally shy away from that kind of demo.

Its also true that in a small room in particular with agood setup one might get away with a lot more in this regard.

But it just does not seem like a natural fit for a lover of loud rock music to attack it with a SET amp.  It may still sound quite nice, just not the best for that kind of music.   

Then again we have to accept compomises somewhere usually when it comes to sound quality so one can pick whatever compromises works best for them.

For someone who liten to a variety of music including rock, the advantages may outweigh the disadvantages.    That's what it pretty much always comes down to when making a choice.

In my listening space with about 300b XLS 10watts and Audio Note E Speakers I love the pacing and emotional connection my system provides when listening to rock music. There is much about the way rock music is recorded in the studio with sound and instrumental layering that plays right into a SETs strengths. And the pacing of a great rhythm section is also why SETs are great for rock music. I kinda doubt 45 SET would give me the weight with my speakers when listening to rock. Maybe a direct coupled 2a3 SET would...who knows.

Now if you need gut punching bass at live concert levels you may need huge sub woofers and horns if that is your priority. You mention rock and roll, i am referring to rock music past and present. I don't listen to rock and roll from the 50's, not that it's not great music, it simply not a priority for me. I totally dig Elvis and his first band from the 50s. Have not heard it on my system, I probably should.

Audio Note always has one of teh best sounding rooms at shows I’ve been to.

They seldom have rock music playing, but the larger bass driver and box used and corner placement combined with efficiency and overall quality is a very good example of a system built to be able to do most all things very well.

I’ve stolen the corner placement idea from them and use it with other box speakers I have of similar concept and the bass reinforcement corner placement provides alone might help push a system not otherwise built for rock music over the hump. Along with all the rest.

The only penalty paid I think is depth of soundstage in some cases but most people can probably live with that tradeoff.  Most traditional box designs are not champs at soundstage depth in particular to start with.
you'll find yourself turning it down to 50-60 decibels and about 2-3 watts per channel,
There is a reason that it appears that you don't need the power if you have SETs. It has to do with how they distort and how the human ear/brain system uses higher ordered harmonics in order to gauge how loud sounds are.

SETs don't have measurable distortion at low power levels (the source of their 'inner detail'); as power is increased the 2nd, 3rd and 4th come into play (the source of their 'warmth' and 'bloom') and after about 20% of full power is reached the higher ordered harmonics come into play (at full power most SETs make about 10% THD; if anyone claims less its either because they spec the power at a lower level or because they are running feedback. Because our ears use the higher ordered harmonics as loudness cues, the amp might appear to be more 'dynamic' (since the loudness cues or excess distortion is on the transients where the power is) or it might sound 'loud' simply because of this distortion.

If you take away that distortion it won't sound loud anymore and you will naturally turn up the volume, perhaps by as much as 15 db or more depending on the amps and speakers! Note also that by me telling you this, you will now be aware that distortion is why the amp sounds loud and dynamic so the experience might not be as pleasant as it was before. The cerebral cortex is funny that way. So I might have ruined it for you.

FWIW, about 90% of the time audiophiles are talking about 'dynamics' (and usually the plural not the singular) they are really talking about distortion, and as a result the word 'distortion' can safely be substituted into the sentence without changing its meaning.

Since it really is about high end audio sounding real, the solution is of course either more power or more efficiency or both. The thing is, the real challenge is bass (the holy grail of both SETs and high efficiency loudspeakers), which lacks more as the amplifier power is increased. The bigger the amp, the less bandwidth. That's why the 300b was king 20 years ago, but by 15 years ago the 2A3 supplanted it (sounds better due to greater bandwidth in the output transformer) and finally that got supplanted by the 45. IOW there is an economy of scale! The result is unconvincing bass (I played string bass in several orchestras for many years- I'm hard to please in that regard) and no way around it. The smaller amps play bass better but the speaker efficiency you need to really show off what the amp does means you can't have any bass. This is excluding the use of a subwoofer of course.
Atmasphere, I have read your posts on this subject of loudness in a SET amp over the past few months and started to listen for those queues of loudness in my system. It may be because I am running at slightly over 10 watts ( 375v plate to heater, 85ma, 2700ohm primary on my audio note output transformers) but I rarely hear those loudness queues you are speaking of. Even on very dynamic orchestral music I hear power and it even seems that there is additional headroom to spare.

My sound is very different than that of a large horn system. I've heard a large horn system with sub woofers and it can play at concert levels without strain. Sounds like real instruments. That's the focus of this particular horn system. I've heard CH AMPS and YG speakers and this seemed to have more headroom than mine. But these systems also don't have the touch and texture and layering of my system. My system doesn't do instruments at concert levels, and if it did I would have the police knocking on my door here in Brooklyn ny. Honestly who can stand live concert hall level music in their living room anyway. I've listened to a string sextet in a large living room and the group put out a lot of sonic energy and many times it sounded loud...too loud. If that's the goal of your system your hearing will be gone very soon. That's not the goal of my system, my system does take me inside the music to the heart in a most addictive way. 

Mapman, I’ve heard speakers like volti Vitoria that are based on klipsch Lascala that are more immediate sounding than Audio Note. There are lots of speakers I’ve heard but that do many things better than AN, but as you say they do many things well and play lots of different music and do well with 8watts. It’s difficult to find speakers that are good at getting to the heart of many types of music.
jetrex yes I've heard the Volti speakers at shows as well and understand what you are saying.
The volti vittora have that immediacy and warmth that I found captivating. They are huge and expensive and some say they need a subwoofer, but wow!. They may need more than 8 watts to come alive. I heard them with what I think was a push pull 300b amp.

Hi Jet,
I respect and appreciate the many contributions of Atmasphere as I know you do as well. I do agree with your comments written above regarding SET loudness/distortion. In addition to my 8 watt 300b SET I also have a 40 watt EL 34 push pull(PP) and a 100 watt 6550 PP amplifiers. I use all 3 on my Coincident 94 db (14 ohm load) speakers. 95 to 100 db is loud IMO and sounds loud with all three amplifiers. That SPL isn't perceived as any louder with the 8 watt SET. The SET is my preferred choice due to its superior tone, emotional engagement, musical pace and flow. It's just more natural and resolved/transparent. Jet our experiences are very similar and this includes a broad genre of music.
Hi Charles, yes I agree with you about Atmasphere's many helpful posts. This particular subject helped me very much to listen for those ear hurting loudness queues. Would be very interesting to take a sound loudness meter to three for four different types of systems and see at what db started to hurt ones ears
In all honesty I'm not a fan of loud music ,recorded or live. A few weeks ago my wife and I went to a bar featuring live electric blues. It was just too loud and unenjoyable for the entire group of us. I know some like it cranked up this way and more power to them. I visit jazz venues far more often (usually unamplified) 95-100db is still loud. I don't need or want this volume at home on a regular basis. Personal preference for sure.
The easy test is if you can turn up the volume and things are in fact much louder but do not seem to be, that’s a good sign. You can tell by how well you can hear other sounds in the room at same level with volume down then up, like someone talking to you.

My Bel Canto Class D amps (lots of NF, high damping factor) do this quite well despite those things usually working against it "in theory".     Class D amps are a different breed for sure.

Also happens often in live concerts where you don’t realize how loud teh music is until you try to talk to someone.
I just think people hear in all manner of different ways. At live venues I can readily realize the volume has increased without having to engage in the talk test. Good discussion.
I haven't been posting as much as I used to because I realized when I would render opinions I started to think they have very little real meaning since as Charles says and I agree, we all hear differently. We all have different systems, rooms, cables, musical preferences. It's no different in this thread. Rock music sounds a certain way in my room. I can describe it as good but if twenty people came for a listen only about 5 might like it.

The absolute sound is truly a pipedream.   Most likely no two people would agree even if they heard it.

I do believe though that there are best practices to be followed in assembling a system that facilitates getting to the best sound possible  for most anyone faster than otherwise.
Hi Jet,
You consistently provide meaningful thoughts and perspective. I understand what you reasoning is for less frequent forum posting.  This endeavor of  assembling high quality audio systems is absolutely a very personal undertaking.  It is a true reflection of how we hear and react to the music we enjoy. Naturally our desires and goals will vary across a pretty wide spectrum. 

This explains the enormous number of options available to us in the form of audio products,. Amplifiers of many different topologies, circuits and power. All manner of speaker categories to choose amongst,  same plethora of choices for sources as well.  It's no wonder why we all have different systems that vary in individual components and obviously sound/music reproduction outcomes. How could it be any other way?

Jet when you write that perhaps only 5 of 20 listeners may like rock music heard in your system, that's okay. The only relevant point is that the sound is presented as you like it. Once you've determined what type of sound you want the next step is to go about achieving it. This is the key to long term home audio  listening contentment. I believe that you are there. 
SET amplifiers from 6-12 watts can drive most of my horn collection to Rock concert SPL levels in home. But you do have to have a massive horn loaded design to do this and it must be designed for lower power.  I cheat a bit I have 1 system that is horn loaded to 75hz and with that I run a powered bass system this can run on the wee output of a 45 SET amplifier and still produce peaks of 108db 3 meter before its going into massive distortions. I know many do not mind when the SET amp does so its a bit pleasant but I find it fatiguing and prefer to not push the amp or loudspeaker. I have no limits on music I play no limits on SPL but still no free lunch.                                                                                                             Hoffman’s Iron Law of Speaker Building

1) Bass Extension

2) Efficiency

3) Small Enclosure

The law is that you can only have two of these three attributes in speaker building.  Ideally we would want all three, we want speakers with good bass, can play really loud, and are small.  Unfortunately we cannot have all these.

The horn system I heard recently was really big with two Altec Lancing speakers for the lower mids per channel. It think the cut off point was 50hz and then 18 inch sub woofers took over. These subs were driven by 500w Crown amps. 50hz and above is handled by a 26w SET amp by Art Audio. The sound of this system playing rock music was a moving expirence. Pure dynamics and immediacy. This was a huge system that required a large room and nieghbors that are far far away. All of the horns in this system where made of wood with lots of tender love and care. The drivers for the horns are very expensive...the whole system is very expensive....but when one expiriences a system like this one is confronted by what is possible in reproduced sound and forces the listener to evaluate their own system.
I owned a pair of Altec A7s for years run both full range and later biamped, mostly for live sound applications…the rare times I used these for stereo playback they were simply amazing, and you could run them from 20 watts…(My KLH model 20 compact system could get these things singing!). Likely not the most accurate things, but there's a "wooden" tone to them that is really appealing, along with that amazing middy horn (able to put out some serious sizzle also). I, and most every audio fan/musician I know from those days who is still alive, have moved on to the world of more accurate and more full range things that actually fit in a listening space smaller than Versailles…now for PA it's all about clear small horn loaded speakers with subs, which are simply better…not woody, just better. Still…loved the A7s.
but I rarely hear those loudness queues you are speaking of. Even on very dynamic orchestral music I hear power and it even seems that there is additional headroom to spare.
The way you would notice them is if the system sounds loud.

The use of a powerful subwoofer system can help out an SET quite a lot!