Fact is:-
(and this comes from being all of musician as well as sound & race car engineer),
so, I have to make a comparison.
I see these guys all the time, particularly on German Autobahns and in Russia, where the biggest bloated Maybach or Bentley is now ultima-chic!
It used to be enough to have 300bhp and a 911.
Now it's not enough to have 550, 600, 650, or 700 bhp to power a 2.6T monster with wheels weighing 1/4 of a tonne, because once it starts it's never enough.
The German "super car" status symbol is the symbol of all that is bloat.
Particularly those with MATT BLACK paint and 4 not just 2 exhausts (wow it must be fast!).
Get one of those bloated Audis on a mountain alpine road, A7, Q7, big Beemer, 4 door Porsche ....give me a well sorted Lotus of 1/4 the weight - CIAO! 😀
The p.e.n..s
measuring competition starts....wow mine gives 1000W, what does yours do? 1200W 🙁
Now we see a comparable trend in "hi end", with the 8000-10 000Euro speaker cables in pure silver, the beryllium tweeters (yep what happens one day when we scrap this highly toxic element?)....the simply GIGANTIC power supplies with farads of capacitors at 700V....the latest generation DAC, the humungous triodes, AC processing cleaners, and enormously expensive turntables to read off some of the most distorting nonlinear devices ever made (the vinyl record, which has a high velocity at the outside edge and low velocity in the centre), so the resolution is miserable compared with even PCM audio...which is in fact used to master them anyhow...
I see a trend.
Speculation bubbles are made of this.
Each time you see the kind of insane systems being put together, and the market saturate, you know there is a final big crash coming.
Drop a 500 000 USD sound system in a luxury yacht and what do you have.
Some poor b..ggr, with far too much to spend showing off to his equally stupid mates
When the crash comes, the elite get wealthier and the poor not.
What we entirely lose sight of ?
ONLY LIVE MUSIC is any good.
Recorded music is dead.
Dead as a dodo.
The only place for live music is in broadcast radio.
I am listening to Roque d'anteron live piano festival on France Musique the last nights.
It's magnificent, it makes anything like this nutter Kevin Scott look totally stupid, because broadcast audio FM stereo doesn't have a FR exceeding 40-17khz, a channel seperation just about hitting 30dB, and a dynamic range if lucky of about 25dB +/- 5 depending on who's compressor is being used at the concert end.
The only use for hifi or as they like to call it "hi end" audio is to reach approximately this level of performance and render living music something approaching how it may be for the ideal person in that ideal concert hall (I won't even begin to describe the ravages of a place like the Albert Hall, which is has always been a nightmare acoustically).
The ideal speaker?
The one that vanishes, like when you turn the lights out,.
The one that you can have a glass of St Emilion by candlelight and makes our trend to digital crap at least not sound quite so crap as all those algos have made it sound, after processing the heck out of it ,- like bad fast food.
Btw as to 15khz, can (still) just about hear that at a pinch.
I have regularly tested young people's hearing and was horrified to see dead spots in their audition Frequency spectrum caused by extensive listening in ear devices with mp3 sources.
These are kids of 9-14 years old, which normally have the finest hearing genes can ever have given them, for all their lives.
fact is, the "fast food" ultra bloat diet not only makes them more and more often obese quite young, but like the excess of sugar, the excess of sound processing makes their hearing die young.
All we need now is some Audio guru to come along 20 years later to sell them a 150 000 $ "hi end" sound system, when they are actually totally incapable of understanding what music actually is, because they are so used to masking and algos as facts of life.
I have a lot to do with the local hi end shop.
It cracks me up seeing the "hi end" cables themselves, the little wood blocks lifting the cables off the floor, the 1001 tweaks of little weights on the CD, the pointed little feet off the bottom of the modules and the blingy amps they connect to them,but they can't even correct the sh..ty room acoustics they stuff all this in...
It was the same in Mulhouse France, the same sort of shop, with the same sort of unbelievable stupidity.
Artisans du s x n x??
My name for them is "dilletantists of sound", or "dubious nutters of sound".
They don't even deserve respect for stocking it in such places.
(and this comes from being all of musician as well as sound & race car engineer),
so, I have to make a comparison.
I see these guys all the time, particularly on German Autobahns and in Russia, where the biggest bloated Maybach or Bentley is now ultima-chic!
It used to be enough to have 300bhp and a 911.
Now it's not enough to have 550, 600, 650, or 700 bhp to power a 2.6T monster with wheels weighing 1/4 of a tonne, because once it starts it's never enough.
The German "super car" status symbol is the symbol of all that is bloat.
Particularly those with MATT BLACK paint and 4 not just 2 exhausts (wow it must be fast!).
Get one of those bloated Audis on a mountain alpine road, A7, Q7, big Beemer, 4 door Porsche ....give me a well sorted Lotus of 1/4 the weight - CIAO! 😀
Like the Bloated cars, the bloated hifi goes with it.
The p.e.n..s
measuring competition starts....wow mine gives 1000W, what does yours do? 1200W 🙁 Now we see a comparable trend in "hi end", with the 8000-10 000Euro speaker cables in pure silver, the beryllium tweeters (yep what happens one day when we scrap this highly toxic element?)....the simply GIGANTIC power supplies with farads of capacitors at 700V....the latest generation DAC, the humungous triodes, AC processing cleaners, and enormously expensive turntables to read off some of the most distorting nonlinear devices ever made (the vinyl record, which has a high velocity at the outside edge and low velocity in the centre), so the resolution is miserable compared with even PCM audio...which is in fact used to master them anyhow...
I see a trend.
Speculation bubbles are made of this.
Each time you see the kind of insane systems being put together, and the market saturate, you know there is a final big crash coming.
Drop a 500 000 USD sound system in a luxury yacht and what do you have.
Some poor b..ggr, with far too much to spend showing off to his equally stupid mates
When the crash comes, the elite get wealthier and the poor not.
What we entirely lose sight of ?
ONLY LIVE MUSIC is any good.
Recorded music is dead.
Dead as a dodo.
The only place for live music is in broadcast radio.
I am listening to Roque d'anteron live piano festival on France Musique the last nights.
It's magnificent, it makes anything like this nutter Kevin Scott look totally stupid, because broadcast audio FM stereo doesn't have a FR exceeding 40-17khz, a channel seperation just about hitting 30dB, and a dynamic range if lucky of about 25dB +/- 5 depending on who's compressor is being used at the concert end.
The only use for hifi or as they like to call it "hi end" audio is to reach approximately this level of performance and render living music something approaching how it may be for the ideal person in that ideal concert hall (I won't even begin to describe the ravages of a place like the Albert Hall, which is has always been a nightmare acoustically).
The ideal speaker?
The one that vanishes, like when you turn the lights out,.
The one that you can have a glass of St Emilion by candlelight and makes our trend to digital crap at least not sound quite so crap as all those algos have made it sound, after processing the heck out of it ,- like bad fast food.
Btw as to 15khz, can (still) just about hear that at a pinch.
I have regularly tested young people's hearing and was horrified to see dead spots in their audition Frequency spectrum caused by extensive listening in ear devices with mp3 sources.
These are kids of 9-14 years old, which normally have the finest hearing genes can ever have given them, for all their lives.
fact is, the "fast food" ultra bloat diet not only makes them more and more often obese quite young, but like the excess of sugar, the excess of sound processing makes their hearing die young.
All we need now is some Audio guru to come along 20 years later to sell them a 150 000 $ "hi end" sound system, when they are actually totally incapable of understanding what music actually is, because they are so used to masking and algos as facts of life.
I have a lot to do with the local hi end shop.
It cracks me up seeing the "hi end" cables themselves, the little wood blocks lifting the cables off the floor, the 1001 tweaks of little weights on the CD, the pointed little feet off the bottom of the modules and the blingy amps they connect to them,but they can't even correct the sh..ty room acoustics they stuff all this in...
It was the same in Mulhouse France, the same sort of shop, with the same sort of unbelievable stupidity.
Artisans du s x n x??
My name for them is "dilletantists of sound", or "dubious nutters of sound".
They don't even deserve respect for stocking it in such places.
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It's no rant.
It's a perfectly valid comparison between the moster inefficient bloated bling, and the lightweight little thing that Colin Chapman designed.
The little Lotus I quoted is your "high effiency" solution, brakes, goes round corners and accelerates like fury with tiny horsepower.
So why am I putting ESL speakers in my car?
Same reason.
Your high efficiency speaker has to have the same characteristics.
Low inertia, high electro-mechanical efficiency (powerful magnets), good damping and good linearity when presented with a typical IMD test.
They are both engineered to do a high performance job.
No suprise then that JansZen' electrostatics do this job well, including his astonishing new ESL headphones.
It's not so suprising to see in a typical well made violin bow, the same attention to detail.
The same approach is in a Steinway model D, and again the same approach again in something like the Roque open air acoustic concert hall.
hi definition concert hall?
You bet, it's the best one in the world!
Go from Steinway model D set up by the swiss expert, in the hi definition concert hall source to France Musique live direct, play back on a hi efficiency amp & speaker system, and you are approaching something worthwhile listening to.
It's a perfectly valid comparison between the moster inefficient bloated bling, and the lightweight little thing that Colin Chapman designed.
The little Lotus I quoted is your "high effiency" solution, brakes, goes round corners and accelerates like fury with tiny horsepower.
So why am I putting ESL speakers in my car?
Same reason.
Your high efficiency speaker has to have the same characteristics.
Low inertia, high electro-mechanical efficiency (powerful magnets), good damping and good linearity when presented with a typical IMD test.
They are both engineered to do a high performance job.
No suprise then that JansZen' electrostatics do this job well, including his astonishing new ESL headphones.
It's not so suprising to see in a typical well made violin bow, the same attention to detail.
The same approach is in a Steinway model D, and again the same approach again in something like the Roque open air acoustic concert hall.
hi definition concert hall?
You bet, it's the best one in the world!
Go from Steinway model D set up by the swiss expert, in the hi definition concert hall source to France Musique live direct, play back on a hi efficiency amp & speaker system, and you are approaching something worthwhile listening to.
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Thanks for the detailed post that's spot on topic! 🙂
I have been looking at repurposed PA speakers as possible contenders, ever since a guy at work loaned me his DJ speakers (QSC K12, active 2-ways) to audition at home. I was impressed. They had an extremely realistic midrange (well recorded spoken voice was eerily in-the-room-with-you), solid bass, but again the upper mids sounded 'electric', a little harssssshhhh.
That experience led me to two things:
1) I'd consider active speakers with DSP, and
2) PA speakers might be getting so good that they rival dedicated 'hi-fi' speakers for sound quality (in some cases, anyway).
Since diysoundgroup designs what are essentially PA-style speakers for home theater use, I figured they might be the answer. That has been problematic, though. I was ready to buy a pair of kits, build them up and give them a try, but supply chain issues have made them out of stock for months now. I may still do that, though. I've been curious about those for years, and the only people who have opinions about them are home theater buffs, not tyoob audiophools like me. Almost every single diysoundgroup user has told me their speakers are designed for use with subwoofers (even the 15" 2-ways), so plan on that. I guess their cabs are tuned for a mid-bass rolloff that allows easy crossover to active subwoofers. That would make sense for home theater installations, but mucks things up for standard stereo (2.0) usage.
On a whim, I bought a pair of JBL LSR305 active speakers. I had low expectations, but they really impressed me. They do have severe limitations. They are a weenie 5" 2-way after all. But at low to medium SPLs, near-field, they're really quite good. The controlled dispersion waveguide concept works, for me at least.
One person suggested I try a pair of Behringer 15" 2-ways (I forget the model number right now -- something like B215XL?). They're really cheap, and they're supposed to be good enough that you can get an idea if that kind of speaker will work for you. They're out of stock everywhere, but I have a pair on order. Due date is Sept/Oct. It will be interesting to hear how that turns out. Again, I have low expectations. If I don't like them, I'll either return them or sell them off.
Now you mention the Peavey SP2. I would never have considered those. The freq resp graphs look OK, but that's for a version that's no longer made. The SP2 designation has been in Peavey's line for decades, so I don't know which version you have. Does yours look like the ones in either of the attached photos?
Wayne Parham has a line of speakers called pi Speakers. The Three pi model is his mid-line 2-way with an oblate-spheroid waveguide loaded compression tweeter driver. It's basically a PA-style speaker engineered for hi-fi. This might be the way to go. https://www.pispeakers.com/Products.html
So, it looks like diysoundgroup and pi Speakers offer speakers that fit the mold of an SP2-style big 2-way with compression tweeter designed specifically for in-home use. Could this be the way to go?
Finally, there are kits being sold here and there. Perhaps a 2-way coaxial based on an Eminence Beta 10CX woofer with Selenium D220TI CD? But then again, there's that problem with coaxial mounting and weird midrange/crossover region problems.
Anyhow, it's a good point you raised.... Are there PA speakers or pro cinema speakers that fill the bill?
--
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I can add a bit of detail about Eminence 10CX and a Selenium 220i CD driver.
Image courtesy of craigtone, one of our members. 🙂
This is the famous WLM Diva:
Gives you an idea of the box. 6moons audio reviews: WLM Diva Monitor with Diva Control
Interestingly another member, Mike Chua has a splendid design:
Osprey-II Revisited (Eminence 10CX with Selenium D220ti) – AmpsLab
No idea if it does classical too well, but a lot to like!
Classic FM Playlist
Fond of me ol' Classical. Generally low distortion is the name of the game with complex music.
Image courtesy of craigtone, one of our members. 🙂
This is the famous WLM Diva:
Gives you an idea of the box. 6moons audio reviews: WLM Diva Monitor with Diva Control
Interestingly another member, Mike Chua has a splendid design:
Osprey-II Revisited (Eminence 10CX with Selenium D220ti) – AmpsLab
No idea if it does classical too well, but a lot to like!
Classic FM Playlist
Fond of me ol' Classical. Generally low distortion is the name of the game with complex music.
My SP2 speakers look like the ones on the left. The best sounding version, 2004, the ones with the distortion spec on the datsheet. IMHO 2004 has the rounded looking tweeter horn, 2 vents, 2000 hz crossover, speakon connectors, and a wedge shaped box to reduce the beaming of the mid range from the woofers. 2004 was made for about 18 years, and since identical drivers are still available from Peavey, used ones shouldn't be a risk. I haven't heard the 1000 W rated version SP2 in the right picture and can't assess it's sound.
I have my SP2 on poles 2 m in the air since the tweeter directs sound down at the audience. I have mine twisted to face me at my couch 3.2 m from the speakers on the left wall. They are 2 m apart and .5 m from a hard plaster wall, centered in a 3.8 m width room. Ceiling is 3.2 m, acoustic tile.
I previously had 1997 SP2-XT which were the same drivers, 1200 hz crossover, wedge shaped tweeter horn, parallelapiped box, unvented. Those were stolen 9/2020. The high end was a little fuzzier in my piano test, but good enough when SP2 2004 were rare on the used market. Those had a specification for wide beam width at 500 1000 2000 hz etc which probably was a feature of the low crossover. The 1200 hz crossover limits the amount of power the speaker can handle on pink noise, as the RX22 driver is limited to 70 W. The 2004 version presumably has a narrower beam width on midrange.
I've also heard nice words said about 2 ways York U15, Yamaha 15, JBL 4367 (copied by asathor, see the thread) and Klipsch Heresy. None of those has showed up used within 1000 miles, and none are for sale new here except Yamaha, which I wouldn't buy. Never heard any of them.
I have heard Peavey 1" tweeter PV15, and didn't like the mid-range. Okay for guitars & basses in bar bands I suppose. Keyboard people tend to like the Peavey KB300 which sound pretty smooth in the stage shows I've seen (Bowling Green Newgrass festival). KB300 is self powered and contains a 3 input mixer with effects.
I was going to build SP2 clones with a Eminence DeltaPro-15A (new) woofer and a couple of used wedge shaped Peavey RX22 horns from ebay, but finding the real thing for $400 the pair has stopped that project at the buy mdf stage. The ones I build would be very ugly and may be burglar resistant as a result. Same 54-17 khz target frequency range. I do really need a 15" woofer dedicated to 30-54 hz as i listen to pipe organ, and Beethoven Appasionata sonata has some low octave piano notes, but the box for that is different (venting) than a 15" woofer that also does mid-range to 2000 or 1200 hz. Might be the same driver.
Happy shopping.
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adason - I was playing along 😉
indianajo - I'll keep my eyes peeled for a used pair of passive SP2 of the right vintage. None around here now, but I'm sure they pop up from time to time.
I've heard Klipsch Heresy a couple times. I really dislike Klipsch speakers. A lot.
system7 - I've been in contact with Michael Chua and was thinking of the Osprey-BR as a possible project. Eminence Beta 10CX are out of stock pretty much everywhere, but I'm hoping to track a pair down. I also need to purchase a pair of the Selenium D220Ti cds, so the cost of drivers will be about $300 USD, and then I'll need to spend a bit for crossover parts, probably another $80 to $100 USD. But it's certainly doable. The main attraction for me is that I have the cabs from the old Klipsch KG52, which fit the Beta 10CX drivers perfectly, flush mounted and everything. They're a little larger than what Michael designed for (55 liters as opposed to Michael's 45l), but I can make that work. I could even fill parts of the cab inside to make it 45l. The best thing about Klipsch speakers is their cabinets. Nicely made, nice and stout.
indianajo - I'll keep my eyes peeled for a used pair of passive SP2 of the right vintage. None around here now, but I'm sure they pop up from time to time.
I've heard Klipsch Heresy a couple times. I really dislike Klipsch speakers. A lot.
system7 - I've been in contact with Michael Chua and was thinking of the Osprey-BR as a possible project. Eminence Beta 10CX are out of stock pretty much everywhere, but I'm hoping to track a pair down. I also need to purchase a pair of the Selenium D220Ti cds, so the cost of drivers will be about $300 USD, and then I'll need to spend a bit for crossover parts, probably another $80 to $100 USD. But it's certainly doable. The main attraction for me is that I have the cabs from the old Klipsch KG52, which fit the Beta 10CX drivers perfectly, flush mounted and everything. They're a little larger than what Michael designed for (55 liters as opposed to Michael's 45l), but I can make that work. I could even fill parts of the cab inside to make it 45l. The best thing about Klipsch speakers is their cabinets. Nicely made, nice and stout.
Took 9 months to find some here <200 miles, but finally happened. Take your CD player & amp & listen, I did. @ $200 ea I didn't worry about fidelity much, just that both drivers worked. The SP2-XT @ $300 ea, I took a Beethoven piano CD & listened pretty carefully. Take an amp, the Terra Haute owner wouldn't let me plug my FM radio in his 1000 W amp, was afraid I would blow it up. (lots of bar band amp inputs get blown by 75 w guitar amp speaker cables).
Bar band repair services tend to remove the 15" woofer and replace with some kind of cheap trash driver. Don't condemn the sound until you look closely at the woofer. A new 1505-8KADT from a Peavey rep should get you back to specification. tubesandmore.com of Arizona is one such rep selling OEM. Parts-express has some Peavey too. The 22XT tweeter is so infrequently blown that they are routinely available on ebay.
I'm still kicking myself that I didn't take the SP2-XT apart when I had them & measure the crossover components. 1200 hz crossover sealed is a whole different design than the 2000 hz vented boxes I have now. Haven't seen SP2-XT on craigslist/ebay in 15 months.
Were some JBL4367 in NJ on ebay for a long time, but you had to buy a whole theater set of them with lots of subwoofers- $5000. Uhaul would have been $1000.
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I was just reading back a bit, and I notice you are interested in something that will work with a flea-powered 5W SET amp...
I can only tell you what I know.
SET's work best with closed box. They are not good at controlling bass reflex due to significant output impedance.
They also prefer a flattish impedance.
All this is doable. I think we can get highish efficiency too with 8" bass and above.
I have done similar things with a loudish 8" woofer and a 91dB 90mm cone tweeter. Here a Monacor HT22/8:
People have had a good time with the 2Pi speaker as well which looks like closed box:
Some crossovery here:
What kind of Tweeters that match paper woofers?
An Eminence Alpha 10 (FR below) and a loud Vifa 1" tweeter.
I think I could do better than that. But easy enough. 😀
I am looking at using Monacor for in car.
They have a about 4 different small size drivers with different characteristics.
Monacor seem to have improved a lot, because previously they were basically only specialised in 100V line systems -multiple cheapo drivers, for ambience in shops and restaurants and other such (yuck!).
They have a about 4 different small size drivers with different characteristics.
Monacor seem to have improved a lot, because previously they were basically only specialised in 100V line systems -multiple cheapo drivers, for ambience in shops and restaurants and other such (yuck!).
Vented, though for the SET, tuning it with stuffing might be a good compromise: $400 Two "Pi" Tower Loudspeaker Kits by A. Colin Flood
Bearing in mind classic FM is specifically designed for cars, so the sound is highly compressed, bass boosted and generally manipulated,with usually a mp3 archive used to back it all up, as most "independent" broadcasters do.
I suspect the dynamic range is not much more than about 15dB with frequent excursions to exactly 0dB.
The BBC (R3) although having largely destroyed their heritage, and dumbing down nearly everything, are nothing even close to those limits.
system7 - Thanks for the high efficiency 2-way examples.
I was using "5 watt single ended amplifier" as an example of why someone would want a high efficiency speaker for classical music. I'm actually more of a push-pull kinda guy. I built a DC-coupled PP 2A3 amp I like. It makes 6W/ch using an OPT with 5k p-p primary for better damping (at the cost of a watt or two lower power out).
According to the Pi Speakers website, the Two Pi speaker is a bass reflex 2-way, using an Eminence Alpha 10 woofer (PA midbass driver with paper cone, accordion edge) and a Vifa DX25 dome tweeter. Sensitivity looks to be around 95dB/1W/1m, which is great. There's a tower version too, bigger cab for lower bass. Its impedance stays fairly high until about 5kHz and higher, where it dips down to 4 ohms (the DX25 tweeter is 4 ohms nominal).
So, has anyone heard this speaker? There are some very positive comments scattered around the internet, so perhaps this is the best high-efficiency cost/performance contender.
The One Pi looks superficially like the Snell Type J (4 ohms, 91dB/2.83V/1m). I wonder if they sound somewhat similar?
The star of the pi Speakers show is the Three Pi, which is a big 2-way bass reflex using a compression driver/waveguide and 12" PA woofer. It's no more efficient than the Two Pi, and its bass response is a little bit attenuated in comparison. However, its impedance curve is flatter and stays higher (minimum 8 ohms). A horizontal dispersion plot is shown on the Three Pi page, which makes me think the waveguide makes for much smoother horiz dispersion than the dome in the Two Pi. Of course the Three Pi is a lot more expensive than the Two Pi. So there ya go.
I wish I knew someone who's heard these Pi Speakers.
Since I already have a pair of cabs that will fit them, I've ordered drivers for a pair of AmpsLab Osprey-BR. I'm a feeble woodworker, so having the cabs makes this a reasonable project for me. Otherwise the project would involve hiring a cabinet maker to make them for me, which would add a lot to the costs. I'll try to remember to report back here on my findings.
I was using "5 watt single ended amplifier" as an example of why someone would want a high efficiency speaker for classical music. I'm actually more of a push-pull kinda guy. I built a DC-coupled PP 2A3 amp I like. It makes 6W/ch using an OPT with 5k p-p primary for better damping (at the cost of a watt or two lower power out).
According to the Pi Speakers website, the Two Pi speaker is a bass reflex 2-way, using an Eminence Alpha 10 woofer (PA midbass driver with paper cone, accordion edge) and a Vifa DX25 dome tweeter. Sensitivity looks to be around 95dB/1W/1m, which is great. There's a tower version too, bigger cab for lower bass. Its impedance stays fairly high until about 5kHz and higher, where it dips down to 4 ohms (the DX25 tweeter is 4 ohms nominal).
So, has anyone heard this speaker? There are some very positive comments scattered around the internet, so perhaps this is the best high-efficiency cost/performance contender.
The One Pi looks superficially like the Snell Type J (4 ohms, 91dB/2.83V/1m). I wonder if they sound somewhat similar?
The star of the pi Speakers show is the Three Pi, which is a big 2-way bass reflex using a compression driver/waveguide and 12" PA woofer. It's no more efficient than the Two Pi, and its bass response is a little bit attenuated in comparison. However, its impedance curve is flatter and stays higher (minimum 8 ohms). A horizontal dispersion plot is shown on the Three Pi page, which makes me think the waveguide makes for much smoother horiz dispersion than the dome in the Two Pi. Of course the Three Pi is a lot more expensive than the Two Pi. So there ya go.
I wish I knew someone who's heard these Pi Speakers.
Since I already have a pair of cabs that will fit them, I've ordered drivers for a pair of AmpsLab Osprey-BR. I'm a feeble woodworker, so having the cabs makes this a reasonable project for me. Otherwise the project would involve hiring a cabinet maker to make them for me, which would add a lot to the costs. I'll try to remember to report back here on my findings.
There was a reason I posted this link...
What kind of Tweeters that match paper woofers?
Might repay further study. I wouldn't do it like that, TBH. It is usual to correct the Fs resonance on a tweeter with first order. Something like 33uF, 8R and around 1mH for 650Hz here.
A bit of impedance correction on the midbass after the bass coil can help suppress breakup. Maybe 7.5R and 4.7-8.2uF.
Various ways to flatten overall impedance:
Flat Impedance and Flat Power response design.
It is bafflestep that mucks most speakers up on impedance.
These are 8 ohm values that Jeff Bagby worked out for good impedance:
Hope that is useful. It is curious that if you put a driver in a closed box, say 30-50L, it actually goes deeper with a SET amp!
What kind of Tweeters that match paper woofers?
Might repay further study. I wouldn't do it like that, TBH. It is usual to correct the Fs resonance on a tweeter with first order. Something like 33uF, 8R and around 1mH for 650Hz here.
A bit of impedance correction on the midbass after the bass coil can help suppress breakup. Maybe 7.5R and 4.7-8.2uF.
Various ways to flatten overall impedance:
Flat Impedance and Flat Power response design.
It is bafflestep that mucks most speakers up on impedance.
These are 8 ohm values that Jeff Bagby worked out for good impedance:
Hope that is useful. It is curious that if you put a driver in a closed box, say 30-50L, it actually goes deeper with a SET amp!
Utterly OT: that's not Michael Gerzon pictured but Richard Cowderoy, another central figure of OUTRS.
Michael Gerzon Audio Pioneer
But yeah, still much to be learned from these guys, 50 years later.
Some things to consider...
Eminence Beta-12CX 12" Coaxial Driver
Eminence ASD1001 1" HF Titanium Horn Driver 1-3/8"-18 TPI
Doesn't go really deep in sealed but a transmission line has a bit nicer behavior than a standard ported and might work quite well.
If you want to go three way for a little more bottom end you can run the coax as more of a midrange tweeter combo and use a more substantial bass driver on the bottom.
Eminence Beta-15A 15" Driver
Eminence Beta-12CX 12" Coaxial Driver
Eminence ASD1001 1" HF Titanium Horn Driver 1-3/8"-18 TPI
Doesn't go really deep in sealed but a transmission line has a bit nicer behavior than a standard ported and might work quite well.
If you want to go three way for a little more bottom end you can run the coax as more of a midrange tweeter combo and use a more substantial bass driver on the bottom.
Eminence Beta-15A 15" Driver
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As I understand it, the higher Zout of the SET amp raises the Q of the total system (amp+speaker), so you get a bass boost.
I can see this in WinISD, by raising the Series Resistance setting in the Signal tab. E.g., in a model of Beta 10CX in a 2 cu ft (57 liter) cab, the bass response is flat down to 55Hz with 0.1R series resistance, but there's a +2dB boost centered around 90Hz with 2.0R series resistance and the F3 is brought down a couple Hz.
Maybe that's one of the attractions of SE amps. A more 'full' sound due to a modest bass boost...?
EDIT TO ADD: Oh wait... Wow have you ever been there before. Interesting how sealed box works better for high Zout amps.
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Which brings me to the other point.
classical music reproduction is pretty much hopeless without 4 channels.
Unless you have a couple of rear speakers also involved, to bring in decent rear ambience (low level), most stereo recordings sound pretty flat, and this from years of experience (we also made some highly successful live surround sound recordings).
This rear info is low power, ideally suited to SET type amps of low power.
This makes front channel info far less critical, and reduces the need for generally higher powers.
I use some omni rear speakers for this, for which a 1-3W amp output is entirely successful.