We should reject hard-to-drive speakers more often

Measurements from a reputable source always help. Most makers do not overdo the specifications for fear of either confusing people or scaring them off. It’s just the way it is.

Again it’s a different ballgame these days for those willing to use Class D amps. Freedom of choice rules. That and reliable measurements. The more the merrier. I’ve read of some supposedly easy to drive speakers that turned out not to be. A good rule is the smaller and more bass extended the less easy they are likely to be. Fritz speakers are the ones I know of that go to great extremes to provide an easy load but they are not very “efficient”.

In the literature for his Eminent Technology LFT-8 loudspeaker, designer Bruce Thigpen states he can make his LFT driver any impedance he wants, and chose 11 ohms (when implemented in his LFT-8 loudspeaker, the complete speaker---with dynamic woofer---becomes an 8 ohm load). That’s why the LFT-8 is a better choice for tube amp lovers than Maggies (at least in terms of the issue of impedance). Maggies are a 3-4 ohm loudspeaker, not good for most tube amps (the Music Reference RM-200 being a notable exception). I cite Maggies and the LFT-8 together as both are planar-magnetic loudspeakers.

However, both the ET LFT-8 and Maggies are very low in sensitivity. The older Maggies (.6 series) could be bi-amped, a good way to address low sensitivity: use a brute force amp on the woofer, a refined one on the midrange and high frequency drivers. .7-series Maggies can not be bi-amp, at least not without internal surgery (the crossovers are series, unlike the parallel used in the .6-series). The LFT-8 can easily be bi-amped (it comes fitted with separate woofer and LFT panel binding posts).

@erik_squires You are probably 100% correct. Clearly we like gear so this will continue. Maggies are the one hard to drive speaker that I make exception for.

I believe it all depends on what the listener wants and is looking for. I have not found an amp that cannot drive my Lascalas, but the quality and characteristics of each amp leaves me to prefer one over the other. I had AR9s, DQ10s, Kappa 9s, Gale 401s, panels, and many other hard to drive speakers. I had many an amp that could drive them without clipping, but they all failed ( the speakers ) in the dynamics department. Like I said, it is up to the listener to select what suits him / her best. Always, MrD.

To reject hard to drive speakers would be to reject many a great sounding speaker. Some speakers that appear hard to drive from a quick glance at basic specs, turns out they are easier to drive than first thought. All depends on where the dips in impedance exist, among other parameters/measurements take the JBL 4309’s for instance....they look to be a difficult load @ 4 ohms and 87 db...however , in real world listening conditions, they are seemingly a pretty easy speaker to drive, based on most positive reviews I’ve read about them.

Pretty much any speaker will PLAY with lower power, but also most good speakers, even "efficient" ones, will sound better with more power (this has nothing to do with the accuracy of the reproduction chain, of course; "loud" does not mean "accurate", obviously.. 

Anyway, Maggies will play OK with low power, but if you want the MOST out of them, more is better,and there is no thing such as "too much" unless you have an amp that misbehaves.  I would guess that is true with any "inefficient" speaker.

Match your hardware to your speakers.  Low "watt" tube amps/integrated will drive your "efficient" speakers nicely, I am sure.  ARC makes a couple, as do others, I am sure.

Cheers!

I’ve generally been keen on having speakers that are higher sensitivity.

Recently, I built a pair of Seas coax speakers. 4 ohm, 80dB efficient. 
Driving them with a 30w class A amp wit( a large power supply 

Not where my sonic interests are - or so I thought.

These things sound amazing! 
 

Don’t get me wrong. I very much want to build a 15” 100dB coax set up in a coffin sized box, drive them with a SET. But, that’s not an option at the moment. And these low sensitivity speakers have shown me just how good inefficient speakers can sound when powered accordingly.

Im less reluctant to consider difficult speakers after listening to these for the past several months.

@bdp24 is spot on!

There are plenty of people enjoying their "hard to drive" speakers likely with no idea they’re hard to drive. They somehow managed to buy an amp that works (i.e. just about any decent amp)...for shame! Don’t they sit through endless egomaniac John DeVore youtube videos? (and maybe pay through the nose for a plywood box with 2 drivers because, hey man, it's 10 ohms) Or read every tedious tech review attached to Stereophile reviews? You mean they just sit there and enjoy music and have NO IDEA their speakers are horribly flawed? Wow man...what a shame...

@wolf-garcia: Well whatta ya know, someone else who considers John DeVore a smug, sanctimonious kinda guy! I haven’t heard any of his speakers (which may sound great; Art Dudley, Ken Micallef, and Steve Guttenberg certainly thought/think so), but they sure don’t appear to be priced according to the industry-standard price-of-parts X 7. I guess DeVore considers his time much more valuable than that of mere mortals.

@bdp24 I'm appreciating your comments and I've heard DeVore speakers and the SuperNines sounded awesome.  There are so many excellent speakers available, so when I saw the price the speakers didn't make there way into my home.

To be fair there's a lot of excellent audio equipment my wallet has eliminated from consideration...

Since my wife doesn't like my speakers but we both love of tube gear, we're keeping our tube gear and now looking for efficient 'enough' speakers. I mean, my amp has 150wpc in pentode mode so what might be the problem? Woofers. But there are efficient speakers with built-in class D amplifiers that release the burden of your fine tube gear playing full range. Let the tube gear focus on the mids and tweets where the majority of the music lives.

Maybe I'll find out one day.

this month's Stereophile has a review of the Heresey speakers, which are super efficient. The reviewer used a coupe flea 2-3 watt amps then used a Parasound 21+ which had more balls and sounded more organic

For clarity ( no pun intended ) it is the Klipsch model Lascala, Revision AL5 that was just reviewed by Stereophile, but it IS part of the Heritage line. Klipsch does have a model called the Heresy, which also has been around a long time, which has also gone through many iterations. My best always, MrD.

It’s funny how them junk infinity’s as some call them

still sound as good or better in some cases then what is being 

produced today at 5 times the cost. Yes the crossovers was 

a pain to work with but back in the early and mid 80’s they was state-of-the-art the art. The IRS beta can go against about any 30,000 dollar speaker made today. And yes you should have to rebuild them now hell they are going on 40 years old. So yes stuff wears out. I own a set of Kappa 9.1 series 2 and I would put them up against any speaker made today under 15,000 dollars. 

I’ve owned many of the aforementioned hard to drive speakers and overall, they could not sound as natural and relaxed as an efficient horn speaker.

Interesting...I’m considering MBL 101E speakers, but I’m hesitant due to them being hard to try.

@ricred1 MBLs are easier to drive than they might appear. That is because they are omnidirectional and when measured, the microphone is placed 1 meter away from the speaker. Most of the output of the speaker is thus not picked up. Effectively in a room you can add 6dB to their rated sensitivity. So they can be driven be amps of much less power than you might expect!

OK, thinking about this this is less about the gear and more about the awe created by hard to drive speakers. Like we somehow want to make the speakers happy because they are so demanding. Maybe we should get speakers that are happy with any amplifier instead??

@erik_squires This is a good point.

I’ve been telling people for years now that the harder the speaker is to drive, the more distortion your amplifier will make. Especially with respect to lower impedance, this is easy to see in the specs of any amplifier. Its also audible by making the amp less detailed (since distortion obscures detail) and often harsher (since more higher ordered harmonics are created).

So what I tell people is that if high quality audio reproduction is your goal, your amplifier dollar investment will be best served by a loudspeaker of higher impedance (8 Ohms or more) that is also easy to drive (no weird phase angles and higher efficiency).

Lower impedance speakers have a hidden cost of the speaker cable being far more critical to best performance. Lower efficiency speakers suffer thermal compression in their voice coils. There are some attempts to mitigate the latter problem, but whatever the technique is can also be applied to higher efficiency speakers with no downside.

If your speaker requires more than 100 Watts to really make it sing, you have an impractical speaker! This is because of the logarithmic nature of the human ear (which is why we use deciBels). If 100 Watts won’t do, how much power will you need? To make the speaker play twice as loud subjectively, you’ll need about 1000 Watts. How many amps of that power really sound like real music without being oppressive? How many can afford that? For this reason, even very expensive loudspeakers are often fairly easy to drive.

The only real advantage of 4 Ohms might be that your amp can make 3dB more power if its a solid state amp that can double power into 4 Ohm as opposed to 8. So you have a weak 3dB argument for that, if sound pressure as opposed to sound quality is your goal- good luck with it; 3dB is a slight increase in volume to the ear...

So if you want a really decent, musical system, difficult low impedance loudspeakers should be avoided. It does not matter ’how good it sounds’ to you; if that same speaker were simply higher impedance it would sound even better (speaker designers take note of this simple method of causing your speaker to sound smoother and more detailed at the same time).

"@ricred1 MBLs are easier to drive than they might appear. That is because they are omnidirectional and when measured, the microphone is placed 1 meter away from the speaker. Most of the output of the speaker is thus not picked up. Effectively in a room you can add 6dB to their rated sensitivity. So they can be driven be amps of much less power than you might expect!"

Please suggest a couple of integrated amplifiers that can drive MBL 101e speakers.

Please suggest a couple of integrated amplifiers that can drive MBL 101e speakers.

My experience is limited to the mbl 101e. It was rated at about 81 dB which you would think is crazy inefficient. Its also a 4 Ohm load, climbing to 8 Ohms in the upper midrange. But it does not have any weird phase angles so there's that.

So add 6dB and you're at 87 which still isn't great, but that's a lot better than 81!

Now you have to figure the size of the room. In a moderate sized room most of the time a 100 Watt amplifier would do the job fine. So there you have a bit of info as to what to look for. I can't say more without knowing the room size and liveliness. 

atmasphere,

My room is L-shaped...front wall is 20’ wide, length is 26’, rear wall is 26’ wide, and 9’ ceiling. My room is rather "neutral", not too lively and not dark.

As @bdp24 noted, if you can drive the bottom 2-3 octaves with a separate amplifier, it provides many more options for the rest of the range.

I have planar-magnetic dipole line arrays which are ~98db/w sensitivity, nominally 8 ohms with a minimum impedance of about 5 ohms. I'm driving these with a 300B SET amp and they sound glorious, but they only play down to about 170Hz.

The woofers for the bottom few octaves are considerably less efficient and driven with their own 370W class A/B amp and provide plenty of output to below 20Hz.

The combination can play full-range music louder than I want to listen in my 27' x 17' listening room. 

Obviously a bi-amped system is not for everyone, but by splitting out the bass, the rest of the range can be much more efficient without sacrificing sound quality.

I have owned several of both types, 86db to 100db efficient and I have found that the more efficient speakers play more effortlessly without sounding forced…more relaxed with better dynamic scale.

I have tried, relentlessly, for 30 years to find a high efficiency speaker I enjoy.  It has been a total failure, I have tried hundreds if not thousands of pairs.  Everything by Klipsch makes my ears bleed, Zu's excite my cats too much, Tannoys and most others are ridiculously expensive and leave me completely cold. When amplifiers with more than 30 watts were expensive it was worth the effort. I now use a 40 watt tube amp to drive Audio Physic speakers that are 89dB and 4 Ohms, the work effortlessly. 

@ricred1 

My room is L-shaped...front wall is 20’ wide, length is 26’, rear wall is 26’ wide, and 9’ ceiling. My room is rather "neutral", not too lively and not dark.

With those speakers in a room of that size I would expect you'll need about 200-400 Watts. I don't know of an integrated amp that makes that much power. 

I think I understand where Eric is coming from.

In my view, it is all right that there is a wide range of speaker technologies, ranging from ultra-efficient to very much inert such as certain panels and plasma tweeters. They all have their unique sound characteristics, their inherent strengths and weaknesses. So we have a wide range of choice and experience.

However, what I find sad is the fact that there has a been a trend to make such speakers hard to drive which necessarily need not be hard to drive. That tendency was fueled by folly to imitate the more expensive hard to drive technologies with the much cheaper regular electrodynamic drivers - just plop in a crossover to kill the output level and suck out the amplifiers energy and waste it as heat. That way manufacturers can boast that their normal speakers are now hard to drive, just like the coveted hard to drive technologies.

What the unsuspecting customer is unaware of, is the fact that their inefficient beast would likely sound much better if it had been designed with a proper crossover, and used proper driver complement in the first place. As, the second reason for speakers being inefficient is that the driver compelemnt does not match each other and the designers need to use excessive crossover EQ to match them, So, effectively, covering up poor parts choices (which are always driven by the lower cost).

Now, as far as getting these insensitive speakers at low prices - there's nothing wrong with that. The folly is though, that these badly designed speakers are often sold at a premium.

Now, that's the reason for rejection. But I do understand varietas delectat, and people while being very frugal im most situations, are willing to be completely vulnerable when it comes to well-marketed products.

After all, who would question the integrity of such companies, as for example B&W?

PS: while a high power amp CAN drive a 2R load, it sounds much better, with a fraction of distortion driving an 8R load..... had that 2R speaker been designed with proper driver complement & crossover, it would sound significantly better with the same beast of an amp...

Good topic, Erik.

A difficult speaker load is created foremost by its passive crossover, more so really than (a purer load) low impedance and low sensitivity as a function of the drivers sans passive XO. Combining higher sensitivity, higher driver impedance (i.e.: 8 ohms minimum, as pointed out by @atmasphere ) with an active approach would be ideal in making the most of both amps and cables, and in effect the sound coming from the speakers with the better, direct amp-driver coupling.

What I don’t get is seeing these complex passive filters in many a high-end segment speaker that really only nurtures the forced existence of crazy expensive amps, and which comes down to the need for them to be more or less impervious to load in the face of steep phase angles and the occasional ultra-low impedance dips in the lower frequencies. All the more reason to go active and start throwing those mega amps under the bus, because actively they wouldn’t be needed any longer.

If indeed there’s merit to the claim of people consciously looking for speakers that are known to be a difficult passive load, for reasons apparently that it’s somehow deemed a desirable trait in a speaker, it would seem a fool’s errand; to my ears difficult-to-drive speakers usually can’t shake off an inherent sensation of them actually sounding like a difficult load, irrespective mostly of any beast of an amp thrown at them, so why bother with such speakers in the first place?

I always wonder that too. I think the original reasons were that the loudspeakers were cheaper and so were the higher powered solid-state amplifiers. But that’s not really true anymore.

Also for cone speakers (generally) just shrink the voice coil and widen the gap and “bingo” you’ve got a much flatter frequency response (and usually less expensive manufacturing cost)

I have tried multiples of pairs of rather low sensitivity loudspeakers.

Dozens of them…not 100’s though (likely BS on anyone having tried 1000’s of pairs lol)

They always leave me dry, but many of friends and family seem to enjoy them so again it’s all subjective.

I’ve got  both types of systems now (one in the basement another in outer building)

For the low sensitivity system I’ll get compliments on how “smooth” or “nice” they sound.
To me I’ve come to take these adjectives as code words for “flat”, un-exciting or “not dynamic”

But it’s the never ending story, and taste can’t be argued.

I just returned a pair of zu audio dirty weekend speakers. Very sensitive speakers.  Tried a pair used Bowers and Wilkins 705s. The original version. Much less sensitive. To my ears, more natural and clear. I don't think sensitivity is an issue at all. Just whether I like the sound.

@brev I get that this was your experience which I don't argue. But the sensitivity of the speaker does matter. FWIW, if you have the standmount version of the 702, its a pretty easy speaker to drive despite being a little less sensitive.

If this were the case about Loudspeakers not the most efficient like  Truly Great speakers like the MBL 111. Omni directional speakers would be ignored , or the Excellent Apogee ribbon speakers from our great audio past , or Maggi Magnetic 🧲 planer speakers .if you have the extra watts  they like and a bit of extra room , they provide very life like reproduction 

of music ,their longevity in Audio is a testament to their popularity with other Audiophiles, myself also  owns Dynaudio speakers That are 86 db efficient ,they sound very good but they too like a few watts to. Bring  them front and center 

we are talking literally a few extra watts to bring out all the low level details , to me a small sacrifice .why don’t Erik state what exactly his Audio system is made up of 

so maybe he can point out what we maybe missing  !!

@erik_squires I encourage you to read about Hoffman's Iron Law. Can't have your cake and eat it too. ;-) 

https://www.salksound.com/blogtopic.php?id=3

@atmasphere  Yes, the 705s are not that hard to drive. But whether the speakers were sensitive or not was not the issue. Did I like the sound? I know two people who have Maggie's and 400 watts in each monoblock to drive them. They love them.  I see no reason to consider the fact that a speaker is hard to drive as a negative in and of itself. If you don't have or can't afford the power to drive them, then sure, it's a factor. 

Yes, the 705s are not that hard to drive. But whether the speakers were sensitive or not was not the issue. Did I like the sound? I know two people who have Maggie's and 400 watts in each monoblock to drive them. They love them.  I see no reason to consider the fact that a speaker is hard to drive as a negative in and of itself. If you don't have or can't afford the power to drive them, then sure, it's a factor. 

@brev 

This is why it makes a difference: the harder you push the amp, the more difficult the load, the more distortion the amp will make. The other thing to consider is that not all really high powered amps are all that musical- its pretty well known that smaller amps tend to sound better.

I suspect you're using the same amp since both the speakers you mentioned are fairly easy to drive. But consider that if 100 Watts won't do it, you'd need 4 to 8x more power to do the job and as you point out, that can be expensive.

Also keep in mind that while the ZU is easy to drive, its not the only speaker that is meant to be easy to drive and there a number that IMO are also better sounding (while also being more efficient).

@atmasphere  The question for me is not whether the sensitivity of one's speakers matters in terms of integrating them into a system. Obviously it does. Nothing you are saying is new to me. The question is whether low sensitivity speakers are bad and they should be avoided. I think that's silly.  That is just a silly as if I said from my experience the high sensitivity is bad. That a speaker is difficult to drive just means you need to get gear capable of driving it. I think the great majority of people who own such speakers have got suitable power for them. 

That a speaker is difficult to drive just means you need to get gear capable of driving it. I think the great majority of people who own such speakers have got suitable power for them. 

Of course that is very true. But like I mentioned earlier, if it were a simple thing to have the speaker be the same but otherwise higher impedance/easier to drive, it would be instantly smoother and more detailed both at the same time since the amplifier would be lower distortion.

This is audible; Steve McCormick makes a very competent solid state amplifier that can easily double power into 4 Ohms as opposed to 8 Ohms. The Anticables guy makes a device called the ZERO that is an autoformer that allows you to drive a 4 Ohm load while the amp sees an 8 Ohm load. He has a letter from Steve that states while Steve's amp can easily drive 4 Ohms, it sounds better driving the same load through the autoformer. I'm sure the autoformer has losses and the like; its pretty good bet that if it were not needed the result would be even better.

That does indeed read like a good bet Ralph.  

Don't know how to explain it; driving our North Creek crossovered B&W Matrix 801 S2 speakers (87dB sensitivity, nominal 6 Ohm with benign phase angles and amplitudes) with only our 100 watt monoblocks (2x6BL7 + 4xKT77) sounds both better...and louder!...than driving the woofers with a Jon Soderberg modified Threshold Stasis 2 (~225 watt/ch.) and the tube amps driving the midrange and tweeters. 

I chalk it up to coherence tricking my brain into thinking it's louder...are there decibel meter apps for smart phones?  No need for responses to that...Google here I come.

Having recently place the Vandersteen Sevens in our Listening Room.  83.5db.  Never would have thought to pair them up with a SET 28wpc stereo amp but there you go, drove the hell out of them.  So you need to try things in order to find what will work in your system.

Happy Listening.

@ bigkidz +1

The theory doesn't always hold true.

I drive my W/P5.1 with Pioneer M-22 2×30 Watt A-Class, sounds amazing.

Speaker designers are driven by their education, experience, practice, and their personal sense of hearing, and they're sometimes also biased by what they or their marketing partners believe is consumer preference at a certain price point. How each speaker designer arrives at his product goal creates a whole variety of synergies, dependencies, and sound profiles. None of those resulting designs are wrong or hard to drive unless the home audio consumer market stays away from the product or the reviewers kill it.

Basically today, there is so much speaker choice in the marketplace at literally all price points that something perceptibly hard to drive is essentially a side issue because there are always identically excellent choices that are ideally suited to someone's existing amplification and room and physical cabinet size preferences. 

Suggesting that "hard to drive" is a no-no implies that development decisions by speaker designers should be limited. I think that's counter-productive. 

Buddy of mine a long time ago owned the TOTL ( at that time ) MBL. He was running them with the TOTL ( at that time ) Jadis gear. Vinyl and cd were used. The system sounded remarkable, as far as tone and spatial properties were concerned. One day, I brought over my Crown Reference ( whatever the " audiophile " home version was at the time, as I no longer own it ). Talk about dynamics and control. MBL / Crown were a match made in heaven. IMO, for what I wanted, that pairing was dabomb. Owning Lascalas at that time as well, my buddie’s system, with the Crown ( fully balanced, 2 20 amp dedicated circuits ), was a revelation. I played my vinyl of Santana’s Amigos album, and when Europa came on, I cried like a baby. Knowing the story behind the song, written by Carlos and Tom, it has always been a deep deep listen for me....but.........I never had that same reaction using my Lascalas, or anything else for that matter. I might say, it was the BEST listening experience I ever had, listening to a system. I give the credit to the MBLs. So, they needed power. I sure did not care. Phenomenal ! Another point. My analog rig did not equal his, and digital did not equal analog ( back then ).My best, always. MrD.

It was more specifically the Crown Studio Reference. It was awesome, back them. I have not heard a GAN amp in my system yet. I have tried other class D, none which did anything new I do not have with my current collection of amps. As I enjoy class A, and I enjoy mosfets, I am sure there will be one coming my way ( Ralph, are you listening ? ). I am behind Wolf in the line....MrD.

So Erik when did you start drinking your wine with amirm at Audio Science Review, specs are important but saying a 16 ohm speaker design is better than 4 Ohm speaker design strikes me as hyperbole.

saying a 16 ohm speaker design is better than 4 Ohm speaker design strikes me as hyperbole.

@jeffrey75  Since I've never said or alluded to anything like that statement I don't feel obligated to defend it either.  I encourage you to read all of my posts, in addition to my original on this thread.

We need to reject hard-to-drive speakers as being Hi-Fi.

I guess I missed the point of this statement, and yes I have read many that is why I mentioned amirm.

I guess I missed the point of this statement,

Yes you completely missed the nuance I meant this with, and explained in depth later, and instead applied your own meaning to those words.  Try reading the next three sentences also.  It seems you are conflating my words with those of others who are making other, related points, which I am most certainly not.

Further, I really appreciate the camaraderie you have shown me by immediately suggesting I don’t belong here and should be at ASR, regardless of how you interpreted my statement. That was really elegant and I’ll absolutely attempt to emulate your behavior when I interact with others going forward.

Late to the party, but I’ll never understand why folks don’t put systems together as a system and not just parts. Seems like folks just run to the net any buy used thinking it will all play well together. So many great products for all to enjoy, but not if they don’t play well together in the sandbox. Jmho. Not always about hard to drive, but I can say for my ears I usually gravitate to speakers that are easy to drive for most amps. 

This topic deserves 🙄

Class D is going to make high sensitivity speakers obsolete.  Amplification is a solved problem and the only thing left is to make it cheaper.  The high end audio world has to a decent degree accepted that the Benchmark amp is essentially perfect.  Some people want a particular flavor and that's fine, they can buy what they like.  For those of us who want a straight wire with gain, class D is there.  It's taken decades but there are now a bunch of class D amps that measure about as well as the Benchmark.  And some of them are very powerful.  The Hypex NCx500 module measures about as well as the Benchmark and is starting to show up in finished designs.