High sensitivity (99) with mid powered (50 to 100 wpc/tube) amps?

I was running my Forte IV with a pair of 40 watt Quicksilver mono amps and for me it's plenty of power and sounds great.   I also run them with a 300b Amp that's only around 7 watts.   Sounds beautiful, but runs out of steam if you crank it up loud.   

I think that would be a great combo,  especially where you can switch between triode and Ultralinear .   It's like having an amp with two personalities .

They are very different from your 805.   I will use my sub sometimes but they really don't need a sub.   I have my sub crossover set low, it's only playing below 50 hz with a steep crossover slope. 

@oddiofyl , what catches my interest is their small foot-print. It’s almost as small as the B&Ws I am currently running. They are actually lower than the B&Ws. I don’t think that they would overwhelm the room.

I guess what I was initially wondering about was: it seems from all I’ve read that speakers rated with sensitivities in the high 90s were usually paired with (and possibly intended to be paired with?) amps with very low wattage, such as SETs, and that made me wonder if they would NOT pair well with amps producing more power. So I was up late last night reading reviews, and I read one by Steve Huff (who said he loved them) but he initially used with (I think it was) a Cary SLI300 and it was way too noisy. Which then made me think that if your amp made any noise at all, a speaker with an efficiency as high as 99 would really amplify that noise? With that typed, I do not hear any noise from my B&Ws when system is on but no music playing. I do, however, hear an almost inaudible hum if I get up really close to my amps . . . I think it is coming from the transformer(s).. So I was wondering if that would be picked up by a speaker that efficient?

As far as their small foot print, would their height of only about 3’ cause a problem with near field listening? I mean my ears would definitely be above the tweeter and I would be close.

I know that MD has (I think it is) a 60 day audition period, but despite their (the speakers) relatively small foot print, at 72 Lb.s each, I imagine it would cost a fortune to return them.

I have been investigating this too — I have Quicksilver Mono 60's (25wpc and up, depending on output tubes) and am looking at Forte IV's and Cornwall's.

All I've heard from folks (including on Klipsch forum, which the OP should check out) is mid-powered tube amps sound just lovely with sensitive speakers. Indeed, a buddy of mine who has very sensitive wide baffle speakers (not Klipsch) runs things as low as 8 wpc up to 75 wpc and the speakers always sound great.

When you say near field, how far from the speakers would you be listening to them?  How far apart would the speakers be?  If it were me, I don't think you should be too concerned with the power of your amplifier especially if you like to crank it up once in a while.  Make sure you give them time to break in.  If it doesn't work out then return them.  My two cents.

Thanks @hilde45  , I think that one of the sites that I did a quick pass through was the Klipsch forum and I am not sure what the original thread topic I clicked on was, but I remember a bit of an argument about whether the Forte IV would be too much bass for a small room and whether the ported Heresy IV would be better.  This consideration is applicable to me, because I am listening, presently, in a quite small room at near field.  That is one of the nice things about the sub I would like to get out of the equation, I can tune the bass to my liking.  However, I am thinking that the bass from the Forte IV would be of much higher quality.

I really would love to upgrade my speakers if I can find the right pair at the right price (and these Forte IVs just about meet the latter category), and I do appreciate MDs audition period policy, but I'd like to think that I am going to like them, as I do not think I am going to like shipping 144 Lb.s of speakers back to Chicago.

Anyway, good advice on the Klipsch forum . . . I am going to spend some time there.

@jc4659 , I actually wasn’t worried about not enough power, I was worried that too much power might not be compatible with a sensitivity of 99? My ancient B&Ws are listed as being 87, and my Cary has no problem at all driving them in 50 wpc triode, and especially now that they are in a real small room.

As far as how near field it is? I went back to measure, but I recently uprooted almost EVERYTHING to get to something else, so with stuff all over the floor, I cannot even see where I marked the spots to return my speaker stands to. (I think I am going to get that restored as my next project today.)

But anyway, for dimensions, the front of my drivers are about 3’ from the front wall (which from what I have read of the Forte IV so far is no problem as everyone seems to be putting them a lot closer to the wall than that) and the "polite" B&Ws and I site in an equilateral triangle with all the points being about 4’ from each other. (And I do note that the Fortes don’t have a much bigger footprint than the B&Ws.)

Which I realize is way close, but life is full of compromises and it is what it is. However, with well recorded/mastered source material and the lights off (which is how I always listen) the speakers and walls disappear. With poorly recorded &/or source material, the effect makes me almost nauseous. Some day we may be back in the living room, but I do not see that day happening real soon.

Keep in mind the passive radiator used in the FIV; they need to be experimented with the distance to the rear wall. I find the design to be too low, so a base of some kind can be used to elevate them, or you can create a tilt up elevating the F from the front. They have a very different presentation to the B&W. I am a bit surprised actually that the change of speakers has come up since the power cable discussion was started, not too long ago. Matt, do not take this the wrong way, please, but I see you as just another listener who is a bit lost in the direction of where you want to take your music listening experience. Truth be told, you are not alone, as I communicate with many people, and this is very common. I love the Klipsch Heritage line, and I feel the CWIV should be the way to go. Also, to get them to be problem free, you would do well to dampen the horns with a Dynamat type product. I am very sorry if my words are taken hurtfully. Last thing. Most people listening to recorded music today through a hifi rig (making them an audiophile), are listening for / to the wrong things, ime. They do not want to accept the recording for what it is, which is a collaboration of many various elements that make it very imperfect. But one thing for sure is on our recordings; the "musicianship". So, while many folks want to hear more "space" of a stage, more "tone" from a violin, more "sound" beyond and around the actual boxes / panels, they miss the integrity of the music itself. This, is my experience. I love my system (although I use many different power amplifiers through rotation). My system conveys to me that one most important quality I look/listen for. That connection "with the musicians". Again, I apologize. Good luck my friend. Always, MrD.

Heresy are great but Forte IV are much better.  I replaced my Heresy III with the Forte and they give you a lot more low end with the same footprint.  Heresy need a sub to sound like a full range speaker.  

I am very sorry if my words are taken hurtfully.

Not at all, @mrdecibel . I value your input!

As far as my questions regarding power cords and my interest in speakers:

back when I bought the SA10 the salesman from MD told me that it would really benefit from a different power cord. I won’t say that I took that with only a grain of salt, but it wasn’t high on my list. I learn a lot from simply reading posts on this site, and a while ago the subject of digital and RF came up, and I started to put 2 and 2 together (hopefully i did?) and I thought, "Ohhhh, maybe the salesman was not just trying to sell me a cord I do not need." I mean, the better the machine (and I bought that machine because it is, in theory, no slouch, and the 3 pieces of digital separates I was using dated back to the ’90s and I felt they must be obsolete) the more something like a power cord might make it perform. Kind of like a performance engine . . . do certain things to a real dog and you are wasting time and money because a true dog is never going to perform regardless of what you do, but make certain changes to a real thorough bread, and the difference it can make is remarkable. Not all engines, for example, react the same way to headers. I was thinking the relationship to digital and power cords might be the same.

As far as speakers: that subject has been on my mind for a long time. I’ve posted numerous queries about speakers that have came to my attention on MD and when a speaker thread comes up, if the speakers are in my ballpark I frequently ask questions.

My present speakers are B&W 805s, but they are the ancient Matrixes that I bought going on 30 years ago. As much as I like them, I cannot help but think that they are the weak link in my system. And as much as I like what I get from my system in my compromised room, I cannot help but think updating my speakers MIGHT be like night and day. 30 years ago when I bought those B&W 805s they replaced a pair of NHT monitors, and the more and more I listened to the 805s the more and more I liked to listen, and at the time the $1600 list seemed like a lot for speakers (30 years ago) but I was totally okay with it. Those speakers did everything for me that I thought speakers could do. I have a pair of 1980s vintage re-ribboned Magnepans I bought from a friend back in ’01, and I never could get those Maggies to perform to the level of those old 805s.. It could be that those Magnepans are not as forgiving as the 805s when it comes to placement (I’ve had them in both my living room and my present small listening room) but regardless, I always wanted to hook my 805s back up. About 20 years ago, when I was a different person, I would switch my amp to ultralinear and I’d play music so loud that the picture I was seeing in my soundstage was like a balloon getting bigger and bigger and bigger . . . and it was clean but so loud I thought that they (the 805s) might explode. OR on other nights I’d switch them to triode and listen to them whisper. ((Prior to my present Cary amp I had a pair of unreliable ARC VTM 120s I drove them with, and I remember listening to Lou Reed’s (live red book) Rock And Roll Animal (specifically Intro then Sweet Jane then Heroin) so loud it scared me.

All that was to say that once upon a time I was very happy with the 805s, but to repeat: I now think that they are probably the weakest link in my system. Well, maybe the room is, but I can address the speakers way way way easier than the room.As far as listening to music. All I know for sure is that when I get the right CD in (and usually it is a SACD) there is air and bloom and detail and depending upon the recording the soundstage extends beyond the wall;

(I always listen in the dark)

and I hear textures and inflections in the vocalists voice and it makes me very happy. However, with what I feel is a source of lesser quality, it is hard to listen to. As an example, the last SACD I listened to before I disconnected and dismantled was Jacintha covering James Taylor on a SACD titled, if I remember correctly, Fire And Rain. By the time it had played through, my eyes were literally moist.

However, I cannot help but thinking that my ears were missing something listening to those old B&Ws and that I could be even happier if I could provide my ears with that something via different speakers.

Again, I apologize.

And again: are you kidding? There is absolutely NOTHING to apologize for!!!

Matt, I am sorry to hear that. Feeling nauseous when listening to much recorded material, is quite severe, and again, you are not alone. I fortunately enjoy everything I listen to...recorded well or not....as I listen to the performance, 1st and foremost. TY for being easy on me. Always, MrD.

@mrdecibel , well, "nauseous" was hyperbole. As is "nails on a chalkboard." What I would say, in all honesty, is that I find poorly mastered and/or recorded CDs to be lifeless and un-engaging with a very flat sound stage. Often I find them to sound bright or even shrill when I try to put a little muscle behind a song I really like. And the room I am in probably exacerbates this. However, when I get good source material in the SA10, it is immediately evident.

Matt, I am sorry to hear that. Nauseous is a feeling that never occurs with me when I listen to any of my recorded music.

I somehow got the impression that you listen to mostly vinyl? And I am also under the impression that most vinyl sounds "nicer" than most digital? I cannot personally attest to that, the last TT I had was part of a Magenevox (I don’t even know if I am spelling that right) rack system I bought in ’79, and I gave it & my LP collection to my sister when I went overseas in ’83, and back in those days our idea of being an audiophile (we actually had never heard the term) was to crank it up ’til it clips, and then back it down a hair. But I am locked into digital, and it is 99% likely that it will be digital for me until the day I die or they are feeding me meds that are crushed up and stirred in with pudding/whichever comes first.

But I am thinking that you are probably listening to better source material than I am a lot of the time.

. . . back to power cords and speakers, @mrdecibel , a power cord upgrade is an easier component to entertain playing around with than a speaker upgrade is.  Even on the level of a one thousand dollar power cord (although I would have to think hard before pulling that trigger/or for that matter, even a $500 power cord).  But a $50 dollar cord?  As @soix  once told me about installing affordable jumper cables in my speaker inputs IN ADDITION TO the shotgun biwiring I was doing (and I probably paraphrase to a certain extent), "How many tweaks are there that you can do for $25?"  Meaning if it works:  FANTASTIC!  And if it doesn't work:  no great loss, it was worth trying.

And I am on the cusp of ordering two more of those cords.  Procrastination just happens to be one of my fatal flaws.  

@immatthewj

I auditioned the Forte IV a couple weeks ago and cannot recommend them. I was looking at the possibility of a more full range bass response than my Spendor D7.2 towers and a more present, dynamic presentation.
Unfortunately the Forte IV sounded slightly dark and un involving in comparison.
The bass could be very deep and enjoyable but it seemed slow and disconnected from the music. It was also missing the mid bass punch my speakers have. On one of my demo tracks talking heads psycho killer live, it opens with a tight and punchy bass line.  The punch was totally missing from the Forte IV.  
This was very weird to me because I listened to the Forte III a few years ago and loved them!  Similar amp too.  They had everything the IVs lacked except for a bit too much cabinet coloration.  
If you have the budget, give the Pure Audio Project Duet 15 a try.  

Thank you for the input, @avanti1960  , I did a quick google and the Pure Audio Project Duet 15 is a bit out of budget right now.  I am not quite as excited about the Fortes as I was last night (last night I was thinking that in the morning, or on Monday moring, I'd be ready to call up MD and pull the trigger).  That often happens with me.  

Anyway, I do not want to go to a speaker that would be a lateral move or a slightly above lateral move.  And as I typed earlier, as much as I appreciate MD's generous audition period, I would also like to advoid mailing a140 Lb.s of speakers back to them.  that was why I was interested in thoughts on them, and, to be redundant, my first thought was whether speakers that are that efficient pair well with the kind of wpc I currently am using.  (I would truly like to try the low [powered SET with high efficiency speaker route, but if that happens, it is down the road.  Just for grins, I did browse ebay to see what Dennis Had had going at the moment.)

Anyway, thanks again for your input based on your experience with them.

As far as your Spendor towers, are those the ones that are two way speakers mounted in a cabinet as opposed to a speaker stand?

@immatthewj,

Nice pair of JBL's for sale in State College, PA see here!

Mike

Thanks, Mike . . . State College is a doable trip and after a few googles that seems like a helluva deal on them, but still a "tad" over my budget, and from what I read, they are "big room speakers"?

few tips from another person who is/has run hi efficiency speakers.

The power is fine for the Klipsch's more then you will need but not excessive. 

The first issue you may encounter; Is your system quiet enough for the speakers?  Took me a while to find components that were, tube and also quiet enough for the LaScala's (105db) I had.

Tubes that are bad or going bad will show signs sooner, maybe a good thing.

Preamps/or preamp stages that have low enough over all gain to have a usable volume range. This also ties into over all gain being being too hi. Took me a while to find a pre-amp that had a good usable volume range and was dead quiet. 

Another thing you may want to find tubes that are a bit on the smooth/laid back side of the sound spectrum as the horn loaded tweeters in the Klipsch's can excite some people. also the Forte's are not good really close to the wall as they have a passive radiator in the back to support the bass. 

Thanks, @glennewdick  !  That is great input!  Seriously.  My preamp does have a lot of gain.  There is no noise that I can hear from the speakers with no music playing, but there is a very soft hum from the preamp itself.  It's not enough to bug me, and the only reason I know it's there is because of how it sounds when I turn the preamp off.  I believe that these are not going to be the right speakers for me.  I'd still like to try them out and see for myself, but if they had more cons than pros, I am thinking that sending a pair of speakers that weigh 144 Lb.s back would be a bitch.  Again, thanks for addressing the questions I asked on this.

tube amp hiss/hum has been a common complaint of tube afficiandos running super efficient speakers..

@immatthewj @hilde45 There's no downside to running a bit more power on a higher efficiency speaker! I've done it for years (my speakers are 98dB). I've found that many lower powered amps make just as much noise floor as higher powered amps, so noise isn't an issue.

Distortion is; with less distortion comes greater transparency. There are many PushPull tube amps that easily rival the best SETs and usually use less expensive power tubes.

Thank uou for your input on that part of my question, @atmasphere  .

 @atmasphere Wrote:

  There's no downside to running a bit more power on a higher efficiency speaker! I've done it for years (my speakers are 98dB).

I agree!

@immatthewj,

Look at the Quicksilver Horn Mono amplifier, it is designed specifically for use with very efficient speakers and it's affordable. See here! FWIW, my speakers have an efficiency of 2.7% and sensitivity of 96dB. 😎

Mike

@atmasphere Thanks for the input and advice, Ralph!

Thanks, @ditusa  , but I am having to stretch things to get into new speakers . . . an new amp is out of the question.

I think, however, if something happened in my life that allowed me to start (somewhat) fresh, I'd like to go the low powered SET route (I was specifically thinking about some of the Dennis Had stuff) with speakers in the high 90s.

I have a pair of upgraded Quartets (crites tweeters and xover) the Forte's little brother and run it with a 6 watt Grommes PHI-26.  For the price it sounds amazing.  I feel like i'm listening to live music vs my de Capos in my home system.

I think, however, if something happened in my life that allowed me to start (somewhat) fresh, I'd like to go the low powered SET route (I was specifically thinking about some of the Dennis Had stuff) with speakers in the high 90s.

@immatthewj If you use a lower powered SET (up to 7 Watts or so, which might be a 300b), the speakers really should have sensitivity/efficiency in the 100s.

Zero feedback SETs have about 20-25% usable output power (relative to full power) because higher ordered harmonics show up above those power levels, causing the amp to sound 'dynamic' (since power is most needed on the leading edge of transients) because the ear uses higher ordered harmonics to figure out how loud sounds are. When the 'loudness cues' are only on the transients you get that 'dynamic' quality but its really how distortion is interacting with the ear.

Also if you push the amp it will sound 'loud' because of these harmonics, which is why so many people say they really don't need that much power. There are sound pressure level apps for your phone that will winnow out the truth of that- you find that 'loud' is considerably lower than you might expect.

So if you really want to hear them do what they do best, you need a very efficient speaker!

When the amp has less higher ordered harmonics its very natural to turn the volume up higher and use greater power; its the mark the better systems that they do not sound 'loud' at any volume! There are lower powered PP amps (5-20 Watts, class A) that have considerably higher usable power (90-95% instead of 20-25%) and are every bit as involving and musical as the best SETs, but with wider bandwidth and greater detail as well.

I have no problem running my CW4's with a 50wpc Moonriver integrated, with no noise, dead quiet.  They are also happy with Ralph's Class D Ganfets and a pair of Belles Aria Monoblocs.  All quiet.  But, if I try to use my Sugden A21SE class A integrated, the noise is very apparent, and not very enjoyable.  Just goes to show, you never know until you try it.

Thanks @atmasphere  , @doni  and thanks to all.  I did finally get off of the fence, but I felt a bit nervous about the Forte IVs after all I have read here, and sending them back would be a bitch.  As I just typed, I did get off the fence and I just got through hooking up a pair of Revel M126Be's which are on the other side of the sensitivity spectrum at 86 with 8 ohm minimal impedance.  They were B stock from MD, and I have 60 days to decide, and at 22 Lb.s each, if I do send them back it won't be so bad.  They are lookers, but there are some things I didn't know that may have made me consider not ordering them.

But, I'' listen with an open mind.

Thanks again.

I run a pair of 101db 16 ohm 15” coaxial Altec 604Cs with a pair of NYAL Julius Futterman OTLs, converted to triode and rated 135 watts each.

It’s worked for me for 39 years.