Helping a friend choose some speakers for a home cinema setup (gasp - not diy!), I've come across Klipsch synergy speakers. My friend is keen on them, and I'm perplexed by them, in particular their quoted efficiency seems ridiculous!
Take the F-3 for example. 97 db @ 2.83v/1m and "8ohm compatible." It has a horn loaded CD and two 8" midbass drivers in a bass reflex enclosure with bass down to 35 Hz.
How do we get such high efficiency?
Working backwards, let's assume that there is no BSC and that the impedance is a little on the low side, meaning that this is not a true sensitivity rating as the input power is in fact more like 1.5w giving us say 1.5 dB extra. So in reality it is more like 95.5 dB for two drivers. That means each driver must be 92.5 dB sensitive. That is a bit of a stretch. If you look at hifi drivers of that size designed for the same bandwidth, 91 db is about as good as it gets, unless the driver has a sloping response with greater midrange sensitivity to tweak the numbers up.
So with some fudging, I can get within 1.5 db. But what should it be? Using those drivers with a sensible 3db of BSC, we should in fact see 91 dB as the efficiency to allow us to place it into the room rather than against a wall. Or, if we accept wall placement, using it only for home theatre, then 94 dB.
I've wondered, what is the point in using a CD/horn with small hifi drivers? A waveguide loaded dome should do just fine.
Or have Klipsch found the magical piece of unobtainium in driver design? I'd like to see their SPL response given 1w of input.
I found their sound surprisingly good - tonal balance seemed reasonable, although I found them lacking in the sweeter sound I'm used to and the deeper soundstage and box resonance free sound of my open baffle speakers.
Can anyone shed some more light on this? I know this topic has come up before, but I'd like to tackle it again.
Take the F-3 for example. 97 db @ 2.83v/1m and "8ohm compatible." It has a horn loaded CD and two 8" midbass drivers in a bass reflex enclosure with bass down to 35 Hz.
How do we get such high efficiency?
Working backwards, let's assume that there is no BSC and that the impedance is a little on the low side, meaning that this is not a true sensitivity rating as the input power is in fact more like 1.5w giving us say 1.5 dB extra. So in reality it is more like 95.5 dB for two drivers. That means each driver must be 92.5 dB sensitive. That is a bit of a stretch. If you look at hifi drivers of that size designed for the same bandwidth, 91 db is about as good as it gets, unless the driver has a sloping response with greater midrange sensitivity to tweak the numbers up.
So with some fudging, I can get within 1.5 db. But what should it be? Using those drivers with a sensible 3db of BSC, we should in fact see 91 dB as the efficiency to allow us to place it into the room rather than against a wall. Or, if we accept wall placement, using it only for home theatre, then 94 dB.
I've wondered, what is the point in using a CD/horn with small hifi drivers? A waveguide loaded dome should do just fine.
Or have Klipsch found the magical piece of unobtainium in driver design? I'd like to see their SPL response given 1w of input.
I found their sound surprisingly good - tonal balance seemed reasonable, although I found them lacking in the sweeter sound I'm used to and the deeper soundstage and box resonance free sound of my open baffle speakers.
Can anyone shed some more light on this? I know this topic has come up before, but I'd like to tackle it again.
Very short woofer coils, so the instant the speaker needs to produce any bass below 100Hz, instant distortion.
A sloped up frequency response.
Pick your sensitivity measurement at the 4kHz spike.
I bet the speakers minimum impedance drops below 4ohms.
There is no free lunch, just exaggerated claims based on incomplete information.
And yes, you would never want a CD horn in a home environment with a low RT60.
A sloped up frequency response.
Pick your sensitivity measurement at the 4kHz spike.
I bet the speakers minimum impedance drops below 4ohms.
There is no free lunch, just exaggerated claims based on incomplete information.
And yes, you would never want a CD horn in a home environment with a low RT60.
I've seen the measured responses of a dozen or so Klipsch speakers and they hold up to spec, but they do use somewhat of a "trick" to get the numbers higher. This was pointed out to me by a former boss of mine who used to be a systems engineer at Klipsch. I've attached a (crude) drawing of a typical Klipsch speaker on axis amplitude response. The horn keeps the sensitivity high on the upper end of the response. On the low end of the response a big ported box is used which results in a peak around tuning. Where the midwoofers' response is flat (in the mass controlled region) the response does drop a little bit. This is how they get the nominal sensitivity high.
Attachments
Ahhh, now that's making sense, thanks.
Jack, could you elaborate on the short VC?
How is that an advantage with efficiency?
Surely this would mean no real xmax, hence no real bass capability. They do appear to be fairly conventional midbass drivers, I'd imagine with 4 - 6 mm xmax.
So far I've found with efficient speakers, they haven't sounded good enough to make the extra output useable. I heard some Adire HE10s next to some Focal MTM speakers, and the Focals sounded listenable at a louder volume. The HE10s would happily go much louder than my ears wanted - too harsh.
I'd love to hear an efficient high output system with the relaxed sound I get from my system, but I haven't found one yet. Not a big issue right now, but there will come a time where I'll be considering an array of smaller conventional hifi drivers vs pro drivers.
Jack, could you elaborate on the short VC?
How is that an advantage with efficiency?
Surely this would mean no real xmax, hence no real bass capability. They do appear to be fairly conventional midbass drivers, I'd imagine with 4 - 6 mm xmax.
So far I've found with efficient speakers, they haven't sounded good enough to make the extra output useable. I heard some Adire HE10s next to some Focal MTM speakers, and the Focals sounded listenable at a louder volume. The HE10s would happily go much louder than my ears wanted - too harsh.
I'd love to hear an efficient high output system with the relaxed sound I get from my system, but I haven't found one yet. Not a big issue right now, but there will come a time where I'll be considering an array of smaller conventional hifi drivers vs pro drivers.
My experience measuring my old Heresy speakers shows that the high efficiency rating was a bit of a stretch. The tweets may have been 97dB, the mids 94dB or 95dB and the woofer came in at only 92dB. The frequency response was very tilted up and very rough.
Twin woofers when closely spaced may gain 6db in sensitivity over a single. Add two more and your up even more- also don't forget the mirrored pair reflection on the floor and the additional boundary gain from the rest of the room
For example run a pair of these in parallel - 8 inch woofer
99- 100 db with 2.83 volts is probable with these eights
For example run a pair of these in parallel - 8 inch woofer
99- 100 db with 2.83 volts is probable with these eights
Hi,
You can see a meassurement of a klipsh here...
Stereophile meassurement
High reflex tuning as mentioned.
You can see a meassurement of a klipsh here...
Stereophile meassurement
High reflex tuning as mentioned.
Go here, to see that the system is rated at 8ohms, but in fact has a minimum impedance of below 4.
http://www.stereophile.com/loudspeakerreviews/204klipsch/index1.html
http://www.stereophile.com/loudspeakerreviews/204klipsch/index1.html
Klipsch horn efficiency
Horn loaded speakers are inherently higher efficiency that any other loading methods, by a long shot. Klipsch is one of the oldest manufacturers experienced with horn designs, as they go back to the tube-only amp days when amp power was low by today's standards...particularly if you were a "high-ender" running Class A bias tube amps. It was not uncommon for tube audiphiles to be running 5W or less into speakers, and in such a scenario Klipsch was viewed as a revolutionary design.
In order to effectively extend that efficiency to lower frequencies, the horn had to be larger and larger. Klipsch was innovative in the way that they "folded" the length of the horn is their designs so that the resulting box could be practically placed in a living room. You may also recall the later Voice Of The Theater speaker from Altec Lansing, a huge front-loaded horn enclosure popular in (you guessed it) stage and movie theaters "in the day" (I actually built a pair of these myself with better drivers and stronger construction, at a point when I was renting a huge old mansion with the 14ft ceilings and large living room that "needed" them).
As is the art & science here, there are of course trade-offs, and deep base is one of those in horn designs as there is a practical limit of bass response as compared to eg tuned port bass reflex loaded designs, but IF you're after efficiency it's still impossible to beat a Klipsch horn even today. It's a niche hobby today, but there are still horn enthusiasts that are bi/tri amping customized multiple driver Klipsch horns with both Class A tube & solid state electronics. The sound is pretty unique and even phenomenal, altho not my first choice personally.
Horn loaded speakers are inherently higher efficiency that any other loading methods, by a long shot. Klipsch is one of the oldest manufacturers experienced with horn designs, as they go back to the tube-only amp days when amp power was low by today's standards...particularly if you were a "high-ender" running Class A bias tube amps. It was not uncommon for tube audiphiles to be running 5W or less into speakers, and in such a scenario Klipsch was viewed as a revolutionary design.
In order to effectively extend that efficiency to lower frequencies, the horn had to be larger and larger. Klipsch was innovative in the way that they "folded" the length of the horn is their designs so that the resulting box could be practically placed in a living room. You may also recall the later Voice Of The Theater speaker from Altec Lansing, a huge front-loaded horn enclosure popular in (you guessed it) stage and movie theaters "in the day" (I actually built a pair of these myself with better drivers and stronger construction, at a point when I was renting a huge old mansion with the 14ft ceilings and large living room that "needed" them).
As is the art & science here, there are of course trade-offs, and deep base is one of those in horn designs as there is a practical limit of bass response as compared to eg tuned port bass reflex loaded designs, but IF you're after efficiency it's still impossible to beat a Klipsch horn even today. It's a niche hobby today, but there are still horn enthusiasts that are bi/tri amping customized multiple driver Klipsch horns with both Class A tube & solid state electronics. The sound is pretty unique and even phenomenal, altho not my first choice personally.
That Stereophile review has to be the most squirming, apologetic, and most manf-friendly 'critique' ever written. Shameful.
Klipsch relies mostly on ancient (left-over) name recognition and a particularly exciting sound, like Bose, to still peddle their tiresome wares. I remember a salesman's A-B switching demo in the later 80s comparing a medium-sized Klipsch with the equivalently priced Polk (10A?) relying on the extra loudness of the Klipsch to 'prove' they sounded better. Methinks this still continues today.
Klipsch relies mostly on ancient (left-over) name recognition and a particularly exciting sound, like Bose, to still peddle their tiresome wares. I remember a salesman's A-B switching demo in the later 80s comparing a medium-sized Klipsch with the equivalently priced Polk (10A?) relying on the extra loudness of the Klipsch to 'prove' they sounded better. Methinks this still continues today.
Has anybody done DIY Klipsch 62/82/RF-/ like simple 2-way high efficiency monsters?
Seems that basic idea is simple, two woofers paralelled + tractrix / constant directivity horn with CD.
If you want easy load you must find nice 13-16 ohm midwoofers. Sensitivity should not be make too high because box volume is always what defines bass depth. Drivers can be quite sensitive that overall sensitivity remains high after some BSC.
Seems that basic idea is simple, two woofers paralelled + tractrix / constant directivity horn with CD.
If you want easy load you must find nice 13-16 ohm midwoofers. Sensitivity should not be make too high because box volume is always what defines bass depth. Drivers can be quite sensitive that overall sensitivity remains high after some BSC.
getting bass drivers with flat response and good sensitivity is tough. Usually the qts drops as spl 1w/1m goes up, then there is no bass under 100hz. And smaller drivers just don't have the magnet size.
I'm working on a klipsch pseudo-clone (but lower spl sensitivity) using a silver flute 4ohm 8" paired with the mcm round horn with a jbl compression driver (probably 2407a). I burning away a bit of spl from the tweeter.
I could use the 6.5" shielded 8 ohm silver flute in a pair to get up to 96db, or use 1 for baffle step.
Norman
I'm working on a klipsch pseudo-clone (but lower spl sensitivity) using a silver flute 4ohm 8" paired with the mcm round horn with a jbl compression driver (probably 2407a). I burning away a bit of spl from the tweeter.
I could use the 6.5" shielded 8 ohm silver flute in a pair to get up to 96db, or use 1 for baffle step.
Norman
For low distortion you should wind a coil that is significantly longer than the magnetic gap. Unfortunately that extra coil length contributes DC resistance but sees little or no B field. It is no different than adding external DCR to a coil.
Force, F=Bli. The coil inside the gap adds Bl (B field and conductor length). Coil outside the gap adds no Bl just reduces i by increasing R.
David S.
If we alloy little harder load 3-4 ohms, there is lot of possibilities in 8 ohm 6,5-10" connected parallel. SPL ~95-97 dB minus BSC what is needed.
Horn loading a driver is the mechanical analog of an impedance matching transformer. The energy is delivered efficiently at the throat of the horn where pressure is high and as the horn increases in cross section the coupling to the lower pressure of the room at large occurs gradually. This make the speaker able to fill large auditoriums with very little amplifier power. Horn type speakers were developed for the motion picture industry at a time when 5 or 10 watts was as much amplifier power as you had. The penalty is that to produce deep bass the horn must be enormous. Klipsch's trick is to keep folding the horn back on itself as its cross section increases and where sound exits the enclosure the walls of the room become an extension of the horn. That is why it is designed for a corner.
The price is that even with Klipsch's idea bass response from an enclosure small enough to fit in most homes is not adequate. AR1W and its decendants beat huge horn speakers in the lowest octave of sound for linear response and low distortion hands down. The price is that you need much more amplifier power. In 1955 that was an expensive problem. Today it's nothing.
The price is that even with Klipsch's idea bass response from an enclosure small enough to fit in most homes is not adequate. AR1W and its decendants beat huge horn speakers in the lowest octave of sound for linear response and low distortion hands down. The price is that you need much more amplifier power. In 1955 that was an expensive problem. Today it's nothing.
Klipsch uses horn tweeters which help the high end
PA style woofers take care of the low end and when talking that style, I mean low Xmax with very light weight coils and cones.
To get an idea, just look at full range speakers. The Fostex FE series 6.5 inch full range is 94 dB 1w/1m and a Mark Audio 6.5 inch full range is 87 dB 1w/1m.
7 dB is a HUGE difference! However, the Fostex has 1mm of Xmax and the Mark Audio has 8.5mm. Fostex has a Vas of 37 liters and the Mark Audio 28 liters. The Mark Audio will go lower in frequency and provide better bass response than the Fostex.
All depends on what you want, what "sound" you like and if you're going to run subwoofers. Another option is a different Fostex with 1.85mm of Xmax and a lower Fs, requires a Vas of 27.8 liters and the efficiency takes a hit at 92dB 1w/1m.
It is not magic, the lighter the cone the higher the efficiency--very much so when running multiple drivers.
I'm pondering near field monitors at my computer desk and want to check out full ranges. However, the Topping USB DAC amplifier pushes 15 watts at 4 ohms and around 9 watts at 8 ohms--not a lot of power. 87 dB at one watt does not leave much for peaks--but 94dB at one watt does! Maybe get two of the Fostex 92dB models with 1.85mm Xmax and make the second one a "0.5" woofer (parallel second full range with a simple inductor rolling off at around 500 Hz for baffle step correction) At the bass end where the 0.5 woofer operates, it's 4 ohms so I'll see a huge +5dB gain (approx) since two 1.85mm of Xmax 6.5 inch full ranges should be enough for music at 15 screaming watts.
To really drive you nuts--since very efficient speakers require very little power to create sound...they need less wattage. This reduces distortion which should improve sound (in theory) As always, reality tends to laugh at
some theories but marketing won't!
PA style woofers take care of the low end and when talking that style, I mean low Xmax with very light weight coils and cones.
To get an idea, just look at full range speakers. The Fostex FE series 6.5 inch full range is 94 dB 1w/1m and a Mark Audio 6.5 inch full range is 87 dB 1w/1m.
7 dB is a HUGE difference! However, the Fostex has 1mm of Xmax and the Mark Audio has 8.5mm. Fostex has a Vas of 37 liters and the Mark Audio 28 liters. The Mark Audio will go lower in frequency and provide better bass response than the Fostex.
All depends on what you want, what "sound" you like and if you're going to run subwoofers. Another option is a different Fostex with 1.85mm of Xmax and a lower Fs, requires a Vas of 27.8 liters and the efficiency takes a hit at 92dB 1w/1m.
It is not magic, the lighter the cone the higher the efficiency--very much so when running multiple drivers.
I'm pondering near field monitors at my computer desk and want to check out full ranges. However, the Topping USB DAC amplifier pushes 15 watts at 4 ohms and around 9 watts at 8 ohms--not a lot of power. 87 dB at one watt does not leave much for peaks--but 94dB at one watt does! Maybe get two of the Fostex 92dB models with 1.85mm Xmax and make the second one a "0.5" woofer (parallel second full range with a simple inductor rolling off at around 500 Hz for baffle step correction) At the bass end where the 0.5 woofer operates, it's 4 ohms so I'll see a huge +5dB gain (approx) since two 1.85mm of Xmax 6.5 inch full ranges should be enough for music at 15 screaming watts.
To really drive you nuts--since very efficient speakers require very little power to create sound...they need less wattage. This reduces distortion which should improve sound (in theory) As always, reality tends to laugh at
some theories but marketing won't!
hi Norman - does the Silver Flute 8 seem suitable for a K-coupler? does it hold power well?
re: power - I've K-horns and Advents - depending upon what the game player wants, Henry's speaker might make more sense overall and if it had employed a sealed cloth surround like the old KLH, might get my vote.
110+ dB at 1M peak on a drum in my 18x28 foot room isn't very loud at 10 feet. A 10" fullrange in a reflex will fall apart. Karlson coupling helps.
re: power - I've K-horns and Advents - depending upon what the game player wants, Henry's speaker might make more sense overall and if it had employed a sealed cloth surround like the old KLH, might get my vote.
110+ dB at 1M peak on a drum in my 18x28 foot room isn't very loud at 10 feet. A 10" fullrange in a reflex will fall apart. Karlson coupling helps.
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