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Luxman Solid State or Vacuum Tubes Amplifier


Vivek Batra

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7 hours ago, polizzio said:

Same goes for Klipsch, known for their very high speaker sensitivity data. No magazine or on line testing I have ever read or seen has equaled Klipsch's claims of individual Heritage speaker sensitivity data @ 2.83 volts (1 watt), one meter distance testing. Is Klipsch lying too? I have read at least one longtime member here on the forum who alluded the Klipsch sensitivity data is false or exaggerated.

They include 4dB of room gain to their sensitivity spec. I personally feel they should stop doing it. Most people do not shove their speakers into corners.

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3 hours ago, xoundmind said:

Can you please explain “room gain” as it relates to sensitivity.

 

thanks

 

As mentioned above by Dean, the 4 db added to their sensitivity measurements after testing @ 1 watt input (2.83 volt) @ a distance of 1 meter. Most manufacturer loudspeaker testing is done in a anechoic test room. So Klipsch adds 4 db of generated sound pressure level to account for the end user's room gain. 

 

Seems rather arbitrary to me, not every user's room is the same size, flooring surface, dampening qualities. But it does make their (Klipsch) published sensitivity data appear really impressive.

For example, a 10 db gain from X level equates to a doubling of the sound pressure level.  For example 100 db to 110 db.

 

Huge difference between playing your LaScalas @ 2.83 volt input in a 12x12' bedroom (door closed) with a tile floor, versus say a 30x30' LR with wall to wall carpeting and many sound dampening furnishings and/or an open floor plan. Actual distance to the listener's ears from the transducer is a big factor too. The room gains for each room in my analogy are quite different. So to test your product (loudspeaker) for sensitivity and add a 4 db room gain arbitrarily on top of the actual test result seems disingenuous to me. Just my opinion. Kipsch sensitivity data is on another level compared to other home loudspeakers. Also as I mentioned above, numbers that second party testing can never realize (such as audiophile websites/testing/review data). Or in the old days published audiophile magazines.

 

Most home loudspeaker sensitivity numbers are usually 84 to 95 db @ 1 watt input . Try to find any other loudspeaker brand/manufacturer @ any cost equaling 104 db sensitivity in their published data.

Hopefully I made myself clear above. Dean has way more expertise than I.

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4 minutes ago, polizzio said:

 

As mentioned above by Dean, the 4 db added to their sensitivity measurements after testing @ 1 watt input (2.83 volt) @ a distance of 1 meter. Most manufacturer loudspeaker testing is done in a anechoic test room. So Klipsch adds 4 db of generated sound pressure level to account for the end user's room gain. 

 

Seems rather arbitrary to me, not every user's room is the same size, flooring surface, dampening qualities. But it does make their (Klipsch) published sensitivity data appear really impressive.

For example, a 10 db gain from X level equates to a doubling of the sound pressure level.  For example 100 db to 110 db.

 

Huge difference between playing your LaScalas @ 2.83 volt input in a 12x12' bedroom (door closed) with a tile floor, versus say a 30x30' LR with wall to wall carpeting and many sound dampening furnishings and/or an open floor plan. Actual distance to the listener's ears from the transducer is a big factor too. The room gains for each room in my analogy are quite different. So to test your product (loudspeaker) for sensitivity and add a 4 db room gain arbitrarily on top of the actual test result seems disingenuous to me. Just my opinion. Kipsch sensitivity data is on another level compared to other home loudspeakers. Also as I mentioned above, numbers that second party testing can never realize (such as audiophile websites/testing/review data). Or in the old days published audiophile magazines.

 

Most home loudspeaker sensitivity numbers are usually 84 to 95 db @ 1 watt input . Try to find any other loudspeaker brand/manufacturer @ any cost equaling 104 db sensitivity in their published data.

Hopefully I made myself clear above. Dean has way more expertise than I.

👍🏻 Many thanks for the thorough explanation. 

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How many here listen in an anechoic chamber 😄

 

A loudspeaker sensitivity measurement/claim that doesn’t take into account the real world environment (ie: Listening rooms) is extremely lacking and still doesn’t place all loudspeakers on an even playing field as some seem to believe.
 

Room gain, loudspeaker polar response, loudspeaker power response are not accounted for in an on-axis measurement for sensitivity in an anechoic or quasi anechoic measurements yet all these factors are at play in how we perceive the sensitivity of a loudspeaker.

 

All advertised loudspeaker sensitivity measurements should come with a disclaimer of how they were arrived at otherwise they are all of limited use and should be used with some caution.

 

Klipsch’s method is a reasonable attempt IMHO to account for the way most of us use a loudspeaker in our rooms. Yes every room is different but to ignore the room influence and other aspects of the loudspeaker’s performance (ie: polars for example) isn’t the answer for sensitivity measurements.!!!

 

So for those saying Klipsch is being deceptive in their Sensitivity Claims what is your idea for an accurate and reliable way to perform the measurements that is directly related  to what we actually perceive in our listening rooms..?

 

miketn

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1 hour ago, mikebse2a3 said:

 

 

So for those saying Klipsch is being deceptive in their Sensitivity Claims what is your idea for an accurate and reliable way to perform the measurements that is directly related  to what we actually perceive in our listening rooms..?

 

miketn

 

It is deceptive. Measuring your speaker sensitivity readings under lab conditions then arbitrarily adding 4 db to the reading. How come other manufacturers just report their speaker sensitivity readings as they are measured?

Try to find any home loudspeaker offered at any price (other than Klipsch) proclaiming a sensitivity level @ 1 watt of 105 db. Anywhere on earth. 

 

When magazines or audiophiles conduct loudspeaker sensitivity readings they usually measure outside in a field  or empty parking lot to remove any room gain or reflections. Because they do not have access to an anechoic chamber. 

 

When Josh Ricci @ databass.com measures subwoofer output, do they arbitrarily add 4db to the readings after the measurements?  Nope. They want a fair and consistent measurement standard/test conditions. For all brand subs or DIY boxes.

 

Why doesn't Klipsch just report the data as measured, like every other loudspeaker manufacturer in the world? Oh I know why, because it makes their speakers appear hyper efficient, superior to all others and not even close.

 

Klipsch doesn't need to add 4 db. The horn design/compression drivers are so efficient they would still be dominant. Look i realize my view isn't popular here, but I prefer truth versus inflated claims.

 

 

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5 hours ago, Deang said:

They include 4dB of room gain to their sensitivity spec. I personally feel they should stop doing it. Most people do not shove their speakers into corners.

 

How far back was this practice put into place? Seems like the type of bullshit we're led to believe PWK would not tolerate.

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12 hours ago, polizzio said:

Same goes for Klipsch, known for their very high speaker sensitivity data. No magazine or on line testing I have ever read or seen has equaled Klipsch's claims of individual Heritage speaker sensitivity data @ 2.83 volts (1 watt), one meter distance testing. Is Klipsch lying too? I have read at least one longtime member here on the forum who alluded the Klipsch sensitivity data is false or exaggerated.

 

 

My guess is that Klipsch, knowing that speakers are listened to in a room, rather than In an anechoic chamber, publishes their sensitivity as it would be in a room.  There is a tiny number in superscript next to their ratings, that leads the reader to the footnote, "Sensitivity in an average listening room."   The AES speaker positioning of any of the Heritage speakers would be inappropriate for listening.  A Klipsch engineer on this forum said the difference is about 4 dB.  I understand this is convenient for Klipsch, and may have come from the PR department, but it also is reality based, in a way.

 

Klipsch's sensitivity ratings pre-dated the current standards.  For instance, they used to spec the Klipschorn at "104 dB at 4 feet at 1 w," or 54 dB using an EIA rating.  The slow constellations wheeled on.   In modern times, moving from 4 feet to 1m, (3.28 feet), about 8.6" closer -- therefore louder --  probably increases SPL by an amount that rounds off to 1 dB, so they were rated at 105 dB at 1m at 1w (2.83v into 8 ohms).  Actual measurements were probably taken at a much more distant spot, to let the speakers integrate, then they did the math.

 

In those days, Paul Klipsch recommended that all speakers be placed in, or very near, a corner.  That amounted to
"Manufacturer's Instructions," which is where the speakers should be placed and measured.  Moving a speaker from out in a room into a corner produces an increase of 6 dB or more. 

 

[Certainly, an older K-horn, without a sealed back should be measured in 1/8 space, i.e. sealed (with rubber, or the like) in a trihedral corner.  It is recommended that even the new K-horns, with their factory sealed backs, still be placed in the close proximity of a corner, but now can be toed toward the listeners.  This didn't stop Stereophile from -- impertinently, both meanings intended -- measuring them outside, not in a corner, raised off a driveway on a furniture dolly.  Even then, they got 101 dB, 1m, 2.83v, exactly 4 dB below Klipsch's in-room result.]

 

The entire (original) Heritage line all may benefit from being in a corner, providing that a few absorbers are placed to prevent nearfield reflections of the midrange from the side walls.  See @Chris A, "Corner horn imaging" on this forum.

 

 

 

 

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6 minutes ago, Thaddeus Smith said:

 

How far back was this practice put into place? Seems like the type of bullshit we're led to believe PWK would not tolerate.

I learned about it in 2002, when Sound and Vision Magazine measured the RF-7, showing it to be a 99dB@2.83v loudspeaker. There is a crazy thread about this in the archives somewhere. 

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There really aren’t any industry standards that satisfy all the variables that result into a sensitivity figure that is universally valid...!!!

 

The best we can hope for is a list of the conditions and assumptions made that result into a manufacture’s stated/advertised sensitivity specs. Then we might be able to make reasonable assumptions when we compare one manufactures specs to another’s which uses different methods and assumptions.

For example subtract -4db from Klipsch’s stated sensitivity value if room gain wasn’t used in another manufacturer’s stated value if all other variables are identical (which in the real world is very unlikely because the variables are many and there are no accepted standards industry wide from what I’ve been able to see so far).

 

Some other things to consider when sensitivity measurements are taken.

https://peavey.com/support/technotes/concepts/THE_LOUDSPEAKER_SPEC_SHEET_GAME_2005.pdf

 

miketn

 

 

 

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