Speaker Sensitivity: Advertised vs Measured

[MZKM]

Did you ever get a reply from Klipsch on how they rate sensitivity?

Per the spec sheet, the Klipsch Heresy IV's I am testing are rated at 99dB/2.83v @ 1m. But, they have a footnote for this that states:
"Sensitivity in average listening room"

Are they adding 3dB for in-room effects? Cause, based on what I'm seeing in my data, it sure looks that way. I mean, wth does that even mean when you have a spec'd voltage and distance? Seems pretty silly to me. Just wondering if they may have given you a more definitive reply.

Here was my email to them:

Spoiler

Hello,

This is somewhat of a technical question, but are you able to tell me how your speaker sensitivity ratings are obtained? Is it anechoic, estimated in-room, A-weighted & anechoic, M-weighting, etc.? Is it over the entire rated frequency range, is it a set range used on all your speakers (e.g., 300Hz-3kHz?), is it simply at the loudest frequency, etc.? Is it done just on the on-axis or some listening window response?

I see your Heritage models state the sensitivities are in-room estimated, is that true for the other passive model lines as well?

I see different companies sometimes using different parameters, people online stating X company is always overstated by Y decibels, etc.

I feel I could make a more informed buying decision if I knew how much wattage I would have to need to meet my loudness needs.

Thank you,

Here is their email reply:

As an engineering-driven company, Klipsch considers frequency graph measurements proprietary information for our consumer products and does not publish this information.

We utilize custom equipment within our world-class engineering and technology centers that enable us to ensure consistent, precise performance of our horn-loaded loudspeaker systems. With our unique technology delivering controlled directivity, our acoustic engineers have done the work upfront to ensure that Klipsch speakers deliver powerful and smooth sound with a consistent coverage pattern.

Measurements are taken from a distance from the speaker baffle to replicate actual in-home listening and a real-world scenario. In addition, controlled directivity helps to ensure proper flat, smooth frequency response is consistent in-room, and within various room environments, which negates the use of automatic room correction in AV electronics. Our goal is to create the most powerful, best-sounding speaker at an optimal price.

Please note that response measurements taken close to the baffle do not accurately depict a system's total sound delivery into the room, and therefore are not representative of the true-to-life experience.

______
For sure the most formal, PR-esque response I have gotten.

 

[iakovis]

Great job. Thanks

 

[Hon]

Klipsch specs the Cornwalls at 102dB @ 2.83V / 1m and 119dB continuous output @ ???. The 2.83v/1m method seems more genuine than 1w/1m @ 8ohms.

This discussion is insightful, with many worthwhile points. Don't fans of the traditional large Klipschs--the Cornwalls and the LaScalas (105dB @ 2.83V / 1m)--often point to a kind of impressive, super wide dynamic range? I've been wondering about this factor in high efficiency speakers. Is it real? Worth investigating?

 

[Hon]

Here was my email to them:

Spoiler

Hello,

This is somewhat of a technical question, but are you able to tell me how your speaker sensitivity ratings are obtained? Is it anechoic, estimated in-room, A-weighted & anechoic, M-weighting, etc.? Is it over the entire rated frequency range, is it a set range used on all your speakers (e.g., 300Hz-3kHz?), is it simply at the loudest frequency, etc.? Is it done just on the on-axis or some listening window response?

I see your Heritage models state the sensitivities are in-room estimated, is that true for the other passive model lines as well?

I see different companies sometimes using different parameters, people online stating X company is always overstated by Y decibels, etc.

I feel I could make a more informed buying decision if I knew how much wattage I would have to need to meet my loudness needs.

Thank you,

Here is their email reply:


______
For sure the most formal, PR-esque response I have gotten.

That's the same reply I got when I asked Fresh Direct why they left all the long stems on their baby spinach!

 

[Inner Space]

Don't fans of the traditional large Klipschs--the Cornwalls and the LaScalas (105dB @ 2.83V / 1m)--often point to a kind of impressive, super wide dynamic range? I've been wondering about this factor in high efficiency speakers. Is it real? Worth investigating?

Somewhat real, and definitely worth investigating. Any big speaker's practical dynamic range is defined at one end by your room's noise floor, and at the other by the cabinet's distress when dealing with high volumes. Generally big Klipsch cabinets get a bit busy and blurry at elevated levels. I have 3 pairs of La Scalas in different locations and find their most attractive characteristic is their absolute ease and articulation at medium-to-medium-high levels. The drivers are hardly working at all, and distortion is low. I guess that's a by-product of wide dynamic range and high efficiency.

 

[MZKM]

Klipsch specs the Cornwalls at 102dB @ 2.83V / 1m and 119dB continuous output @ ???. The 2.83v/1m method seems more genuine than 1w/1m @ 8ohms.

This discussion is insightful, with many worthwhile points. Don't fans of the traditional large Klipschs--the Cornwalls and the LaScalas (105dB @ 2.83V / 1m)--often point to a kind of impressive, super wide dynamic range? I've been wondering about this factor in high efficiency speakers. Is it real? Worth investigating?

Do note that’s in-room and corner loaded, at least they state this in the specs, their traditional speakers are using the same parameters but they don’t give this caveat.

Erin has measured the Heresy IV, the spec is 99dB but in actuality the average is ~94dB, still well above average, just not as insane.

 

[mhardy6647]

This topic (sort of) came up at AK yesterday, so I looked up a few Stereophile reviews of Klipsch loudspeakers.
Now, I grant you this is anecdotal, but there just might be a hint... a whiff... of a trend.

[Wrote I there] Klipsch's current sensitivity specs are inflated, apparently (presumably) by adding in a few dB for real-world "room gain" and/or (perhaps) some imaginative interpretation of "nominal impedance".
Whether that's good or bad is in the eye of the beholder, I suppose.

e.g.,

The Klipsch [Forte III]'s specified sensitivity is an extraordinary 99dB/2.83V/m; my estimate was lower, at 95.2dB(B)/2.83V/m, but this is still 8dB higher than the average sensitivity of the speakers I have measured over the past 30 years. This speaker will play loudly with a mere handful of watts. Klipsch specifies the Forte III's nominal impedance as "8 ohms compatible." I found that the speaker's impedance magnitude (fig.1, solid trace) dropped below 6 ohms only in the upper bass and in the valley between the twin low-frequency peaks that define the reflex woofer loading. The minimum value is 3.65 ohms at 125Hz. However, the electrical phase angle (dotted trace) is sometimes extreme, and there is a current-hungry combination of 5 ohms and –49° phase angle at 90Hz. Despite its high sensitivity, the Forte III will work best with amplifiers that are comfortable driving 4-ohm loads. And the very large difference between the average impedance in the lower midrange and that in the treble means that the speaker might sound a touch bright with tube amplifiers having high output impedances.

source: https://www.stereophile.com/content/klipsch-forte-iii-loudspeaker-measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Klipsch Reference Premiere RP-600M's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield responses. I left the grille off for the measurements, The Klipsch's specified sensitivity is an extraordinarily high 96dB/2.83V/m. My estimate was much lower, at 89.6dB(B)/2.83V/m, though this is still higher than is typical for a small two-way speaker. Fig.1 shows that the RP-600M's impedance magnitude (solid trace) remains above 10 ohms for the entire treble, which means that in this region at least, the Klipsch is very efficient, the speaker drawing significantly less current from the partnering amplifier than would a nominal 8 ohm design. The impedance is lower in the midrange and bass, with a minimum value of 3.5 ohms between 180 and 220Hz. There is also a current-hungry combination of 5.3 ohms magnitude and –42° electrical phase angle (dotted trace) at 128Hz, which suggests that the RP-600M will work best with tube amplifiers when driven from their 4 ohm output-transformer taps.

source: https://www.stereophile.com/content/klipsch-reference-premiere-rp-600m-loudspeaker-measurements

Klipsch specifies the Klipschorn's sensitivity as 105dB/2.83V/m, which is extraordinarily high. My estimate was lower, at 101.1dB(B)/2.83V/m, but this is still the second-highest sensitivity of all the speakers I have measured over the past 30 years. (The highest was the Auditorium 23 Hommage Cinema, which features a measured voltage sensitivity of 102dB(B)/2.83V/m.) The Klipschorn's sensitivity is a whopping 18.6dB higher than the sensitivity of the BBC LS3/5a I always measure at the same time I test a speaker (to ensure that I haven't made an error in setup). This speaker will play loudly even with flea-powered amplifiers driving it. And at typical listening levels, the drive-unit diaphragms will hardly be moving, which implies low distortion.

Klipsch specifies the Klipschorn's nominal impedance as "8 ohms compatible." This is optimistic: Not only does the speaker's impedance magnitude (fig.1, solid trace) drop to 3 ohms in the midbass and 2.7 ohms in the upper bass, but the electrical phase angle (dotted trace) is sometimes extreme. There are current-demanding combinations of 4.1 ohms and –43° phase angle at 44Hz and 4.1 ohms and +43° phase angle at 139Hz. Despite its very high sensitivity, the Klipschorn will not be at its best with amplifiers that are not comfortable driving 4 ohm loads.

source: https://www.stereophile.com/content/klipsch-klipschorn-ak6-loudspeaker-measurements

[I further wrote] "I left the impedance curve comments in, too -- as another illustration of the "spin" that 21st Century Klipsch likes to put on things.

see also, e.g., https://www.theabsolutesound.com/articles/klipsch-heresy-iii-loudspeaker"

 

[MZKM]

Added breakdown stats:

 

[MakeMineVinyl]

I get what you mean about it not being a continuous range, I chose not to do that as it isn’t as easy to see the differences compared to the line chart, though I could be swayed. Error bars are for +/- values, which isn’t what we have here.

View attachment 68824

Could you use an Olde English font for the text, and perhaps a background in parchment style, with a faux picture frame around it all? Oh, and I'm not all that crazy with the color of your bars.

 

[ampguy]

Perphaps the Tekton Sensitivity is also in-room estimated e.g. corner loaded, like Klipsch? What's the standard, or is there one for measuring sensitivity?

 

[MZKM]

What's the standard, or is there one for measuring sensitivity?

You can see in my other comments that many manufacturers do it differently. The most modern standard is 300Hz-3kHz anechoic, but some do 1kHz and others in-room. And of course many don’t outright state what their parameters are.