Speaker Sensitivity Measurements... Calculated In-Room or Anechoic??

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Spatial Audio

Got a question for the community... we've had quite a few calls about the published sensitivity on the S6. We use our anechoic measurements since that measurement is easily proven and is not subject to room treatment, size, furnishings, etc. But, we have heard that most people expect that manufacturer specs are provided in the "most generous" light possible. When it comes to sensitivity, that means adding 3-6dB to the anechoic measurement or using a prepared space that provides a maximum in-room boost in order to present a number that is possible but not necessarily what a customer would experience. Or, they may use a calculated number without physically measuring their actual performance.

What do you all expect from a manufacturer when you read a published sensitivity rating?

FullRangeMan

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In my experience a 3-way cross-over decrease at least 1dB the sensitivity from the raw woofer-midrange drivers, knowing it I would expect the manufacturer to be very conservative in the sensitivity item, optimistic values may lead to discontent after the purchase IMO.

If I were a manufacturer I would not want to be known for publishing unrealistic figures, which would lead me to publish two values for sensitivity, the usual anechoic and an average room value for clients have an additional information for guidance.

Tyson

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So many reviewers are measuring speakers nowadays it’s best to go with the most accurate measurement.

Early B.

This is a marketing issue. A speaker with low sensitivity (i.e., mid-80's) is an automatic deal killer for me, especially for an open baffle design. When I initially saw the S6 on your website, I immediately eliminated it as a possible purchase based on its low sensitivity. I'm probably not alone, so I'd suggest a real-world measurement. To be transparent, Spatial could say something like, "Although the S6 measured 85dB sensitivity anechoically, the in-home response will be 88-90 dB." The next sentence can explain why or point the reader to a white paper or link to an independent source that explains how speaker sensitivity is calculated. This statement would keep me interested in the S6 and I'd appreciate the integrity of the information provided. Another option is to get an independent in-room measurement from a trusted source and use that number.   




 

Mr. Big

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This is a marketing issue. A speaker with low sensitivity (i.e., mid-80's) is an automatic deal killer for me, especially for an open baffle design. When I initially saw the S6 on your website, I immediately eliminated it as a possible purchase based on its low sensitivity. I'm probably not alone, so I'd suggest a real-world measurement. To be transparent, Spatial could say something like, "Although the S6 measured 85dB sensitivity anechoically, the in-home response will be 88-90 dB." The next sentence can explain why or point the reader to a white paper or link to an independent source that explains how speaker sensitivity is calculated. This statement would keep me interested in the S6 and I'd appreciate the integrity of the information provided. Another option is to get an independent in-room measurement from a trusted source and use that number.   

Having a good amp with a well-made power supply and 85Db is no problem. My DQ10s from 40 years ago was 85Db if I recall and my Dynaco stereo 70 at 35 watts per channel drove them as loud as I wanted, a 100 Watt Threshold class A shook my room on a Telarc recording, and when I 1st heard the DQ10's at the dealer he was using the ML Mark Levinson ML2's at 25 watts class A. Go figure.




 

RonN5

So the question seems to be if the measurement is 85 db anechoic...what is it in a real room which has some rear, side, floor and ceiling reinforcement...as well as another 3db for two speakers.

Looking at a number of the various calculators...40 watts gets you 92-94 db at the listening position 9' back which is pretty darn loud...and there are a lot of great sounding tube and solid state amplifiers that can do 40 watts...maybe not the Raven ....but then again, are people going to spend $20k on a pair of amplifiers to drive a $5k speaker.

The real question in my mind is what is the safe level of power the speaker can handle without blowing the tweeter?


Early B.

Having a good amp with a well-made power supply and 85Db is no problem. My DQ10s from 40 years ago was 85Db if I recall and my Dynaco stereo 70 at 35 watts per channel drove them as loud as I wanted, a 100 Watt Threshold class A shook my room on a Telarc recording, and when I 1st heard the DQ10's at the dealer he was using the ML Mark Levinson ML2's at 25 watts class A. Go figure.

I have an 8-watt amp, so I'm not gonna buy 85dB speakers. But even if I had a 200wpc solid-state amp, I still wouldn't buy inefficient speakers because they're ummm... inefficient. The audiophile mind believes that 95dB has to be "better" than 85dB, regardless of the technical reality of it. That's why I said it's a marketing issue.   

thestatman

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The real figure of use to a consumer is not a number but a graph.   It is the in room averaged pink noise across the audio spectrum measured at the listening chair in 5 different rooms.   Of course, we have never ever seen such a chart but it tells us most of what we want to know.   

Why doesn't Spatial lead the field here and put such a chart on their website where it is downloadable?   What downside is there to Spatial to do that?   You should add to the graph the specced watts into 4ohm of the amplifier used.   Generally I would go with 400w/4ohm so I know the amplifier headroom isnt a restricting factor on the graph produced.   Its up to me if I want a 2 watt tone control as my amplification medium.

There, the challenge is out there!   Go Spatial!!

Mr. Big

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The real figure of use to a consumer is not a number but a graph.   It is the in room averaged pink noise across the audio spectrum measured at the listening chair in 5 different rooms.   Of course, we have never ever seen such a chart but it tells us most of what we want to know.   

Why doesn't Spatial lead the field here and put such a chart on their website where it is downloadable?   What downside is there to Spatial to do that?   You should add to the graph the specced watts into 4ohm of the amplifier used.   Generally I would go with 400w/4ohm so I know the amplifier headroom isnt a restricting factor on the graph produced.   It's up to me if I want a 2-watt tone control as my amplification medium.

There, the challenge is out there!   Go Spatial!!

Every room impacts the perceived spl of a speaker, room acoustics, etc. Hardwood floors, Vinyl floors carpeted floors, pad weight, curtains, room treatment, etc. Make solid speakers with good design and measurements and real listening to music, so many speakers are so tilted to give detail today where they lost musical weight and soul like turning up the treble on a receives or eg system. Systems used to be emotional and give you the impression of real people in the room performing. The old tube Dynaco stereo 70 sounds more like what you hear live than many $$$$$ amps today. Because Dave Hafler used recorded instruments to see how close his amp could sound like the tape, in fact, OPUS 3 Records early recordings used the Stereo 70 for their recordings and they were some of the best recordings you could buy back in the golden age of this hobby.

dls123

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Every room impacts the perceived spl of a speaker, room acoustics, etc. Hardwood floors, Vinyl floors carpeted floors, pad weight, curtains, room treatment, etc. Make solid speakers with good design and measurements and real listening to music, so many speakers are so tilted to give detail today where they lost musical weight and soul like turning up the treble on a receives or eg system. Systems used to be emotional and give you the impression of real people in the room performing. The old tube Dynaco stereo 70 sounds more like what you hear live than many $$$$$ amps today. Because Dave Hafler used recorded instruments to see how close his amp could sound like the tape, in fact, OPUS 3 Records early recordings used the Stereo 70 for their recordings and they were some of the best recordings you could buy back in the golden age of this hobby.

If you all want a data point, Sam (the speaker designer) told me that the 24 watt/ch Blackbird mono amps drove the S6 to loud levels with no issue at all.  I believe they used their Valhalla (about 30 wpc) as well with no issue.  So a 20+ watt tube amp is no issue for the little S6.   At the Dallas show we drove the Q3 with the Blackbirds to screaming levels without any sense of strain.  You don't need a 400W amp, and if you get one you will be doomed to listening to solid state with a speaker that is very tube friendly.   A 2W single ended tube amp may be a bit of a tone control, but I assure you the Blackbirds or the much more budget friendly Valhalla is NOT a tone control.

thestatman

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Agree, Don.   20 high quality watts is what most speakers ever need.   Plus tube amps have soft clipping behaviour typically.   I was referring to a mega watt amp to produce a graph, not what I would choose to use for actually listening.
Kudos on your design work BTW.

dls123

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Agree, Don.   20 high quality watts is what most speakers ever need.   Plus tube amps have soft clipping behaviour typically.   I was referring to a mega watt amp to produce a graph, not what I would choose to use for actually listening.
Kudos on your design work BTW.

OK, got it.   I talked to Sam today about something else and I confirmed the they ran the new S6 with the Valhalla and it drove them very loud with no issue at all.   So there is a data point for people considering the new speaker.  It is 86 dB anechoic, but it behaves like at least 89 dB in room and that is easy for a 20+ watt tube amp.

FullRangeMan

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OK, got it.   I talked to Sam today about something else and I confirmed the they ran the new S6 with the Valhalla and it drove them very loud with no issue at all.   So there is a data point for people considering the new speaker.  It is 86 dB anechoic, but it behaves like at least 89 dB in room and that is easy for a 20+ watt tube amp.
Anechoic measurement are 1 speaker, usually in a room there is two loudspeakers (+3db).

Bingenito

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Interesting thread

Audiophiles are interesting creatures. Firm beliefs grounded in common misconceptions and marketing nonsense. Some grow out of it and learn, others never do.

As for sensitivity specifications unless you are using an Anechoic Chamber or Klippel we are really probably talking about projected Anechoic vs in room and how people want to me marketed to.

All of these data points are equally “accurate” with the right footnotes to qualify how the spec was achieved

RonN5

I realize there are audiophiles that over time have realized that they don't prefer the sound of lower sensitivity speakers...but the opposite is also true.

I'm more from the school of let the sound of the speaker speak for itself.  I loved the Sapphires at 93 db...and also the LRS+ at more of a real world 83db.  One thing I have come to believe based on owning the Pass XA25...25 watts rated and more like 75 watts real world is that...speaking only for myself...I don't really need 200,400, 600 or a 1000 watts to listen at 80 db...I can get great sound from 100 watts or less.

One final thought...I strongly believe that we all have our own sound preferences...and therefore, the speaker/amp synergy can't be underestimated.

Spatial Audio

I want to thank everyone who took time to respond to this question. We want to provide meaningful data points that audiophiles can use (if they choose) to compare relative performance and move to the next phase of their evaluation toward a purchase decision. On the Spatial website we have changed our published sensitivity from anechoic to "in-room" with a maximum of +3dB to the anechoic measurement. That means, if we can measure a >3dB gain for our speakers in a room typical of the size where we expect the speaker to be placed by a customer, we will only add 3dB to the anechoic measurement. We believe this provides a legitimate, yet conservative, real-world performance indicator for comparison with other products on the market.

While numbers can help, we know they don't tell the whole story. (Several of you pointed this out.) System synergy and room dynamics as well as the type of music played and personal sound preference of the listener make this hobby a never-ending journey. Perception of sound can change as we age. Our tastes in music can change over time. The system we had (and loved) in our 20's probably isn't what we would most enjoy listening to in our 50's and 60's.  This is why we believe the 45-day in-home trial is the best way to audition new speakers, amplifiers, cables... Your music in your room.