SoundStage! Network NRC Measurements for Focus Audio

Jeff Fritz · Nov 13, 2010

Hi guys,

I know a number of you guys pay some attention to our NRC measurements. I thought I might start a thread that provides the links when there are new ones. You guys can discuss and we can answer any questions you might have.

Here is a set on the Focus Audio FP50:

http://www.soundstagenetwork.com/in...us-audio-fp50-loudspeakers&catid=77&Itemid=18

We have three more sets of speaker measurements coming out December 1, as well.

amirm · Nov 13, 2010

Thanks Jeff. I like them!

Question, do you know what the axis for THD+N is not labeled?

amirm · Nov 13, 2010

Also, is there a tutorial on how to interpret the graphs?

Jeff Fritz · Nov 13, 2010

amirm said:
Also, is there a tutorial on how to interpret the graphs?

Here is the tutorial:

http://www.soundstagemagazine.com/measurements/test_loudspeakers.htm

amirm · Nov 13, 2010

Wonderful. Thanks.

Any chance the axis for the THD+N graph can be labeled?

Jeff Fritz · Nov 13, 2010

amirm said:
Thanks Jeff. I like them!

Question, do you know what the axis for THD+N is not labeled?

It's at the top under Setup. In this case tweeter axis. Basically it is what the manufacturer states, but generally 36-39", which is considered average seated listening height.

Jeff Fritz · Nov 13, 2010

tomelex said:
Agreed, the THD plot in db is not user friendly IMO.

I think that it would be nice if the db/% THD relationships were either done in % on the graph or the db/% table is shown on the graph for easier interpretation. Very few audiophiles think in terms of db, although the speaker industry has used this technique because, especially in the past, audiophiles would be rather annoyed to see speaker distortions way above 1% or 5% for their favorite speakers.

Anyway, perhaps just a reference to the tutorial on the chart would be nice for non technical (most audiophiles).

Just a comment and observation in the lines of continuos improvement.

Tom

Yeah, I can ask. Here is a handy calculator in the mean time:

http://www.sengpielaudio.com/calculator-thd.htm

I think we may be the only ones doing Deviation of Linearity. That gives you a good idea of how the drivers compress under increasing power.

amirm · Nov 13, 2010

Jeff Fritz said:
It's at the top under Setup. In this case tweeter axis. Basically it is what the manufacturer states, but generally 36-39", which is considered average seated listening height.

So to clarify, the THD numbers for the lower graph are the db numbers on the left? Shouldn't the sign be negative for those then?

microstrip · Nov 13, 2010

Hi also valuate the Soundstage measurements, and looking at these measurements I would immediately outclass this speaker - one more fatiguing speaker, too much treble for my taste.

But look at the review - it seems not to be the case :

Quoting Doug Schneider from Soundstage "I’m pretty familiar with Focus’s designs, and it didn’t take me long to figure out that the Prestige FP50 delivered a bit more energy in the highest highs than most of their other models do. With a poorer tweeter, this could easily be a bad thing; the speaker would likely sound bright and/or brittle. But with the Scan-Speak Revelator D30, the FP50 never sounded bright, and certainly never edgy or crisp or fatiguing -- plucked guitar strings were never steely, cymbals never splashy or hard." And concludes "I was particularly taken with the way the FP50 reproduced voices -- richly and robustly, with strong detail and iron-fisted incisiveness -- and prominent yet effortless highs that sounded exceptionally airy but never bright. The FP50 is a distinctively voiced speaker that I really like."

One can be tempted to ask : what is the value for the average reader of an incomplete set of measurements if they can mislead us so easily?

Jeff Fritz · Nov 13, 2010

microstrip said:
Hi also valuate the Soundstage measurements, and looking at these measurements I would immediately outclass this speaker - one more fatiguing speaker, too much treble for my taste.

But look at the review - it seems not to be the case :

Quoting Doug Schneider from Soundstage "I’m pretty familiar with Focus’s designs, and it didn’t take me long to figure out that the Prestige FP50 delivered a bit more energy in the highest highs than most of their other models do. With a poorer tweeter, this could easily be a bad thing; the speaker would likely sound bright and/or brittle. But with the Scan-Speak Revelator D30, the FP50 never sounded bright, and certainly never edgy or crisp or fatiguing -- plucked guitar strings were never steely, cymbals never splashy or hard." And concludes "I was particularly taken with the way the FP50 reproduced voices -- richly and robustly, with strong detail and iron-fisted incisiveness -- and prominent yet effortless highs that sounded exceptionally airy but never bright. The FP50 is a distinctively voiced speaker that I really like."

One can be tempted to ask : what is the value for the average reader of an incomplete set of measurements if they can mislead us so easily?

Wow, tough crowd.

These are anechoic measurements. In a room the balance will change because of furnishings, carpets, etc. You could very easily surmise that these will sound quite neutral in-room, albeit extended as Doug says, due to absorption. I think the point here is that anechoic measurements will not look like in-room measurements, and vice versa. If you were to see a roll-off in the highs anechoically, a too-mellow in-room balance might result.

Jeff Fritz · Nov 13, 2010

amirm said:
So to clarify, the THD numbers for the lower graph are the db numbers on the left? Shouldn't the sign be negative for those then?

No, because the scale is absolute. So at 100Hz, with the speakers playing at 90dB, the distortion rises to 65dB, or -25dB. That translates to roughly 5.6% distortion.

microstrip · Nov 13, 2010

Jeff Fritz said:
No, because the scale is absolute. So at 100Hz, with the speakers playing at 90dB, the distortion rises to 65dB, or -25dB. That translates to roughly 5.6% distortion.

And more than 30% at 60Hz. Coupled with a terrible impedance curve, these measurements show apparently poor anechoic measurements for a very good sounding product...

RBFC · Nov 13, 2010

microstrip said:
And more than 30% at 60Hz. Coupled with a terrible impedance curve, these measurements show apparently poor technical performance for very good sounding product...

Perhaps it's just that we've become accustomed to this type of performance from even the "better" designs...???

Jeff, have you seen any measurements in the bass region of any loudspeaker that kept single-digit distortion under 100 Hz and over 90 dB playback level?

Lee

Jeff Fritz · Nov 13, 2010

microstrip said:
And more than 30% at 60Hz. Coupled with a terrible impedance curve, these measurements show apparently poor anechoic measurements for a very good sounding product...

The distortion does rise substantially. It's producing almost no output at the frequency -- falls off a cliff.

I would not characterize these as poor measurements all around, however. Some of the high-profile brands that are discussed here all the time have much worse, particularly in the FR department; on and off axis.

Jeff Fritz · Nov 13, 2010

RBFC said:
Perhaps it's just that we've become accustomed to this type of performance from even the "better" designs...???

Jeff, have you seen any measurements in the bass region of any loudspeaker that kept single-digit distortion under 100 Hz and over 90 dB playback level?

Lee

Speakers like the Salon2: http://www.soundstagenetwork.com/measurements/speakers/revel_ultima_salon2/

Check out the PSB Synchrony One: http://www.soundstagenetwork.com/measurements/speakers/psb_synchrony_one/

microstrip · Nov 13, 2010

RBFC said:
Jeff, have you seen any measurements in the bass region of any loudspeaker that kept single-digit distortion under 100 Hz and over 90 dB playback level?
Lee

The classical Wilson Audio WATT/Puppy 7 has less than 1% at 80 Hz and less than 5% at 50 Hz. Some Dynaudio's have similar distortion values.

c1ferrari · Nov 13, 2010

Jeff Fritz said:
Wow, tough crowd.

Dear Jeff,

I'm enthralled by this stuff

Truly, this thread...the questions posed and the replies offered are most instructive. Keep up the good work and detail to measurement!

Now, I've got to stop reading "gearslutz" and liquidate some assets so I can procure an Audio Precision

RBFC · Nov 13, 2010

Jeff Fritz said:
Speakers like the Salon2: http://www.soundstagenetwork.com/measurements/speakers/revel_ultima_salon2/

Check out the PSB Synchrony One: http://www.soundstagenetwork.com/measurements/speakers/psb_synchrony_one/

Jeff,

I looked at the first graph of THD on the Salon. It looks like the distortion products lie between -30 and -40 dB below the signal!

Lee

Jeff Fritz · Nov 14, 2010

microstrip said:
And more than 30% at 60Hz. Coupled with a terrible impedance curve, these measurements show apparently poor anechoic measurements for a very good sounding product...

I think there also has to be some context here. The distortion measurements are at 90dB with pink noise! Have you ever listened to pink noise at 90dB? It will run you out of the room. It is far more demanding than music at 85dB, which is what many will consider average listening.

Far more relevant in most listening sessions are what the speaker is doing well with FR, on and off axis, and other parameters. I'm not saying distortion is not important -- heck, we measure it for a reason -- but that some context is needed. And when taking all this into account, I surely disagree that these are overall poor measurements and that the review isn't consistent with them. The review is adamant about the bass limitations, for instance -- think about how many times you read these days about minimonitors with huge bass. Most times it just ain't so.

This is a small bookshelf speaker meant for high-resolution sound in a small space, perhaps augmented by a subwoofer.

Jeff Fritz · Nov 14, 2010

Doug Schneider, who is at the NRC when these measurements are taken, and who has a great knowledge of the technical side of them, wanted me to share a few of his comments. This is exactly why we need threads like this. Doug's words:

1) Distortion is measured at 2 meters, and plotted at 2 meters (we plot the regular at 1 meter). 90dB anechoic at 2 meters is 96dB at 1 meter, approximate 99dB in-room single speaker, 102 db in-room 2 speakers. For a 5" to play like that isn't bad at all.

2) The frequency response is actually very good on axis and off. Not ruler-flat but extremely controlled.

3) You can't put % on the graph. It's relative to each point and because the response isn't perfectly flat, the distances would be all over the place.

4) The industry uses dB because in engineering terms it's a better way to "speak."

SoundStage! Network NRC Measurements for Focus Audio

[Industry Expert]

Banned

Banned

[Industry Expert]

Banned

[Industry Expert]

[Industry Expert]

Banned

VIP/Donor

[Industry Expert]

[Industry Expert]

VIP/Donor

WBF Founding Member

[Industry Expert]

[Industry Expert]

VIP/Donor

Member Sponsor & WBF Founding Member

WBF Founding Member

[Industry Expert]

[Industry Expert]

Similar threads