Monitor Audio Gold 300 loudspeaker In-Room Measurements

Sidebar 3: In-Room Measurements

The following measurements were made at a single mike position at ear height (for a seated listener) using the OmniMic measurement system from Parts Express. Averaging multiple readings around the listening position has not been shown to offer more revealing results in my room than a single reading point, apart from smoothing out some minor ripples in the graph. All the graphs here were smoothed to 1/6th octave. While these results will not be as precise as those made with the tools used for our full suite of measurements (which dial out the effects of the room), they do provide a useful look into how the Monitor Audios performed in my listening space. All rooms act as a crude equalizer on the sound of any system, and the result will vary both from room to room as with regard to speaker positioning.—Thomas J. Norton

1019Gold300-In-RoomFig1

Fig.1 Monitor Audio Gold 300, frequency response at the listening position, left channel in red, right channel in blue.

1019Gold300-In-RoomFig2

Fig.2 Monitor Audio Gold 300 (red), Monitor Audio Silver 10 (blue), frequency response at the listening position, left channel only.

1019Gold300-InRoomFig3

Fig.3 Monitor Audio Gold 300, effect of tone controls: Tone controls off in red, tone controls on (treble +1, bass –1) in blue, left channel only.

1019Gold300-In-RoomFig4

Fig.4 Monitor Audio Gold 300, influence of listening-window averaging. Single point in blue, 12-point average around the listening chair in red.
COMPANY INFO
Kevro International
US distributor: Monitor Audio USA
902 McKay Road, Suite 4
Pickering, ON L1W 3X8, Canada
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COMMENTS
beave's picture

From the review: "The design's benefits are a largely resistive load, no significant inductance (dome tweeters have an inductive voice-coil that complicates crossover design)..."

From the measurements: "...the phase angle exceeds +40° above 10kHz, presumably due to the inductance of the MPD tweeter's drive system."

JRT's picture

Air Motion Transformer tweeters exhibit flat resistive impedance response with respect to frequency in the audible frequency range. Not sure about impedance a decade or two higher.

Look at the data sheets of the Dayton Audio AMT series of tweeters.

http://www.daytonaudio.com/index.php/loudspeaker-components/loudspeaker-drivers-by-series/amt-series.html

beave's picture

That's what the review says.

But the measurements show a significant phase angle in the impedance in the highest frequencies.

Bogolu Haranath's picture

That significant phase angle you are mentioning (above 10 Khz) is not the region of the cone upper midrange frequency ........ It is in the MPD ribbon tweeter frequency range :-) .........

beave's picture

My post referenced the tweeter, not the midrange.

JRT's picture

I'm not sure what they might be doing in the crossover in the tweeter's filter network to clean up the tweeter's wave guide response, and what they might be letting happen in the ultrasonics to reduce component count. It does seem to exhibit a high Q low pass rolloff in the top octave, the high Q peak providing a little lift and associated rininging, the peak visible in figures 4 and 5. The associated peaking filter in that top octave shows as a sag in the rising impedance curve in figure 1.

edit: It was pointed out to me that JA1's measurements include some resonance present in the top octave in all of his loudspeaker measurements, and that seems to be obfuscating the behavior of the low pass here.

Bogolu Haranath's picture

There is a little peak at appox. 16 to 18 Khz region in the frequency response, but it is not anything significant ........ I have seen worse 'oil can resonance' peaks and dips in the frequency response of some metal dome tweeters ....... But those peaks and dips are usually above 20 Khz :-) ......

JRT's picture

With exception of a slight psychoacoustic dip in the range of 2kHz to 4.5_kHz, the response appears to be within a few dB of nominal above the baffle edge diffraction step and associated correction.

Bogolu Haranath's picture

That is the famous 'BBC dip' in that frequency ....... But that dip is not much in this speaker ....... Usually that dip is purposefully engineered to be -5 db or more :-) .......

JRT's picture

Psychoacoustic dip at the link:

https://www.linkwitzlab.com/models.htm#H

Bogolu Haranath's picture

Yes .... Your reference mentions the name 'H.D Harwood, BBC research department 1976' ....... Anyway, that dip is popularly known as 'BBC dip' :-) ........

beave's picture

I see a similar response in the datasheets for the drivers you linked to previously from Dayton Audio. I think it's inherent in the driver and not due to any crossover design.

But I don't see any ringing in figure 9. Isn't that little black slice always there in JA's plots and something he has mentioned as being the line rate of his monitor?

JRT's picture

...for pointing out the issue of the monitor.

Bogolu Haranath's picture

Also, that significant phase angle is not in the crossover region between upper midrange and MPD tweeter, which is 3 Khz :-) .........

JRT's picture

Look in the top octave, not the crossover frequency. They are shaping response up there.

Bogolu Haranath's picture

True ..... There is significant drop-off of FR, say from above 18 to 19 Khz ....... I don't know whether that makes any significant audible difference ...... Look at the TJN's in-room FR measurements ........ There is a lot of drop-off of the FR in the top octave :-) .........

JRT's picture

If the high frequency low pass response exhibits high Q, then the associated peak near the corner of that low pass would provide some lift in the response, and there would be some ringing associated with that.

Note that graphics show eight curves while the keys at the bottom of each identify nine. Regardless that error in identifying curves, the graphics are good enough to show Q affecting peaking and ringing. The brown curves look like textbook 2nd order Butterworth (Q=0.7071) and the yellow curves look like textbook 2nd order Linkwitz-Riley (Q=0.5000).

Source of graphics: https://e2e.ti.com/blogs_/b/analogwire/archive/2015/06/12/is-your-op-amp-filter-ringing-look-at-q

edit: It was pointed out to me that JA1's computer monitor causes a problem that falsely shows some resonance present in the top octave in all of his loudspeaker measurements, and that seems to be obfuscating some of the behavior of the low pass here.

beave's picture

Again, as mentioned above, hasn't JA said that it's an artifact of his video monitor?

JRT's picture

I do appreciate that you pointed that out to me, but did not see your comment before this morning. My comment has been edited to reflect that problem associated with the monitor. I would not want to mislead anyone with erroneous observations.

Bogolu Haranath's picture

BTW ..... Hi-Fi News has reviewed the Monitor Audio Gold 100 bookshelf/stand-mount speakers (EISA award winner) which probably use similar type of tweeters ....... Hi-Fi News measurements show similar type of peak around 15-16 Khz, with a sharp drop-off of FR above 20 Khz :-) ........

Bogolu Haranath's picture

If you want to see how 'oil can resonance' looks like (which I mentioned above), see the Hi-Fi News measurements of KEF R11 (EISA award winner) ......... But, those peaks and dips are way above 20 Khz ...... KEF is one of the companies, which uses Aluminum domes for tweeters :-) ........

Bogolu Haranath's picture

Another example ...... There seems to be some type of filter being used for high frequency roll-off for the GoldenEar speakers ....... GoldenEar also uses ribbon tweeters ....... Look at the FR measurements of GoldeEar Triton Reference by Hi-Fi News ......... There is a sharp drop-off of FR above 20 Khz :-) ........

Bogolu Haranath's picture

Here comes the 'king' of all FR measurements ......... See Hi-Fi News measurements of Dali Callisto 6C ...... Nice 'BBC dip' in the presence region and a sharp drop-off above 20 Khz ...... Very 'dramatic' FR :-) ........

Bogolu Haranath's picture

Interestingly TJN used +1 db boost in the treble frequency :-) .......

JRT's picture

Its a subjective choice in voicing the crossover.

Bogolu Haranath's picture

Goes to show the usefulness of tone controls/EQ :-) ........

JRT's picture

Al₂O₃ aluminum oxide, aka Corundum, aka Alumina ceramic, and in single crystal natural gemstone or synthetic is Ruby and Sapphire.

Al₂O₃ is also the surface coating result of aluminum anodization.

https://sundoc.bibliothek.uni-halle.de/diss-online/04/04H055/t2.pdf

MIL-A-8625
Type I chromic acid anodizing
Type II sulphuric acid anodizing
Type III sulphuric acid hard anodizing

There are processes that can produce a significantly thicker anodize, and some might refer to that as ceramic coating. It probably sells better than anodized aluminum. The Alumina ceramic is more rigid and more brittle than the aluminum substrate. It is more difficult to get a consistent thick layer of Alumina on a thin substrate of aluminum of a controlled shape without breaking the resulting item, because it can be fragile. Ask anybody who suffered through breaking an Accuton diaphragm, not inexpensive.

https://accuton.com/en-home/produkte/lautsprecher/keramik

Bogolu Haranath's picture

Revel is one example company, which uses DCC (deep ceramic composite) Aluminum cones :-) ........

Bogolu Haranath's picture

Additional note ........ The Beryllium dome tweeters used in Revel speakers show almost flat frequency response to 20 Khz :-) ........

Bogolu Haranath's picture

Time for Stereophile review of Polk Audio Legend L800 floor-standing speakers, with SDA technology ..... About in the same price range, $6,000/pair ....... See S&V review :-) .......

ringmeraudioguy's picture

I don’t understand the above commenters, seemingly trying to show their knowledge of test results and exhibiting blatant, ‘I know better than you’ statements. Such pedantry is boring. Just listen to the music!!

Chris Gramer's picture

These "Monitor Audio Gold 300" speakers look markedly different than those being sold by Crutchfield. Does MA reuse model names for multiple generations of speakers?

Example:
https://www.crutchfield.com/p_893G300PB/Monitor-Audio-Gold-300-Piano-Black.html?cc=07&tp=185

Just wondering. Thanks!

beave's picture

The model under review here is the 5th generation of Monitor Audio's Gold series, so it's sometimes referred to as the Gold 300 5G.

The one in your Crutchfield link is the previous generation Gold 300 (although it was just known as the Gold 300, not the Gold 300 4G).

Usually Monitor Audio doesn't reuse model names for multiple generations of speakers. But in this case, they sort of did.

hdkeith's picture

I have been auditioning the Gold 300 and Silver 500 7G and I am struggling to justify the price delta. As pointed out at almost 3X the price it is not even double the performance. The strength of the Gold is the tweeter. I have spent hours going back and forth and on some track the Silver 500 seems to have tighter bass vs. the Gold being a tad more laid back. The Gold tweeter is amazing and strings are just so lifelike. the silver highs are a tad bright, maybe just becasue the Gold is so neutral. Most of the cost is the better cabinet with more reinforcement, but again, not sure it justifies 3X the cost. I would have zero hesitation if they dropped the mid/tweeter from the Gold in the Silver 500 and called it a Silver 700 and added $1K per speaker and I would pay it, but the difference in US is 3X which I can't really justify.

hdkeith's picture

I had auditioned these 3 times against Silver 500 7G and these are more refined with higher end due to the ribbon. Here in the US they are just too darn expensive. Here the Gold run about 3X the Silver 500 and most of that I am sure is the beefier cabinet and materials in the cabinet. I just can't bring myself to spend this much as much as I love their sound.

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