Harbeth Monitor 30 Speaker Review

[digitalfrost]

Linkwitz on the BBC dip:

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

Personally, I have a slight (2dB) dip at 3khz built into the harman curve. As well as a 2dB bass boost at 60hz. Listening to music should be fun, and a little punch in the bass and a little less harsh highs achieve this for me . I listen to a lot of guitar music that is not very well recorded and it certainly helps. In the day and age of easy EQ and DRC, maybe this choice should be left to the end user.

 

[phoenixdogfan]

I noticed one of the newer members made an allusion to driver materials having some salutary influence on the reproduced sound of a speaker. All things being equal, I wonder how true this assertion really is. I know it's a great marketing point for some of the companies making and marketing five and six figure designs, but if those materials really made a difference, how would they not be revealed in measurements?

Maybe some of the members with a better technical background can weigh in on this. Do things like Beryllium tweeters make an audible difference, and lead, for example to a superior tweeter over, say, a silk dome or even an aluminum or magnesium dome. Perhaps rise times are shorter with the Beryllium, but does this feature translate to better sound?

Same question is also raised for ceramic or graphene midranges and woofers. Does employment of these materials, make for audibly superior drivers? And, if so, where does that show up in the measurement set?

 

[carlob]

I noticed one of the newer members made an allusion to driver materials having some salutary influence on the reproduced sound of a speaker. All things being equal, I wonder how true this assertion really is. I know it's a great marketing point for some of the companies making and marketing five and six figure designs, but if those materials really made a difference, how would they not be revealed in measurements?

Maybe some of the members with a better technical background can weigh in on this. Do things like Beryllium tweeters make an audible difference, and lead, for example to a superior tweeter over, say, a silk dome or even an aluminum or magnesium dome. Perhaps rise times are shorter with the Beryllium, but does this feature translate to better sound?

Same question is also raised for ceramic or graphene midranges and woofers. Does employment of these materials, make for audibly superior drivers? And, if so, where does that show up in the measurement set?

Read this: https://www.harbeth.co.uk/usergroup...ve-unit-and-crossover-issues.2215/#post-44546

 

[Absolute]

I noticed one of the newer members made an allusion to driver materials having some salutary influence on the reproduced sound of a speaker. All things being equal, I wonder how true this assertion really is. I know it's a great marketing point for some of the companies making and marketing five and six figure designs, but if those materials really made a difference, how would they not be revealed in measurements?

Maybe some of the members with a better technical background can weigh in on this. Do things like Beryllium tweeters make an audible difference, and lead, for example to a superior tweeter over, say, a silk dome or even an aluminum or magnesium dome. Perhaps rise times are shorter with the Beryllium, but does this feature translate to better sound?

Same question is also raised for ceramic or graphene midranges and woofers. Does employment of these materials, make for audibly superior drivers? And, if so, where does that show up in the measurement set?

This is a complicated topic, maybe better to start a thread about it or search the forum? In short, yes. There will be differences between drivers and how they sound due to resonances, break-ups, force factor, energy storage etc. Differences won't be because this or that material, it's far more complex.

 

[carlob]

This is Harbeth patent for their Radial cone: https://worldwide.espacenet.com/pub....com&locale=en_EP&CC=GB&NR=2269511B&KC=B&ND=5

and https://worldwide.espacenet.com/pub...rue&FT=D&date=19940209&CC=GB&NR=2269511A&KC=A

 

[Thomas Savage]

New topics equals new threads please.

 

[MZKM]

Preference Rating
SCORE: 5
SCORE w/ subwoofer: 7.5
https://docs.google.com/spreadsheet...Q4tLDUbvxrIE-6-vPymk25aMF9fMnoxG2mmjw/pubhtml

 

[spacevector]

Sensitivity ("efficiency") is almost always given as a single number by the manufacturer but it varies based on frequency:

What does the phase curve in the Sensitivity graph signify? Seems odd numbers going from 0 to -2e5 .

 

[napilopez]

Yes, even the fantastic Devialet Phantom Gold has the same dip;

View attachment 47539


https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153

To my ears it pulls back the soundstage too much, but it's certainly forgiving for most music.

It's pretty weird that the gold have this dip when the tiny phantom reactor does not(or at least have a way smaller one). I have a slight suspicion this might've been due to measurement setup as the same dip appeared in my own until i adjusted my measurement rig a fair bit, but I'd imagine the folks at the NRC know better than me. Wish there were another anechoic measurement of it to settle this itch though.

 

[JohnYang1997]

I like to think differently. What would the frequency response look like without engineering the "bbc dip" Will there be a peak at crossover frequency? If it's going to be much worse then I can say the dip is doing good. Regardless, it is not a excellent performer but a decent one. A lot of people like the sound.

 

[MZKM]

What would the frequency response look like without engineering the "bbc dip" Will there be a peak at crossover frequency?

Why would the absence of a dip result in a peak?

The reason the BBC dip was invented was the speaker they had was flat on-axis, but peaks off-axis ~4kHz, so they tamed the sound power by adding a dip on-axis; this lead to the confusion that flat on-axis is not enjoyable sounding.
Now, lots of speakers do have constricted directivity around there (tweeter having wide dispersion), so Audyssey’s intention isn’t wrong, but they are taming the response to have a dip, instead taming the excess energy to make it neutral.

 

[carlob]

Since this is an old model - after that there was the Monitor 30.1 and now the Monitor 30.2 - it would be interesting to measure the 30.2

 

[edechamps]

What do you think?

Ok, well, I guess in this particular case it doesn't matter if you chose to ignore CTA-2034-A again and arbitrarily decided to use the twitter as reference axis, since, for this particular speaker, it looks like the manufacturer specifies that the tweeter is the reference axis, so it amounts to the same:

Ideally, the stands should place the tweeter about level with your ear when seated at your usual listening position — the so-called ‘reference axis’

 

[ctrl]

@amirm what the heck is going on with the impedance plot? Specifically showing the bass resonance region? Never seen an impedance sweep that ragged.

Indeed, that looks very strange. Maybe a defect, e.g. a bad solder joint or a contact problem.

It is a very high resolution sweep (0.73 Hz). The typical published ones are likely at much lower resolution.

I don't believe that's the reason. Chassis measured by me so far only had such a jagged impedance curve if there was a defect or a loose contact when measuring.
Like this one (green the bad one - defect, yellow good):

Thumbs up for your high resolution sweep, makes it easier to detect resonances.

 

[DDF]

It is a very high resolution sweep (0.73 Hz). The typical published ones are likely at much lower resolution. Do you want me to go in that direction?

Keep high resolution! Do you feel that's the difference? No windowing needs to be applied to impedance measurements since there's no acoustic measurement being made. Mine are routinely better than 1 Hz, as are impedance traces other builders share with me from the web. A tester would have to go out of their way to make the measurement low resolution, for no real purpose.

I understand how frustrating it is fielding questions about test outcomes from so many visitors. So, please take the following solely in the spirit of trying to help, sharing some of my experience in this area.

Vibration can create chaotic signatures in the impedance trace. For example, vibration is very hard to control in free air measurements for Thiele Small parameters, causing noisy impedance traces that look similar to the Harbeths. I was discussing this with Ken Kantor many years ago, and he shared same experience "You really need to kill any parasitic vibration in the driver to get a clean, symmetrical impedance curve"

This usually doesn't affect in-box measurements, since mounting the driver steadies the frame enough to avoid these artifacts, so I usually wouldn't suspect this. However these wiggles could be caused by a vibration somewhere in the speaker itself, for example loose driver bolts (I understand its an older model)? Or perhaps very high measurement levels causing non linearities to be excited.

As well, room reflections if large enough can also affect the impedance sweep. Please see figure 5d and the analysis here:
http://pub.dega-akustik.de/ICA2019/data/articles/001506.pdf

Comparing signatures with the Harbeth:

This shouldn't affect the substantive outcome (doesn't appear to affect frequency response measures), but just food for thought.

 

[amirm]

The Stereophile measurements and gated measurements in general should have enough resolution at around 3KHz. Any differences are likely due to the difference speaker models and the fact that Stereophile's listening window doesn't include vertical data.

Well, his graphs are so small and low resolution that you can't see the underlying resolution of the measurements.

 

[amirm]

As well, room reflections if large enough can also affect the impedance sweep.

That is probably the reason as the "basic" measurements are NOT anechoic.

 

[ahofer]

I reconciled myself long ago to the idea that what I hear on my Harbeths (again the SHL5+AE) might not be textbook accuracy. My subjective take, FWIW.

My wife's a viola player, so that makes a good reference point for me, and we go to classical concerts about once a week. So I pay particular attention to string instrument timbre, and it seems unusually right to me. They also sound like much larger speakers, are easy to listen to for long periods of time (not "harsh", "lean", or "bloated", in my own subjective terminology), and I perceive good resolution of multiple instruments in symphonic music. Listening fatigue and instrument resolution are attributes I've had trouble with in other speakers I've used and auditioned. The Harbeths were so different in these ways, using the same playlist used with all the other auditions, that I kind of sat up and took notice in the audition (compromised by audio memory, etc., of course).

I wonder if any of the features/bugs played a role. Different speaker, so hard to know.

 

[napilopez]

Well, his graphs are so small and low resolution that you can't see the underlying resolution of the measurements.

True, I'm not sure what the smoothing is either. But my hunch is harbeth retuned the speaker, like the L100 Classic vs L100.

 

[ctrl]

Please do not kill the messenger...

Still find the range 5kHz to 10kHz a bit conspicuous