Buchardt S400 Speaker Review

[thewas]

The "100dB" measurements of the Genelec are actually at 97-98dB in the bass. So yes, assuming (1) no measurement error and (2) that direct comparison is possible despite these two measurements having been taken under very different conditions, the Genelec can produce an additional 1dB or 2dB in the bass than the S400 before distortion rises to similar levels.
I would not call that a significant difference.
I certainly wouldn't place it outside the realm of experimental error, given the very different circumstances under which the two measurements were made.

The question is how much is the distortion of the S400 with a couple of dB less, is it as low as the Genelec one or just lower that at the ASR measurement?

Yes, in the same class sure. But for an extra 0.5", you might ask for an extra 1 or 2dB of clean bass performance, which is what we seem to get - right?

Is it really 0,5" bigger as I usually most chassis makers make nowadays only 5, 6(.5), 8 class etc drivers?

I have no doubt that a slight easing off of drive voltage - even equivalent to just 1 or 2dB lower in output level - would result in distortion charts that look very similar to those of the M040 posted above.

You could be right of course, but since we have no measurements for now its just speculation and can't be used for a rational comparison.
Please don't get me wrong, I don't want to claim with this that the S400 is a not good loudspeaker, but especially at that price the competition is very tough.

 

[thewas]

@amirm, sorry to ask you again to do extra work in this area, but perhaps you'd be willing to take two distortion measurements in future: one at a moderate SPL (83 or 86dB perhaps?) and one at 96dB.

I think 96dB is going to be either at or beyond the excursion limits of most 6.5" or smaller standmounts, which is going to make it difficult to discern much about each speaker's bass performance when driven within its limits.

Since distortion sweeps can be done very quickly, I would even recommend using the 5dB spacing that many other sources use, so 80, 85, 90, 95, 100, etc. dB.

 

[Tangband]

So far the resonance around 500Hz has not disturbed any listening test...
You can see in the animation of @BYRTT in Post#391, the peak at 520Hz becomes a notch with increasing angle - what should the equalizer do at this point?

You would have to reduce the resonance at 500-600Hz of the passive radiator. What is the cause of the resonance?
It could be a surround or membrane resonance of the passive radiator. Or a standing wave in the cabinet (damping halfway up the cabinet would help, but also weaken the low bass reproduction).

I think that the resonance is coming from a standing wave inside the cabinet. It makes sence if you look at the size of the cabinet. The cure is more damping material, I would recommend sheep wool. But that may slightly change the tonal balance of the speaker.

 

[GelbeMusik]

The cause is probably the passive radiator. The passive radiator has a strong resonance around 200Hz.
... which fits quite well with Amir's measurement.

Furthermore, the 200Hz resonance of the passive radiator could ...

But at low frequencies harmonic distortions are masked quite well. At 80-90Hz, for example, HD2 is masked up to almost 30% HD at 90dB.
...
hifi-selbstbau.de

It appears to become a bit speculative. If ones searches desperately enough, within a complex dataset, one might find everything.
Regarding the masking, I don't trust these curves (they may look 'scientific', but they actually are not; and the full discussion there is 'non public'--hmmm). I easily detect harmonic distortion of way lower level, in the bass.

But, again: with harmonics that high, intermodulations lurk around the corner--the fundamental with its own harmonics, go figure … To dive a system into such vast non-linearities chaos, literally, has to be expected. To argue regarding perceptibility in this regime is an approach an engineer shouldn't take seriously.

I'm European, and easily could shake hands with Mads, the designer of the Buchardt on a daily basis. So I jump out of this due to lacking objectivity. I'm neither in the target group. I'm happy since about 6 years (?!) with an Econowave design in some 'decadent' realization, courtesy of 'Zilch'. I only question, together with Toole, what 'book shelf speakers' are actually made for

 

[tuga]

But at low frequencies harmonic distortions are masked quite well. At 80-90Hz, for example, HD2 is masked up to almost 30% HD at 90dB.

The question for me is whether such a high level of distortion won't affect the quality of the lower-bass and sub-bass, namely a congested sound lacking in definition or clarity and also a smudging of the ambience. I'm thinking about orchestral music as usual.

This may not be the case at lower levels, 96dB at 1m is extremely loud (for continuous sound).


Perhaps we need adequate listening assessments performed by trained listeners after all...

 

[QMuse]

Because it depends also on the size and position(s) of the woofers, ports and baffle.
And even if assuming those are very similar for compact bookshelf speakers, there are more problems to this approach.

IMO bookshelves shoud be tested on stands and floorstanders on the floor. How they interact with the room regarding their woofers, ports and baffle is speaker related and has nothing to do with room EQ.

Lets assume we take a loudspeaker with a flat response down to 20 Hz as reference on which we create our "universal room EQ". In most rooms such a loudspeaker would need quite some reductive EQing in the lower bass due to room gain and modes. Many experienced loudspeaker manufacturers know that fact and tailor their low end response to be falling to compensate for that. In this case using our ""universal room EQ" would make those loudspeakers sound to bass shy, so its even counterproductive.

I think we shouldn't take into account if loudspeaker manufacturer choosed to implement falling low end to make better sound without room EQ. Manufacturer should have implemented such feature as a switch so it could be disabled. The same goes with similar feature at HF, but from what I have seen they are indeed usually implemented so LF and HF shelving can be disabled.

 

[tuga]

In this context room EQ should be considered as a room treatment which would also affect equally all speakers you put in that room.

Maybe ASR should get a treated room and a small trained listener panel.

 

[Mads Buchardt]

Thanks for the detailed comments Mads. Much appreciated.

On this point, it is not material. All the visualizations are in far-field. Changing the distance parameter simply changes the SPL values, not the graph. Far field means 1/r reduction in SPL occurs and that is that. For this graph, we don't care what the SPL values are as absolute.

What can make a difference is angular resolution. I am not in front of my workstation but I may have run the visualization at 1 degrees rather than default of 5. This brings out more details in the soundfield than 5 degree would although both are much better than what others publish.

Sorry, but No. This is not right. The NFS will not just assume same result at any distance, this is the essence of the system, that when you move to different distance, you get NEW results. We can show that easily by showing you our 2m vertical contour plot and same contour plot at 66cm distance below:

It is evident, that you see a difference between the two plots – especially in the LF region. The reason for this is because at nearfield, your relative distance from visualization point to the LF drivers is shorter. The circle below simple has the speaker physically shifted upwards to the left. Also – rear-driver contribution to SPL rearside will be unevenly high, due to relative distance to front-driver is shorter, due to nearfield evaluation.

This explains why ‘nearfield’ contour plot see the increase in LF output at position above the speaker – the questionmarks in your figure. Our suggestion would be – moving forward – show contour plots in far-field, especially, when you are dealing with speakers that has some distance between the drivers.

 

[Juhazi]

Thank you Mads! I've been questioning too small mic distance all the time here. NFS extrapolation algorithm works pretty well anyway, I was expecting bigger difference.

So far there is only one floorstander tested by Amir, and it's low bass was strange...
https://www.audiosciencereview.com/forum/index.php?threads/revel-f35-speaker-review.12053/

 

[QMuse]

So far there is only one floorstander tested by Amir, and it's low bass was strange...
https://www.audiosciencereview.com/forum/index.php?threads/revel-f35-speaker-review.12053/

Do you think it is related to small mic distance so it couldn't record the port output well?

 

[tuga]

In ideal conditions yes, but if you see how most homes sizes and loudspeakers are here in Europe at least where I live, people tend to get a big peak around approximately 35 Hz with a linear deep bass loudspeaker which is still quite far away from the Harman target curve, see also this article https://www.hifi-selbstbau.de/grund...sinn-und-unsinn-einer-grenzfrequenz-von-20-hz (you can use google or deepl.com to translate it to English)
In my previous house I needed to most negative bass EQ to get my desired Harman target curve with the loudspeakers that had the most linear bass out of my collection (Neumann KH310). Even in the acoustically better room of a friend of mine you can see that loudspeakers with linear bass need quite some bass reduction to reach the Harman target https://www.audiosciencereview.com/...s/best-room-response.12715/page-7#post-382707


I see it similarly, for me its also not a problem as I anyway use EQ, but for many it can be, that's why either choice of a loudspeaker designer can be "right".

The type of construction also impacts bass performance. Drywall and timber board on joist floors are a lot lossier than brick/block walls and concrete slab floors.

 

[tuga]

If Amir were willing to then it might make sense to correct room interference below 200Hz, but only if he were to perform adequate listening assessment in his listening room with the speakers in the best location at the correct listening distance for that particular topology.

As the listening test are currently performed it doesn't really matter.

 

[Thomas savage]

If you want to discuss EQ'ing speakers , start a thread about it. No more off topic discussion.

@QMuse , @thewas_ you have both smashed this thread with off topic debate about applying speaker EQ , can I ask you why neither of you thought to start a new thread ?

I just don't get what's so hard about doing this. You can make a amends by giving me the post numbers so I can move this all out into an appropriate thread.

 

[QMuse]

What is meant by directivity here is the speaker’s radiation pattern, not the localizability of the frequencies...

You wouldn't believe how those 2 are tightly related.

 

[QMuse]

If you want to discuss EQ'ing speakers , start a thread about it. No more off topic discussion.

@QMuse , @thewas_ you have both smashed this thread with off topic debate about applying speaker EQ , can I ask you why neither of you thought to start a new thread ?

I just don't get what's so hard about doing this. You can make a amends by giving me the post numbers so I can move this all out into an appropriate thread.

True, my apologies. Can I kindly ask you to move our posts starting from #516 to a new thread named by your choice so this thread stays clean?

 

[Thomas savage]

True, my apologies. Can I kindly ask you to move our posts starting from #516 to a new thread named by your choice so this thread stays clean?

What do you want to call it ? I will make it ( he's says while wondering why he's volunteered for this)

 

[ctrl]

It appears to become a bit speculative. If ones searches desperately enough, within a complex dataset, one might find everything.

It is of course speculative to assume that some of the harmonic distortion could be caused by the strong resonance of the passive radiator around 200Hz.

Such mind games are fun (well, others are totally annoyed by it) and have a learning effect for me.
One wonders how one could make a proof of this and builds, only in thought, an internal Helmholz absorber (a BR chamber inside the loudspeaker cabinet) which exactly absorbs the 200Hz resonance, into the cabinet of the Buchardt - would this reduce the harmonic distortions in the range 60-120Hz?

Regarding the masking, I don't trust these curves (they may look 'scientific', but they actually are not; and the full discussion there is 'non public'--hmmm). I easily detect harmonic distortion of way lower level, in the bass.

Well, the entire audio compression algorithms are based on such masking effects.
Of course, there are individual differences in perceptibility and unfortunately, when such studies are passed on, the standard deviation of the samples is usually lost.

But the magnitude of masking should be right. Whether the masking is up to 30% at 90Hz@90dB HD2 or only up to 20% at individual samples is not so decisive - it is a tendency, a reference value.

But, again: with harmonics that high, intermodulations lurk around the corner--the fundamental with its own harmonics, go figure … To dive a system into such vast non-linearities chaos, literally, has to be expected.

That is the question. If much of the distortion is due to the passive radiator, IMD might not be increased compared to other speakers with a 6'' woofer, since high frequencies are almost exclusively contributed by the bass-midrange driver.
The SB17NBAC35 driver (if it's built into the Buchardt) shows very low harmonic distortion up to 2kHz according to a review - which gives hope for moderate IMD.

The question for me is whether such a high level of distortion won't affect the quality of the lower-bass and sub-bass, namely a congested sound lacking in definition or clarity and also a smudging of the ambience. I'm thinking about orchestral music as usual.

Only a hearing test can give an answer

There are voices that are convinced that it is precisely the distortions, which are nothing more than overtones, that contribute to the low bass being perceived as tight and clear - Others, of course, see it the opposite way.

 

[thewas]

What do you want to call it ? I will make it ( he's says while wondering why he's volunteered for this)

What about "Unique room EQ for loudspeaker comparisons?"

 

[TimDH]

What is meant by directivity here is the speaker’s radiation pattern, not the localizability of the frequencies...
Anyways, I strongly disagree that all speakers have “pretty much the same directivity ther

Can you identify the speaker in the upper plot with such controlled directivity at low frequencies? Thanks

 

[GelbeMusik]

… Such mind games ...
Well, the entire audio compression algorithms are based on such masking effects.
Of course, there are individual differences in perceptibility and ...

Well, You name it. Regarding the hearing thresholds for distortion, that You presented, exactly these particular curves are not from experts in that filed. They are derived by a technician, interpreting sources from somewhere else, using disputable methods, and were never verified. It's an admittedly elaborated mind game of no further relevance. Better get original data from real scientific sources, e/g the MP3 algorithms parameters. Only I wonder, if they would rather cut the fundamental, and keep the overtones (harmonics) instead

'nough said