Buchardt S400 Speaker Review

[thewas]

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

https://www.genelec.com/w371a
https://assets.ctfassets.net/4zjnzn...f44ec7867f674a109a/W371A_operating_manual.pdf

 

[edechamps]

This is understood. And I noted it in the review. Using your recommended axis did lower fidelity of the sound field extrapolation but that was limited to higher frequencies. In lower band where we saw the directivity issues, it was just as accurate as the tweeter center. It had the benefit then of showing the reference axis being your recommended one so there would be no objection that I did not use the correct manufacturer reference axis.

As has been pointed out many times previously (by me and others), there is still an objection because the axis used for the centre of expansion is not the same thing as the reference axis used for post-processing calculations (e.g. spinorama computation). So far I've only seen you tweak the former, with predictably disappointing results. Everyone agrees that's the wrong thing to do, including @Mads Buchardt himself.

We still don't know what would happen if one were to adjust the reference axis used for spinorama computation. Which, by the way, is not exactly the same thing as picking a different vertical angle, because spinorama is computed in the far field, and pure geometry tells us no angle can possibly intersect a parallel line when the distance is infinite. Now, it's quite possible the difference is negligible, but we won't know until we try.

 

[MZKM]

As has been pointed out many times previously (by me and others), there is still an objection because the axis used for the centre of expansion is not the same thing as the reference axis used for post-processing calculations (e.g. spinorama computation). So far I've only seen you tweak the former, with predictably disappointing results. Everyone agrees that's the wrong thing to do, including @Mads Buchardt himself.

We still don't know what would happen if one were to adjust the reference axis used for spinorama computation. Which, by the way, is not exactly the same thing as picking a different vertical angle, because spinorama is computed in the far field, and pure geometry tells us no angle can possibly intersect a parallel line when the distance is infinite. Now, it's quite possible the difference is negligible, but we won't know until we try.

Not a vertical difference, but the next speaker to be reviewed advocates for listening 40°-60° off-axis (though the 20° axis seems most neutral), and I’m wondering if Amir can accommodate for this (I would hope the Klippel software can just be told do so, as measurement points are taken all around, not just the Spinorama required ~70 points). One can manually shift the horizontal off-axis degrees, but I would assume due to baffle diffraction that one can‘t simply take the difference of 0° & 20°H and apply that offset to the vertical data.

 

[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?

It seems to start before that , I wish you people just created new threads for new discussions .

It's a nightmare having to go through it all trying to work out what's what.

 

[QMuse]

It seems to start before that , I wish you people just created new threads for new discussions .

It's a nightmare having to go through it all trying to work out what's what.

Ehh, complaining non-stop about his job..

 

[thewas]

It seems to start before that , I wish you people just created new threads for new discussions .

It's a nightmare having to go through it all trying to work out what's what.

Apologises also from my side, the problem is it's hard to foresee if that a sub-discussion will evolve in something larger where an own topic makes sense.

 

[Thomas savage]

Iv moved the 65 posts out to the new thread.

https://www.audiosciencereview.com/...ue-room-eq-for-loudspeaker-comparisons.12978/

Ehh, complaining non-stop about his job..

View attachment 61123

Cheeky bastard.

 

[QMuse]

Iv move the 65 posts out to the new thread .


Cheeky bastard.

See, that was really a piece of cake for U, so no need to act as drama-queen.

 

[Juhazi]

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

F35 has two bass drivers and is tall. I guess NFS didn't sum their output right. As well backside port's output is not summed right?

 

[amirm]

F35 has two bass drivers and is tall. I guess NFS didn't sum their output right. As well backside port's output is not summed right?

There is no summing involved in NFS.

 

[thewas]

Iv move the 65 posts out to the new thread.

https://www.audiosciencereview.com/...dspeaker-comparisons.12978/page-3#post-386519


Cheeky bastard.

Thanks again, here is a link to the new topic https://www.audiosciencereview.com/...ue-room-eq-for-loudspeaker-comparisons.12978/

 

[QMuse]

F35 has two bass drivers and is tall. I guess NFS didn't sum their output right. As well backside port's output is not summed right?

When saying "summing" I believe you are referring to a technique where response of each woofer and port is measured nierfield and then summed but I think NFS doesn't work that way.

It could however be that NFS was simply not able to record properly contribution coming from port because mic was too close.

 

[QMuse]

There is no summing involved in NFS.

Eh, yes - you beat me to it, but mic being too close can still be an issue with rear ported floorstanders.

 

[andreasmaaan]

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.

Which review are you talking about?

 

[andreasmaaan]

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

I'm not sure which sources are being discussed in this post, but masking thresholds are well-researched and documented in the field of psychoacoustics (which fwiw I am not in). There's not a lot of mystery left.

 

[ctrl]

Which review are you talking about?

German magazin Hobby Hifi 2018-6.
SB17NBAC35 driver: At 90dB HD2, HD3, HD5 is from 180Hz to 2.1kHz about 0.1% or below.

 

[andreasmaaan]

German magazin Hobby Hifi 2018-6.
SB17NBAC35 driver: At 90dB HD2, HD3, HD5 is from 180Hz to 2.1kHz about 0.1% or below.

Ok, that sounds plausible/correct to me in half space.

The thing in the case of the S400 is that below around 500 Hz we're essentially in 4pi territory owing to baffle step, which means Amir's distortion measurement at 96dB is equivalent in the bass to a 2pi measurement at 101 or 102dB.

Did the review measure the woofer at such SPLs? (I don't have access to the magazine contents.)

 

[Juhazi]

There is no summing involved in NFS.

I meant that soundwaves from two radiators and port don't sum "right" before reaching the mic. Interference is excaggerated. That's why NFS gets poor data to extrapolate. That's also seen in Mads's 0,7m vs. 2m graphs.

 

[napilopez]

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:
View attachment 61105
View attachment 61106



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.
View attachment 61107

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.

Thank you Mads! I've been questioning too small mic distance all the time here. NFS interpolation 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/

@Juhazi, unless I am mistaken, I believe Buchardt is saying that this is a setting in the software, not that the physical mic in the real world has to be further. I mean, measuring at 2m isn't exactly nearfield and seems to somewhat negate the point of getting the NFS. Such a distance is never showed in Klippel's videos, and I'm not even sure the arm goes that far.

Is this correct @Mads Buchardt ?

 

[ctrl]

Did the review measure the woofer at such SPLs?

Nope, only at 90dB.
In the test field of the nine 6-6.5'' bass-midrange units, the SB17NBAC35-8 driver had the lowest harmonic distortion at 90dB in the said frequency range.