The Buchardt S400 is a recent critical darling that's catapulted to the top recommendations in its price bracket. I've had the pleasure of listening to them for some time while working a full review at my job, but as usual, I like sharing measurements separately here. I'll present these below and some quick thoughts later.
But first, I'd also like to give kudos to Buchardt for providing extensive measurements on its own site. It actually helped me catch a mistake with my measurements at one point - my laptop's sound 'enhancement' app had turned on its EQ at some point, throwing off my data with an artificial 'V' shape. I knew from looking at Buchardt's data that something was seriously off. Thankfully, this had happened before so I knew what the culprit was. I would have eventually caught the problem anyway, but having readily available data made it easier.
So yeah, this is one of the only speakers I've measured so far where the manufacturer already provides plenty of data, and it's fun to see how Buchardt's data compares to my own.
Of course, bear in mind that there are plenty of variables here, from equipment used, to measurement techniques, to the fact I'm measuring in an apartment and not an anechoic chamber.
Here's the quasi-anechoic horizontal response from 0-75 degrees. The listening window is an average of 0 degrees, ±15/30 horizontal, and ±10 vertical. Nearfield bass spliced at 400 Hz and compensated for baffle step. Measurements are made from 1m, with the reference axis between the waveguide and woofer, as recommended by Buchardt in its manual.
This is a seriously impressive result that mostly echos Buchardt's measurements. Buchardt's shows a slight rise in the treble and more energy in the top octave, but I'd happily consider them 'close enough.' It feels good to verify provided specs in the real world.
That massive waveguide is doing its job, leading to one of the flattest listening window responses and smoothest directivity I've seen on a speaker, active or passive. You can also see it's a fairly high directivity design and that the flattest response seems to be around 15-30 degrees off-axis.
Bass output is impressive too, especially when you realize the S400 is actually a fairly compact bookshelf. It's significantly smaller than, say, the KEF R3, but reaches nearly as low.
Turning to the vertical response, things are less pretty, as usual with vertically-aligned speakers. Buchardt shows early reflections curves for ceiling and floor bounce on its site, but only provides a full contour response for the horizontal data, so I was curious to see how the vertical fared (the horizontal response is more important, but still).
First, here's the response at 0/5/10/15/30 degrees. I normally do this tight set of vertical measurements more to get an idea of how to optimally position speakers, as most speakers are far more sensitive in the vertical axis than horizontal. We see this clearly with the S400:
(Keep in mind the '0' position looks a bit different for the horizontal one because I typically perform this measurement by placing the speaker on its side to rotate around the reference axis. This usually leads to a slightly different response, but with vertical measurements, I'm more interested in dispersion trends than individual curves).
That's quite a bit of variation even at just 5 degrees above or below the reference axis. I repeated these measurements a few times just to be sure, including from a 2m distance just to make sure it wasn't a driver integration distance issue.
Thankfully, it's not as audible as it looks from a typical far-field listening position. This may be because the sound actually smooths out at larger vertical angles, meaning your vertical reflections shouldn't be too bad. Here's the vertical response out to 75 degrees above and below the reference axis:
The graphs are messy, but you can see the dips and peaks smooth out as you move further away, suggesting they don't affect the overall tonal balance in-room too much. However, the finicky vertical response within the listening window suggests that:
The hype around the S400 seems well deserved.
But first, I'd also like to give kudos to Buchardt for providing extensive measurements on its own site. It actually helped me catch a mistake with my measurements at one point - my laptop's sound 'enhancement' app had turned on its EQ at some point, throwing off my data with an artificial 'V' shape. I knew from looking at Buchardt's data that something was seriously off. Thankfully, this had happened before so I knew what the culprit was. I would have eventually caught the problem anyway, but having readily available data made it easier.
So yeah, this is one of the only speakers I've measured so far where the manufacturer already provides plenty of data, and it's fun to see how Buchardt's data compares to my own.
Of course, bear in mind that there are plenty of variables here, from equipment used, to measurement techniques, to the fact I'm measuring in an apartment and not an anechoic chamber.
Here's the quasi-anechoic horizontal response from 0-75 degrees. The listening window is an average of 0 degrees, ±15/30 horizontal, and ±10 vertical. Nearfield bass spliced at 400 Hz and compensated for baffle step. Measurements are made from 1m, with the reference axis between the waveguide and woofer, as recommended by Buchardt in its manual.
This is a seriously impressive result that mostly echos Buchardt's measurements. Buchardt's shows a slight rise in the treble and more energy in the top octave, but I'd happily consider them 'close enough.' It feels good to verify provided specs in the real world.
That massive waveguide is doing its job, leading to one of the flattest listening window responses and smoothest directivity I've seen on a speaker, active or passive. You can also see it's a fairly high directivity design and that the flattest response seems to be around 15-30 degrees off-axis.
Bass output is impressive too, especially when you realize the S400 is actually a fairly compact bookshelf. It's significantly smaller than, say, the KEF R3, but reaches nearly as low.
Turning to the vertical response, things are less pretty, as usual with vertically-aligned speakers. Buchardt shows early reflections curves for ceiling and floor bounce on its site, but only provides a full contour response for the horizontal data, so I was curious to see how the vertical fared (the horizontal response is more important, but still).
First, here's the response at 0/5/10/15/30 degrees. I normally do this tight set of vertical measurements more to get an idea of how to optimally position speakers, as most speakers are far more sensitive in the vertical axis than horizontal. We see this clearly with the S400:
(Keep in mind the '0' position looks a bit different for the horizontal one because I typically perform this measurement by placing the speaker on its side to rotate around the reference axis. This usually leads to a slightly different response, but with vertical measurements, I'm more interested in dispersion trends than individual curves).
That's quite a bit of variation even at just 5 degrees above or below the reference axis. I repeated these measurements a few times just to be sure, including from a 2m distance just to make sure it wasn't a driver integration distance issue.
Thankfully, it's not as audible as it looks from a typical far-field listening position. This may be because the sound actually smooths out at larger vertical angles, meaning your vertical reflections shouldn't be too bad. Here's the vertical response out to 75 degrees above and below the reference axis:
The graphs are messy, but you can see the dips and peaks smooth out as you move further away, suggesting they don't affect the overall tonal balance in-room too much. However, the finicky vertical response within the listening window suggests that:
- You should take care with vertical positioning, especially since the tweeter being below the woofer might mean the reference axis is a bit lower than optimal. That said, the S400's baffle is set at a 2 degree recline, ostensibly for phase alignment purposes but helping out a bit here too.
- You might not want to use these as nearfield monitors. Any vertical movement would be exaggerated in a nearfield situation, and you're getting more direct sound and less reflected sound to balance out the wonkiness within those initial ±30 vertical degrees or so. Now that I think of it, I'd seen a few people mention the S400 don't sound as good in the nearfield and this may be why.
The hype around the S400 seems well deserved.
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