Buchardt S400 Speaker Review

[Chromatischism]

Indeed you want to see the inside face of the speakers. I have crossed them in front and they're okay, but not as good.

@Daverz what part of the sound would you say is most changed by the EQ you've been using?

 

[HammerSandwich]

Why crossing in front? Isn't the spin symmetric about the axis?

Time/intensity balancing can widen the sweet spot with CD speakers.

 

[Daverz]

Time/intensity balancing can widen the sweet spot with CD speakers.

Yes, I thought of that, but wanted to have some clarification. For a single listener the wider sweet spot it's not that compelling, IME.

Indeed you want to see the inside face of the speakers. I have crossed them in front and they're okay, but not as good.

@Daverz what part of the sound would you say is most changed by the EQ you've been using?

I was afraid someone might ask that.

I'll have to do a bit of A/B testing and get back to you on that. I use REW to generate an impulse response from the given filter settings and use brutefir as the convolution engine The way brutefir works on LMS, I have to restart a track before a filter takes effect, so true A/B is difficult. I have an idea to filter/not filter the test tracks and then interleave segments of them.

 

[Daverz]

Indeed you want to see the inside face of the speakers. I have crossed them in front and they're okay, but not as good.

@Daverz what part of the sound would you say is most changed by the EQ you've been using?

I created some test files with alternating unfiltered and filtered audio every 10 seconds. I can't hear any change in tone or other qualities when going from one 10 second segment to the next.

EDIT: perhaps the filtered sound is a bit more articulate (because of the HPQ?). It's very subtle, and perhaps imaginary .

I implemented the filter a bit differently this time, using this Python module

https://gist.github.com/endolith/5455375

to generate biquads and applying those directly to create the filtered audio. Here are the biquads for the 9 filters of 'Buchardt S400 APO EQ Score 1 96000Hz', if anyone wants to check my work:

[[ 0.99736924 -1.99473848  0.99736924  1.         -1.99472087  0.99475608]
[ 0.99953008 -1.99116681  0.99182768  1.         -1.99116681  0.99135776]
[ 0.99912502 -1.98671402  0.99305399  1.         -1.98671402  0.99217901]
[ 0.99806503 -1.94940125  0.96700735  1.         -1.94940125  0.96507238]
[ 1.00081705 -1.95514448  0.97941866  1.         -1.95514448  0.98023572]
[ 1.01491429 -1.81457104  0.90220048  1.         -1.81457104  0.91711478]
[ 1.01514476 -1.23964739  0.79878632  1.         -1.23964739  0.81393108]
[ 0.95462115 -0.26866242  0.30139568  1.         -0.26866242  0.25601683]
[ 1.04768798  0.94691839  0.62143221  1.          0.94691839  0.66912019]]

 

[recboil]

I'm new to to ASR but have been lurking for a while. I own a pair of the S400's and I'm curious if anyone has any experience with the Signature Edition's (SE) upgraded crossover. Mads told me that you can purchase the upgraded SE crossover for $750 euro (seems way overpriced IMO but I'm a novice). Would this be worth the investment? What could I expect to change from the original crossover? Out of curiosity,

Here are some specs of the SE crossover from their website. Attached is a photo of the SE crossover as well.

"The SE crossover is equipped with a high-end crossover made by the Danish Jantzen Audio team. We use Superior Caps for the tweeter network and Cross Caps for the woofer network. All inductors are baked air coils for low distortion. Resistors are Superres 1% tolerance."

Just out of curiosity, I know the A500 comes with the tweeter in the top position with the woofer below. What would happen if I switched positions of the tweeter on my S400 so that it's on the top position as well like the A500? I'm sure Buchardt would've done this if it sounded better but just curious if it'd actually do any good.

 

[Chromatischism]

I'm new to to ASR but have been lurking for a while. I own a pair of the S400's and I'm curious if anyone has any experience with the Signature Edition's (SE) upgraded crossover. Mads told me that you can purchase the upgraded SE crossover for $750 euro (seems way overpriced IMO but I'm a novice). Would this be worth the investment? What could I expect to change from the original crossover? Out of curiosity,

Here are some specs of the SE crossover from their website. Attached is a photo of the SE crossover as well.

"The SE crossover is equipped with a high-end crossover made by the Danish Jantzen Audio team. We use Superior Caps for the tweeter network and Cross Caps for the woofer network. All inductors are baked air coils for low distortion. Resistors are Superres 1% tolerance."

I own the S400s and love them.

Unless they post measurements showing clear benefits, I would say no, it is not worth it. That money could be better spent elsewhere.

Just out of curiosity, I know the A500 comes with the tweeter in the top position with the woofer below. What would happen if I switched positions of the tweeter on my S400 so that it's on the top position as well like the A500? I'm sure Buchardt would've done this if it sounded better but just curious if it'd actually do any good.

Not for the S400. It is on the bottom for alignment purposes. The A500 achieves this with DSP, something the S400 does not have. In the end, it's really not a big deal.

There may be a benefit to the bottom tweeter that's not often talked about. You know how everyone says that you want to listen to your speakers at ear height because above the tweeter is not good? Well on the S400 that's effectively below the tweeter, where many of us have carpet that will absorb some of the floor reflection. Being that the floor reflection is the worst on this speaker, that helps reduce its effect on what you hear.

 

[BYRTT]

...What would happen if I switched positions of the tweeter on my S400 so that it's on the top position...

Using Amir's spindata below animation that toggles per 2000mS should highlight the anechoic pattern if you physical flip speaker around ..

 

[PKAudio]

I think S400 baffle is tilted 2deg backwards. WG is quite deep so SB17 is on the top to achieve acoustic centers alignment. At least this is what Mads mentioned somewhere else if I recall correctly.

 

[mSpot]

Just out of curiosity, I know the A500 comes with the tweeter in the top position with the woofer below. What would happen if I switched positions of the tweeter on my S400 so that it's on the top position as well like the A500? I'm sure Buchardt would've done this if it sounded better but just curious if it'd actually do any good.

Mads talked about this on the Facebook forum. The tweeter is positioned more forward than the woofer for time alignment. With the tweeter on top, the cabinet would look like it's leaning forward. He put the tweeter on bottom purely for cosmetic reasons. If you don't mind how it looks, you can flip it over and the drivers would still be time aligned. The sound may be affected for better or worse depending on your stand height, listening height, and change in room interaction. In the case of the A500, Mads put the tweeter on top for cosmetic reasons, and he is able to do time alignment between the drivers using the speaker's DSP.

 

[Chromatischism]

Ok, I took him literally when he said swap the drivers, not flip the speaker upside down.

 

[recboil]

Ok, I took him literally when he said swap the drivers, not flip the speaker upside down.

haha you were correct in that I was literal. Really appreciate everyone's deep insight. Time alignment and having the help of DSP with the A500 makes complete sense to me.

$750 sounds grossly overpriced for the SE crossover, especially when the parts on Parts Express are miles away from that. Now I'm thinking I could just swap out some of the parts myself or buy the Schiit Loki Mini +

 

[Chromatischism]

haha you were correct in that I was literal. Really appreciate everyone's deep insight. Time alignment and having the help of DSP with the A500 makes complete sense to me.

$750 sounds grossly overpriced for the SE crossover, especially when the parts on Parts Express are miles away from that. Now I'm thinking I could just swap out some of the parts myself or buy the Schiit Loki Mini +

Have a good sub yet?

 

[Daverz]

For $750 you could get a miniDSP 2x4 and two more channels of amplification to replace the internal crossover with an external digital one. I assume that would void the warranty, though, and you'd also have to add more speaker terminals for the second channel. Disclaimer: I've never done this and probably have just enough knowledge to be very dangerous.

 

[recboil]

Have a good sub yet?

Not yet but eyeing all the great micro-sub options from SVS, KEF, etc.

 

[Chromatischism]

Not yet but eyeing all the great micro-sub options from SVS, KEF, etc.

Skip them and go straight to HSU, Rythmik, PSA, JTR.

 

[Chromatischism]

I did some recent testing and wanted to share my findings on this controversial "crossover dip" that seems to dog the speaker score.

If you look at Buchardt's measurements, they give the early reflections breakout. You can see that the crossover dip is mostly seen in the floor bounce, with some appearing at the wall bounce:

I think this is a good thing as we can absorb most of it with carpet or a thick rug. If the drivers were swapped and this dip headed for the ceiling, we'd have a harder time handling it. Do not place these speakers upside down!

Here is my latest in-room measurement. It is a moving mic average around where my head rests with 40 averages of 32k FFT pink periodic noise. I load the measurement twice, setting one to 1/48 and the other to psychoacoustic smoothing for visual purposes.

We're looking to see if the crossover dip in the 2500 Hz region, shown above in Buchardt's floor reflection measurement, makes an appearance...

...and it does not. At least not to any meaningful degree. Therefore I'm sticking with the hypothesis that my carpet is completely absorbing the floor reflection, leaving me with an in-room response that is mostly the listening window + early reflections without the negative vertical (floor) curve. I would assume people with hard floors may get a different result.

I then followed up with some YouTube frequency sweeps (this one and this one) in order to listen with my ears. In the first one it stays pretty much the same (excepting the modal issues) until a very slight reduction in level at 2100-2300 Hz, then the sweep gets louder starting at 2500 Hz through 4500 Hz or so. This was the loudest part of the entire range. It settled back down to the < 2100 Hz levels once it passed about 4500 Hz.

It was easier to hear in the reverse clip, but it's still faint.

You can see the rise in the Klippel early reflections and sound power measurements from about 2500 Hz, which may be what I was hearing. It could also be my ears which are sensitive there.

It took me several listens, back and forward, to hear a small drop at 2100-2300 Hz. You have to listen closely and it passed briefly so it seems narrow. Folks, I don't think this is a large concern. I think I've pretty thoroughly dispelled the concerns about the S400 crossover dip both with in-room measurements and a listening test. At least, with my ears and with carpet. Any questions, feel free to ask...

 

[mSpot]

I think this is a good thing as we can absorb most of it with carpet or a thick rug. If the drivers were swapped and this dip headed for the ceiling, we'd have a harder time handling it. Do not place these speakers upside down!

It would be interesting to see comparison measurements with the S400 upside down. A couple of factors need to be considered. One is that in most listening setups (typical for standmounts), the speaker is much closer to the floor than from the ceiling. Another factor is that normally the front baffle is tilted slightly up, but when upside down the front baffle would be tilted slightly down.

 

[Chromatischism]

It would be interesting to see comparison measurements with the S400 upside down. A couple of factors need to be considered. One is that in most listening setups (typical for standmounts), the speaker is much closer to the floor than from the ceiling. Another factor is that normally the front baffle is tilted slightly up, but when upside down the front baffle would be tilted slightly down.

I'd love to do this but I have them stuck to the stands so I don't knock them off (come really close a couple of times)...

 

[mssngpeces]

So I just saw that a new version of Buchardt S400 is coming (called S400 MK2) :

https://buchardtaudio.com/collections/passive-speakers/products/s400-mkii?variant=40547825647781

According to darko, new bass/mid driver (now made of paper), a larger cabinet with internal bracing and a redesigned crossover :

https://darko.audio/2021/08/buchardt-readies-s400-mkii-standmount-loudspeaker/

The question is how much those changes will positively impact the measurements of the previous version and if any of it will address its previous “flaws”.

 

[Chromatischism]

That is very interesting, thanks for sharing.

And wow, they brought the crossover from 2650 Hz all the way down to 1800 Hz for that little tweeter