Buchardt A500 Measurements and Spinorama

[napilopez]

Got a little paranoid about not having done enough measurements before my review, so did some more today.Unfortunately the 1,800Hz crossover isn't on buchardt's site anymore (they said it was a test), and that's what I most wanted to test to see how it affects vertical directivity.

My previous spin was for the nearfield tuning. Here it is for the stock tuning. I used a 5.5ms gate this time instead of 6.5ms because there's a small reflection from my setup affecting the region below 800Hz, especially the vertical measurements. Not sure why this speaker seems to be a little more sensitive to this than others in this respect:

Note how the upper bass and lower mids are more directive with this tuning than the nearfield one or some of the other tunings. This is evident in a few ways. Look at the horizontal components of the ER curve, for example:

Something about this tuning creates a bit of a null around 200 Hz to the rear. Not sure exactly the thinking or how behind doing this, but it does have an impact on the in-room measurements too, reducing a null I normally get around there.

Also visible in the polars:

Which is noticeably different from the nearfield tuning below 500Hz

Although the nearfield tuning is also more directive than usual.

Unfortunately I won't be able to do any more measurements as I am preparing to move, but I do have a few more measurements to share.

 

[kaka89]

Thank you @napilopez . First time seeing how adjusting cross over and EQ can affect speaker's behaviour in directivity.

A speaker like this with different tuning might help us understand people's preference on directivity and how it impact the sound in a room. (like bigger sound stage). Wish A500's tuning reload process could be easier then maybe people can do a bind test too.

 

[ezra_s]

Congrats @napilopez in your new article, just found it!

https://thenextweb.com/plugged/2020...this-feels-like-the-future-of-hi-fi-speakers/

 

[HifiFan]

@napilopez I really enjoyed reading your A500 full review at TNW. Thank you for explaining how to read the charts and graphs
Anyway, I hope you can do further measurements and comparisons of the master tunings. One particular area I'm interested is the "New Stock Tuning v.2". Inside that folder, there's "Same tuning- but set to 40hz instead of 25hz". This would be a good option for those using subwoofers. Perhaps this tuning also lowers the bass THD as it won't be driving the woofers that hard.

 

[Chromatischism]

Anyway, I hope you can do further measurements and comparisons of the master tunings. One particular area I'm interested is the "New Stock Tuning v.2". Inside that folder, there's "Same tuning- but set to 40hz instead of 25hz". This would be a good option for those using subwoofers. Perhaps this tuning also lowers the bass THD as it won't be driving the woofers that hard.

If you're using bass management, rolling off the speakers to blend them with the subs is already taken care of so I'm not sure there's a benefit there.

 

[phoenixdogfan]

I humbly return that I feel completely the opposite . If you can make a speaker extend down to 25Hz without it sounding awful why not?

In any case, I'm not sure if you read the earlier part of the thread, but the A500 come with multiple tunings, including one that lets you limit bass to about 44Hz (-6dB). So you can do that too. You can use it as a 3 way or a 2.5-way. The choice is yours.

Personally, the way I see it, it doesn't matter how good your speakers are. If they don't have sub-bass, they are incomplete. It's like making a pizza and forgetting the cheese. Unless the distortion is awful and utterly distracting -- which I do not think is the case with the A500 at all -- I will take high distortion sub-bass 100 percent of the time over no sub-bass.

Not everyone can afford to or wants to have subwoofers. I hate the idea of needing subwoofers in general, but I generally use two of them because I have to. But make no mistake: I'd much rather get rid of them.

Anyway, small speakers are getting better at handling high bass all the time. The best example of this to me is still the devialet phantom reactor, a pair of which could comfortably play 25Hz at 95 dB in my living room from 10ft/3m away -- which is louder than I ever listen. (not room corrected, just demonstrating bass)

View attachment 80048

True but if I bought these I'd use the 44hz tuning. I already have a sub (SB 2000) and DL3, so I'd use that rather than their room correction and get a full range with high quality room correction and hopefully some dynamic oomph, with good directivity in a nice looking package for l.t. $5k.

Might be a really good alternative to D & D 8cs or GGNTKT M1s.

Holy crap. I just went to the subjective review. Way to much distortion. Forget everything I just wrote. Just looks like a dealbreaker to me.

 

[napilopez]

True but if I bought these I'd use the 44hz tuning. I already have a sub (SB 2000) and DL3, so I'd use that rather than their room correction and get a full range with high quality room correction and hopefully some dynamic oomph, with good directivity in a nice looking package for l.t. $5k.

Might be a really good alternative to D & D 8cs or GGNTKT M1s.

Holy crap. I just went to the subjective review. Way to much distortion. Forget everything I just wrote. Just looks like a dealbreaker to me.

Well if you already have a sub and a DL3 setup and are planning on keeping them, there doesn't seem like there too much of a point of buying a speaker like this anyway. The changing bass directivity is very cool and has an audible impact, but in terms of value I imagine it'd be best for most people to opt for the S400 and EQ.

Anyway, I'm not very fond of evaluating THD metrics for reviews but I understand that's something some people care about. I'd still say you shouldn't dismiss a speaker automatically for bass distortion though.

Like Instar in the other thread, I use dual subs regularly,(sb-1000+ KEF Lube 8b) but listen in a much larger space (16-18 ft ceilings, an open area basically 30 feet long). I listen to a lot of bass-heavy music but didn't miss the subs and decided to leave them off for most of time with the A500s. Not to say things didn't sound better with the subs, but if I were starting fresh with the A500s I'd be happy without them.

In fact, my impression early on with the A500 was that they had some of the cleanest bass I'd heard other than the D&D 8C, which for that matter also has more distortion than a good speaker+subs system, for similar reasons. The more-directive than usual bass has a bigger impact than distortion, imo.

Instar clearly did notice a big enough difference, so as always YMMV.

 

[fredoamigo]

it seems to me that I read somewhere that they should soon find themselves on the klippel of amir ?? did mad Buchardt send an A500 copy to seattle ?

 

[srrxr71]

Pushing the physics a little hard huh? Generally these bookshelf style is sought after by people living in apartments. I don’t think my neighbors would appreciate extension down to 25Hz.

I can see these as great nearfield studio monitors.

 

[napilopez]

Pushing the physics a little hard huh? Generally these bookshelf style is sought after by people living in apartments. I don’t think my neighbors would appreciate extension down to 25Hz.

I can see these as great nearfield studio monitors.

Depends on your listening habits really. I just moved, but lived in an nyc apartment with neighbors adjecent to four directions while I had the A500s and never had a noise complaint. And I ran dual subs most of the rest of the time.

 

[Mnyb]

The level of 25Hz in music is rarely a problem. It’s usually LFE effects in movies that gets the neighbours

And usually a bit higher in frequency anyway ?

The directivity of 25Hz is poor they may not know it’s you “was that a truck outside “

 

[Sancus]

Pushing the physics a little hard huh? Generally these bookshelf style is sought after by people living in apartments. I don’t think my neighbors would appreciate extension down to 25Hz.

I can see these as great nearfield studio monitors.

People have the idea that you have to be super quiet in apartments or something but it depends on the construction. In wood-frame low rises, yes, it's an issue. In your typical concrete-firewalled high rise, you can scream at the top of your lungs and nobody's ever going to hear you. I have to play >100dB(with a 5.1.2 system) for a neighbour to even notice. And I could play even louder probably if the speakers were pointed towards external walls. The soundproofing material under flooring is just by itself specced at a minimum of STC 72(72dB reduction avg 125hz-4khz). Certainly, very loud low bass can still be audible but you have to take it to truly extreme levels for it to be audible over general city noise.

 

[andreasmaaan]

If I have understood you correctly, you are saying that the three resonance ranges between 500-2000Hz are possibly due to your measurement - right?

I also find the range 4-5.5kHz interesting. There seems to be a disturbance in the radiation pattern of the waveguide under angles.
View attachment 79169
This also seems to be present in Buchardt's measurements. Whereby the comparison is not very easy, since Buchardt has his measurements transformed to a distance of 10m.
View attachment 79170

Does a reflection within the waveguide or from an edge of the cabinet act in this frequency range, which leads to cancellation and peaking in the angular frequency responses?

This is a classic trait of straight-walled constant-directivity horns, sometimes referred to as waisting or waistbanding, and it occurs at frequencies of wavelength roughly comparable to the dimension(s) of the mouth of the horn.* It can be ameliorated by flaring the mouth, which looks to be the method used here. If the flare is large enough, waisting can be reduced to negligible levels. However, this increases the mouth size of the horn without a fully commensurate decrease in the frequency down to which directivity is controlled. Presumably Buchardt judged the degree of flaring of the mouth of this horn to be the best compromise between off-axis performance and size in the circumstances.

*Or the point at which the straight-walled section of the horn transitions to a flare. I'm just speculating here, but I presume this horn begins to flare when it is around 8 or 9cm wide, the wavelength of which corresponds to a frequency of around 4kHz.

 

[ctrl]

Unfortunately the 1,800Hz crossover isn't on buchardt's site anymore (they said it was a test), and that's what I most wanted to test to see how it affects vertical directivity.

That is a pity! I would have been interested if this would have suppressed the resonances in the range 1.5-2kHz.
It seems to me that in this range both the 6" chassis and the passive radiator show (suspension?) resonances.

Particularly noticeable seems to be "rear ER", which points to the passive radiator.

Presumably Buchardt judged the degree of flaring of the mouth of this horn to be the best compromise between off-axis performance and size in the circumstances.

Guess you're right.
To get a "feeling" for the lateral radiation, I look at the normalized axis frequency response compared to the 60°-FR.
This does not look bad. There is a dip around 4kHz, but that is always better than humps in the FR.

If I compare this with the S400, the lateral radiation was improved - but the measurements were made with different equipment.

If the measurements are comparable, then the lateral radiation of the A500 has improved slightly compared to the S400.

Have any changes been made to the waveguide from version S400 to A500?

 

[andreasmaaan]

If the measurements are comparable, then the lateral radiation of the A500 has improved slightly compared to the S400.

Have any changes been made to the waveguide from version S400 to A500?

I'm not sure whether it's the same waveguide or not, but one possible alternative or additional explanation is that the crossover point is lower and/or the slope is steeper on the A500 (indeed I would assume at least the latter to be the case), thereby reducing the contribution of the woofer's output on the speaker's lateral radiation in the 2.5kHz-5kHz region (i.e. the octave approximately above the crossover frequency of the S400).

 

[ctrl]

but one possible alternative or additional explanation is that the crossover point is lower and/or the slope is steeper on the A500 (indeed I would assume at least the latter to be the case), thereby reducing the contribution of the woofer on the speaker's lateral radiation in the 2.5kHz-5kHz region.

Yep, that might be another possible explanation.

But if the measurements of the A500 on the website show the standard setting, the filter used is a normal LR4 - so, as far as I know, identical to the filter used in the S400.

 

[andreasmaaan]

Yep, that might be another possible explanation.

But if the measurements of the A500 on the website show the standard setting, the filter used is a normal LR4 - so, as far as I know, identical to the filter used in the S400.

View attachment 85358

Fair point, although even if both speakers are nominally LR4 with the same XO frequency, the XO points and slopes can't be exactly the same. I guess what I'm saying is that there is going to be enough overlap of the outputs in the octave above the XO point for any differences in polar radiation to at least be conceivably attributable to the differing influences of the woofer (it is 10dB down at 4kHz in the A500, for example). And of course it could equally be that the waveguides are actually different, I totally agree.

 

[asruser2020]

New review and measurements from SoundStage network:

https://www.soundstagesimplifi.com/index.php/equipment-reviews/145

I really don't like the visible screws on the front of the drivers.

 

[Chromatischism]

Whatever you do, don't use the covers. Not only do they look bad, but they sound bad, too. Maybe if you're away and you need to keep others' fingers out of them. I like the walnut finish.

 

[Chromatischism]

They didn't provide any new measurements, only the ones from the company.