Grandinote Mach 8 XL vs Mach 9 speakers

[Kozak170]

False, Does not work at all with e.g dome tweeters

That’s not quite right either.
Even in dome tweeters, the acoustic center still corresponds closely to the point where motion originates, the voice coil or diaphragm apex depending on geometry.
The dome’s curvature shifts the apparent center slightly forward, but it doesn’t change the fact that timing alignment is defined by the origin of motion, not the visible surface.
That’s why designers still measure the effective acoustic center of each driver when aligning systems, regardless of cone or dome type.

Just look at designs from Vandersteen or Thiel, both use dome tweeters yet employ sloped baffles to achieve proper physical time alignment.

Passive loudspeakers have a significant time delay for low frequencies anyway. If well designed, 10 ms..are really good

Group delay explanation and measurement (in audio)

Group delay is often confused with phase delay, and for good reasons. Here is a clear group delay explanation, and measurement using ARTA.

audiojudgement.com

That’s a different kind of delay, Group delay in low frequencies is mostly caused by the system’s acoustic loading and crossover slope, not by misalignment between drivers.
It affects the phase rotation of bass frequencies but has little to do with the physical time offset between the acoustic centers of mid and high drivers.
When we talk about time alignment, we’re referring to the synchronization of transient arrival across drivers, not low-frequency group delay.
A system can have excellent bass group delay and still suffer from poor time coherence if the drivers are not physically aligned.

Of course, an active loudspeaker with a FIR filter transmits an input signal with almost no time delay (take a look at the group delay measurement of the loudspeakers). Talk to Neumann in Berlin; they have perfected this technology.

P.S
If anyone is interested, this explains very well where the acoustic center is defined.

Time/Phase Alignment, Acoustic Center, Lobing etc.

What is up and down?

purifi-audio.com

P.P.S
They make amazing woofers too

That’s true for active systems, but that’s a different design philosophy.
FIR correction can linearize phase and group delay very effectively, but it does so through digital signal processing, not through acoustic geometry.
In passive designs, the acoustic alignment of the voice coils and the natural time behavior of the drivers still define coherence at the source.
Digital correction is impressive, but it’s a separate approach, one that compensates after the conversion, not through the mechanical integrity of the system itself.
Both methods can work beautifully when executed well; they just solve the problem from opposite ends.

 

[sbo6]

I read it but it was so generic that it didn't merit comment. You were making a point of the fact that Kozak is criticizing 1/2 the speaker designs, which implies that you think those are good designs...otherwise, you would have simply agreed with him

You misinterpreted and assumed.

Unlike you few who seem to judge and know all about speaker design, I go by my ears and 40 years' experience. And what that has told me is - There's more than one way to design a speaker and all implementations can be excellent <> horrible and everything in between.

Same with audio gear, I'd argue you get more sonic performance now more than ever, hardly "most are crap" IME. So, we'll have to disagree and leave it at that.

 

[sbo6]

No, if the drivers are poor and mismatched, there is too much cabinet (whatetever the material), complexity in crossover, requires more grip, all these factors in one speaker add up, require bad electronics, and you can only make them horrible or less horrible.

That's called a bad implementation. See my post above.

 

[morricab]

You misinterpreted and assumed.

Unlike you few who seem to judge and know all about speaker design, I go by my ears and 40 years' experience. And what that has told me is - There's more than one way to design a speaker and all implementations can be excellent <> horrible and everything in between.

Same with audio gear, I'd argue you get more sonic performance now more than ever, hardly "most are crap" IME. So, we'll have to disagree and leave it at that.

I have about the same amount of experience and I stand by my statement. Perhaps my years as a reviewer have made me much more critical and difficult to impress.

 

[sbo6]

I have about the same amount of experience and I stand by my statement. Perhaps my years as a reviewer have made me much more critical and difficult to impress.

You are funny... You think because you get paid to do what everyone does makes you better at it?

Here's the difference -

Subjectively - I'm a musician and know what instruments sound like on and off the stage and in the studio.
Objectively - I can verifiably hear -45DB distortion level between a reproduced and original stimulus via the Klippel listening test (on my office system, not headphones). Take the test and feel free to share your results, reviewer.

Perhaps you're fooling yourself, perhaps.

 

[DasguteOhr]

That’s not quite right either.
Even in dome tweeters, the acoustic center still corresponds closely to the point where motion originates, the voice coil or diaphragm apex depending on geometry.
The dome’s curvature shifts the apparent center slightly forward, but it doesn’t change the fact that timing alignment is defined by the origin of motion, not the visible surface.
That’s why designers still measure the effective acoustic center of each driver when aligning systems, regardless of cone or dome type.

Just look at designs from Vandersteen or Thiel, both use dome tweeters yet employ sloped baffles to achieve proper physical time alignment.

This is a very poor example; this slanted baffle may provide an excellent impulse response. However, in vertical terms, the window becomes very small for a flat frequency response. As far as I know, Thiel used 6 dB filters. In order to produce a flat frequency response, many correction elements had to be integrated into the crossover to enlarge the window for listening to music.An angled baffle without taking the crossover into account and an impulse measurement is useless.

Sorry offtopic , I'm outta here.

 

[Kozak170]

This is a very poor example; this slanted baffle may provide an excellent impulse response. However, in vertical terms, the window becomes very small for a flat frequency response. As far as I know, Thiel used 6 dB filters. In order to produce a flat frequency response, many correction elements had to be integrated into the crossover to enlarge the window for listening to music.An angled baffle without taking the crossover into account and an impulse measurement is useless.View attachment 161095

Sorry offtopic , I'm outta here.

That’s a fair observation, but it’s only part of the picture. Yes, Thiel’s designs did rely on shallow 6 dB slopes and precise physical alignment, and that inherently narrows the vertical listening window. But that’s a trade-off made in favor of true time and phase coherence, something most multi-order crossovers can’t achieve no matter how much correction is applied.
A sloped baffle alone is meaningless, but when combined with a phase-coherent 6 dB network, it preserves impulse integrity at the source rather than fixing it after the fact.