Different filters on identical drivers

[presscot]

I discovered a commercial speaker manufacturer did something interesting. They use ‘the same tweeter’ in various speaker models. But the high-pass filter for these tweeters has only two configurations. And it is conventional second-order slope.

A ) C1 = 4.7 uF, L1 = 0.3 mH
B ) C1 = 6.8 uF, L1 = 0.2 mH

Type A will be found in all ‘bookshelf’ models that are equipped with these tweeters while type B will be found in ‘floor-standing’ with the same condition. For the crossovers of midranges, they are three-way speakers, they are the same on all models. The difference is only on tweeter’s.

Can anyone tell the difference between these two types of crossover or conjecture the reasons for them, please?

 

[presscot]

Well, the truth is that I’m thinking it might involve to the lobing, off-axis, baffle width, something similar to these. But, my knowledge in Physics and Acoustics isn’t much enough to confirm anything, so I came to ask people here. Could anyone who understands it please help explain?

 

[Scottmoose]

Those [or some] may [or may not] be the case, but without knowing what the speakers are, all anybody can do is speculate since it's impossible to know. Realistically we'd need to know what the drivers are, their positions on the baffle, frequency, impedance & phase responses to do more.

 

[presscot]

we'd need to know what the drivers are, their positions on the baffle, frequency, impedance & phase responses to do more.

Ok, let me give two of them for comparison. They’re ADS L880/2 and ADS L1290/2 speakers. Their tweeters and midranges are identical while differences are on woofers and cabinets.

ADS L880/2
Box dimension: 330mm. (W) x 585mm. (H) x 295mm. (D)

ADS L1290/2
Box dimension: 265mm. (W) x 1063mm. (H) x 300mm. (D)

 

[Sonce]

Can anyone tell the difference between these two types of crossover or conjecture the reasons for them, please?

Different voicing for different positions: bookshelf and floor-stand.

 

[A4eaudio]

Possibly: Different woofers may require a different high pass filter on the midrange. Different components on the mids' high pass will affect the behavior of the componenta on the mids' low pass and require different components on the tweeter.

 

[NIXIE62]

There are various filters, Butterworth, Bessel, Chebyshev, Linkwitz ... plus matching mid drivers and tweeters.

 

[NIXIE62]

When designing a crossover, it is important to achieve the desired acoustic response, and the electrical filter is generally different from the theoretical (calculated) one. Most often, it is a custom filter to nicely fit the drivers by phase and amplitude.

 

[AllenB]

Perhaps Sonce is right about lobe direction. Not sure why only the tweeter was changed, it may have to do with the change in box width but could be other things.