Help me understand this crossover

[Doobrey]

I’m considering purchasing a Wharfedale diamond 12.3 which has has 2.5 way design.

Diamond 12.3 – WHARFEDALE

www.wharfedale.co.uk

What are the benefits of this 2.5 way over the 12.2’s 2 way? Is it only adding bass quantity or does it result in a clearer mid range?

Thank you in advance

 

[voodooless]

One is a bookshelf, the other is a floor stander. Conceptually they share a lot. Basically, they added an extra bass unit to the floor stander. Then you have two options:

1) make it a 3-way, where the middle driver only takes care of the midrange
2) make it a 2.5-way, where the middle driver also does bass duty, just like in the 2-way

The 2.5-way will generally have more and cleaner bass because it has two drivers to do that. The upper driver is also doing midrange duty. When done correctly, this concept will give you baffle step compensation for free, so higher sensitivity vs a 3-way.

Crossover-wise, it's a 2-way crossover, with an extra low pass for one of the bass drivers (usually an extra coil in series with that driver)

 

[Doobrey]

Thank you for the detailed reply, that’s just what I wanted to hear, I’d much rather have bass clarity over added quantity. In this case i will for for the floor stander over the larger bookshelf.

 

[voodooless]

Please note that the 12.3 has two 130mm drivers, while the 12.2 has one 150mm driver. In practice, the difference might not be that big. it's still 50% more surface area though.

 

[BenB]

To answer the question posed by the diagram, "NO". The proposed series 0.5-way circuit doesn't work. Both of those woofers will have the same current pass through them, and thus they will behave identically.

One is a bookshelf, the other is a floor stander. Conceptually they share a lot. Basically, they added an extra bass unit to the floor stander. Then you have two options:

1) make it a 3-way, where the middle driver only takes care of the midrange
2) make it a 2.5-way, where the middle driver also does bass duty, just like in the 2-way

The 2.5-way will generally have more and cleaner bass because it has two drivers to do that. The upper driver is also doing midrange duty. When done correctly, this concept will give you baffle step compensation for free, so higher sensitivity vs a 3-way.

Crossover-wise, it's a 2-way crossover, with an extra low pass for one of the bass drivers (usually an extra coil in series with that driver):

 

[voodooless]

To answer the question posed by the diagram, "NO". The proposed series 0.5-way circuit doesn't work. Both of those woofers will have the same current pass through them, and thus they will behave identically.

Good catch, the serial proposed way does indeed not work properly. I'll remove the image to prevent confusion.

 

[Zapper]

Please note that the 12.3 has two 130mm drivers, while the 12.2 has one 150mm driver. In practice, the difference might not be that big. it's still 50% more surface area though.

And the 12.3 has much more cabinet volume.

 

[Doobrey]

And the 12.3 has much more cabinet volume.

What benefit does having a higher internal volume bring?

 

[JSmith]

Loudspeaker Enclosure Design Guidelines

ESP - Loudspeaker Enclosure Design Guidelines.

sound-au.com

JSmith

 

[radix]

What benefit does having a higher internal volume bring?

The larger the volume, the more efficient the speaker is at reproducing lower frequencies. That's a vast simplification.