Model 19/Valencia horn offset

[les winter]

I'm building another pair of Model 19 clones. I noticed that the plans show the lf driver mounted to the front of the baffle board and the horn flange mounting surface is 2" back. On the Valencia's that I owned, the lf driver was on the back of the baffle board as was the horn flange. Anyone know why these are so different?

thanks
Les

[fpitas]

The offset will affect the phasing of the drivers at crossover. With passive crossovers, it's a juggling act between the relative phase from the crossover outputs and the physical offset of the drivers to get the desired phase alignment at the listener. With DSP active crossover, you can simply dial in the correct delay between drivers to account for offsets, so it becomes somewhat less critical.

[GM]

Right, some alignments use 'gapped' XOs to account for the lack of proper physical offset, i.e. LF, HF may be around 500, 1300 Hz = ~800 Hz nominal while others use a 3/2 slope order to account for the LF's extra ~90 deg of phase rotation, so impossible to compare 'apples-to-apples' phase alignment by just looking at the component's relative physical offsets even if the VCs are in vertical alignment.

GM

[les winter]

Thanks GM. That is exactly what I was looking for.

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Thanks fpitas.