Ekta Grande baffle changes

[dublin78]

Please could anyone comment on the affect of not narrowing the baffle of Troels Gravessen's Ekta Grande design around the midrange and tweeter?

Ekta GrandeScanSpeak 18W/

I would propose to keep the same baffle width, but keep it flat (this is for aesthetic reasons in order for the cabinets to be more in keeping with my home decor). I would use a 10mm, or 20mm roundover on the baffle sides and top. All driver positions would be the same, and the cabinet would still be raked back 5 degress

 

[acencsu]

I imagine you'd have to incorporate some baffle step compensation in the crossover. I'm no expert and can't really tell if there is some already in there but I imagine putting it in/increasing it would change the crossover quite a bit. Maybe someone with more expertise could chime in but perhaps putting them up against the wall would alleviate some of this effect?

 

[dublin78]

I have dug out some photos to demonstrate my question better.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Both speakers have identical drivers, identical driver placement, identical crossovers, identical internal volumes, and identical port tuning. One has a chamfered baffle around the midrange and tweeter, the other has a flat baffle.

How and why would these sound different?

If I were to roundover the edges with a 20mm bit, would this go some way to compensate?

 

[Shaun]

My guess is that it won't make a lot of difference, as the chamfers on the white enclosure are relatively shallow. Unless you are doing it for visual effect, I don't think you should bother with a 20mm roundover. The effectiveness of the technique is dependent on the radius of the roundover relative to the wavelength of the sound emitted from the adjacent driver. I'm too lazy now to work out what 20mm translates to in terms of frequency and wavelength, but I reckon it's worth checking out.

 

[dublin78]

That is good to hear.

10mm would probably look nicer. I will have to do some trials.

The larger roundover would make the cabs look narrower, and reduce the percieved mass.

 

[Mikelo]

I discussed this with Troels while getting ready to build these and you would need to adjust the crossover. I'd measure on baffle and model with some crossover software.

 

[dublin78]

This was the conclusion I came to as well. Why use half of a proven design?

I have moved house since my last post, and these cabs would not suit my new living space for visual reasons. I have sold the drivers, and am thinking of a smaller (physical sized) project...