line array with Fostex FE127E

[ramses67]

As a first attempt, I have made a 10 liter bass reflex box
for the FE 27E, following the Fostex plan on their website.
The sound is very good: clear mid and highs, very reasonable bass (from about 70 Hz), and stunning detail, space and dynamics. Loudness is limited, however.

Now I want to bring this sound a stage further and plan to build a floorstander with three FE127E each in a line array. For the bass I intend to use my REL Q150MKII.

Do the FE127E need separate chamber of about 10 liter each (with separate ports) or is it possible to combine the volumina to 30 liters and use the same port? Or do I have to alter the port dimensions?

Any advice would be very welcome!
Ramses67

 

[Scottmoose]

You've have to adjust port dimensions. Nothing to stop you building a single box internally divided with a port for each subdivision.

Be aware you're very probably going to loose a lot of HF, and have phase issues by doing this due to comb-filter effects.

 

[adason]

that's right, you are asking for trouble in treble area
/due to the size of the driver used and spacing/
use tweeter in the middle of an array

 

[flg]

You might consider only the center driver for the area above BSC? This would avoid the comb filter Bis possibly? You need them mounted as close as possible😀

 

[Dumbass]

I agree with the others who fear combing issues.

A smarter approach is a push-push bipole MLTL design like those shown at
http://www.planet10-hifi.com/boxes-fostex.html

 

[ramses67]

Thank you all, it seems that simply put a few FE127E's in a line array isn't automatically a good idea........
The bipole design is very interesting, as is thinking about a set of completely separate 10 liter boxes, aimed in position.
Pictures coming soon!

 

[Dumbass]

Thank you all, it seems that simply put a few FE127E's in a line array isn't automatically a good idea........

I can only surmise you haven't read the nflawp. Read it.