Anybody built the Fostex horn designs?

[leadbelly]

Any feedback on the manufacturer's own designs for Fostex?

I particularly like the FF85K back loaded horn design, but I find the writeup kinda fishy:

FF85K

Especially where they show the response graph with the big crater at 100-200Hz, but then say that's just the 1 m response, actual listening position is OK.

Make sense?

[chops]

It doesn't sound so fishy to me. Not all speakers sound good in the near-field. Plus, you have to remember that those tests are also made in an anechoic room.

Since all loudspeakers are designed to sound best when set up in a regular, everyday room, that is where it counts. Some loudspeakers are meant to sound best with the help of room interactions like 1st and 2nd reflections and standing waves to reinforce where the output of the loudspeaker is lacking at the 1 meter mark.

And don't forget that room placement plays a huge factor on how the loudspeaker sounds.

I hope this sheds a little light on things for you.

[Brett]

It's a path length difference. There is a delay in the rear radiation because it's travelled so much further. I bet the distance is close to correct for a 180* phase difference at the frequency of the dip. If that sort of thing really concerns you, don't use a rear horn, and don't ever look at an IMP response of a speaker at the listening position in a room. Can you say Himalayas?

Cheers

[leadbelly]

Thanks,

Actually, what I really meant and should have said more clearly is:

Why would the manufacturer show only the one response curve, with a noticeable defect, explain the defect as not present in the listening position, but not show the response curve for the listening position or any other response curve for that matter?

Is this a case of a tech paper written to an audience more knowledgable than me, or a manufacturer slapping a coat of paint on a rusty car?