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jcomba
03-03-2011, 11:38 PM
Hi! I would like to build a pair of bookshelf speakers. I have a pair of Le8t with the PR8. I also just got a pair of Fostex ft90h for cheap so thinking about putting those parts together. I don't realy know how low I can run those super tweeters and how good it can blend with the le8t. So I'm looking for some advices and thoughts on this project. Thanks!

badman
03-04-2011, 08:39 AM
Hi! I would like to build a pair of bookshelf speakers. I have a pair of Le8t with the PR8. I also just got a pair of Fostex ft90h for cheap so thinking about putting those parts together. I don't realy know how low I can run those super tweeters and how good it can blend with the le8t. So I'm looking for some advices and thoughts on this project. Thanks!

Well, for starters, you'll need to build a box and measure the LE8T with PR in the box. About 2 Cubic feet of enclosed volume with moderate stuffing (it'd be underdamped if you did just wall lining or no stuffing) would make sense, and I'd strongly suggest doing a large curvature on the front baffle edges- those parts deserve the very best.

The crossover will be tough, but not TOO bad, you could try a simple series crossover around 8k. Linked is a crossover article that gives you the basic ideas as well as some resources and useful links.

Ideally, if you can build a good bass alignment box, you would want to measure the LE8t response with the enclosure and design the XO from there. You can always add foam blocks or the like to reduce effective volume if the box is oversized.

Oh, and you may very well wish to source a transformer for the tweeter attenuation- they can be pricey, but it's a much more elegant solution than an L-pad or resistors.

http://enjoythemusic.com/diy/0311/crossover.htm

4313B
03-04-2011, 09:13 AM
Oh, and you may very well wish to source a transformer for the tweeter attenuation- they can be pricey, but it's a much more elegant solution than an L-pad or resistors.Just bi-amp the whole mess if resistor pads are that scary.

spkrman57
03-04-2011, 09:28 AM
Run the LE-8t full range and use a .5 mfd or 1 mfd oil cap in series for the tweeter horn using the value that lets the tweeter horn level best match the LE-8t.

Ron

keith141
03-04-2011, 08:09 PM
This is my DIY project 35 years ago.

LE8T+PR8 is running at full range.
LX2 is used to run LE20.

jcomba
03-04-2011, 09:36 PM
Thanks to all for your replies. I wish I could have had things to measure responses of my speakers, but I don't, and it will be my verry first diy crossover. I can live with l-pads anyway, since I hown my own pair of l-paded pair of jbl (l112) I've learned by myself thats it's not the worse thing ever produced and I can laught to verry expensive systems and speakers by my "are you joking i'd rather go naked than use l-pad" l112... Sorry getting carried away. I've found this link http://simpleok.up.seesaa.net/image/fostex1987-15.jpg Maybe a good lead fot the FT90H. Good to see that people where already making diy fron le8t way before i was born. Owww and I have another big question. How can I know how to adjust the pr8's weights in order to tune them?

jcomba
03-10-2011, 09:59 PM
I also have two pairs of le8t one with lansaloy suroundings, brown glue, this one have whider dustcap, and one with standard black foam, and they sound quite different. Testing them without their suroundings, the older ones have more high frequencies extention. Maybe the duscap inside damping?