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PostPosted: 05 Jan 2009, 18:17 
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Joined: 05 Jan 2009, 16:48
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Hi all,

After some reading, I decided to try to build a full range bookshelf based on a Fostex FE127E, as a first DIY project.
My room is small (about 10m^2). I don't mind loosing some low frequencies since they tend to resonate with the walls.
I will try to follow the plan given by Rabbitz here. I have read that these speakers sound really good when associated with valve amps.
I have an old Rogers A75 Series 2 amplifier. I think it was designed to match the Rogers ls3/5 bookshelves (83dB). It is a solid state amplifier capable of about 2x40W output power.
The efficiency of the FE127E bookshelves would be 90dB. Do you think building these bookshelves would be pointless in my case?

Regards,


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PostPosted: 05 Jan 2009, 19:57 
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Joined: 06 Jun 2008, 20:12
Posts: 972
Location: Houston, TX
Its a classic build for a first build. What would make you wonder if its a waste of time? Just curious as maybe there is something we dont know.
You will probably need a subwoofer if you listen to other than Jazz. Well, a sub would be nice, but not necessary.
These speakers are only 90db per watt, but thats 105db at full power. Thats pretty loud. Your room is very large, but I imagine you will sit about 3-4m from the speakers. Thats a perfect distance. Keep them the same distance apart.
Its a great first build. I say go for it!
Ri

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PostPosted: 06 Jan 2009, 03:55 
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Thank you for your reply, Ri.

I was wondering if the high efficiency of the FE127E (when compared to the ls3/5 would be a problem) for my amplifier. In other words, will the amplifier drive the FE127E properly since it was designed to match the ls3/5? If it can't, building this bookshelves would be pointless and I should go for another type of speakers.
My room is not large at all. It is about 2.5m large and 4m long. The speakers will be very close to the wall and I will sit about 2m from them.

Ludo


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PostPosted: 06 Jan 2009, 08:36 
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Joined: 28 May 2008, 21:53
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Location: Winnipeg, CANADA
Hi Ludo, welcome to the forum.
It will work fine with a higher efficiency driver. You will just need less power to play as loud.
Cheers, Gio

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PostPosted: 06 Jan 2009, 08:53 
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I was just looking up his amp and speakers :)
Thanks Gio
Ri

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PostPosted: 06 Jan 2009, 18:35 
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Thank you for your advices Gio and Ri.
I will definitely go for these BR.
Does the BR cabinets for the FE127E need damping? I didn't see damping advices on the link given in the firs post of this topic.
Also, I read that damping a BR speaker does not affect the parameters of the loudspeakers (impedance, ...) and damping the cabinets will just allow to affect the relexions in it. This discussion was based on different parameters measurements. Even if the different parameters shifts are not significant, do you think this will affect the sound of a BR?

Ludo


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PostPosted: 06 Jan 2009, 20:58 
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It will. At the very least damp the wall behind the driver. While you are in there :) do the sides to. Might get some pillow stuffing and, before you seal the box permanently, fill the cab. Then listen and remove or add stuffing till you like what you hear. The stuffing does what you said, but it also makes the driver think the box is a bit larger.
Ri

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PostPosted: 07 Jan 2009, 03:44 
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I thought, the virtual increase of the volume was just for closed cabinets.
Do you have some links on how to built a speaker cabinet (which tools to use, how to make a perfect circular hole, how to paint,...) "for dummies"?

Ludo


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PostPosted: 07 Jan 2009, 08:36 
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Location: Houston, TX
Ludo, you're here! We will help you build them.
Simple really. You need a Lowes or Home Depot. Let them cut it for you. You can use a router to make all the pieces fit into each other really nice, but not necessary. Some people will take a 45 degree chamfer bit and cut out the back of the hole for the driver so let a little more air move around the driver.
Use a hole saw to cut your hole. You its a saw shaped like a circle and attached to a drill bit. OR, sometimes it is two little blades attached to a drill bit. Either way they work great for the holes. The one with two blades is recommended as it is usually adjustable and you only need buy one then. Thats all. If you dont have a Lowes or Home Depot you need a saw that will cut straight. If you can do that without a table saw then more power to you. I cant!
Oh, you need clamps. The big ones that will clamp a foot or more. As many as you can afford.
You could use a soldering iron and solder to attach the internal wires to the speaker and binding posts.
So,
Table saw
Drill
Hole Saw or Jig Saw
Router if you get fancy
Clamps
Glue/nails/screws
Thats it.
We are here for you. Take pictures/post them/ask questions
Ri

You can use glue to hold the sides together

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PostPosted: 07 Jan 2009, 10:58 
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Joined: 05 Jan 2009, 16:48
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Thanks for your help, Ri.

There is an equivalent to Home Depot where I live (south of France), so I will get the wood cut there. Concerning the speaker's hole, I will use a jig saw.
I will get through this probably next week. I will try to take pictures.

Again, thank you for your help (I think I will need some more for the painting).
Ludo


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