What size subwoofer

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Hello ,

I just completed a nice pair of bookshelf speakers
Using a pair of Fostex fe103en drivers. I next need to design
A subwoofer using a plate amp but I'm conflicted
About the size of the driver. A 8 inch or a 6.5
Anyone have expirience with this arrangement ?

If the ferrite version is anything like the neodymium version, 25L is huge.

For that driver, make it 15L, tuned ~40Hz.

Some questions for the OP.
1 - how loud do you want to go?
2 - how low do you want to go?
3 - how much space can you allocate for this project?
4 - how much power is available?
5 - how much money is available?
6 - how are your woodworking skills?
7 - (linked to #2) what sort of music do you listen to?
8 - have you tried BSC on your full-range speakers?

Answer these, and we'll be able to recommend something that'll do what you want. No point using a 6"er if you want loud movie effects.

Depends on the size of your room and if you want to go for a ported or selad box design I would say. Believe it or not 2 Jordan Eikonas in a MLTL design and you don't need a subwoofer at all - good down to 25Hz in a good sized room. Personally I don't think that bass it totally directionless. A musical bass note (other than a pure sinewave) contains a full harmonic structure of higher notes and it is these that locate the sound if you can do it stereophonically and coherently as possible.
1) not loud -match the fostex but accurate and some pop
And some good low extension.
2) 30 hz give or take.
3)well something that is inline with the book shelf speakers.
I'd say max size for sub 24"x24" or so
4) 100w plate amp
5) 250 -300 dollars
6) above average
7)classical jazz pop. Folk. Classic roc
8) NoI

Thanks Chris

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Okay, I'd recommend trying baffle step compensation on your current speakers.

Here's some reading.

This should make the speakers sound considerably "warmer".

However, they still won't do bass (which is, I suspect, what you're after here).

An 8-10" subwoofer will probably suit you fine.

Something like this: Dayton Audio RSS210HF-4 8" Reference HF Subwoofer 4 Ohm 295-456

Now, what cabinet?

You'll need to add that driver's Thiele-Small Parameters, but then you're off. Download WinISD Pro.


Ya, I'd go 10" or even 12". Why only 8"?

I'd expect the 8" to go much louder than the Fostexes: when turned up a bit, there's a lot of distortion in the upper midrange of the Fostex FE1** line, which is why so many of them are subject to extensive cone treatment (IMO, this doesn't fix the problem entirely, though appears to help).

If the 8" will outrun them, why bother going bigger?

Here they are

I think I will use an 8. Off to the races. Here are the speakers.



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