FR125 & Extremis crossover ?

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planet10 said:



It is also to be noted that so far all of our extremis designs are based on Paul's woofer.

dave



Like Dave said, frequently with the Extremis driver the 2 main challenges are finding an amp small enough for the enclosure - and if it's a vented box, fitting the ports inside. ...

Once you find a formula that works, you tend to stick with it.
 
thanks...

those are some great ideas and advice...I do like the idea of setting up two apex JR. subs with amps in each speaker...and the value route for right now might probably be the best way to go until I have learned more.

Sorry its taken me a while to respond. I've been trying to learn more about DIY speaker building, so I don't make hasty and expensive decisions. My FR125S are breaking in very nicely - I've picked up some Belden speaker cable that has also taken some break-in. The highs have become much softer, they're becoming a bit more sensitive, the mids are still spectacular and detailed, and the LF has become less compressed. Over-all very nice sounds coming from these little boxes. At times, and with volume, it feels like these things don't need too much more to fill my apartment. I am happy with the sealed design - I think vented they might become a bit too boomy in my apt.

I am still considering many of the options everybody has offered and am researching different speakers. There doesn't seem to be too many speakers that have the frequency extension that the extremis does. Ideally I'd like to get away with building something that doesn't require extra amplification (reduced cost, the primary consideration right now). Do you think its possible to run the Apex JR's in series with the FRs without extra amplification? What kind of sensitivity do you think is required to get the LF extension proper without a plate amp? Also, with the plate amps - I am guessing that they only have low pass filters without high pass - is that correct?

thanks again for all the advice and comments, I believe I have become hooked on the DIY speaker thing and am considering a couple of projects for family members to get my experience up a bit...primarily - on ebay there's sets of four Vifa logic glass speakers for 60$ and was thinking of pairing them with some Apex JR. tweeters, with basic X-overs - any thoughts?

best,
matt
 
Re: thanks...

Matthew P. said:
Also, with the plate amps - I am guessing that they only have low pass filters without high pass - is that correct?

Most plate amps have two inputs, one line level and one speaker level. It also will have a set of speaker outputs. If you hook the amp up with the line level, there is usually nothing at the speaker out. If you hook up the speaker level inputs, you will have a full range output at the speakers. I believe some of the plates even offer a high pass on the speaker outputs but not sure.

EDIT: In an apartment you might need only one woofer box with two drivers.
 
frugal-phile™
Joined 2001
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Many plate amps have a high pass -- usually 1st order -- for the sats. i'd ignore that and use a high quality cap in front of the sat amps input.

When you are trying to XO really low passively the big XO parts required can easily cost more than a small sub amp....

We got a pair of these ($93) to try out http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-784

An externally hosted image should be here but it was not working when we last tested it.




dave
 
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