HI All,
It's fall here in Canada and as it gets colder I start to itch for a DIY hifi project. I have a pair of CSS FR125s drivers and have tried them in an open baffle last year but I fpund a base a bit lacking.
Can anyone suggest a tryuly excellent enclosure design for these? Maybe a horn of some type (I'm not intimidated by difficult woodworking
). Maybe a nice BR (I read about miniOnken byt I'm not crazy about the shape and looks?
I anxiously await your suggestions,
Or, should I just sell them and get different drivers?
I want something really cool to build that performs way above the price of the project.
Thanks
Rafal
p.s.
They will be driven by gainclone.
It's fall here in Canada and as it gets colder I start to itch for a DIY hifi project. I have a pair of CSS FR125s drivers and have tried them in an open baffle last year but I fpund a base a bit lacking.
Can anyone suggest a tryuly excellent enclosure design for these? Maybe a horn of some type (I'm not intimidated by difficult woodworking
). Maybe a nice BR (I read about miniOnken byt I'm not crazy about the shape and looks? I anxiously await your suggestions,
Or, should I just sell them and get different drivers?
I want something really cool to build that performs way above the price of the project.
Thanks
Rafal
p.s.
They will be driven by gainclone.
Want bass? You could try a BIB:
Zilla's BIB page
I built a set out of cheap pine boards to try out the concept. In my 14' x 11' x 8' room, they go low enough to excite the (untreated) room's 40 Hz resonance. Total response in room is UP several dB at 40 Hz, there's way too much bass! On some recordings it can be a very fun effect (e.g. in the Overture on Joni Mitchell's album Don Juan's Reckless Daughter, Jaco Pastorius makes his entrance with a huge, deep bass note that he lets ring on. Through the BIB's it's
!). Then sanity sets in, and I realize that my room really needs some bass traps.
The bass is not just plentiful, it's tuneful and articulate, and the woofer is well controlled enough that they don't flap around or bottom out.
I'm not entirely pleased with the midrange. The predicted responses for BIB's are always a bit ragged, and these seem to have a dip that robs voices of some of their proper weight. Probably not helped at all by the much-too-lively pine cabinet. I need to play with better damping materials in the bottom of the line. I'm also in the process of adding a 'supra-baffle' to one of the cabinets to see if that helps. I'll post on that in the BIB thread when I have had time to listen.
I have also listened to the FR125's in open baffles. The sound in the BIB is dramatically different - the mids are more colored, but there is real bass there. Since you already have a pair, it might be worth a try.
Zilla's BIB page
I built a set out of cheap pine boards to try out the concept. In my 14' x 11' x 8' room, they go low enough to excite the (untreated) room's 40 Hz resonance. Total response in room is UP several dB at 40 Hz, there's way too much bass! On some recordings it can be a very fun effect (e.g. in the Overture on Joni Mitchell's album Don Juan's Reckless Daughter, Jaco Pastorius makes his entrance with a huge, deep bass note that he lets ring on. Through the BIB's it's
!). Then sanity sets in, and I realize that my room really needs some bass traps.The bass is not just plentiful, it's tuneful and articulate, and the woofer is well controlled enough that they don't flap around or bottom out.
I'm not entirely pleased with the midrange. The predicted responses for BIB's are always a bit ragged, and these seem to have a dip that robs voices of some of their proper weight. Probably not helped at all by the much-too-lively pine cabinet. I need to play with better damping materials in the bottom of the line. I'm also in the process of adding a 'supra-baffle' to one of the cabinets to see if that helps. I'll post on that in the BIB thread when I have had time to listen.
I have also listened to the FR125's in open baffles. The sound in the BIB is dramatically different - the mids are more colored, but there is real bass there. Since you already have a pair, it might be worth a try.
Rafal,
I would suggest that you build my bipolar MLTL speaker design that uses a FR125S and a WR125S in each box. The drivers are mounted back to back (the WR on the back side) and you'll get really good bass in a relatively small, easy to build MLTL floor standing speaker. You can find plans and a write-up at:
CSS FR125S/WR125S Bipolar MLTL Loudspeaker
You might find a recent thread on the Audioroundtable forum of interest. It was started by Fred Thompson who built my bipolar MLTL FR125S/WR125S design. The thread starts at:
GPAF Treasure
and another bipolar MLTL listening impression thread on Audioroundtable at:
Bipolar Speaker Listening ImpressionsA
If you have questions, you can contact me.
Jim
I would suggest that you build my bipolar MLTL speaker design that uses a FR125S and a WR125S in each box. The drivers are mounted back to back (the WR on the back side) and you'll get really good bass in a relatively small, easy to build MLTL floor standing speaker. You can find plans and a write-up at:
CSS FR125S/WR125S Bipolar MLTL Loudspeaker
You might find a recent thread on the Audioroundtable forum of interest. It was started by Fred Thompson who built my bipolar MLTL FR125S/WR125S design. The thread starts at:
GPAF Treasure
and another bipolar MLTL listening impression thread on Audioroundtable at:
Bipolar Speaker Listening ImpressionsA
If you have questions, you can contact me.
Jim
An externally hosted image should be here but it was not working when we last tested it.
hi
Jims design is a nice one, I'd go with that if I wanted floorstanders and a little more max. SPL.
But the FR125s' are also perfect for little monitor like speaker, because of their great bass extension. I just heared a version in 6.5 Litres Closed Box, with a highpass to tame the basspeak. It's amazing what comes out of these little boxes, good & deep bass, nice mids and very smooth hights - bass is not as deep as in my double sized bass reflex version, but enought!
Here's a link to a german forum, where you find plans, filters and a messured FR - Cyburgs-Monitor
Great little drivers, I wouldn't sell them!
best, LC
Jims design is a nice one, I'd go with that if I wanted floorstanders and a little more max. SPL.
But the FR125s' are also perfect for little monitor like speaker, because of their great bass extension. I just heared a version in 6.5 Litres Closed Box, with a highpass to tame the basspeak. It's amazing what comes out of these little boxes, good & deep bass, nice mids and very smooth hights - bass is not as deep as in my double sized bass reflex version, but enought!
Here's a link to a german forum, where you find plans, filters and a messured FR - Cyburgs-Monitor
Great little drivers, I wouldn't sell them!
best, LC
Unlike every other driver i have played with, if you model for max bass, you will end up with too much bass. Lovechild's suggestion is interesting, small sealed will help limit the LF excursion, the cap will roll it off even earlier and adjust for too a high a Q. The cost of a decent passive cap could run almost as much as the drivers thou. This would be best implemented as a PLLXO in your amp.
My favorite box for the 125 is still the miniOnken. If the cosmetics don't grab you, the same tuning can be executed in other ways (i'm happy to help reshape them). The nature of the ports makes them close to aperiodic, so you can't just bang a round port into them.
10-13 litres sealed is good for an unassisted design (still wouldn't hurt to add a cap in the amp).
None of the ML-TLs i've heard for these -- including my own -- were completely satisfactory. I'd like to hear them in the GM bipole sometime -- just take the Griffin bipole and double the xSection (or just put one driver in Jim's box).
The 1 horn designed for the FR125s -- the PAWO -- never worked well with the CSS drivers (and is not really a horn, but daline-like with an expanding TL section). There is a suggested fix to make the FR125 work in the PAWO, but i don't know of anyone who has tried it.
The FR125 will never get you the mids of a Fostex, but it has its own strengths.
dave
My favorite box for the 125 is still the miniOnken. If the cosmetics don't grab you, the same tuning can be executed in other ways (i'm happy to help reshape them). The nature of the ports makes them close to aperiodic, so you can't just bang a round port into them.
10-13 litres sealed is good for an unassisted design (still wouldn't hurt to add a cap in the amp).
None of the ML-TLs i've heard for these -- including my own -- were completely satisfactory. I'd like to hear them in the GM bipole sometime -- just take the Griffin bipole and double the xSection (or just put one driver in Jim's box).
The 1 horn designed for the FR125s -- the PAWO -- never worked well with the CSS drivers (and is not really a horn, but daline-like with an expanding TL section). There is a suggested fix to make the FR125 work in the PAWO, but i don't know of anyone who has tried it.
The FR125 will never get you the mids of a Fostex, but it has its own strengths.
dave
SHOW ME THE MOTOR!
Seriously though, benefits of an underhung motor shine through in midrange. The XBL^2 motor is better when working hard, but within the 'happy' place, an underhung motor will slap an overhung motor around in terms of performance every time (all else being equal). Now, the FR125 does have a lovely motor design for an overhung, being excursion linear and having a shorting ring, but still at MOST volumes you use such drivers at (and before IMD becomes bothersome, which is the biggest excursion limiter in a small fullranger, IMO, NOT the motor) the underhung has a pretty good advantage.
All that said- the FR125 is a great driver
and is the topic of my most current (running parallel with a pair of nifty stands) speaker project- little sealed sphere enclosures (at this size, the backwave can be effectively damped by the stuffing due to the high frequency)Dave,
We have been down this road before. After a lot of simulations with Martin King's MLTL spread sheet, the conclusion that I reached was that GM's original MLTL parameters will not be optimum if one assumed that they were for a single driver in the box. The design in the link below is correct for two drivers in the box which is the bipolar design. I have verified this design via measurements and it is spot on to the MJK spread sheet MLTL simulations for the equivalent of two drivers in the box. Furthermore, others have heard and built this bipolar design and have been favorably impressed as I pointed out in my earlier post in this thread. Thus I have full confidence in the design that is in the link for the dual drivers in the box bipolar design.
I wouldn't recommend that anyone place just a single driver in the box that I describe in the link. If you want to hear a decent bipolar MLTL, then build or arrange to hear the design in the link.
Jim
The CSS FR125S/WR125S Bipolar MLTL Design That Works
Jim,
ML-TLs are incredibly volume tolerant (for instance 1 FE127 works fine in the ML-TL designed to be a bipole). GM's original design as developed using his methodology is 1 driver in a box similar to yours. That yours works well is a testament to the tolerance of ML-TLs. It is still a point of interest to see how this driver works in GM's box... he has a pretty good track record delivering designs that exceed expectation. I'm still on a quest for the FR125 that delivers what it does and comes close to the midrange magic of a Fostex.
dave
ML-TLs are incredibly volume tolerant (for instance 1 FE127 works fine in the ML-TL designed to be a bipole). GM's original design as developed using his methodology is 1 driver in a box similar to yours. That yours works well is a testament to the tolerance of ML-TLs. It is still a point of interest to see how this driver works in GM's box... he has a pretty good track record delivering designs that exceed expectation. I'm still on a quest for the FR125 that delivers what it does and comes close to the midrange magic of a Fostex.
dave
planet10 said:
What would the issues encountered be in a bipole MLTL using a FR125 on the rear and a Fostex of some sort (Fe127?) on the front? I suppose there would be a few problems with mismatched efficiency, Q, and Fs. Are there any Fostex that fit the same cutout that could be tried?
max
even better, the Extremis for those enamoured of the XBL motor.
It's not hard to be impressed by the performance/size ratio of the XBL designs, but until Hoffman is repealed ( I understand GWB has his staff working on that as we speak, and thanks to domestic security measures, they know that we are) the sensitivity issues make system integration trickier for those systems using high efficiency main speaks and low powered tube amps. No matter how clean the crossover function, you're likely to have disparate signatures in the final power stages.
It's not hard to be impressed by the performance/size ratio of the XBL designs, but until Hoffman is repealed ( I understand GWB has his staff working on that as we speak, and thanks to domestic security measures, they know that we are) the sensitivity issues make system integration trickier for those systems using high efficiency main speaks and low powered tube amps. No matter how clean the crossover function, you're likely to have disparate signatures in the final power stages.
The WRs were considered because the volume of the deflectors is not that large,,, but with a slighly deeper deflector an extremis would fit (22 liters required)
We do have some more extremis woofers coming up... and these we'll be able to hang onto for a bit to give them a really good eval.
dave
We do have some more extremis woofers coming up... and these we'll be able to hang onto for a bit to give them a really good eval.
dave
The off-topic Fostex posts have been split-off to their own thread....
http://www.diyaudio.com/forums/showthread.php?s=&threadid=87558
dave
http://www.diyaudio.com/forums/showthread.php?s=&threadid=87558
dave
Need Small Sub
22 Liters Sealed or Ported?
I am looking for a project using the Extremis driver. I just finished a pair of ported FR125 bookshelves (totally awesome) and want to add a sub....
I am thinking of using a TL design and making it look somewhat like an organ pipe.
-Thoughts?
planet10 said:
22 Liters Sealed or Ported?
I am looking for a project using the Extremis driver. I just finished a pair of ported FR125 bookshelves (totally awesome) and want to add a sub....
I am thinking of using a TL design and making it look somewhat like an organ pipe.
-Thoughts?
- Status
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