Here we see one FF225WK Met with its proud owner.
I have been meaning to get some of these built for getting on for two years
after reading about the ones that Bill, (Lousymusician) built and showed at the Burning Amp festival.
I did design the original FE108ES mets to work close to walls and it looks with these larger versions
that Dave and Scott have kept to that original design brief.
This particular cabinet is based on the Scottmoose/Planet10 cabinet for the old FE207E but with
revised port dimensions to accommodate the new Fostex driver characteristics.
They work beautifully in my room, with a neutral, unfatiguing sound and plenty of speed, depth and micro-dynamics.
Bass is even-handed and detailed, which is something I had been worried about, but no bother, they work fine at the bottom end.
As they run in, the bass seems to be reaching further and further down, but with no trace of boom.
I like them a lot. My wife thinks they are beautiful so no WAF problems, though I didn't expect there to be.
An externally hosted image should be here but it was not working when we last tested it.
I have been meaning to get some of these built for getting on for two years
after reading about the ones that Bill, (Lousymusician) built and showed at the Burning Amp festival.
I did design the original FE108ES mets to work close to walls and it looks with these larger versions
that Dave and Scott have kept to that original design brief.
This particular cabinet is based on the Scottmoose/Planet10 cabinet for the old FE207E but with
revised port dimensions to accommodate the new Fostex driver characteristics.
They work beautifully in my room, with a neutral, unfatiguing sound and plenty of speed, depth and micro-dynamics.
Bass is even-handed and detailed, which is something I had been worried about, but no bother, they work fine at the bottom end.
As they run in, the bass seems to be reaching further and further down, but with no trace of boom.
I like them a lot. My wife thinks they are beautiful so no WAF problems, though I didn't expect there to be.
Cheers Dave,
You and Scott have done a great job expanding the Metronome concept from a single model to the range we have now.
I went down a side road into open baffles for a while, but I'm very glad I returned to the Met (spurred on by my wife,
who had had enough of flat bits of wood all over the lounge; so much so that she paid for the design and build by Colin)
I mean who was I to argue?
You and Scott have done a great job expanding the Metronome concept from a single model to the range we have now.
I went down a side road into open baffles for a while, but I'm very glad I returned to the Met (spurred on by my wife,
who had had enough of flat bits of wood all over the lounge; so much so that she paid for the design and build by Colin)
I mean who was I to argue?
I have some material that is 95.38" x 7.878" x 5/8" (Kahrs wood flooring) that I'm looking to use to build a pair, and maybe 2 pair, of Metronomes. Whether the material will be good sounding we'll see. My question is on the dimensions. I have a pair of FE 126e and a pair of 5" Radio Shack 40-1041 drivers. The dimensions from the tables say 48" x 7.75 internal for the front and rear baffles. I'm really close with what I have (cutting each sheet in half) but ever so slightly short, and then that's internal, external needs another few inches. Can I just make the top slightly wider and the box shorter, or will that impact the sound? Which is the most critical dimension? I couldn't help but notice that the heights are all nice round numbers for the various drivers, so I'm guessing it isn't too critical.
In any case I'm doing the Radio Shack drivers by trial and error as I have yet to find any TS parameters for them, and I've searched multiple times over the years. I've had them in cardboard metronomes with the 126e spec for while and they sound OK.
In any case I'm doing the Radio Shack drivers by trial and error as I have yet to find any TS parameters for them, and I've searched multiple times over the years. I've had them in cardboard metronomes with the 126e spec for while and they sound OK.
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Well, you could measure them.
Anyway, from long experience with RS drivers, its magnet, frame size and rated Fs, efficiency; a ~ 1.0 Qts, 0.15 ft^3 Vas is close enough for me.GM
TQWT = TQWP = Tapered Quarter Wave Tube/Pipe
These are a pipe/transmission line open at one end, where the closed end is smaller then the open end.
Also called a Voigt Pipe.
These suffer from a lot of ripple and can be dramatically improved by mass-loading them (restricting the terminus/opening). This is often implemented with a small pipe as in a bass reflex (which confuses a lot of people)
Hence ML-TQWT = ML-TQWP = ML-V
When the 1st ideas of this kind of load in the form of a cone (which Steve took to a pyramid) it was completely missed that with a taper in 2 axis, the actual "shape" of the volume is quadratic and not linear. They are closely related and as tolerent as they are a Met can usually be simmed as an ML-V.
http://www.frugal-horn.com/metronome.html
dave
These are a pipe/transmission line open at one end, where the closed end is smaller then the open end.
Also called a Voigt Pipe.
These suffer from a lot of ripple and can be dramatically improved by mass-loading them (restricting the terminus/opening). This is often implemented with a small pipe as in a bass reflex (which confuses a lot of people)
Hence ML-TQWT = ML-TQWP = ML-V
When the 1st ideas of this kind of load in the form of a cone (which Steve took to a pyramid) it was completely missed that with a taper in 2 axis, the actual "shape" of the volume is quadratic and not linear. They are closely related and as tolerent as they are a Met can usually be simmed as an ML-V.
http://www.frugal-horn.com/metronome.html
dave
Hi there: Google-up: quarter-wave.com the Martin J King site. ...regards, Michael
So they are finally finished. I broke the drivers in mounted in an open baffle for 200+ hours. They are built using 3/4 birch plywood. The top 4 feet of the insides are lined with 4mm laminate flooring felt. First impressions, The image is incredible and detailed. Right away i was hearing parts of the music that i could not hear with my Zigmahornets. These things revealed the limitations in my SE EL-84 amp and the 6EM7 amps i have. When i run my DIYTube ST-35 the sound is clear and clean. I have had several people listen to them so far and have come up with some limitations. The midrange is almost too forward and the bass is lacking. I know they will never be a rock and roll kick you in the chest style speaker but the bottom end is just not balanced with the rest of the frequency. I believe i have three options to tune these things in, Stuffing, Play with the port size and length, or a BSC filter. Where should i start? What changes can i expect from each method? I have considered that my amp is lacking the bottom end reproduction. running with a friends old heathkit solid state 120w amp there was an improvement in the bottom end. If i can sell some of the equipment i have it will fund the building of the tubelab SE with some CSXE 25W Edcor outputs. I hope these pictures came through.
Thanks,
Paul
Thanks,
Paul
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Hi Sherpa,
The first thing that concerns me is that you appear to have lined three sides. When I did my first build (FE108eSigma) I lined all sides of the interior. What a disaster! I had to cut into the port baffles on the bottom to get in so I could remove the lining from the front and sides. On all three of my Met builds I have lined only the back, from top to bottom.
The FE108eSigma Mets have a BSC of 1 mH and 4.5 ohms. The F120A didn't need any BSC. The Fe167e have a BSC of 0.7 mH and 2.2 ohms. Not sure what the FF125wk might need, but it sounds like they need some.
Cheers, Jim
The first thing that concerns me is that you appear to have lined three sides. When I did my first build (FE108eSigma) I lined all sides of the interior. What a disaster! I had to cut into the port baffles on the bottom to get in so I could remove the lining from the front and sides. On all three of my Met builds I have lined only the back, from top to bottom.
The FE108eSigma Mets have a BSC of 1 mH and 4.5 ohms. The F120A didn't need any BSC. The Fe167e have a BSC of 0.7 mH and 2.2 ohms. Not sure what the FF125wk might need, but it sounds like they need some.
Cheers, Jim