Re: Re: Re: A new Metronome is born!
The typical wider than deep aspect also lends itself well to a bipole, eliminating any need for BSC.
The 1st metronome we are going to build will be bipole FE126 or FE127.
dave
lousymusician said:
The typical wider than deep aspect also lends itself well to a bipole, eliminating any need for BSC.
The 1st metronome we are going to build will be bipole FE126 or FE127.
dave
lousymusician, if you want the detailed description of the differences between BR & ML TQWT & variations, go to Martin's site & have a read of his white papers, and also the full project documentation of his Project 2 ML TQWT. That should bring you fully up to speed.
In the suggested cabinets on the new Frugal-horn site which should be coming on-line v. soon, there are suggestions for BSC circuits. However, the FR for all the ML Metronomes are deliberately shaped not to roll-off as would normally done to counter room-gain, so in conjunction with near-wall placement, this should go some way to alleviating the need for compensation. Alternatively, the bipoles will, as Dave mentions, probably prove to be the best of the lot. The design really lends itself to this layout.
In the suggested cabinets on the new Frugal-horn site which should be coming on-line v. soon, there are suggestions for BSC circuits. However, the FR for all the ML Metronomes are deliberately shaped not to roll-off as would normally done to counter room-gain, so in conjunction with near-wall placement, this should go some way to alleviating the need for compensation. Alternatively, the bipoles will, as Dave mentions, probably prove to be the best of the lot. The design really lends itself to this layout.
Re: Re: Re: A new Metronome is born!
Hi Bill Thanks for the positive comments.
Re Martin's worksheets, I am of course aware that these are very highly regarded and have been optimized over quite a few years. It is just that I am very excited at the moment as you can imagine that my first experience of these modelling systems with my own and now with your report on your speaker has proven to work so well in a real room.
I had used a couple of box design programs before around five years ago and had been distinctly underwhelmed with the results, so much so that I had virtually given up on software packages and had become thoroughly dissillusioned with speaker design in general as nothing current seemed to offer anything but forward, shouty mids, one note bass and treble that could strip the enamel from teeth.
The Metronome design grew out of these frustrations and was developed from first principles and a quarter wave speaker by Castle Acoustics I had heard at a dealer's that used mass loading in the form of a narrow slot that ran all the way around the base apart from a washer placed at each corner to maintain the correct gap. The Castle speaker was a straight sided folded MLQWT and was the only box speaker I had heard at that time that sounded right to me; but it was fiendishly expensive at around $2500 in your money ( this was around 1993)
The Metronome arose out of a strange combination of memories of the sound of that Castle speaker, the truncated pyramid form, Terry Cain's Abby, Quarter wave loading, part of a wash stand made by Norm Abram on his New Yankee Workshop TV program and a photograph of the Eiffel Tower in Paris (hence the base arches).
With Scott's help, tuning the enclosure with the correct mass loading as given by Martin's sheets we finally got something that worked properly.
It is now left to Scott, Dave, and guys like yourself to push the design further with bigger cabinets etc.
You guys have the facilities and up to date experience with modern computer modelling software to get the best out of the concept at larger sizes.
Thanks for pushing it further than I ever could have with my meagre resources
Steve 🙂
lousymusician said:
Hi Bill Thanks for the positive comments.
Re Martin's worksheets, I am of course aware that these are very highly regarded and have been optimized over quite a few years. It is just that I am very excited at the moment as you can imagine that my first experience of these modelling systems with my own and now with your report on your speaker has proven to work so well in a real room.
I had used a couple of box design programs before around five years ago and had been distinctly underwhelmed with the results, so much so that I had virtually given up on software packages and had become thoroughly dissillusioned with speaker design in general as nothing current seemed to offer anything but forward, shouty mids, one note bass and treble that could strip the enamel from teeth.
The Metronome design grew out of these frustrations and was developed from first principles and a quarter wave speaker by Castle Acoustics I had heard at a dealer's that used mass loading in the form of a narrow slot that ran all the way around the base apart from a washer placed at each corner to maintain the correct gap. The Castle speaker was a straight sided folded MLQWT and was the only box speaker I had heard at that time that sounded right to me; but it was fiendishly expensive at around $2500 in your money ( this was around 1993)
The Metronome arose out of a strange combination of memories of the sound of that Castle speaker, the truncated pyramid form, Terry Cain's Abby, Quarter wave loading, part of a wash stand made by Norm Abram on his New Yankee Workshop TV program and a photograph of the Eiffel Tower in Paris (hence the base arches).
With Scott's help, tuning the enclosure with the correct mass loading as given by Martin's sheets we finally got something that worked properly.
It is now left to Scott, Dave, and guys like yourself to push the design further with bigger cabinets etc.
You guys have the facilities and up to date experience with modern computer modelling software to get the best out of the concept at larger sizes.
Thanks for pushing it further than I ever could have with my meagre resources
Steve 🙂
Scottmoose said:
Scott,
I've read through Martin's white papers. I think I understand what his models are doing. The question I was trying to explore was, when does a BR box become an ML-QWR? Just when we say it does?
I guess I can answer that question in two ways.
First, when the line length becomes long enough for the lowest quater wave resonance to be lower than the box resonance predicted by T & S.
Second, all BR boxes ARE to some extent QWR's, just not well designed ones! That is, the resonances exist, but they are too high in the driver's response band to be of any help in tuning the low frequency performance of the system.
Is that on the right track?
Yup. It's a different approach to the design, and the line between the cabinet types is a very hazy one indeed. There's no exact transition.
I can't get over how this stuff never gets boring for me
even though I know scant about any of it.
At some point I will want to try the Metronome.
even though I know scant about any of it.
At some point I will want to try the Metronome.
Nurse! 😀
I sort of define TQWT as horn variations -just end loaded with linear expansion. Hyper simplistic I suppose, but works for me. I'll probably revise this view at some point over the next, oh, ten minutes, but it'll do until then. 😉
I sort of define TQWT as horn variations -just end loaded with linear expansion. Hyper simplistic I suppose, but works for me. I'll probably revise this view at some point over the next, oh, ten minutes, but it'll do until then. 😉
Has anyone tried one of Dave's modded 126s in this yet? Since I first saw this project it has me torn on what I plan to do for speakers. I had planned to do the Frugel Horn but the Metronome looks like a much better (simpler to make) first project for me. I plan to get the modded drivers from Dave but would like to hear from the group any thoughs on one project VS the other. Both projects get high WAF feedback so no help there. Thanks.
Hi
This is a very difficult question to answer as it depends on what you want.
If you want elegance, extremely high WAF and are willing to sacrifice a bit of efficiency then the Metronome is the one to go for. Very easy to build and to get sounding good.
But the trouble is we would need to know what the rest of your system is.
The Frugel Horns being more efficient than the Metronomes would suit a low powered tube amp better, but what sort of SPLs do you want?
Speaker choice is such a personal thing that it is vey hard for me to give advice without coming across as a salesman for my particular way of thinking and the designs I favor.
A bit of a rambling inconclusive answer but that's the nature of trying to give advice on speakers.
Steve
This is a very difficult question to answer as it depends on what you want.
If you want elegance, extremely high WAF and are willing to sacrifice a bit of efficiency then the Metronome is the one to go for. Very easy to build and to get sounding good.
But the trouble is we would need to know what the rest of your system is.
The Frugel Horns being more efficient than the Metronomes would suit a low powered tube amp better, but what sort of SPLs do you want?
Speaker choice is such a personal thing that it is vey hard for me to give advice without coming across as a salesman for my particular way of thinking and the designs I favor.
A bit of a rambling inconclusive answer but that's the nature of trying to give advice on speakers.
Steve
Thanks for the feedback. My current system consists of an ASL MG SI15-DT amp that in SET mode produces 5 watts and in PP produces 15 watts(KT-88 tubes)/Adcom GFP-565 preamp/Dual 1245 TT/Early Playstation SCPH 1001 model CD player and old Bose 2.2 speakers. The pre and speakers are loaners from a friend until I work out my own gear. I am keeping an eye out for a good deal on a Dynaco PAS 2 or 3 to replace the Adcom so I can give that back. The speakers are the week point as far as I can tell at this point and should be easily replaced with something DIY. Thats what leads me to the Metronomes or the Frugels.
On the design side I have been wondering it adding something to the inside top flat area would do anything for the sound. Something small and shaped like the larger Metronome itself but hanging upside sown like a stalactite. This would eliminate any potential reflections between the flat bottom and the top. Any thoughts on this idea?
On the design side I have been wondering it adding something to the inside top flat area would do anything for the sound. Something small and shaped like the larger Metronome itself but hanging upside sown like a stalactite. This would eliminate any potential reflections between the flat bottom and the top. Any thoughts on this idea?
Steve Cresswell said:
The Frugel-Horn is mostly more efficient because it uses FE126e. The horn loading improves the efficiency in the bass allowing them to play louder (and without care for BSC).
An alternative would be to do a bipolar FE126e or 127e Metronome. No BSC issues, Still the elegant -- easier to build -- Metronome presentation, the price you pay is needing 4 drivers instead of 2. The bipole will also not need a corner and probably goes a bit lower.
dave
Audio Nirvana or Hemp or ?
Hi
I am thinking of making my first Full-range project, based on the Metronome.
I have not decided on the driver, but I am thinking of either the Hemp or Audio Nirvana 10/12.
Do any of your guys have experince with these drivers in the Metronome, or if so, which one would you recommend.
A final question: Have anyone tried the Metronome as a bipol?
Brgds,
Brian
Hi
I am thinking of making my first Full-range project, based on the Metronome.
I have not decided on the driver, but I am thinking of either the Hemp or Audio Nirvana 10/12.
Do any of your guys have experince with these drivers in the Metronome, or if so, which one would you recommend.
A final question: Have anyone tried the Metronome as a bipol?
Brgds,
Brian
FE127e Metronome built
Well, kindof, my inability to read a plan meant that, although L, Zd and the terminus are as suggested , “So” ended up being 5,976 mm2 (not 3,264 as designed) and “S1” 33,620 mm2 (not 25,988), so it’s 1.3 times bigger at the bottom and 1.8 times bigger at the top than designed. C’est la vie, at least when me and a saw get together… Construction is from 18mm birch ply and the interior is lined with “Treadmore” carpet underlay.
They are powered by a Charlize, and WAF is evaluated by my long suffering other half. The sound is evaluated my me, but I really don’t know that much so when I say they have plenty of bass, yet are incredibly detailed and rich with a huge soundstage, that’s in comparison to my old Tannoy Revolution R2’s. On fire-up they were a bit shouty but they quickly calmed down to produce terrific imaging - piano and vocals are a real treat. The only thing that’s bugging me now is wondering what they could be like it they were the correct dimensions.
What the consensus – rip a saw down the length of them and re-glue to get the correct dimensions or live with it? At the moment it’s going to take a miracle not to take the saw to them tonight, but they do sound sooo good.
Well, kindof, my inability to read a plan meant that, although L, Zd and the terminus are as suggested , “So” ended up being 5,976 mm2 (not 3,264 as designed) and “S1” 33,620 mm2 (not 25,988), so it’s 1.3 times bigger at the bottom and 1.8 times bigger at the top than designed. C’est la vie, at least when me and a saw get together… Construction is from 18mm birch ply and the interior is lined with “Treadmore” carpet underlay.
They are powered by a Charlize, and WAF is evaluated by my long suffering other half. The sound is evaluated my me, but I really don’t know that much so when I say they have plenty of bass, yet are incredibly detailed and rich with a huge soundstage, that’s in comparison to my old Tannoy Revolution R2’s. On fire-up they were a bit shouty but they quickly calmed down to produce terrific imaging - piano and vocals are a real treat. The only thing that’s bugging me now is wondering what they could be like it they were the correct dimensions.
What the consensus – rip a saw down the length of them and re-glue to get the correct dimensions or live with it? At the moment it’s going to take a miracle not to take the saw to them tonight, but they do sound sooo good.
Hi Gus
Glad you like your new builds.
To be quite honest I would leave them alone.
Your error has produced a bit more Vb which is not so much of a problem as
it would have been if you had erred the other way and produced
too little Vb.
Scott or Dave might be able to suggest some form of alteration to the
base port compensate so taking a rip saw to them would be a
bit radical in my view and would ruin the work you have put into them.
The imaging is one of my favourite aspects of my FE108EZ Metronomes
When we did a Fostex shootout at Steve Shiels place last September, Scott and I found the image these things threw was so good we could actually walk around the performers in the sound stage. The double horns Scott designed were also capable of the
same trick.
The Metronomes are a very musical speaker, not as dynamic as a horn but very easy on the ear and extremely realistic.
Don't get the rip saw out yet! 😱
Steve.
Glad you like your new builds.
To be quite honest I would leave them alone.
Your error has produced a bit more Vb which is not so much of a problem as
it would have been if you had erred the other way and produced
too little Vb.
Scott or Dave might be able to suggest some form of alteration to the
base port compensate so taking a rip saw to them would be a
bit radical in my view and would ruin the work you have put into them.
The imaging is one of my favourite aspects of my FE108EZ Metronomes
When we did a Fostex shootout at Steve Shiels place last September, Scott and I found the image these things threw was so good we could actually walk around the performers in the sound stage. The double horns Scott designed were also capable of the
same trick.
The Metronomes are a very musical speaker, not as dynamic as a horn but very easy on the ear and extremely realistic.
Don't get the rip saw out yet! 😱
Steve.
dimitri said:
Drivers are wired in phase. As far as the box is concerned they are 1 larger driver. The outside world sees tham as a bipole.
dave
Re: Audio Nirvana or Hemp or ?
Brian,
Can't help with the Audio Nirvana, I've never heard one. I think I'm the only one so far to try the Hemp Acoustics in the Metronome cabinet. I've posted elsewhere about my love / hate relationship with the Hemps. I like them in lots of ways, they are efficient, fast and dynamic, and they have a good bottom end. I also tend to think that they are a bit too forward sounding for my taste. On that point I seem to be in the minority so make of it what you will. I use a simple shelf network to bring down the upper range a bit, which helps, but I suspect it's not really optimized.
As far as the Metronome cabinet, I have done no measurements yet but my ears tell me it's a much better than the basic bass reflex box in which i first had the Hemps. The mids are smoother, the bass better defined and it probably goes a bit deeper (though the rolloff starts a bit higher, so it's a little leaner in the midbass).
Overall, if you want to try the Hemps, the Metronome is a great design. I would recommend using some form of baffle step compensation, which will cut efficiency a bit but give (IMO) a more balanced sound. I might recomend waiting a little while to see what changes Hemp Acoustics will make in their driver, but at the pace they're going it could be a long wait.
Oh, I do have both channels up and running now. Still not sanded or finished, though. Gotta love wide angle barrel distortion. 🙄
briandk said:
Brian,
Can't help with the Audio Nirvana, I've never heard one. I think I'm the only one so far to try the Hemp Acoustics in the Metronome cabinet. I've posted elsewhere about my love / hate relationship with the Hemps. I like them in lots of ways, they are efficient, fast and dynamic, and they have a good bottom end. I also tend to think that they are a bit too forward sounding for my taste. On that point I seem to be in the minority so make of it what you will. I use a simple shelf network to bring down the upper range a bit, which helps, but I suspect it's not really optimized.
As far as the Metronome cabinet, I have done no measurements yet but my ears tell me it's a much better than the basic bass reflex box in which i first had the Hemps. The mids are smoother, the bass better defined and it probably goes a bit deeper (though the rolloff starts a bit higher, so it's a little leaner in the midbass).
Overall, if you want to try the Hemps, the Metronome is a great design. I would recommend using some form of baffle step compensation, which will cut efficiency a bit but give (IMO) a more balanced sound. I might recomend waiting a little while to see what changes Hemp Acoustics will make in their driver, but at the pace they're going it could be a long wait.
Oh, I do have both channels up and running now. Still not sanded or finished, though. Gotta love wide angle barrel distortion. 🙄
