planet10 said:
Who, may i ask, donated the 207
dave
Hi Dave It was a friend from the World Designs Forum.
Hi Bill
Hearing about your success with the larger design and seeing the photos on Dave's site
prompted me to investigate a pair of bigger ones.
My wife was happy with the full size cardboard mock-ups I made so I've decided to get them built fast before she changes her mind.
Steve
Metronome build progress report (long)
Hi,
My buddy Bob and I have built two pair of Metronomes, or at least we have speakers built to the point where they "emit sound", as my wife puts it. Here's our story so far. This is a first-time speaker-building project for both of us. Hopefully, this tale will be useful for somebody contemplating building metronomes. Or at will be worth a chuckle.
I'll post this in three chunks. The first is the tale of building. The second post is my attempt at a mini-review of what the things sound like. (Originally a response I wrote in another forum when somebody asked.) Then, there's Bob's observations. I was going to edit them into this post, but it's too long already.
First off, going in, this project LOOKED quick and easy. One Saturday afternoon, maybe two tops and we would have cabinets built. We though this would be a quickie effort that would yield some cheap speakers for our similarly-sized dens. Well, everybody reading this knows how silly that was. About six Saturday afternoons, a couple of Sunday mornings and at least half a dozen runs back for more supplies brings us to this point.
Our Metronomes are from Dave Dlugos' plans, using the Fostex Fe127e. Originally, we were going to do one set with Planet10-modified drivers and one with stock drivers, so we could compare the two later, but both pairs use the modified drivers.
The good news is that you can build these speakers using only hand held power tools. The bad news is that, for the most part, you'll probably have to.
Part of the motivation for this project was to use my father-in-law's unused and partially dismantled woodshop. Thus, we had at our disposal a terrific table saw. But sadly, it was mostly used as - a table. The other bench-mounted tool we had at hand was a 12" disk sander. This turned out to be a fabulous tool. It saved us from h-o-u-r-s of tedium.
The twin culprits that conspire against your table saw are the trapezoidal shape of the Metronomes and the fact that their panels are more than 48" long. If you're clever and you have a lot of space around your table saw, you might be able to work out some solutions. Of course, if you've got a panel saw, you're golden. For the rest of us, it will be a straightedge and a handheld circular saw. (We used a 40 tooth blade with good effect on the 3/4" birch plywood we used for the build.
Now I have a great straightedge. But it's 48 inches long. So the first of many head-scratching sessions ensued. A six foot length of aluminum angle seemed like a good idea until we priced one at the local hardware. Fortunately, Bob had an antique carpenter's straightedge that we pressed into service. (Subsequently, I discovered that now there are self-clamping straightedges like mine that have T-slots and a base plate for your circular saw, thus making a poor man's panel saw for about 100 bucks. We're I to do this again, I would check that out.)
With the 12" disk sander, we felt empowered to cut some parts a little fat and true them up later. Be forewarned, however that this works better on some parts than others. It best to be pretty precise.
In order to lay out the parts efficiently on a 4' by 8' sheet of plywood, we had the "point ends" of the panels overlapping. Have a jig saw handy, as you'll find you can't free the part from the sheet with the circular saw.
We chose to make all our cuts at 90 degrees and use the disk sander to make the slight miters on the top and bottom pieces and the top and bottom of the assembled boxes. This despite the fact that we were able to use the table saw to make the top and bottom pieces. By that time we were well acquainted with the sander, so we just went with the flow.
We cut the arches at the bottom of the speaker and the driver hole with a router. Another head-scratching session. We didn't have a Jasper Jig or the inclination to march to Woodcrafters with $40 to buy one. Eventual solution: A Lexan window pane from Lowes was $3. I splurged on an new 3/16 drill bit to drill the guide holes and also act as the pivot peg. But then a couple of the radii we wanted to cut put the pivot pin right under the solid part of the router base. More head scratching. A disk of scrap plywood worked as a spacer to allow room for the pin. But this then meant we needed longer fixing screws to attach the improvised guide to the router. Another trip to the hardware. (On my router, the fixing screws are M4, by the way.) It was well worth the effort. If we had tried to use the jigsaw, we'd still be at it.
We used t-nuts and Allen screws for driver mounting. If you go this way, be careful when you chamfer the inside of the driver hole. You'll have to make sure you don't cut away the wood where the t-nuts will go.
We used # 0 biscuits and TiteBond to glue the pieces together. I can't over emphasize how much of a sanity saver that biscuit joiner turned out to be. Highly recommended. Make sure you have lots of clamps on hand. Did I mention that the speakers are trapezoidal? And they looked so simple on the drawing. Clamping note: Use an extra clamp right at the bottom to make sure you get a good bond on the little corners of the "Eiffel Tower" arch. The joint tends to pull open there.
For the testing phase, we have left secured the backs with screws, so we can open the boxes. I wouldn't think of screws as a good permanent solution, though. As soon as everything is sorted out, we'll glue the backs on. We did install pads and t-nuts for the bottoms rather than gluing them in, just in case we ever have to get inside. I don't know how effective this will be. Those cabinets are pretty skinny. But it seemed like a good idea at the time.
We used the table saw and the biscuit joiner to fabricate the infernal holey braces. Here, the trapezoidal shape made things a bit easier. To make the holey brace fit snugly, just tap it toward the top of the speaker. Now we haven't as yet coupled the driver to the braces. The chance of distorting the driver baskets was just too scary. We left about 3/32" of a gap between the brace and the back of the magnet. The plan is to use either Blu-Tac (which is orange nowadays for whatever reason) if we want an absorptive, resistive coupling, or the old model airplane technique of impregnating soft balsa with thin CA if we want to make a rigid structure that fits exactly. But right now the speakers sound great, so coupling the drivers and braces is on hold.
The plan is to veneer the speakers as soon as we're sure everything is in order. The veneer sub-project is a little daunting. The veneer will cost more than all the other components put together. I did remember to mention the bit about how that shape and the greater-than 48" dimension puts all the difficulty in this, right? A couple of times at least. Here, we're talking buying, handling, and trying not to screw up huge and shockingly expensive pieces of veneer. In my case. I might build and veneer a little pair of surround or desktop speakers to gain some experience before taking on the Metronomes. Bob's pair are currently residing in his living room, so he' in a bit more of a hurry to get on with it.
As I write this, the grills have yet to be built. We're planning to use magnetic mounts, concealed under the veneer and go for something "Alavon-ish" (And no, we'll probably never listen to them with the grills on, but they'll look cool.)
I burned in my pair for 100 hours in the garage before listening to them. (Dave put a bunch of break-in time on the driver pre-mod and recommends about 100 hours afterwards.) I'm listening now and my pair either does or doesn't need a touch of polyfil to (maybe) tighten up the bass a tad. We'll let you know how that goes.
The jury is still out on baffle step compensation filters. We don't hear (at this point anyway) a lack of bass or a shout. I would think the shout would be the more likely symptom of a baffle-jump for this skinny baffle, at least according to the baffle step filter calculator I found online. We certainly wouldn't want to harm that fabulous midrange coherency. Anybody out there who has built Fe127-based Metronomes, please jump in with your feelings here.
We'll put some preliminary listening impressions in another post now and post a little more authoritatively later. It's our plan to corral some friends with experience in the business to have a listen and record their impressions. One thing I found difficult when I was researching this project was trying to divine exactly WHAT various DIY designs sound like. Commercial products have the advantage that they are reviewed by journalists and can be auditioned in showrooms. A taste of DIY reviewing has given me more respect for those guys at Stereophile and 6 Moons, but we'll give it a go.
Given the finite number of speaker required in my house, I kind of doubt I'll ever be contributing great designs back to the community, so some probably embarrassing critical commentary will have to be my contribution in consideration of the time and knowledge that the DIY community has given so generously to us all.
Thanks to everybody whose hard work made this possible!
-Carl
Hi,
My buddy Bob and I have built two pair of Metronomes, or at least we have speakers built to the point where they "emit sound", as my wife puts it. Here's our story so far. This is a first-time speaker-building project for both of us. Hopefully, this tale will be useful for somebody contemplating building metronomes. Or at will be worth a chuckle.
I'll post this in three chunks. The first is the tale of building. The second post is my attempt at a mini-review of what the things sound like. (Originally a response I wrote in another forum when somebody asked.) Then, there's Bob's observations. I was going to edit them into this post, but it's too long already.
First off, going in, this project LOOKED quick and easy. One Saturday afternoon, maybe two tops and we would have cabinets built. We though this would be a quickie effort that would yield some cheap speakers for our similarly-sized dens. Well, everybody reading this knows how silly that was. About six Saturday afternoons, a couple of Sunday mornings and at least half a dozen runs back for more supplies brings us to this point.
Our Metronomes are from Dave Dlugos' plans, using the Fostex Fe127e. Originally, we were going to do one set with Planet10-modified drivers and one with stock drivers, so we could compare the two later, but both pairs use the modified drivers.
The good news is that you can build these speakers using only hand held power tools. The bad news is that, for the most part, you'll probably have to.
Part of the motivation for this project was to use my father-in-law's unused and partially dismantled woodshop. Thus, we had at our disposal a terrific table saw. But sadly, it was mostly used as - a table. The other bench-mounted tool we had at hand was a 12" disk sander. This turned out to be a fabulous tool. It saved us from h-o-u-r-s of tedium.
The twin culprits that conspire against your table saw are the trapezoidal shape of the Metronomes and the fact that their panels are more than 48" long. If you're clever and you have a lot of space around your table saw, you might be able to work out some solutions. Of course, if you've got a panel saw, you're golden. For the rest of us, it will be a straightedge and a handheld circular saw. (We used a 40 tooth blade with good effect on the 3/4" birch plywood we used for the build.
Now I have a great straightedge. But it's 48 inches long. So the first of many head-scratching sessions ensued. A six foot length of aluminum angle seemed like a good idea until we priced one at the local hardware. Fortunately, Bob had an antique carpenter's straightedge that we pressed into service. (Subsequently, I discovered that now there are self-clamping straightedges like mine that have T-slots and a base plate for your circular saw, thus making a poor man's panel saw for about 100 bucks. We're I to do this again, I would check that out.)
With the 12" disk sander, we felt empowered to cut some parts a little fat and true them up later. Be forewarned, however that this works better on some parts than others. It best to be pretty precise.
In order to lay out the parts efficiently on a 4' by 8' sheet of plywood, we had the "point ends" of the panels overlapping. Have a jig saw handy, as you'll find you can't free the part from the sheet with the circular saw.
We chose to make all our cuts at 90 degrees and use the disk sander to make the slight miters on the top and bottom pieces and the top and bottom of the assembled boxes. This despite the fact that we were able to use the table saw to make the top and bottom pieces. By that time we were well acquainted with the sander, so we just went with the flow.
We cut the arches at the bottom of the speaker and the driver hole with a router. Another head-scratching session. We didn't have a Jasper Jig or the inclination to march to Woodcrafters with $40 to buy one. Eventual solution: A Lexan window pane from Lowes was $3. I splurged on an new 3/16 drill bit to drill the guide holes and also act as the pivot peg. But then a couple of the radii we wanted to cut put the pivot pin right under the solid part of the router base. More head scratching. A disk of scrap plywood worked as a spacer to allow room for the pin. But this then meant we needed longer fixing screws to attach the improvised guide to the router. Another trip to the hardware. (On my router, the fixing screws are M4, by the way.) It was well worth the effort. If we had tried to use the jigsaw, we'd still be at it.
We used t-nuts and Allen screws for driver mounting. If you go this way, be careful when you chamfer the inside of the driver hole. You'll have to make sure you don't cut away the wood where the t-nuts will go.
We used # 0 biscuits and TiteBond to glue the pieces together. I can't over emphasize how much of a sanity saver that biscuit joiner turned out to be. Highly recommended. Make sure you have lots of clamps on hand. Did I mention that the speakers are trapezoidal? And they looked so simple on the drawing. Clamping note: Use an extra clamp right at the bottom to make sure you get a good bond on the little corners of the "Eiffel Tower" arch. The joint tends to pull open there.
For the testing phase, we have left secured the backs with screws, so we can open the boxes. I wouldn't think of screws as a good permanent solution, though. As soon as everything is sorted out, we'll glue the backs on. We did install pads and t-nuts for the bottoms rather than gluing them in, just in case we ever have to get inside. I don't know how effective this will be. Those cabinets are pretty skinny. But it seemed like a good idea at the time.
We used the table saw and the biscuit joiner to fabricate the infernal holey braces. Here, the trapezoidal shape made things a bit easier. To make the holey brace fit snugly, just tap it toward the top of the speaker. Now we haven't as yet coupled the driver to the braces. The chance of distorting the driver baskets was just too scary. We left about 3/32" of a gap between the brace and the back of the magnet. The plan is to use either Blu-Tac (which is orange nowadays for whatever reason) if we want an absorptive, resistive coupling, or the old model airplane technique of impregnating soft balsa with thin CA if we want to make a rigid structure that fits exactly. But right now the speakers sound great, so coupling the drivers and braces is on hold.
The plan is to veneer the speakers as soon as we're sure everything is in order. The veneer sub-project is a little daunting. The veneer will cost more than all the other components put together. I did remember to mention the bit about how that shape and the greater-than 48" dimension puts all the difficulty in this, right? A couple of times at least. Here, we're talking buying, handling, and trying not to screw up huge and shockingly expensive pieces of veneer. In my case. I might build and veneer a little pair of surround or desktop speakers to gain some experience before taking on the Metronomes. Bob's pair are currently residing in his living room, so he' in a bit more of a hurry to get on with it.
As I write this, the grills have yet to be built. We're planning to use magnetic mounts, concealed under the veneer and go for something "Alavon-ish" (And no, we'll probably never listen to them with the grills on, but they'll look cool.)
I burned in my pair for 100 hours in the garage before listening to them. (Dave put a bunch of break-in time on the driver pre-mod and recommends about 100 hours afterwards.) I'm listening now and my pair either does or doesn't need a touch of polyfil to (maybe) tighten up the bass a tad. We'll let you know how that goes.
The jury is still out on baffle step compensation filters. We don't hear (at this point anyway) a lack of bass or a shout. I would think the shout would be the more likely symptom of a baffle-jump for this skinny baffle, at least according to the baffle step filter calculator I found online. We certainly wouldn't want to harm that fabulous midrange coherency. Anybody out there who has built Fe127-based Metronomes, please jump in with your feelings here.
We'll put some preliminary listening impressions in another post now and post a little more authoritatively later. It's our plan to corral some friends with experience in the business to have a listen and record their impressions. One thing I found difficult when I was researching this project was trying to divine exactly WHAT various DIY designs sound like. Commercial products have the advantage that they are reviewed by journalists and can be auditioned in showrooms. A taste of DIY reviewing has given me more respect for those guys at Stereophile and 6 Moons, but we'll give it a go.
Given the finite number of speaker required in my house, I kind of doubt I'll ever be contributing great designs back to the community, so some probably embarrassing critical commentary will have to be my contribution in consideration of the time and knowledge that the DIY community has given so generously to us all.
Thanks to everybody whose hard work made this possible!
-Carl
Metronome build part 2 -Mini Review (Long)
Hi All,
(This is more ore less a re-post of a message I wrote on Computer Audiophile.)
The FE127e-based Metronomes are playing as I write this. They're pretty impressive, as it turns out. These things offer a fair dose of the magic for a couple hundred bucks for drivers and a sheet of plywood from Lowes. I get the single-driver thing now. Here are some early impressions. Tim - I don't know if any if this rambling will be helpful for you, but here goes.
There's resolution to the max. Midrange dynamics are quite good. Imaging is very good. The bass is full and satisfying, if not the last word in power or control - more on that later.
Overall, the sound is very involving, toe-tap-y. M Ward's "Helicopter" played on random play. It had me snapping fingers and dancing around the den. And this is not what you would call a dynamic recording. My copy is an MP3 from eMusic at that. A friend who heard the speakers a few days after I wrote this post originally said they have a "high fun factor", meaning even if they're not your cup of tea, they're fun to listen to.
The first thing that grabs you is the detail. We're talking a level of resolution and coherence that's in the same league as the Apogee ribbons in my main system. We're talking in the same league as good headphones, for crying out loud. I'm waiting to hear the lower midrange thinness that usually lurks around components that are "detailed". Haven't heard that yet. No, this is the real detail deal. Vocals, particularly, are spot-on. Performers breathe, make sounds with their mouths and just palpably "exist", right there in the soundstage. The hand claps in the background of "Jersey Girl" by Holly Cole on "Temptation" sound like - hands. Clapping. Real hands clapping. Right where they should be. (I have no idea how much of the soundstage is a reproduction of what happened in the real space when the recording was made of not. Doesn't matter. It sounds convincing enough to suspend disbelief. That's what matters.)
Familiar vocals sound like the vocalists who perform them (like they do live, or like my accumulated impressions from lots of recordings played on lots of systems) Margo Timmons and Natalie Merchant on the Cowboy Junkies' "Trinity Revisited" serve to illustrate. It's Timmons and Merchant, as vividly drawn as they would be on my AKG 701s (same DAC, but the headphones enjoy somewhat more upscale amplification.)
Still worried about brightness or etch in the upper mids passing as detail, I tried some harmonicas. William Gallison and Toots Thielemanns. An over-bright Toots Thielemanns is like a ice pick through the brain. You don't have to wonder if something bad is happening. I put on a couple of tracks from "East Coast, West Coast". I sat and listened to the whole album. The cat jumped up on my lap and listened. No brightness problem.
I put on U2's "Rattle and Hum". My wife stopped work and came into the room, sat down on the couch, and proceeded to sing along with Bono. I have no idea what U2 on this system sounded like, but I guess it the singing I did hear was an indication these things can't have been too bad on the "musically involving" front.
I tried the "Scherherazade". (Which, by coincidence, is playing at background level by choice of Slimserver's Random Play as I type this paragraph). At reasonable (e.g. pretty loud) levels, the weight and power of a real orchestra, or for that matter, a really good system, was absent. But melodic lines unfolded to be followed, and oh that low level detail. Subtle parts were as good as they would be on a big-buck system. Overall, worse things could happen.
Now then. The bass and treble. Treble, at least as far as it goes, is a delight. It's of the same smooth, detailed cloth as the midrange. Wooden sticks hit metal cymbals with the right timber and bite. That said, I'm pretty sure the last half-octave, at least, is missing in action. There could be more air around instruments. But my very humble, no-name Chinese push-pull amp isn't much in the last octave anyway, so it's hard to really tell what the speakers are contributing or subtracting. Bottom line: The top end is rolled off, but I not grieving for it.
Bass is interesting. F3 for these speakers supposed to be about 50 or 60-Hz. So, I would expect a lightness in the bottom that would extend up to thin-ish lower mids or a one-note thump. But nothing nasty is happening. The bass seems full and rich and quite warm. It's not tight or powerful in an absolute sense - Richard Vandersteen doesn't have to worry about losing Quatro sales here. For that matter, the bass from my Apogee Caliper Signatures is faster. Like an Indy car flying by my sedan, faster. But the cost of one or the other of those systems and the amplification to drive it would be thirty to sixty times the cash spent building these things, so I would expect them to be, ahem, better.
I heard a boominess when the speakers were burning in on radio in the garage that made me think a half a bag of polyfil would be in order to damp a pipe resonance that might be flapping about. I don't hear that as much on real loss-less music from my server. I guess the radio station's idea of appealing EQ just hit the right note over and over. Somehow, with all the listening this afternoon, I didn't quite get to the store to buy that bag of fuzz. I'll get to it. It remains to be seen if the damping will tighten things up or take away some liveliness that's part of the toe-tap appeal. We'll see.
So there's a preliminary take on my first DIY single-driver experience. I hope it helps a little, or provides some amusement or something. I'd like to thank the great people online, at the DIY Audio forum and particularly Dave at Planet 10 Hifi, all of whom have given of themselves to make this hobby accessible to people like me and you. The world may be falling apart in some places, but the sense of community we see on fora like this one makes me feel better about our chances for the future. I feel like it's the least I can do to report back, at least as well as I can, on what the results actually sound like.
Cheers,
-Carl
Hi All,
(This is more ore less a re-post of a message I wrote on Computer Audiophile.)
The FE127e-based Metronomes are playing as I write this. They're pretty impressive, as it turns out. These things offer a fair dose of the magic for a couple hundred bucks for drivers and a sheet of plywood from Lowes. I get the single-driver thing now. Here are some early impressions. Tim - I don't know if any if this rambling will be helpful for you, but here goes.
There's resolution to the max. Midrange dynamics are quite good. Imaging is very good. The bass is full and satisfying, if not the last word in power or control - more on that later.
Overall, the sound is very involving, toe-tap-y. M Ward's "Helicopter" played on random play. It had me snapping fingers and dancing around the den. And this is not what you would call a dynamic recording. My copy is an MP3 from eMusic at that. A friend who heard the speakers a few days after I wrote this post originally said they have a "high fun factor", meaning even if they're not your cup of tea, they're fun to listen to.
The first thing that grabs you is the detail. We're talking a level of resolution and coherence that's in the same league as the Apogee ribbons in my main system. We're talking in the same league as good headphones, for crying out loud. I'm waiting to hear the lower midrange thinness that usually lurks around components that are "detailed". Haven't heard that yet. No, this is the real detail deal. Vocals, particularly, are spot-on. Performers breathe, make sounds with their mouths and just palpably "exist", right there in the soundstage. The hand claps in the background of "Jersey Girl" by Holly Cole on "Temptation" sound like - hands. Clapping. Real hands clapping. Right where they should be. (I have no idea how much of the soundstage is a reproduction of what happened in the real space when the recording was made of not. Doesn't matter. It sounds convincing enough to suspend disbelief. That's what matters.)
Familiar vocals sound like the vocalists who perform them (like they do live, or like my accumulated impressions from lots of recordings played on lots of systems) Margo Timmons and Natalie Merchant on the Cowboy Junkies' "Trinity Revisited" serve to illustrate. It's Timmons and Merchant, as vividly drawn as they would be on my AKG 701s (same DAC, but the headphones enjoy somewhat more upscale amplification.)
Still worried about brightness or etch in the upper mids passing as detail, I tried some harmonicas. William Gallison and Toots Thielemanns. An over-bright Toots Thielemanns is like a ice pick through the brain. You don't have to wonder if something bad is happening. I put on a couple of tracks from "East Coast, West Coast". I sat and listened to the whole album. The cat jumped up on my lap and listened. No brightness problem.
I put on U2's "Rattle and Hum". My wife stopped work and came into the room, sat down on the couch, and proceeded to sing along with Bono. I have no idea what U2 on this system sounded like, but I guess it the singing I did hear was an indication these things can't have been too bad on the "musically involving" front.
I tried the "Scherherazade". (Which, by coincidence, is playing at background level by choice of Slimserver's Random Play as I type this paragraph). At reasonable (e.g. pretty loud) levels, the weight and power of a real orchestra, or for that matter, a really good system, was absent. But melodic lines unfolded to be followed, and oh that low level detail. Subtle parts were as good as they would be on a big-buck system. Overall, worse things could happen.
Now then. The bass and treble. Treble, at least as far as it goes, is a delight. It's of the same smooth, detailed cloth as the midrange. Wooden sticks hit metal cymbals with the right timber and bite. That said, I'm pretty sure the last half-octave, at least, is missing in action. There could be more air around instruments. But my very humble, no-name Chinese push-pull amp isn't much in the last octave anyway, so it's hard to really tell what the speakers are contributing or subtracting. Bottom line: The top end is rolled off, but I not grieving for it.
Bass is interesting. F3 for these speakers supposed to be about 50 or 60-Hz. So, I would expect a lightness in the bottom that would extend up to thin-ish lower mids or a one-note thump. But nothing nasty is happening. The bass seems full and rich and quite warm. It's not tight or powerful in an absolute sense - Richard Vandersteen doesn't have to worry about losing Quatro sales here. For that matter, the bass from my Apogee Caliper Signatures is faster. Like an Indy car flying by my sedan, faster. But the cost of one or the other of those systems and the amplification to drive it would be thirty to sixty times the cash spent building these things, so I would expect them to be, ahem, better.
I heard a boominess when the speakers were burning in on radio in the garage that made me think a half a bag of polyfil would be in order to damp a pipe resonance that might be flapping about. I don't hear that as much on real loss-less music from my server. I guess the radio station's idea of appealing EQ just hit the right note over and over. Somehow, with all the listening this afternoon, I didn't quite get to the store to buy that bag of fuzz. I'll get to it. It remains to be seen if the damping will tighten things up or take away some liveliness that's part of the toe-tap appeal. We'll see.
So there's a preliminary take on my first DIY single-driver experience. I hope it helps a little, or provides some amusement or something. I'd like to thank the great people online, at the DIY Audio forum and particularly Dave at Planet 10 Hifi, all of whom have given of themselves to make this hobby accessible to people like me and you. The world may be falling apart in some places, but the sense of community we see on fora like this one makes me feel better about our chances for the future. I feel like it's the least I can do to report back, at least as well as I can, on what the results actually sound like.
Cheers,
-Carl
Metronome build part 3 - Bob's impressions
Hi,
My involvement in this project began with Carl's mention of seeing some plans for a single driver speaker using smallish drivers with decent efficiency.
The "boxes" looked interesting when I first viewed them on a couple of Internet sites and after looking at the plans we both agreed that they shouldn't be that difficult to construct, a couple of weekends and we'd be finished was our conclusion, sign me up was my response. My plan for the finished speakers was to go with an NAD integrated that is used in a den for video, I wasn't expecting anything great only an improvement over the pair of PSB's that these will replace, a sub woofer would be added at some point.
Carl's comments on the construction process are accurate and my role in the building process was more of an extra pair of hands. I would not have attempted this project on my own having only limited woodworking experience and very little knowledge of the sonic issues that must be considered in the building of the boxes. [Note from Carl: He's kidding. He the much better woodworker.]
As the building process went on I continued my research on the Metronomes through various forums which elevated my expectations to that of ending up with something decent but not great, this assumption could not have been further from the truth.
I did not burn in as Carl but moved the finished speakers into my living room to see what these things had. I figured if they didn't come close to the current speakers ( Castle Isis) I'd put them in the den and forget about them until we got around to doing the veneering. They have since never left the living room.
My system consist of a Cayin TA-30 integrated, the above Castle Isis speakers and a Rega P3 24 as well as an older NAD used for the CD side. The space for this system is approx 14 x 20 ft. with a rising ceiling from 8 to14 ft. The first thing to hit me was the detail, detail like I've never heard before from a speaker, Carl covered it pretty good in his remarks so I won't repeat. The Castles I believe claim a low end of around 60 if I'm remembering correctly - not great but I've lived with it for the twelve or so years I've had them and figured if the Metronomes even came close I'd be impressed, what could you get from a four inch driver I thought? Full bass and once again a nice improvement over what the Castles provided and what I thought was decent for a small box and a five inch driver. My first comments to Carl centered around my concern for the lack of air or space from the Metronomes, something that the Castles did a good job of and something I didn't want to give up. Even with the nice improvement in the bass and the great detail the
Metronomes have, if this didn't improve they'd end up living in the den. The improvements came, taking them directly off the carpet to a scrap piece of 3/4 inch oak was a big improvement, spikes are going in soon which will also help. Any deficiencies I noted early on have since disappeared with more time on the speakers as expected. All in all I'm thrilled with the results and now have a better understanding of all the interest in this whole single driver thing. I'm grateful to Carl for suggesting that we try this project and my thanks to everyone on the forums for providing us a place to share information that makes this possible.
Bob
Hi,
My involvement in this project began with Carl's mention of seeing some plans for a single driver speaker using smallish drivers with decent efficiency.
The "boxes" looked interesting when I first viewed them on a couple of Internet sites and after looking at the plans we both agreed that they shouldn't be that difficult to construct, a couple of weekends and we'd be finished was our conclusion, sign me up was my response. My plan for the finished speakers was to go with an NAD integrated that is used in a den for video, I wasn't expecting anything great only an improvement over the pair of PSB's that these will replace, a sub woofer would be added at some point.
Carl's comments on the construction process are accurate and my role in the building process was more of an extra pair of hands. I would not have attempted this project on my own having only limited woodworking experience and very little knowledge of the sonic issues that must be considered in the building of the boxes. [Note from Carl: He's kidding. He the much better woodworker.]
As the building process went on I continued my research on the Metronomes through various forums which elevated my expectations to that of ending up with something decent but not great, this assumption could not have been further from the truth.
I did not burn in as Carl but moved the finished speakers into my living room to see what these things had. I figured if they didn't come close to the current speakers ( Castle Isis) I'd put them in the den and forget about them until we got around to doing the veneering. They have since never left the living room.
My system consist of a Cayin TA-30 integrated, the above Castle Isis speakers and a Rega P3 24 as well as an older NAD used for the CD side. The space for this system is approx 14 x 20 ft. with a rising ceiling from 8 to14 ft. The first thing to hit me was the detail, detail like I've never heard before from a speaker, Carl covered it pretty good in his remarks so I won't repeat. The Castles I believe claim a low end of around 60 if I'm remembering correctly - not great but I've lived with it for the twelve or so years I've had them and figured if the Metronomes even came close I'd be impressed, what could you get from a four inch driver I thought? Full bass and once again a nice improvement over what the Castles provided and what I thought was decent for a small box and a five inch driver. My first comments to Carl centered around my concern for the lack of air or space from the Metronomes, something that the Castles did a good job of and something I didn't want to give up. Even with the nice improvement in the bass and the great detail the
Metronomes have, if this didn't improve they'd end up living in the den. The improvements came, taking them directly off the carpet to a scrap piece of 3/4 inch oak was a big improvement, spikes are going in soon which will also help. Any deficiencies I noted early on have since disappeared with more time on the speakers as expected. All in all I'm thrilled with the results and now have a better understanding of all the interest in this whole single driver thing. I'm grateful to Carl for suggesting that we try this project and my thanks to everyone on the forums for providing us a place to share information that makes this possible.
Bob
Hi Guys
Thanks for taking the time to post your stories and your impressions of the FE127E Metronome builds.
My son built a pair of these a couple of weeks ago and I must admit, they sound superb. The 127 design seems to be the sleeper of the bunch and quite a little stunner by all accounts.
When I first designed these speakers using the FE108ES full range driver I could not have imagined what I was unleashing. Thanks to Scott and Dave (who designed all the cabinets capable of supporting other drive units) there seems to be a nice family of speakers being developed on both sides of the Atlantic, that not only look great but sound great too.
I now have my original 108ES Metronomes coupled with Blu-Tak to half inch granite slabs spiked into the floorboards. As you guys have said, the improvement in air and space brought about by putting something flat and solid under them was nothing short of astonishing.
I really am going to have to get going on the FE207E Mets, then I might be able to ditch the two subs
Steve
Thanks for taking the time to post your stories and your impressions of the FE127E Metronome builds.
My son built a pair of these a couple of weeks ago and I must admit, they sound superb. The 127 design seems to be the sleeper of the bunch and quite a little stunner by all accounts.
When I first designed these speakers using the FE108ES full range driver I could not have imagined what I was unleashing. Thanks to Scott and Dave (who designed all the cabinets capable of supporting other drive units) there seems to be a nice family of speakers being developed on both sides of the Atlantic, that not only look great but sound great too.
I now have my original 108ES Metronomes coupled with Blu-Tak to half inch granite slabs spiked into the floorboards. As you guys have said, the improvement in air and space brought about by putting something flat and solid under them was nothing short of astonishing.
I really am going to have to get going on the FE207E Mets, then I might be able to ditch the two subs
Steve
Steve Cresswell said:I really am going to have to get going on the FE207E Mets
Steve
Looking foward to these, it will probably be my next project. How far off are you?
Hearing how there rightup turned out (nice job) with the FE127e I can only imagine good things with the FE207e
Been using the Fe127e with the fonken floorstanders for a while now and love them.
port tube length: inner or outer?
I am putting together a FE207e Metronome according to the tables at http://www.frugal-horn.com/metronome-table.html. There it states that the tube should be 3x3 in. 3in inner diameter I presume. What about the length? Is 3in the inner length (this would account for the part going through the wood) or the exposed length on the inside? (This would be tube length minus wood thickness.)
Peter
I am putting together a FE207e Metronome according to the tables at http://www.frugal-horn.com/metronome-table.html. There it states that the tube should be 3x3 in. 3in inner diameter I presume. What about the length? Is 3in the inner length (this would account for the part going through the wood) or the exposed length on the inside? (This would be tube length minus wood thickness.)
Peter
damping my FE207e Mets
Dear Colleagues,
I have started to measure my Met build (FE207e; using build dimensions as found on http://www.frugal-horn.com/metronome-table.html). I have glued the front and sides and put the back on with clamps so I can learn something about the stuffing. For starters I have put 1in acoustic polyurethane foam with an NRC rating of 0.75 (http://www.mcmaster.com/nav/enter.asp?partnum=5692T13) on the sides and back just by the driver (20cm in height at the height of the driver). I also put some 1in egg crate polyurethane foam at the top and bottom (it only has an NRC of 0.25; probably doesn't do anything). I have then endeavored to measure the response with ARTA. I elevated the speaker off the floor (on top of a marble topped nightstand kind of piece of furniture) and have 1.5m of free space all around the driver (as verified by looking at the first echo in the impulse response). I am using the pink noise measurement with 4 times averaging. I am attaching an image of the raw (1/9 octave averaged) measurement as well as the gated measurement (stopping just short of the first reflection) with 1m distance between driver and microphone (head on). The gated response calculation is trustworthy (according to ARTA) from 200Hz onward.
I'd like to ask your help in understanding what I can learn from this. For example, there are severe dips at 78 and 106 Hz. I've taken a number of measurements with different mic distances (e.g., 50cm and 100cm and such, and these dips are fairly consistent though they move a little as I change measurement conditions (78/84Hz resp. 106/124 Hz. Next big dip is at 200 Hz which corresponds to the beginning of the confidence interval (I presume this implies that it is actually due to the wall reflections (floor resp. ceiling). (Why?) What's up with the peak at 2500 Hz? It seems to be at the end of a general upward slope (see the green curve of the gated response) with a rise of 3dB/octave. The green curve also has these dips at 980 and 1450Hz. Are they significant?
I realize these are very elementary questions so I ask your indulgence as I am trying to learn this stuff.
peter
Dear Colleagues,
I have started to measure my Met build (FE207e; using build dimensions as found on http://www.frugal-horn.com/metronome-table.html). I have glued the front and sides and put the back on with clamps so I can learn something about the stuffing. For starters I have put 1in acoustic polyurethane foam with an NRC rating of 0.75 (http://www.mcmaster.com/nav/enter.asp?partnum=5692T13) on the sides and back just by the driver (20cm in height at the height of the driver). I also put some 1in egg crate polyurethane foam at the top and bottom (it only has an NRC of 0.25; probably doesn't do anything). I have then endeavored to measure the response with ARTA. I elevated the speaker off the floor (on top of a marble topped nightstand kind of piece of furniture) and have 1.5m of free space all around the driver (as verified by looking at the first echo in the impulse response). I am using the pink noise measurement with 4 times averaging. I am attaching an image of the raw (1/9 octave averaged) measurement as well as the gated measurement (stopping just short of the first reflection) with 1m distance between driver and microphone (head on). The gated response calculation is trustworthy (according to ARTA) from 200Hz onward.
I'd like to ask your help in understanding what I can learn from this. For example, there are severe dips at 78 and 106 Hz. I've taken a number of measurements with different mic distances (e.g., 50cm and 100cm and such, and these dips are fairly consistent though they move a little as I change measurement conditions (78/84Hz resp. 106/124 Hz. Next big dip is at 200 Hz which corresponds to the beginning of the confidence interval (I presume this implies that it is actually due to the wall reflections (floor resp. ceiling). (Why?) What's up with the peak at 2500 Hz? It seems to be at the end of a general upward slope (see the green curve of the gated response) with a rise of 3dB/octave. The green curve also has these dips at 980 and 1450Hz. Are they significant?
I realize these are very elementary questions so I ask your indulgence as I am trying to learn this stuff.
peter
Just to be sure I understand. With the room reflections I have only things above 200Hz really mean anything in these measurements (else they are contaminated by the reflection). But if anything above 250-300 is due to the driver and not the cabinet I don't really have much left that is under my control... Am I reading this right?Scottmoose said:
What I am fishing for here (in a way) are things having to do with the lining of the cabinets and how that should show up. Also the baffle refraction and how it shows up. Are you saying that the measurements I made really don't help me with those questions?
If I think about corrections I think about the initial 3dB/octave slope and making that flat. But beyond I wonder about any of the peaks and dips. Is that all the FE207e driver? That doesn't match at all what the Fostex measurements show. Is all the ripple due to room effects? (even at high frequencies), or is some of it due to (effectively) missing lining? Where can I see the cabinet action? Is it visible in these measurements? Or am I looking in the wrong place?
Lots of question...
Peter
Basically correct. The cabinet's operating BW is very narrow, below about 250Hz or so. Above that, it's not doing a whole lot, other than providing a solid mounting point for the driver. Below about 200 - 300Hz, the room dominates the response & aside from digital Eq, there's little you can do about it. That's why in-room response plots are really only useful to the person who owns the speaker & the room.
You can see a degree of step-loss coming in from about 480Hz, give or take, due to the cabinets being a ways out from the wall -moving them back will lower that somewhat. The rest is simply the driver's own response. You can actually see the peak you mention at ~2.5KHz in the driver plot Fostex provide. It's just that they happen to smooth their driver plots rather heavily, like all manufacturers do (1/3 - 1/2 octave is usual: 1/9 octave is nowhere near sufficient to sell drivers.)
As for trying to measure damping, you'll want to be measing cabinet (i.e vent) output & look for unwanted harmonic resonances. If there are any, it's not sufficiently damped.
TBH, the more important thing is whether you enjoy the sound. If you do, it doesn't matter one jot what a graph says.
You can see a degree of step-loss coming in from about 480Hz, give or take, due to the cabinets being a ways out from the wall -moving them back will lower that somewhat. The rest is simply the driver's own response. You can actually see the peak you mention at ~2.5KHz in the driver plot Fostex provide. It's just that they happen to smooth their driver plots rather heavily, like all manufacturers do (1/3 - 1/2 octave is usual: 1/9 octave is nowhere near sufficient to sell drivers.)
As for trying to measure damping, you'll want to be measing cabinet (i.e vent) output & look for unwanted harmonic resonances. If there are any, it's not sufficiently damped.
TBH, the more important thing is whether you enjoy the sound. If you do, it doesn't matter one jot what a graph says.