Nice work Jim. They look great! I guess you are not going for the curved sides? Are you going to make a large plywood bottom base to mount everything on top of? If you make the bottom plywood piece with an expanding curved rear horn, it's not too late to make the curved mouth. In any event I think it will still sound good. I noticed that you made a straight cut on the triangular back wing rather than curved. You are very close - almost ready to cap them. I would put stuffing in bend region behind driver and very very little directly under driver as that will attenuate the horn output. The wood fronts look fantastic though. I am really looking forward to getting some thing 1/4 in thick plywood to make facer baffles on mine after seeing how good yours look.
Very nice work and looking forward to first sound!
Your metronomes look great too! If I were to make a Metronome with a Vifa TC9FD, I am thinking of using my Accidental MLTL technique http://www.diyaudio.com/forums/full-range/231951-accidental-mltl-technique.html to size the enclosure base and top dimensios. From running WinISD for the FE108Sigmas, I think the TC9FD's can handle the 44 in high, I just have to adjust the volume based on a bass reflex.
Thanks for sharing.
X
Very nice work and looking forward to first sound!
Your metronomes look great too! If I were to make a Metronome with a Vifa TC9FD, I am thinking of using my Accidental MLTL technique http://www.diyaudio.com/forums/full-range/231951-accidental-mltl-technique.html to size the enclosure base and top dimensios. From running WinISD for the FE108Sigmas, I think the TC9FD's can handle the 44 in high, I just have to adjust the volume based on a bass reflex.
Thanks for sharing.
X
Hi X,
Thanks! The bottoms will be foam core. I went for straight lines so that if I get ambitious later, I will be able to cover the sides with veneer. Top will get another piece of 1/4" ply.
Those Mets were built a few years back when my wood working skills and tools were significantly more primitive than they are now. At the moment the FE108eS are still in their boxes after the Cornucopya experiment. The Mets have the FE103en in them now. Even though the enclosure isn't a perfect alignment for the 103, they are sounding very good. As with the 108, a sub is definitely worthwhile for many types of music.
Cheers, Jim
Thanks! The bottoms will be foam core. I went for straight lines so that if I get ambitious later, I will be able to cover the sides with veneer. Top will get another piece of 1/4" ply.
Those Mets were built a few years back when my wood working skills and tools were significantly more primitive than they are now. At the moment the FE108eS are still in their boxes after the Cornucopya experiment. The Mets have the FE103en in them now. Even though the enclosure isn't a perfect alignment for the 103, they are sounding very good. As with the 108, a sub is definitely worthwhile for many types of music.
Cheers, Jim
You can veneer curved surfaces - veneer just bends right? You are thinking ahead about covering these with wood if you like them and they are a keeper. Good planning.
I saw your post in the Met thread recommending the FE103's sounds like a nice lower cost option. You don't find them too shouty?
I saw your post in the Met thread recommending the FE103's sounds like a nice lower cost option. You don't find them too shouty?
Yes indeed. Sure-Ply scraps from the Cornucopya build. Don't know why, but Sure-Ply is cheaper & better looking than the hardwood veneered 1/4" ply that sits next to it at the local Lowes.
For finish I used some leftover Minwax Polyshades pecan color polyurethane. I decided to go a little darker than the clear polyurethane I have been using on the red oak (which I typically use).
Cheers, Jim
For finish I used some leftover Minwax Polyshades pecan color polyurethane. I decided to go a little darker than the clear polyurethane I have been using on the red oak (which I typically use).
Cheers, Jim
They’re finished! Photo below, again with the small Metronomes and Fonkens Prime for comparison.
Only about 10 hrs on the drivers, but they are sounding rather good. Listening to Miles Davis ‘Round About Midnight at the moment. Pretty good sound stage, smooth mids and decent highs. Instruments are well separated (articulated?). The ambiance of the venue is well presented. When listening to NPR news, you can hear the differences in microphones and environments as they change announcers and locations.
Are the Vifa TC9FD as good as the Fostex FF85k? Certainly not! But for less than $12 per driver, I’m plenty satisfied.
I have used BSC on many of my single driver builds, but none is needed here.
And they do produce bass. Got out my trusty Radio Shack SPL meter and Stereophile test CD. In room response at the listening position:
Hz dB
1K 70
200 66
160 63
125 67
100 69
80 68
63 63
50 65
40 62
31.5 51
While they do produce bass, it’s not what would call clean, articulate and powerful. I note that the enclosures vibrate rather severely--even the baffle. Not too surprising since they are foam core construction, and the baffle (while plywood) is very thin. I suspect that a proper plywood build would yield better performance and be well worth the time and expense.
Executive Summary: A fine speaker if you listen to jazz or small group type music at moderate SPL. If your favorite is Mahler’s 8th (Symphony of a Thousand), then think bigger, much bigger.
Mr. X: Based on this experience, I would say, don’t bother building a Metronome with the TC9FD. The FH3 style enclosure has the characteristics that I like in the Metronome. Probably not surprising, since the acoustic properties are so similar: long, tapered air column with the driver located near the mid-point, port near the floor (and not on the front), and baffle about as narrow as you can get. My thanks for posting the plans for this project!
Cheers, Jim
Only about 10 hrs on the drivers, but they are sounding rather good. Listening to Miles Davis ‘Round About Midnight at the moment. Pretty good sound stage, smooth mids and decent highs. Instruments are well separated (articulated?). The ambiance of the venue is well presented. When listening to NPR news, you can hear the differences in microphones and environments as they change announcers and locations.
Are the Vifa TC9FD as good as the Fostex FF85k? Certainly not! But for less than $12 per driver, I’m plenty satisfied.
I have used BSC on many of my single driver builds, but none is needed here.
And they do produce bass. Got out my trusty Radio Shack SPL meter and Stereophile test CD. In room response at the listening position:
Hz dB
1K 70
200 66
160 63
125 67
100 69
80 68
63 63
50 65
40 62
31.5 51
While they do produce bass, it’s not what would call clean, articulate and powerful. I note that the enclosures vibrate rather severely--even the baffle. Not too surprising since they are foam core construction, and the baffle (while plywood) is very thin. I suspect that a proper plywood build would yield better performance and be well worth the time and expense.
Executive Summary: A fine speaker if you listen to jazz or small group type music at moderate SPL. If your favorite is Mahler’s 8th (Symphony of a Thousand), then think bigger, much bigger.
Mr. X: Based on this experience, I would say, don’t bother building a Metronome with the TC9FD. The FH3 style enclosure has the characteristics that I like in the Metronome. Probably not surprising, since the acoustic properties are so similar: long, tapered air column with the driver located near the mid-point, port near the floor (and not on the front), and baffle about as narrow as you can get. My thanks for posting the plans for this project!
Cheers, Jim
Attachments
Jim,
Fantastic build! Looks great and I am glad that you like them. I noticed that you had fewer braces than I did (3 in the triangular section and 3 in the main section), this could be the reason why they vibrate. I don't have any vibration or rattle in mine. Anyhow, thanks for sharing the measurements. Thank you for trying them out and providing a "second opinion".
Congratulations!
X
Fantastic build! Looks great and I am glad that you like them. I noticed that you had fewer braces than I did (3 in the triangular section and 3 in the main section), this could be the reason why they vibrate. I don't have any vibration or rattle in mine. Anyhow, thanks for sharing the measurements. Thank you for trying them out and providing a "second opinion".
Congratulations!
X
This is exactly what Foam Core is for, and this was my feeling too after building these speakers. I want to build the real FH3's in wood with the proper driver. Although a miniature version in 1/4 in ply with FF85WK's may be kind of cute. I couldn't tell if you ended up curving the rear horn mouth outwards?
That is normal with almost all FC speakers - you can feel them vibrate. Didn't you feel the cornu's vibrate too?
X,
The Cornu didn't vibrate like these do. Probably because they had little going on in the low freqs. And then there was the hole in the upper bass... For whatever reason, the Cornu project didn't work out all that well. But that's why we use foam core, right?
Even if you add in the cost of the Cornu project to the $24 for the Vifas and $6 for the foam core here, the mini-FH3 is still a great bargain. And a bunch of fun as well!
Cheers, Jim
The Cornu didn't vibrate like these do. Probably because they had little going on in the low freqs. And then there was the hole in the upper bass... For whatever reason, the Cornu project didn't work out all that well. But that's why we use foam core, right?
Even if you add in the cost of the Cornu project to the $24 for the Vifas and $6 for the foam core here, the mini-FH3 is still a great bargain. And a bunch of fun as well!
Cheers, Jim