[Johnaki]

Does anyone know where I can get plans for Metronome?

Thanks, John

[JCS]

http://www.frugal-horn.com/metronome.html

Cheers,  Jim

[planet10]

There are only example Met plan drawings for a few mets. The tables give the key numbers to create drawings for other drivers. If your driver is notlisted some helpful soul may derive some numbers for you (note that the FH.com table does not have a complete set of already derived Mets). Best place to ask is here: http://www.diyaudio.com/forums/full-range/85410-metronome.html

dave

[Johnaki]

Thanks all,

From what I've read I'd like to try the fe167e version.  My wife and I have been rebuilding a vintage wooden sailboat and we've got some nice marine ply that we can use for the speaker build.  First, though, I'd like to practice by doing an inexpensive Metronome build for speakers to use in my wood shop.

Any suggestions for a cheap driver that would work with Metronome -- and where to purchase.

Thanks,

John

[planet10]

fe167e version

FE167e has been discontinued for something coming on 3 years. FF165wk is the spiritual replacement. And probably overall a better driver.

dave

[Guy 13]

Hi Johnaki and all Audio Circle members.
Can this help?
http://frugal-horn.com/metronome-table.html

Guy 13

[JCS]

Hi John,

If you want a modestly priced driver, small driver, I can recommend Fostex FE103en. 

http://www.madisoundspeakerstore.com/approx-4-fullrange/fostex-fe103en-4-full-range/

It won't play loud.  It won't make deep bass.  It is a really sweet driver and doesn't have the peakiness of some other Fostex drivers.

You can used the plans for the FE108eS on the site I listed above.  The alignment isn't perfect, but it's close enough.  I know because I built a pair of 108 Mets, then later wanted to get my ears on the 103; so I put the 103 into the 108 cabinets.  The 103 loses about 10 Hz off the bass, but with either driver you really need a sub anyway.

It's a good idea to try a smaller Met first, as you learn about constructing an oddly shaped cabinet.

Three pieces of advice:
-- line the back only!
-- make the port baffle removable so you can get inside to tweek (if needed)
-- I use BSC of 1 mH air core inductor and 4.5 ohm Mills resistor

One more item.  I also built FE167e Mets and like them too,  but the new FF165wk is an even better choice!

Cheers,  Jim

[Johnaki]

Hi Johnaki and all Audio Circle members.
Can this help?
http://frugal-horn.com/metronome-table.html

Guy 13

Thanks Guy,

Yes, I've been pouring over those numbers.  I'm a wood worker with a full shop.  I feel pretty positive about the actual build -- it's pretty easy.  However, the numbers ar making my head spin.

I've decided to go with the plans for the Fostex FE127e because they are so detailed.  I'm going to change the numbers to use the Fostex FE126e for the higher sensitivity rating.  I'll be using a 2wpc SET amp and the higher sensitivity FE126e's should, in theory, make a difference.  The only difference, other than the sensitivity seems to be that the FE126e's are not shielded.  I don't think I'll need that in my listening room.

Another question I have is whether or not to use solid wood or ply.  I mentioned I have some marine grade ply that I could use for the build.  However, I have an Alaska Chainsaw Mill and I've probably got a couple thousand board feet of Cherry, Walnut, Spalted Sycamore and Ash stickered and air dried behind my shop.  I've got to start using it for something, so this seems like a good use for it.  Is there any reason not to use the solid wood for a speaker build?  It seems that most use ply.

Thanks for all the help.  I can use any suggestions.

John

[JCS]

Hi John,

I would stick with plywood rather then solid lumber.  There is a risk of splitting with solid lumber.

I wouldn't put the FE126en in a Met.  Not a good choice of driver for an MLTL.  I think you would do much better using the FF125wk.  Look at Dave's reference to find a Met using FF125wk-- IIRC, it was by AmedeusMozart.

Cheers,  Jim

[Johnaki]

Hi John,

I would stick with plywood rather then solid lumber.  There is a risk of splitting with solid lumber.

I wouldn't put the FE126en in a Met.  Not a good choice of driver for an MLTL.  I think you would do much better using the FF125wk.  Look at Dave's reference to find a Met using FF125wk-- IIRC, it was by AmedeusMozart.

Cheers,  Jim

Thanks Jim,

I'm pretty familiar with the cracking problem.  I've done some musical instrument and boat building with solid wood.  My wood is pretty stable at this point as its been air drying for years.  Certainly ply will be more stable, but I think the indoor environment that these speakers will be living in and proper care should keep any problems at bay.  I was, mainly, wondering if there were acoustic problems with using the solid wood.

The FE125wk looks like a good choice, but I wonder about using it with a 2wpc SET.  I'm new to this.  Why would the FE126e be a poor choice?

John

[Johnaki]

Thanks for all the good information.  Being new to this, it really helps.

Is there a preference for the kind of glue that's used?  I've used Hide Glue when making dulcimers in the past.  I like working with epoxy also.  Does it matter what kind of glue?

Thanks,

John

[JCS]

Hi John,

The FE126en has T/S parameters which indicate it is best used in a BLH.  If you want to use the FE126en, I can recommend the Frugal-Horn Mk3 which you can link to through Dave's (P-10) site.  The sonic presentation will be very much like the Metronome.  It's just shorter and deeper.

With only 2 wpc and 89 to 90 dB sens. you will be limited in SPL and won't want to play anything with large amounts of bass.  I have tried a 2.5 wpc tube amp on my F120A Metronomes (89 dB sens.). They do OK at moderate volumes as long as there isn't a lot of bass--great with jazz & folk; but if your wife starts playing Enya, you will be limited to about 70 dB, as there is a great deal of synth bass in there--something most folks may not even realize, as they don't have speakers capable of reproducing 20 Hz; but whether your speakers can produce usable output down there, your amp is trying to pump out the signal.

I am currently working on a project with the FF225wk which is 93 dB sens.  If you want parameters for a 225 Met, I could help with that.

RE: glue: probably doesn't matter as long as it holds well enough.  I used Elmer's Wood Glue.

Cheers,  Jim

[Johnaki]

Thanks Jim,

I take it from your previous post that the FE165wk would be a good choice.  It's also 94 db sens. The chart Guy mentioned doesn't have the numbers for that driver.  Do you know where I could find them?

Thanks,

John

[JCS]

Hi John,

Let me check and see if it works in the cab for the FE167e. 

Cheers, Jim

[planet10]

FE165wk would be a good choice.... The chart have the numbers for that driver. 

http://www.diyaudio.com/forums/full-range/85410-metronome-88.html#post2708879
http://www.diyaudio.com/forums/full-range/85410-metronome-96.html#post2898754

I wouls suggest plywood for the 1st build (just like cookies you won't be able to stop at 1 )

dave

[Johnaki]

http://www.diyaudio.com/forums/full-range/85410-metronome-88.html#post2708879
http://www.diyaudio.com/forums/full-range/85410-metronome-96.html#post2898754

I wouls suggest plywood for the 1st build (just like cookies you won't be able to stop at 1 )

dave

Thanks Dave,

Another question, is there an optimal thickness to the wood if I go solid wood?  Like I mentioned earlier, I've got a lot of wood that I really need to start using.  It's mostly 5/4 thickness that I mill to any size I want. Also, is there a preferred wood?  I've got a lot of Walnut, Cherry, Ash, Maple and Spalted Sycamor.

John

[JCS]

Dave,
Looks like you have a better memory for what I've done than I do! 

John,
Looks like you're good to go.  Keep us poster on you progress!

Cheers,  Jim

[Johnaki]

Dave,
Looks like you have a better memory for what I've done than I do! 

John,
Looks like you're good to go.  Keep us poster on you progress!

Cheers,  Jim

Thanks guys,

I won't be starting real soon as my wife and I are finishing up a classic cruising sailboat for a summer cruise.  However, I'll be going out to the wood stack to pick some wood for the build.  Ill keep it in the shop for awhile so the moisture content will stabalize to my shop.  I'm thinking some combination of Cherry and Spalted Sycamore would look good!

John

[Guy 13]

Hi Johnaki and all Audio Circle members.
I did a quick search on Google for Spalted Sycamore.
Wow that wood is really nice, if it was me, I would gor for that kind of wood and it would make your metronome enclosure one of a kind, unique and awesome...
I hope I will see some good high quality pictures of that project.

Guy 13

[Johnaki]

Hi Johnaki and all Audio Circle members.
I did a quick search on Google for Spalted Sycamore.
Wow that wood is really nice, if it was me, I would gor for that kind of wood and it would make your metronome enclosure one of a kind, unique and awesome...
I hope I will see some good high quality pictures of that project.

Guy 13

Thanks Guy,

I went out to the wood stack tonight to look for some Sycamore.  I found some, but it wasn't the Spalted.  It is interesting wood.  I cut some real nice Spalted Sycamore this year, but it'll take a year or so to dry.

I'll definitely take some pictures of the build.  Right now my wife and I are finishing up a rebuild of a 1952 classic wooden cruising boat.  It'll go in the water on June 21.  So, we're pretty busy with that.  We're going to circumnavigate Lake Michigan and that will take most of the summer.  I'd like to have the enclosure and driver picked, along with the wood put up in the shop before we go so I can start right in when we get back.

John