We used the Metronomes as a demo for a trade show -- to demonstrate the on-pass coating on a somewhat complex surface -- but figured that few would have the interest in fabricated cabinets. You need about 100 sets to make it economic, they take a lot of space to store and with working cap investment etc...
An externally hosted image should be here but it was not working when we last tested it.
Just so you know--
The Yamaha has a ridiculously high DF; 1000 IIRC, but the Sansui is no slouch either at 400. So both are low output impedance and high DF. (I think by the time you get out to the driver, the difference between DF=1000 and DF=400 is a moot point.) And I still have no idea how the DF would affect the highs. I understand very well that lows can be seriously affected by the DF, but in all cases, the lows are just fine, thank you very much.
And in case someone is wondering about the speaker wire: I started using CAT5e after listening to Martin's home-brew CAT5e cables which he brought along with the tube amp. Dirt cheap and high performance. DIY at its finest!
Cheers, Jim
YIKES!
It took uhmmm, *quite* awhile but I actually read through every post in this page. I think that sort of perseverance must mean that I see a pair of mets in my future.
I have two 4'x8' sheets of pretty nice 3/4" 11 ply just waiting to be made in to something. My current available drivers are Audio Nirvana Super 8s. I'd like to try and make a pair of mets for these, unless they are completely unsuitable? I like the sound they have been making as they have been breaking in in CSA's "2.8mkII" BR but would like to try something a bit more "tuned" for this specific driver. Has anyone ran the numbers on this driver for mets? If not, would someone please recommend the right numbers?
I also wonder, if I make a pair of metronomes for the AN super 8's, are there more recommended drivers that might fit the same enclosure should I choose to upgrade a bit down the road? I'm also considering modifying the base plate so that it could easily be interchanged with a different one to accommodate a very different port arrangement, should a different driver be used. Also considering this build with a suprabaffle, both to reduce the amount of blockage the ANs8's huge magnet assembly might provide to the tuning and also to better facilitate a different driver down the road...
If these will work in a met what are the recommendations for a suprabaffle for the same?
Thanks in advance!
PS I have a few options for amplification including a Sonic Impact T-Amp Gen.1, Dayton DTA-D100a (t-amp), a Yamaha M-65 (bipolar SS with a neat "pure class A" mode at low output), BIAMP Emminence 300 (150wpc@4ohm SS with MOSFET) and a couple of vintage integrated units floating around.
It took uhmmm, *quite* awhile but I actually read through every post in this page. I think that sort of perseverance must mean that I see a pair of mets in my future.
I have two 4'x8' sheets of pretty nice 3/4" 11 ply just waiting to be made in to something. My current available drivers are Audio Nirvana Super 8s. I'd like to try and make a pair of mets for these, unless they are completely unsuitable? I like the sound they have been making as they have been breaking in in CSA's "2.8mkII" BR but would like to try something a bit more "tuned" for this specific driver. Has anyone ran the numbers on this driver for mets? If not, would someone please recommend the right numbers?
I also wonder, if I make a pair of metronomes for the AN super 8's, are there more recommended drivers that might fit the same enclosure should I choose to upgrade a bit down the road? I'm also considering modifying the base plate so that it could easily be interchanged with a different one to accommodate a very different port arrangement, should a different driver be used. Also considering this build with a suprabaffle, both to reduce the amount of blockage the ANs8's huge magnet assembly might provide to the tuning and also to better facilitate a different driver down the road...
If these will work in a met what are the recommendations for a suprabaffle for the same?
Thanks in advance!
PS I have a few options for amplification including a Sonic Impact T-Amp Gen.1, Dayton DTA-D100a (t-amp), a Yamaha M-65 (bipolar SS with a neat "pure class A" mode at low output), BIAMP Emminence 300 (150wpc@4ohm SS with MOSFET) and a couple of vintage integrated units floating around.
coral holey baskets
Hi all,
I am building a pair of original size metronomes, out of 12mm ply, for my coral holey baskets speakers (same size driver) and I just need to know how much acoustic tile to put on the back panel??
thanks Phill
Hi all,
I am building a pair of original size metronomes, out of 12mm ply, for my coral holey baskets speakers (same size driver) and I just need to know how much acoustic tile to put on the back panel??
thanks Phill
You might find that the arcam has a less than ideal output impedance. Very skinny speaker wire may help. A good place to start is some solid core CAT5 strands (a single pair)
dave
dave
To make the best use of all components would I be better off building a lower sensitivity system, say an mtm config TL or something, or is the metronome still a good choice, even with skinny wire?
You should probably read Nelson Pass' article on single driver speakers and current source amplifiers. http://www.passdiy.com/pdf/cs-amps-speakers.pdf
Adding resistance (using wire with somewhat higher resistance) changes the damping, or "Q" of the system.
Thanks for the link. I think I understand it... so It sounds like by using thin speaker wire or putting a resistor in parallel with the driver I can mitigate some of the disadvantages of using a voltage source amp with these kind of drivers. To be honest the mechanics kind of elude me.
But from experience do these speakers still sound good like this? Would I be wasting such a powerful voltage source amp on these speaker designs.
Would I be better running the mets of something like a t amp(though I am assuming this has the same issues as it is a voltage source amp as well) and using the arcam for something else, or just stay away from these full range speaker designs until I can get myself a valve current source amp?
Also are all pentode and triode valve amp designs current source? Where can I read about this(wikipedia has failed me again)?
I think I may end up regretting getting such an expensive SS amp when I wanted to build full range speakers.....
Sorry if this constituted highjacking the thread... I can move it elsewhere if needs be/
But from experience do these speakers still sound good like this? Would I be wasting such a powerful voltage source amp on these speaker designs.
Would I be better running the mets of something like a t amp(though I am assuming this has the same issues as it is a voltage source amp as well) and using the arcam for something else, or just stay away from these full range speaker designs until I can get myself a valve current source amp?
Also are all pentode and triode valve amp designs current source? Where can I read about this(wikipedia has failed me again)?
I think I may end up regretting getting such an expensive SS amp when I wanted to build full range speakers.....
Sorry if this constituted highjacking the thread... I can move it elsewhere if needs be/
Powerwise it is certainly overkill. 100W when 10 or 20 would do. But (likely) even giving up some finese for the power it is still a decent amp.
dave
Well that is handy, as an IT geek I can get cat5 pretty much free, and even if I did have to buy it it is a hell of a lot cheaper than "audiophile grade" speaker wires...
For our purposes, a voltage source amp is one with low output impedance and a current source is an amp with high output impedance. In theory, we talk of zero and infinite (respectively), but in our world 16 ohms of output impedance might be high enough, compared to the speaker, to give the effect we want.
Take a look at the impedance plot for the driver. In a current source style of amp this curve will have an influence on the drive reaching the speaker. To cut a long story short the frequency response begins to take on the shape of the impedance plot, and as you can see it has curves in all the right places 😀
Don't put the resistor in parallel use it in series. Start with something of a couple of ohms and go up if desired. You can trial this on just about any amp as long as it has the voltage available.
Munga - good wire doesn´t improve lousy drivers. When the legs are something that makes you drool a miniskirt gets you going.
HiFi nuts riding on the wave of gazillions of miles of CAT5 made for the communications industry.
dave
Is it really once any series resistance from tiny wire and/or BSC is factored in? Then there's the lower mids dynamic headroom required for some recordings and a 100 W can be too little even with fairly efficient speakers.
GM
Metronome with TangBand W4-1337SD
Hi guys
I have 2 sweet sounding TB W4-1337SD that are laying around and some extra lumber.
Would they suitable for metronomes?
If yes what would be the dimmentions?
Here are the specs:
Qes 0.49
Thanks
Hi guys
I have 2 sweet sounding TB W4-1337SD that are laying around and some extra lumber.
Would they suitable for metronomes?
If yes what would be the dimmentions?
Here are the specs:
NOMINAL IMPEDANCE
8 W
DCR IMPEDANCE
6.8 W
SENSITIVITY 1W/1m
87 dB
FREQUENCY RESPONSE
70-20K Hz
FREE AIR RESONANCE
70 Hz
VOICE COIL DIAMETER
25.4 mm
AIR GAP HEIGHT
10 mm
RATED POWER INPUT
25 W
MAXIMUM POWER INPUT
50 W
FORCE FACTOR, BL
5.37 TM
MAGNET
Neodymium
MOVING MASS
4.61 g
SUSPENSION COMPL.
1053 uMN-1
EFFEC.PISTON AREA
0.0057 M2
Levc
0.015 mH
Zo
28 ohm
X-max
3 mm
Vas
4.86 Litr.
Qts
0.37
Qms
1.51
Qes 0.49
Thanks
Built some metros using Audio Nirvana Super 8"! Thanks for all your help guys (you know who you are) and to everyone else that has inspired me through their own builds and shared war stories 🙂
Sorry for the cruddy photos... spending money on lumber instead of a good camera!
These are NOT an "easy" build, especially if you don't already have the right tools, lots of patience and at least some experience with woodworking.
A few tips that I've learned from my experience that might help someone else:
As said elsewhere in this thread forget all about that nice table saw unless you are equipped to do *straight* diagonal rips in full sheets of 4x8! A skillsaw can be used... I've actually gotten pretty good at "freehand" ripping a pencil line... a guide (I bought an aluminum 100" for $25) using even just a very straight 2x4 and some good clamps *can* be used, but as I learned even a saw you think is pretty straight can show it's failings when trying to follow a guide 96" long! Buy a new saw or learn to freehand! I picked option #2.
Use the best wood glue you can find! I chose close to a pint of Titebond III, "The Ultimate Woodglue", for around US$14. A little goes a long way and if applied correctly this stuff has such a tight bond that the wood will break before the joint does. Make sure you have plenty of clamps (I have 10 and wish I would have had another 4 or 6) or at least a good screwgun and some good drywall screws that can hold stuff together until the glue dries.
A jigsaw with the skinny wood blades... This came in essential in cutting out circles for the port, baffle, brace holes and just minor trimming elsewhere.
Best tool to have at hand: I vote for a decent router with a "flush trim" bit! After cutting all my panels (freehand, mind you), clamping them up to a factory cut edge and then using this router bit to trim away any warbles worked great! It took awhile and I snorted plenty of sawdust but I eventually ended up with a stack of panels that matched very closely (albeit the sides in my build are narrower than the front/backs).
Second best tool: the hot glue gun I bought at a yard sale that came with a bucket of extra sticks! Not only did I put a nice, thick bead of hot glue along all the inner seams (as far as I could reach, anyway) but I also used it in place of screws to build the bottom framework out of 1"x1" that would later allow me to screw a removable (and gasketed) base plate for ease of access or in case I want to try different ports. This also came in quite handy trying to get the top cap air tight! The top cap of these cabinets is probably the most difficult part of the project to cut correctly with a nice "wood to wood" fit. A thick bead of hot glue squished with the use of a drywall screw at each corner assures me that even if the top cap in my build isn't a perfect fit that at least it's air tight!
Sorry for the cruddy photos... spending money on lumber instead of a good camera!
These are NOT an "easy" build, especially if you don't already have the right tools, lots of patience and at least some experience with woodworking.
A few tips that I've learned from my experience that might help someone else:
As said elsewhere in this thread forget all about that nice table saw unless you are equipped to do *straight* diagonal rips in full sheets of 4x8! A skillsaw can be used... I've actually gotten pretty good at "freehand" ripping a pencil line... a guide (I bought an aluminum 100" for $25) using even just a very straight 2x4 and some good clamps *can* be used, but as I learned even a saw you think is pretty straight can show it's failings when trying to follow a guide 96" long! Buy a new saw or learn to freehand! I picked option #2.
Use the best wood glue you can find! I chose close to a pint of Titebond III, "The Ultimate Woodglue", for around US$14. A little goes a long way and if applied correctly this stuff has such a tight bond that the wood will break before the joint does. Make sure you have plenty of clamps (I have 10 and wish I would have had another 4 or 6) or at least a good screwgun and some good drywall screws that can hold stuff together until the glue dries.
A jigsaw with the skinny wood blades... This came in essential in cutting out circles for the port, baffle, brace holes and just minor trimming elsewhere.
Best tool to have at hand: I vote for a decent router with a "flush trim" bit! After cutting all my panels (freehand, mind you), clamping them up to a factory cut edge and then using this router bit to trim away any warbles worked great! It took awhile and I snorted plenty of sawdust but I eventually ended up with a stack of panels that matched very closely (albeit the sides in my build are narrower than the front/backs).
Second best tool: the hot glue gun I bought at a yard sale that came with a bucket of extra sticks! Not only did I put a nice, thick bead of hot glue along all the inner seams (as far as I could reach, anyway) but I also used it in place of screws to build the bottom framework out of 1"x1" that would later allow me to screw a removable (and gasketed) base plate for ease of access or in case I want to try different ports. This also came in quite handy trying to get the top cap air tight! The top cap of these cabinets is probably the most difficult part of the project to cut correctly with a nice "wood to wood" fit. A thick bead of hot glue squished with the use of a drywall screw at each corner assures me that even if the top cap in my build isn't a perfect fit that at least it's air tight!
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Agreed. CNC makes life so much easier.
Proper tools? Take a look at the work of Tilman Reimenshschneider if you want to see how to spin some woodworking.
