A funny comparison of 2 full rangers

[zacster]

A few years ago, maybe 5 or so going by the google search, I built a pair of Metronomes out of cardboard and used Radio Shack 40-1041 drivers. These are 5" full range drivers, 86db by the spec, but I never could find a full TS parameter listing for them. These drivers cost $10 for the pair. The metronomes were built to a FE-126e driver spec as this was the same size. It was a totally unscientific approach to building them. I used cardboard from the TV I just bought, and lots of packing tape. They sounded OK considering the build, produced a bit of bass and rattled like crazy. But the surprising thing was the vocal range, they really could sing. There were dips and peaks all over the place but still sounded OK. It was an hour or 2 of work.

Just 2 weekends ago my wife was cleaning up the room where I had put them, unused for a few years. She asked if I still wanted them and I figured I could take them apart and throw away the boxes. I hooked them up for one last listen and was still surprised at the sound. I even left them hooked up for a couple of days on my main system.

Last week I saw an ad on the swap meet forum for the FE 126e that my "cabinets" were originally designed for so I grabbed them. They arrived yesterday and I put them into the cabinets tonight while my kids watched "Glee". They had the same hole pattern so it was really easy. When I was done the first thing I noticed is how much louder they play with my 6B4G PP tube amp. But the other thing I notice is the vocal "shout" and a total lack of bass. They just didn't sound good, even anywhere near as good as the cheap RatShack drivers I have, in the same "cabinets". One thing they didn't do was rattle, but maybe that's the lack of bass. I was thinking too that since they are used they are also broken in (not that I believe much in that, except that the soft speaker parts will definitely soften with use).

So my conclusions are these: The Radio Shack driver/Metronome combo would be a winner if properly built out of ply. The FE 126e needs a different cabinet altogether, and could possibly never be to my liking. I know there are a lot of builds of the Metronome out there with the 126, but I've never actually heard them. I've considered the Frugel Horns for them, but they are a lot more work than Metronomes. I could build the Metronomes for them and try it, and if I don't like it put the RatShack drivers in.

So, after all that, what do you think?

[Jim Shearer]

I have built three pairs of Mets: FE108eSigma, F120A, and FE167e. They all perform quite well. (Although as I have stated previously, the F120A drivers don't do well with direct coupled SS amps.)

I ran MJK MathCAD models of some other drivers; FE168eSigma comes to mind. I would not consider building Mets with either the FE126 or FE168 drivers. It seems to me that they are not suited to this style of enclosure. Seems like they belong in horns.

Cheers, Jim

[GM]

Yeah, the 126E's Fs is much too high for any bass or even good mid-bass without at least a short horn loading them down to ~60-80 Hz depending on room loading.

GM

[Squeak]

Regarding cardboard, I've sometimes wondered if you could make an enhanced open baffle by mounting the driver on a large piece of cardboard glued to a starshaped frame, to kill the ripples at the edge (Manger style). That would give you an el-cheapo ripple action bipole. With a bit of tweaking, maybe it could work?

[Godzilla]

Going from cardboard to wood cabinets will make the sound better. But this also shows that price isn't always a determining factor when it comes to musical enjoyment. I have a few cheap drivers that sound excellent. Dayton, Radio Shack and NSB's to name a few. In BIBs the cheaper Fostex 165 sounds better to me than the more expensive 168s (older style with whizzer).

[zacster]

I have some wood flooring that is 8" wide and I'm thinking I can make cabinets from that. It may not be ideal material, but I already have it. It is basically 5/8" plywood with a thick 3/16" oak veneer on it. The back plies were not great though.

[phivates]

By all means use what you have, especially when it sounds like something really good. It don't have to be Baltic, know what I'm sayin?

[zacster]

I plugged the Fe 126e cardboard boxes back in and my wife gave an immediate thumbs down. She hasn't commented much on things in the past, and even sort of liked the Radio Shack speakers in the same boxes.

The biggest problem with using the wood that I have is that I'd better finish the floor that it was meant for first. I never did the closet. It would go a long way towards WAF. At least I have plenty for both.

[pjanda1]

I picked up a pair of Radio Shack 6"ers, don't remember the model, NIB in a used video game store (I don't buy video games, but they had the speakers in the window!). Their first enclosures were cardboard OBs made from boxes from Ikea ottomans. GM had some TS specs, and I ended up putting them into sealed boxes. They sounded awfully good. They had a fairly high Q., and in combination with the high VAS, they needed a box size on par with the BetsyK. That was their main downfall for a smaller, lower efficiency speaker. But, folks interested in an inexpensive fullranger should keep their eyes peeled for the old RS drivers. They're out there, sometimes in weird places!

Getting a fullranger to sound decent isn't terribly complicated and doesn't take fancy parts. I discussed this about in my "new cone" post down on my forum, but people often get wrapped up in a bit of marketing speak about a material when they should be concerned about the basic shape of the frequency response you'll get in your system. I say this, because I bet you'd be much happier with the 127. It still wouldn't have a a ton of bass, but the lack of shorting ring would flatten the highs. I bet your "shout" would be much reduced.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[GM]

Originally Posted by Squeak

Regarding cardboard, I've sometimes wondered if you could make an enhanced open baffle by mounting the driver on a large piece of cardboard glued to a starshaped frame, to kill the ripples at the edge (Manger style). That would give you an el-cheapo ripple action bipole. With a bit of tweaking, maybe it could work?

The star pattern would have to be random within a limited frame of ratios to average out its eigenmodes. Better to just offset the driver on a tapered baffle to make a DI-pole.

WRT using any lossy baffle material, it theoretically shouldn't be considered until the driver's Qts exceeds 0.5, then choose an increasingly lossy material with increasing Qts until at a 2.0 Qts, no baffle is required, just a driver loosely suspended in space.

GM