Altec 418B: open or closed back cabinet?

Cliff Kane · From: the late great golden state

Hi folks,
I have an Altec 418B speaker that I would like to put into a cabinet. Will this speaker sound and work best in a closed back cabinet or an open back cabinet? I've never played through a 418B. This speaker will be used for steel guitar and standard electric guitar.
Any preferences on what way to go with the Altec?

Thanks!
Cliff

Jim Dickinson · From: Washington, USA

I grew up working in my family's sound company, our main line of product was ALTEC Lansing, if you cut me I'll still bleed green. I am using a 12" 417 with my Dual Pro, although I am a beginner, I love the transparancy of the Altec speakers.

From my experiece, a 418 likes a closed box better than an open back, although that can be up to what you want to hear. I just ran the Win ISD box prgram on a 418, it says inside volume, of 2.55 cubic feer plus .25 for the speaker will get you flat to about 75Hz, plenty for your use. Says to tune it to 65Hz, use abour a 4.5 inch round port or equivilent. Win ISD is a free shareware program, works well.

I would not go under about two cubic feet, less volume will produce less bass, although you have to decide what you need. I have seen then in boxes as small as a cubic foot.

The 418 is a quick nicely behaved speaker, it will be some faster than a JBL D130 with a more detail. I sold quite a few to steel guitar players years ago, they liked them.

Jim

Cliff Kane · From: the late great golden state

Jim,
thanks for this great info. This is very helpful. Much appreciated.

Cliff

Larry Bell · From: Englewood, Florida

I was very lucky to find a pair of 1970 Standel Custom 15 -- 120W amps. These are great amps, to be sure, but the thing I like best about them is the 418B speaker. Bob Crooks knew how to pick them. That little amp (lighter than a Session 400) does battle with Twin Reverbs on a regular basis and has very few battle scars. I believe that I would have blown D130s to kingdom come under the same conditions.

Naturally, these have open back cabs. I can't comment on how the 418B's sound in a closed cab. From Jim's expert comments, I now wonder how much better it could get. I think the bottom line for Cliff is that he has one of the best sounding, most responsive and robust steel guitar speakers I've ever used -- regardless of the cabinet. I've used every 15 inch JBL ever made for musical instruments and also all the Peavey BW's -- it don't get no better than the 418B, in my book.
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Lee Jeffriess · From: Vallejo California

Cliff, I have always used them in open back cabinets Standel, Rickenbacker, and a 54 Ampeg.
I liked it, I would imagine that a closed back would make a lot more bass.
Jim, the spec you give for the 4.5'' port, what would the cabinet specs be?
Crooks did a lot of RD at Standel concerning drivers they did at one point favor Stephens Tru Sonics, but I think they went to Altec for power handling.
My friend Tim Maag told me he had seen some Standel comparison data on 418 V's D 130, and there conclusion was the 418 was one Db at one Watt more efficient.
To my ears the Altec sounds more natural and musical.
Lee
BTW, Cliff make sure it has an Altec cone in it, if it doesn't get it over to Great plains audio in OK city, it will be the best money you ever spent.

Cliff Kane · From: the late great golden state

Lee: how can I tell if it's an Altec cone? It has a metal dome in the middle, and the number, 21353 3, is stamped on the back of the cone; the fame has the number, 391911, and a square with AL in the top half and 75 in the bottom half of the square, printed on it.

Thanks, guys!
Cliff

Lee Jeffriess · From: Vallejo California

Your good to go Cliff, thats a real Altec cone, and an early 418.
The manufactures code on the cone is correct it usually starts with 21, but I think I have seen the # s start with 22 as well.
Jim would probably have more info.
BTW, the 417 418 421 are all the same Parts, the only differences are the 417 has 12'' cone and the 421 has a ceramic magnet.
Lee

Cliff Kane · From: the late great golden state

Sweet! Thanks, Lee!

Fred Rushing · From: Odin, IL, USA

Anyone know where I can find a 418 or the 12 inch version that can be purchased? Thanks Fred

Tom Wolverton · From: Carpinteria, CA

Cliff - mount that baby up in a cab. and give us a full report. I'm interested in how you like it.
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Cliff Kane · From: the late great golden state

Thanks, Tom. Will do. I have a few options in mind. I'm eager to hear it, too. It was great meeting and talking with you at Jim's.

Cheers!

Lee Jeffriess · From: Vallejo California

Fred, sent you a PM.
Lee

Jim Dickinson · From: Washington, USA

Lee is right, that is an original Holly cone in the 418, later ones used an RDM cone, with a 35xxxx number. The 12" version is a 417, I am using one myself. The 417 and the 418 used exactly the same motor. The later ones used the newer frame and then even later ones used an improved but much heavier cast pot magnet structure tht looked like a round zigurat. The later 421 cones had the lower end of the cone dipped with a laquer to make it rigider for bass, 421s ought to work fine too, the magnetic flux density and the internal topology of the motors was the same as the 417-418. After the industry's wholesale conversion to ceramic magnets the last 417s and 418s, renamed 917-918 used the same magnet as the 421 (921). These got really heavy. Then there were the LF versions of these drivers, which had a soft bass cone which were used for bass drivers in PA and Monitor speakers.
In practice, the 417 is brighter and quicker than the 418, it has a smaller lighter cone and that's what happens, I personally like that.
The bad part of ALTEC being gone is that most have been reconed with non spec parts. The only place to get them fixed right is Great Plains Audio in Oklahoma City, he has the right pieces. The other main recone suppiler in the country has one 12" kit and one 15" kit for any ALTEC speaker, regardless of application.
For the clsed back cabinet, I calculated an internal size of 2.9 cubic feet, inclusive of the driver, with a round 4.5 inch port. One can arrange the dimensions to suit thenselves.
Have fun,

Jim

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