Altec 605 duplex speakers

[allboys]

Can anyone give me an approx. value to a pair of Altec 605 duplex 15" speakers? There is no initial after the 605. They're clean and have been mounted in the same cabinets their entire life. Any information would be greatly appreciated. By the way, the cabinets are not Altec so I am only looking for a value of the speakers themselves. Thanks !!

[thevott]

Probably somewhere between $500 and $1500 for the pair.

MP

[speakerdave]

Originally posted by thevott
Probably somewhere between $500 and $1500 for the pair.

MP

Maybe squeak into the low end of that range.

The 605 is not a 604. It's a less expensive speaker based on the same general principles. If you do a search on the Lansing Heritage website I think you will find in the historical accounts a piece on this speaker that says it was the speaker that may have helped set Altec's fortunes on a downward course because customers who bought it as a substitute for the 604 were seriously disappointed with the sonics. That kind of blunder in customer relations within a professional market gets remembered for a long time.

I have spec sheets on the 605B and the 604E. The magnet weights on the 604 are about double those on the 605, resulting in field intensities which are about 20% greater. One of the results of these differences would be that the 604 would have better high frequency extension in both the tweeter and woofer; this second is important when a fifteen-inch cone is being crossed over at 1500 or 1600 Hz. Assuming moving masses the same in both low frequency sections there would be better cone control in the 604 and so better low frequency fidelity. Also, in the rating methods of the day (mid 70's) the 605B is spec'd at 97 dB and the 604 at 101 dB.

These are all important differences and I believe are the reasons the 604 is a valued classic.

The price range suggested is the range of the 604, in my experience. I doubt the 605 would achieve it.

Regards,

David

P.S. Here is the URL on the history I mentioned: http://audioheritage.org/html/history/jbl-pro/1960s.htm

[thevott]

Thank you for expounding on the subject. I did not, however, place the 605 in the same range as the 604. I simply stated what I have seen them yeild. 604s sets occasionally go for as much as $2000 or more.

MP

[speakerdave]

I hope I wasn't expounding, but maybe I was.

I've never seen 604's go for $2000, though it is conceivable. I've never seen 605's go for anywhere near $1500, and if they have, I think someone has made a serious mistake.

I think the 605 is pretty unusual. I only recall seeing a few pairs on eBay and didn't particularly follow them to the auction end.

I just thought it was important to get that information out about the 605 because readers of this forum may not be aware of the distinction between it and the 604.

I have extensive experience with the 604, but have not heard the 605--so I'm not making any statement about that, except to pass along what I've read.

I've just expressed an opinion, but I've backed it up with some information. This is the thought process I would follow if I were thinking about buying. The 605 may be a viable option for a lot of people, depending on what the price is. I think it's important for people to be aware that it is not the same as the 604 in either performance or value.

Regards,

David

[allboys]

I think I like MP's valuation better :-) of course. I appreciate both of you responding and being very informative.

[speakerdave]

I've done some poking around on the web and see that the distinction between the 605 and the 604 is being blurred in many places, including sites offering the Mastering Lab crossover schematic as if it were equally useful for both. I question that, but what the hey. People can buy what they want.

There might be another distinction worth making. You say your 605 has no letter after it. If they are an earlier version with the green frame and integral stiff paper surround they will be quite a different animal from the 605B and may appeal to a special niche market for use with small tube amps, but I'm getting beyond what I can say with certainty.

Anyway, good luck with them.

David

[johnaec]

How about these at $1575/pr with 15 minutes left on eBay!

1955 RCA LC-1A (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3078682278&category=50597)

[speakerdave]

One for Romulus, one for Remus.

[Steve Mac]

I own a pair of 605B duplex speakers.

It's definitely true that the introduction of the 605 was a huge tactical/marketting error by Altec. But what is not true in my opinion is that the 605B is inferior sonically to the 604E. The mistake Altec made was in not realizing that they had developed maybe the first real audio reference standard for recording studios. The Yamaha NS10 until recently has been the studio reference standard for years and there is nothing special about it other than you can make consistent sounding music remarkably well with them. Sticking a speaker with a smaller magnet structure in the same cabinet and plopping it in a studio that has been mixing and recording music on the 604 for 10 years is in retrospect sheer madness...and well they paid the price for it.

But think about it, was the 605 worse sounding? maybe, maybe not...but is a 99db sensitive speaker inferior to a 103dB or whatever the number is better? no, not by definition...only more sensitive to current flow. A bigger magnet may be a worse sounding speaker or even overkill depending on the implentation. Would a speaker with 106dB sensitivity be superior to the 604E...again no..not by definition. The truth is, both speakers are remarkably sensitive and both have relatively large magnet structures. Does the advent of more powerful, reliable and more stable power amplifiers make sensitivity an overriding issue. I think the answer to be no within reason.

The Q of the 605 speaker is lower than the 604 because of the magnet size, offering more low frequency response. But that doesn't make it better sounding by itself either in my opinion.

I've heard both speakers and in my opinion they are both grand, beautiful sounding speakers. I think that the knock that the 605 took was because of marketting idiocy and because of this it is one of the most misunderstood and underrated speakers ever designed. It will probably become extremely collectible someday what with the number made.

Just my opinion but I think they may be one of the most underrated speakers out there.

[tom1356]

I own a pair of 605B duplex speakers.

big snip...


Just my opinion but I think they may be one of the most underrated speakers out there.

What a first post. I wish I made a product you liked. You would have a job as an ad copy writer.

Well said.

[tgroendahl]

Hello!

Recently I was lucky to win an eBay auction on a pair of Altec Duplex 605B´s.

So far I have only enjoyed the sweet sound of the hf-horns in combination with my recent set-up; 1952 German "Klangfilmstyle" 12" alnico drivers that are mounted in large backloaded horns.

The hf presentation, now only filtered by a 5uF PIO phenolic paper encased capasitor (Jensen) and a few carbon resistors, is very natural and musical.

I hope to have enclosures constructed during easter. Just can´t wait to experience the whole "Duplex sound".
Plan to make the Jeff Markwart 605 x-over: http://home.earthlink.net/~jmarkwart/

I will probably experiment with the an "aperiodic" cabinet, by making a 2.5 feet wide x 3.5 feet tall x 1 foot deep enclosure, with needle thin holes drilled in the backpanel in order to obtain "controlled leakage" instead of a BR.

Does anyone have experience with this sort of cabinet?

I only play vinyl on an EMT 930 + 2A3 SE amp.

Best regards,
Thomas