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Hello all
I'am looking to buy a pair of 604' but don't know which version to buy. Also have seen 904's that have been reconed as 604's, are these as good? The later G's seem like the best on paper but hearing is what it's all about. I've seen some E's local but I worry about the HF being extended enough. Thanks
toby
The subject of which 604 has been covered ad nauseam on this board and over on the Lansing Heritage board.
If you do a search on here for 604 you will get numerous topics.
Why restrict yourself to used, the new GPA ones are available.
I don't know why you are worried about HF from an E. Plenty there, and remove the loading cap if fitted for more.
The GPA 604-8H-III has an extended upper end that is unmatched in any other 604, and it's usable, not just measurable:
http://www.greatplainsaudio.com/604_...eqResponse.jpg
FWIW, while this is an impressive looking response, getting it nominally flat just on axis isn't in today's marketplace, it's how flat off axis that sells it, so when can we expect polar plots or at least the typical 15, 30, etc. degree off-axis overlays?
GM
Well since FR graphs are being posted ( & an off-axis was requested ) ;
Here's a collage I created ( some time back ) showing the effects on FR when the ( first blue ) Urei horn was substituted for that of the stock 604-8G ( egg-crate ) type .
The original response of the 8G is the ( hard to see ) black dotted line .
http://www.hostboard.com/forums/hbmc.../2010/05/1.png
- Here's a critical comparison between the 604E and the GPA unit .
- Scales have been expanded for a closer look-see .
http://www.hostboard.com/forums/hbmc.../2010/05/2.png
- Re; Availability ,the GPA looks the best of the lot ( though I'd need to tailor its' response somewhat between 500 -5000 Hz ) .
- That area is too hot for my liking and would be unlistenable for me , though I guess it's all a personal choice .
- FootNote; It's hard to believe that Altec actually released those FR plots ( for general perusal back in the 70s ) , considering just how mediocre they were .
- Mind you, the originals are very small .
- Here's the curve I listen to now . This works for me ( & my aging ears ) . It sounds good with all types of music ( classical, jazz, opera, modern stuff, older rock , mono stuff from the 1950s , you name it ).
- BTW, that's a 288-8K adapted onto a small Emilar Radial ( @ the size of the 811b ) .
http://www.hostboard.com/forums/hbmc.../2010/05/3.png
- FWIW, the most "critical scale" of the above 3 pics is the FR of my own stuff ( which includes a super critical 1/24 octave smoothing ) / so please no whining about bias .
- On my laptops' monitor ;
10db vertical scale = 1", is applied to the pic of my own stuff ////
,,,,,, while the vertically expanded pic of the GPA 604 ( & Altec 604E ) data is ; 10 db vertical scale = 5/8" .
- FWIW, I find the stock GPA FR plot pretty misleading .
- 20 db vertical scale = 7/8" is too squished and should be changed, IMHO .
<> cheers EarlK
PS #1 ; Buy the GPA and then design yourself a network that gives you your preferred playback curve . That's the route I would follow .
PS #2 ; Here's my cousins' Tannoy 12" HPDs for some comparison ( of when 2 different vertical scales are used / also displaying 2 different types of data smoothing ).
http://www.hostboard.com/forums/hbmc.../2010/05/4.png
Hey Toby. I sometimes wonder if all these plots and graphs are a bit like the piano in a whorehouse. They provide some lively entertainment and diversion, but they hardly substantively impact the primary activity of the business.Quote:
Originally Posted by badtoby
You've answered your own question; as I've noted in bold above. As I read GM's point, horns are directional. Or better yet, high frequencies are highly directional and Altec (amongst others) made the effort through the years to address that. Some designs were more successful than others. But, if you walk across the near field of a pair of Altec 604s in a properly designed cabinet in an anechoic chamber (or any listening space) you will hear "lobes" in the mid and high frequencies. If you do that with a dome tweeter, or different horn designs, maybe they will be less pronounced. So he's asking, "looks good on which paper"? If you look at Erik's <edit> Earl's plots you see this little dip at around 2K and another at about 4.5K. Personally, very much opinion here, I kinda like that. It's the signature sound of these speakers. With the Tannoy's there's a giant bump at 50-100hz. Some people, not all by far, might consider that kinda "boomy".
So what's up with all that? An E, G, H (and I even think K) are all pretty usable, (I think through the years, mostly at radio stations, I've probably heard them all) but these professionals are suggesting that you'll have to work with them, the box, the room, the crossover, the crossover point etc. To my ear, not nearly as well trained as GM's and Eric's <edit> Earl's and handicapped as I am by listening room space constraints and old ears, what I like about any of these systems is their "openness" their midrange dynamics, and a kind of "effortlessness" about what they do. Your mileage may vary.
And if I have incorrectly "interpreted" either you Earl or you GM, my apologies.
And Earl, I love the way "YOUR" plot moves up from about 5K. Mine will eventually have to start that move I think a little lower, like around 3K. I'll be needing help to get that to happen of course.
Toby; you have some reading to do here: Jeff Markwart's Corner - Phase Corrected Crossovers
Dan
Hey Dan,
Who's Eric ?
If you're going to dismiss my graphics / then " at least get my,,,," wellll,,, you know the rest :lol:
<> cheers
Good grief I'm sorry Earl. Hey I got an excuse. Much damaged brain due to stress and underuse. And no dismissal, just had to use that quote I heard recently. Keep them coming. I'll make the appropriate edits.Quote:
Originally Posted by Earl K
Dan
(Assuming mounted etc.) see if you can go listen to them, or post your location (and/or range) and see if anyone here will offer a demo. As mentioned, consider the room they are playing in as compared to your space. Take at least some of your own ref. material of course.Quote:
Originally Posted by badtoby
If not, alas, sometimes you just have to jump in and see what the water is like.
As you research, don't leave out:
- 'big red' (s)
- UREI 811 and 813 (original or 'A' suffixed models, if sticking with the Altec 604).
- Stanley Screamers (?)
* As seen in Earl's first chart, the UREI aftermarket HF horn for the 604 was the '800H'
Do be sure to stop yourself before you have 3 pairs... ;-)
or not
My understanding is that the most significant difference with the "new" H and K 604 is the backwards adoption of the mantaray horn.
I just got a pristine 604-8G with a new cone, new windings, a new diaphragm and a new horn (not the mantaray), as well as Jeff's crossover for the 604-8g, Thanks Jeff. I am going to wait until I finish another set of Cab's to listen to them.
From my experience the biggest flaw in 604's is aged materials and badly designed cabs.
I am borrowing features from Goodmans cabs and forgetting the pi$$ poor way Altec does their joints on the base and top (I prefer 1/4" deep slots all around). The sizes of the cabinet seems good (Stonhenge) but the port is misplaced and badly designed imho. They had it better with the 620A. Goodmans uses an internal shelf undle the port which has sides and a back. It extends about 2 times farther back than the spider and goes up roughly 6 inches lower than the speaker. There are drawings in a Goodmans enclosure guide from 1965. I built one of these for a 12 inch Goodmans triaxial and a 12" University triaxial 312. It is fantastic. Bass responce is clean and well defined but very punchy. To be honest, I now need to rebuild the X-overs in the speakers.