604 Infomation needed

[GARY STONER]

Can anyone tell me the difference between the 604c and the 604e ? I am putting together a retro recording studio and I'm about to start building a set of of 612 cabinets like the ones used in Abbey Road Studios in the 50s and 60s. In fact any info about the speakers and tips on getting the cabinets right would be great. Also what version of the 604 speakers are more desirable the 604c or 604e ? I'm in the UK and new to this great site, Thanks.

[LICORNE]

Hi,

The information on the 604-c is scarce what I managed to find is that it's XO was 1600 HZ.
Peak power 50 watts.

As for the 604E here is the site .

http://www.voiceofthetheatre.com/ima...E.SuperD.1.jpg


http://www.voiceofthetheatre.com/ima...E.SuperD.2.jpg


As to which one is best ;I would prefer the 604-E the early 60's version the XO is 1500 Hz.

My experience is with the 604-8G a true High Fidelity speaker.

[martyh45]

Hi,
The E has a pleated cloth surround on the woofer and the C has paper. HF Diaphragms may be different but I am not sure, the C?s I have seen have aluminum voice coils and the E?s may not. TS parameters for the woofer sections are different for both so properly aligned cabinets will differ. The C?s I have seen have the same 15? frame as B?s, that is the thin frame without the little radial ribs at the mounting ring while the E?s have the 15? frame with ribs. To the best of my knowledge, C?s can be converted to electromechanical E?s by changing cones and maybe the diaphragms. I had both the cones and diaphragms of a pair of C?s replaced with E parts at GPA and the work was absolutely first class.

[Old Guy]

Hi Gary- glad to see you made it. here's some more info.

http://alteclansingunofficial.nlenet.net/Duplex.html

You may want to post here about the 612 cabs- someone may have a real set they don't need. Also some of the fellows here may have built them and can possibly offer advice.

[LICORNE]

Here is the history of the 604 with specs.

Altec 604 HISTORY

Altec 604A (late 40's)
HF horn: 90h40v
X-over:
Power:
Impedance: 16 ohms
Weight:
Magnet: Field Magnet (I think)
Response:
Free Air Resonance:
Frame:
Cone: all paper cone
comment:


Altec 604B (early 50's)
HF horn: 90h40v
X-over: 1000 Hz
Power: 30 watts
Impedance: 16 ohms
Weight: 40 lb.
Magnet: Alnico
Response: 30Hz - 16kHz
Free Air Resonance:
Frame: wrinkled brown paint
Cone: all paper cone
comment:


Altec 604C (mid fifties)
HF horn: 90h40v
X-over: 1600 Hz
Power: 35 watts, 50 peak
Impedance: 16 ohms
Weight: 40 lb.
Magnet: Alnico
Response: 30Hz - 22kHz
Free Air Resonance:
Frame: green hammer-tone
Cone: all paper cone
comment: close sounding to the newer models
604C updated many times by Altec


Altec 604D (looked just like 604C)
HF horn: 90h40v
X-over: 1600 Hz
Power: 35 watts, 50 peak
Impedance: 16 ohms
Weight: 40 lb.
Magnet: Alnico
Response: 30Hz - 22kHz
Free Air Resonance:
Frame: green hammer-tone
Cone: all paper cone
comment: 604D was in the 1957 catalog and was not superceded by the 605 until 1959
after that 604Ds were built one-off for special customers i.e. recording studios


Altec 604E Super Duplex - 1964-65/late 60's
HF horn: 90h40v
X-over: 1500 Hz
Power: 35 watts, 50 peak
Impedance: "8 to 16 ohms" was really nominally 16 ohms
Weight: 34 lb. including network
Magnet: Alnico V magnets
Response: 20Hz - 22kHz
Free Air Resonance: 25Hz
Frame: light grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment: stamped basket diameter is 15"
harder to front load


Altec 604E2 Super Duplex
HF horn: 90h40v
X-over: 1500 Hz
Power: 35 watts, 50 peak
Impedance: "8 to 16 ohms" was really nominally 16 ohms
Weight: 34 lb.
Magnet: Alnico V magnets
Response: 20Hz - 22kHz
Free Air Resonance: 25Hz
Frame: cast frame grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment: later 604E called 604E2 had the later 16" cast basket and tangerine phase plug


Altec 604-8G - early to late 70's
HF horn: 90h40v
X-over: 1500 Hz
Power: 65 watts
Impedance: 8 ohms
Weight: 40 lb.
Magnet: Alnico V magnets
Response: 20Hz - 22kHz
Free Air Resonance: 25Hz
Frame: cast frame dark grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment: Sensitivity was improved - 100 dB SPL, 4 ft. on-axis 1 watt input
(pink noise band limited from 500-3000khz)
cast basket easily rear or front-mount
"tangerine" phase plug came in 1976 with no change in model number
604-8G's can be found w either circumferential phase plugs
or newer radial phase plugs with no indication on the driver label.


Altec 604-8H
HF horn: 60h40v "Manta Ray"
X-over: 1500 Hz
Power: 65 watts continuous
Impedance: 8 ohms
Weight: 34 lb.
Magnet: Alnico V magnets
Response: 20Hz - 20kHz
Free Air Resonance: 30Hz
Frame: cast frame dark grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment: Last of the alnico magnet models
Tangerine phase plug
introduced the newer Mantaray horn


Altec 604-8K (80's/90's)
HF horn: 60h40v "Manta Ray"
X-over: 1500Hz
Power: 75 Watts continuous
Impedance: 8 ohms
Weight: 34 lb.
Magnet: Ferrite Ceramic
Response: 40Hz - 20kHz
Free Air Resonance: 28Hz
Frame: cast frame dark grey paint (16")
Cone: paper cone with an "accordian edge" cloth surround
comment: radial phase plug
more sensitive "SPL" ratings than previous model 604's
smoother HF dispersion due to the CD "Mantaray" horn
improved cross-over networks


Altec 604-8L
HF horn: 60h40v "Manta Ray"
X-over:
Power:
Impedance: 8 ohms
Weight:
Magnet: Ferrite Ceramic
Response:
Frame: cast frame dark grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment: a K with a higher LF power voice coil
uses Pascolite Alluminum H.F. Diaphragm


Altec 604-16X
HF horn: 60h40v "Manta Ray"
X-over:
Power:
Impedance: 16 ohms
Weight:
Magnet:
Response:
Frame: cast frame dark grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment:

Altec 604 Parts
Great Plains Audio
http://www.greatplainsaudio.com/

604-E, 16LN
WOOFER / R604-16E / 16Ω
TWEETER / 34852** / 16Ω


604-HPLN
WOOFER / R904/604-8HP / 8Ω
TWEETER / 34852** / 16Ω

604-8G
WOOFER / R604-8G / 8Ω
TWEETER / 34647** / 8Ω


604-8H
WOOFER / R604-8H / 8Ω
TWEETER / 34647** / 8Ω

604-8K
WOOFER / R604-8K / 8Ω
TWEETER / 34647** / 8Ω

R604-16HPLN, 126HPLN, 16X
WOOFER / R604-16HP / 16Ω
TWEETER / 34852** / 16Ω

604-168X
WOOFER / R904/604-8HP / 8Ω
TWEETER / 34852** / 16Ω

...............................................

[Jim D]

To address the original question, besides the frame edge there is some difference in the LF motors of the C and E. Originally the C voice coil was almost the same height as the magnetic gap thickness, same as the B, the LF top plate was champhered to a thinner dimension. This made for almost no linearity in the bass. The E has a full thickness top plate with a shorter voice coil and has more linearity. The E would be the best of these two models for a studio.
The D is a bit of an enigma, some had C cones, some I have seen have original later accordian edge ALTEC cones with the orange hinges. I do not know the thickness of the D top plate, but, it too may have changed along the way also.
From my experience, there were no E or E2 models with a Tangerine Phase plug, it did not come along till much later. The first 604 with a Tangerine plug was the alnico 604-HPLN, which had the C-D-G "eggcrate" horn and a 421 LF voice coil, was made for MI uses. Our tests of the eggcrate horn shows it unloads at about 1700Hz.
A very few late Gs had a tangerine plug, very few, the H was the first that always had the tangerine.
Not all 604Ks are the same either. Early versions had cast iron magnetic returns. They had problems getting the HF passage through the LF pole piece plated and some "grew" rust growths that look like bugs in this area. Later Oklahoma built ones used steel parts which cured the problem. Toward the end of 604K production, EV managers mandated the 604 use a larger EV magnet, this overdamped the LF performance.
The first 604L was made by Oklahoma for their slant front stage monitor (can't remember the #)and the M600 Monitor. This was a late 604K motor with with high temperature-regular length LF coil and standand K cone and Pascolite HF diaphragm.
When ALTEC Pro had GPA build their 604s, they also used the L designation. It was essentially a late 604K, complete with the overdamped LF section.
Later, we at Iconic, working with GPA, got the top plate thickend and restored the proper LF performance. These units, our 704, the last of the ALpro 604Ls and GPA's unit are best sounding and most linear of any of these speakers ever made, period... All three of these speakers differ in their soft parts, naturally we think ours has the best combination.

To conclude, there is no hard and fast rules about 604s, every suffix variant differs from the other and must be treated separately in application and crossover. Sorry, no simple explanation, JIM