Hollywood Altec 604 RWB

[SUPERBEE]

Thought you all might like to see one!

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[Altec Best]

Very Nice ! But this driver looks like it has been reconed.

[Maron Horonzakz]

How can you tell????

[Steve Schell]

Maron your 604 was built in 1946 or early 1947 an its original cone would have had a paper outer hinge, not the cloth accordian pleat. This type cone was introduced somewhere around 1960 midway through production of the 604D. The accordian suspension was considered by most to be an improvement due to greatly increased durability under hard use and a lower resonant frequency. Some collectors prefer the paper compliance though, contending that the mid-bass performance is more tuneful and accurate.

[herki the cat]

Maron your 604 was built in 1946 or early 1947 an its original cone would have had a paper outer hinge, not the cloth accordian pleat. This type cone was introduced somewhere around 1960 midway through production of the 604D. The accordian suspension was considered by most to be an improvement due to greatly increased durability under hard use and a lower resonant frequency. Some collectors prefer the paper compliance though, contending that the mid-bass performance is more tuneful and accurate.

You should also consider the age & work history of the High Frequency Driver Aluminum Diaphragm __ bending thousands of cycles causing the Aluminum to "work harden" & become significantly less compliant. The resonant frequency also increases with a significant loss of excursion dynamic linearity.

A new Diaphragm makes a world of difference __ However, you need to check with Great Plains Audio Inc., in selecting the correct "800 hz diaphragm part number" to avoid the 500 Hz 802 D parts which were designed to provide increased chamber spacing between the phase plug and the diaphragm dome to accomodate the diaphragm motion for 500 Hz. This results in decreased high frequency performance since the larger spacing performs as acoustical shunt capacitance.

The 802 D also has a backing plate with air holes behind the diaphragm to limit diaphragm travel at low frequencies.

If i am not mistaken, all of these HF drivers were limited to 800 Hz crossover beginning with the Iconic including the legendary superb-sounding 604-C prior to the 802-D Speaker.

:dont-know:You may find this experience enteresting: Early in 1942, An Altec Lansing brochure arrived At Radio station KICA, Clovis, New Mexico, announcing the Altec "604 Duplex Speaker." This made quite a stir in the program production & advertising sales departments. Considering KICA's penchant for high quality broadcast monitoring, I almost bought a pair of Altec 604 Duplex's for KICA, but ultimately decided that our magificient Jensen Monitors were quite adequate.

Later that year at the University of New Mexico, a Field Coil Altec Duplex was advertised in a technical journal; this was probably the same Altec Duplex KICA had considered.

IN 1946, At Allied Radio in Atlanta, Ga, __ on my way home from WW-2, US Navy __ I was was looking for a "Brush Inc., Model PL-50 phono playback arm and cartridge," & I spotted an Altec Duplex Speaker in a glass counter; I asked to hear it. The sales representative had some trouble with the demonstration & ultimately stated "Oh yes!... forgot to turn on the field coil power."

In 1947, the permanent magnet Duplex was selling for $250.00 in all the stores.

[Altec Best]

Maron your 604 was built in 1946 or early 1947 an its original cone would have had a paper outer hinge, not the cloth accordian pleat. This type cone was introduced somewhere around 1960 midway through production of the 604D. The accordian suspension was considered by most to be an improvement due to greatly increased durability under hard use and a lower resonant frequency. Some collectors prefer the paper compliance though, contending that the mid-bass performance is more tuneful and accurate.

+1 Sorry for the delay in responding ! Steve beat me too it. The early RWB drivers have the paper surround and not the pleated cloth surround as Steve has noted.But one other difference of note here is they also had Bakelite spiders in this era with the paper surround cones.Yours has a black pleated spider.


You should also consider the age & work history of the High Frequency Driver Aluminum Diaphragm __ bending thousands of cycles causing the Aluminum to "work harden" & become significantly less compliant. The resonant frequency also increases with a significant loss of excursion dynamic linearity.

A new Diaphragm makes a world of difference __ However, you need to check with Great Plains Audio Inc., in selecting the correct "800 hz diaphragm part number" to avoid the 500 Hz 802 D parts which were designed to provide increased chamber spacing between the phase plug and the diaphragm dome to accomodate the diaphragm motion for 500 Hz. This results in decreased high frequency performance since the larger spacing performs as acoustical shunt capacitance.

The 802 D also has a backing plate with air holes behind the diaphragm to limit diaphragm travel at low frequencies.

If i am not mistaken, all of these HF drivers were limited to 800 Hz crossover beginning with the Iconic including the legendary superb-sounding 604-C prior to the 802-D Speaker.

:dont-know:You may find this experience enteresting: Early in 1942, An Altec Lansing brochure arrived At Radio station KICA, Clovis, New Mexico, announcing the Altec "604 Duplex Speaker." This made quite a stir in the program production & advertising sales departments. Considering KICA's penchant for high quality broadcast monitoring, I almost bought a pair of Altec 604 Duplex's for KICA, but ultimately decided that our magificient Jensen Monitors were quite adequate.

Later that year at the University of New Mexico, a Field Coil Altec Duplex was advertised in a technical journal; this was probably the same Altec Duplex KICA had considered.

IN 1946, At Allied Radio in Atlanta, Ga, __ on my way home from WW-2, US Navy __ I was was looking for a "Brush Inc., Model PL-50 phono playback arm and cartridge," & I spotted an Altec Duplex Speaker in a glass counter; I asked to hear it. The sales representative had some trouble with the demonstration & ultimately stated "Oh yes!... forgot to turn on the field coil power."

In 1947, the permanent magnet Duplex was selling for $250.00 in all the stores.

Very true but, DO NOT send them (Old Diaphragms) to GPA if they are the originals.They will be worth more money with the originals still available for re-selling if you ever decide to part with them.If you send them in for re-mag and diaphragm replacement no care will be given to the old Frams.

What I do when sending for re-mag is, I'll remove the diaphragms (keep at home) then send the driver for re-magnetizing and have the diaphragms sent to me and then I'll install them myself.It is very easy.They have locater pins. ;)

[Altec Best]

[QUOTE=Altec Best;317839
What I do when sending for re-mag is, I'll remove the diaphragms (keep at home) then send the driver for re-magnetizing and have the diaphragms sent to me and then I'll install them myself.It is very easy.They have locater pins. ;)[/QUOTE]

Or you can just have GPA install the new diaphragms.The important part is to keep the originals at home (If they are still Original).