info on 604-HPLN

[altec10]

Hi guy's, does anyone have any info on the 604-HPLN driver? It has a Urie horn fitted and apparently comes with no x-over network. I also believe it was sold as a driver to be used in clubs and discos etc. Any help would be great thanks in advance.
Mike C

[RClark]

when the 604HPLN was introduced at the seminar for contractors back in about 76/77 we were told by stan miller that it was a high powered redesign of the 604 for sound reinforcement applications-----intended use was as the low and high parts of a 3 way system using a larger external horn for the mid frequencies--------a demo was done with the 604's in 817 cabinets with large 288 manta rays for mids-----it was pretty impressive-------the demo utilized a total of 32 of the 604HPLN's in 16 cabinets powered by 16 9440's--------the horn is a altec unit used on the normal 604's------we were told the 8 ohm HF dia was identical to the normal 604 since in high powered applications it would only have been used above 7 to 10 KHZ-----that much i can confirm as i used alot of them------we were also told that the woofer used a spider and vc from the 417 musical products woofer in order to increase its thermal capacity-----the woofer was 16 ohm in order to provide a 8 ohm load in the dual cone 817 cabinet---------it was also sold without a crossover since the 3 way application would no doubt be done electronically--------it can of course be used in a 2 way system at "normal" 604 power levels with excellent results with an appropriate crossover------for the ones i used i copied the urei crossover and modified the component values to accomodate the 8LF/16HF ohm impedances...........RC

[RClark]

sorry but i typed that backwards-----its should be 16 ohms LF and 8 ohms HF..........RC

[joyspring]

Having serviced 604HPLNs in the past, I've noticed the following:

Physically, the cone/voice coil assembly is similar to the 904 Duplex; vented, metal voice coil former (rather than the normal paper formers on 604s), less mechanical compliance and a slightly higher resonant frequency.

Sound-wise, they're very close to the 604.

BobR

[RonSSS]

Bob R

I have a pair of the 904's. I modified them with aluminum diaphragms, removed the loading cap and took out the bug screen.
Very nice sounding.
They only produced the 904 for a year or so didn't they?
Did the 604-HPLN come out before or after the 904. If after, I wonder if they didn't just re-name to the 604HPLN just so it had the 604 familiarity.

[joyspring]

Hi Ron,

The 904's I've seen are essentially 604-8Ks with a different LF cone/voice coil assembly and Symbiotik HF diaphragm.

They appear to be successors to the earlier HP 604s though I'm sure Don or others on this forum would have authoritative info.

So far as Thiele-Small specs are concerned, they are close to the 604-8Ks apart from having a bit higher fs and smaller compliance.

They sound remarkably close (the LF section) to the 604-8K.

BobR

[altec10]

Hi guy's,
Thanks for the great info on the 604-HPLN drivers. I am going to build some new enclosures to house these drivers, and from what I can gather 9 cuft should be fine.(9 cuft will be the unloaded volume) I will vent them using 2 4" vent tubes in each encloser facing rearward, could someone tell me what length to make these tubes to tune these drivers to 40 Hz. Also I have a pair of 18" JBL 2241-h drivers in sub enclosures I wish to sell and use a pair of Altec 18's for the sub bass. I am interested to hear what you guys thoughts are on which drivers to use for the sub bass. I am a bass freak so I will use 2 drivers in one enclosure. I am thinking on the one sub encloser to sum the bottomend, or would it be better to use 2 seperate enclosures? Thanks for any help in advance.
Mike C......