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I've run across this mentioned in passing a few times, but, since I have
some freshened 604C's, I was curious to hear how they might work in the
basic 825 cabinet with the porting optimized by experimentation. Has
anybody here followed this path?
thanks,
Skip
Not yet... but perhaps this winter!
I heard them and loved them many years ago. Wanted to try them again this year, but you have to cut a hole in the rear panel of the box. The coax drivers are a bit too deep to fit.
Or make a new panel with the hole in it.
I remember it as a very nice combo.
I was thinking that, since I would build these from the plans, I might
arrange to fill the volume around the flairs on the sides and maybe the bottom
with foam for rigidity, sort of squaring off the horn into an internal block.
I could then regain the lost volume by making the cabinet deeper front
to back, or maybe just the top half adding enough depth for the 604.
Experimented with 604E in scratch built A7-500 (825 cab) tuned to ~40 Hz using 3/4" marine grade ply and extra bracing. Horn section damped with kitty litter. Wound up lining the top inside of the flare with a thick foam and putting the HF horn mounting angle back on to brace the top. Sounded pretty good to us, but worked even better as a three way with the 511, though the owner ultimately put them in a false wall IB with 515B 'helper' woofers which was best overall.
GM
You may want to ask Analog Addict as he is running a pair of 828's/604's now I think, maybe he can give some help.:)
http://www.hostboard.com/forums/1834553-post1.html
Will the ferrites fit without modding the back panel?
Easily. The ferrite 604's are about the same overall depth as a 515B, give or take a 1/4 inch. The alnico 604's don't interfere much, about the depth of the HF cover, just enough that you have to modify the back panel to accept them.Quote:
Will the ferrites fit without modding the back panel?
Interesting, the rear mount published dims says that it would be a press fit in the 825 and too long for any 828 or clone made from 3/4" or thicker material. Only one way to know for sure though.
GM
Hmmmm..... I have a pair of the ferrite 604s. They are too deep for my cabs. Not by much, just enough. Could be some of the 828 cabs are a bit different?
I'll be over at Analog Addict this afternoon. Don't know if he has the 604 rig running - I'll let you know!
My experience was with 904's, shouldn't they be dimensionally the same as a ferrite 604?
Of course it now occurs to me that the 904's may not have had traditional rear covers, only loading caps as i seem to remember them having the same style loading cap as the 902's on model 14's. That would certainly reduce the depth by a good 1/2 inch vs a driver with HF cover in place. It's been a while, and i never spent a lot of time looking at the combination internally, but i do positively remember the backs being properly installed with no holes in them.
Apologies if i've sent anyone astray.
FWIW, there should be ~8-1/2 inches between the inside of the back panel, and the mounting surface of the woofer baffle of an 828.
Is there no concern for the HF diaphragm being modulated or even damaged by being "contained" in the LF pressure zone?
Thanks to all, and by all means continue!!
GM,
Regarding your comment on using foam on the flat horn top, would it make more
sense to slope the top so it is symmetrical with the horn bottom surface,
equalizing the angles so the expansion remains the same? I assume this is all
intended to stop the cabinet horn from reflecting vertical spill from the small
HF horn on the 604C.
I wonder what the comparability of the VOTT is to the Tannoy Autograph/
Westminster, at least in front of the driver.
Skip
Not by me, at least not in a HIFI/HT app since the small format driver's ~10:1 CR has such a high throat impedance that I doubt it 'feels' it except in the extreme HF where the horn is acting only as a direct radiator. At this point, I can't recall if it audibly rolled off the horn's extreme HF response or not.Quote:
Originally Posted by bfish
GM
You're welcome!Quote:
Originally Posted by Skip Pack
Yes, if you want to make a 604 specific horn cab, though better to rotate the horn to place the straight walls on the sides.
The two are apples n' oranges in that the 825 short horn is to increase the woofer's efficiency to match up to its break-up modes BW, extending the HF horn's useful BW to a lower roll off whereas the Tannoy's front horn is for blending its BLH output to the driver's forward radiation and ~fill in the deep notch where the two out of phase outputs otherwise cancel out.
GM
Again, interesting since the published specs actually show the 904 being 8-7/8" when rear mounted Vs other Ferrites including GPA's as being 8-3/4". Can't say as I'm surprised though, Altec's marketing dept. was already getting pretty sloppy by the mid '70s. You're right though, with loading caps only they should at least fit the 825 and if yours fit a 3/4" thick construction 828, then seems like even a regular rear cover would at least mild pressure fit any of the 5/8" thick cabs, mass loading it to be cab.Quote:
Originally Posted by bowtie427ss
Sounds like we need some folks to measure the various models to see what they really are.
GM
Thank you. Makes perfect sense put that way.Quote:
Originally Posted by GM
Just got back from listening to a pair of 604 in 828 cabs. Yes, the drivers stick out the back. :) They are in Analog Addict's big basement, along with scads of other gear.
They sound pretty darn good, I thought. Quite excellent on vocals like Sinatra, Nat King Cole, etc. Nice piano image too. Good depth. They certainly respond to amp changes. My little SE 6V6 amp sounded pretty good, but A-A's 45 SET was much better. Smoother, more resolved, more dynamic. A real winner, that amp.
The real show stopper though are the big Simplex theater cabs. Similar to a 210 bass cab with dual 515s. 1005/288 on top. Huge sound, never any strain. No hint of woofer box sound at all.
I'd say the 604s in the 828 are really nice. The kind of speaker you could really enjoy in a modest to large room.
Are they the big W's those corner horn behemoths ??Quote:
Originally Posted by Panomaniac
Yes the are. They do fit in the corner, but I'm not sure they are really a "corner horn". Maybe A-A can post a few pix. A whole thread on them would be nice.
[quote=Panomaniac;1838428]Cool !Quote:
Yes they are
Yes that would be nice. I personally would like to see the back chamber and the 515's if easily accessible.And lots & lots of pics. :2thumbsup: :coffeedrinker:Quote:
They do fit in the corner, Maybe A-A can post a few pix. A whole thread on them would be nice
Here's a shot of the back side. Sorry for the crappy image.
It's dark in the Mancave, the better to nurse my throbbing head.
If anyone is real interested, I'll find the real camera and get a better picture.
http://www.hostboard.com/forums/hbmc.../2010/10/2.jpg
I'd be happy to start a thread on the Simplex W's. After all, I have no trouble blowing my own horn(s)....:p
Funny thing about them is that they seem to be a bit of the red haired stepchild of the VOTT family, even though there must have been thousands of them made. Got them playing one of the Lord of the Rings tracks now ( Theme of the Nazgul?) with lots of trumpets, drums, etc. Theater music of course....;)
Anyway, if it helps collect more knowledge and info about them, all the more the better...:2thumbsup:
Yes! A thread in the Simplex system would be great. :flagwaver:
Ditto !!
+1
The Big Dub-A-U I mean W :D :2thumbsup: