Electronics Today International ETI 4000 speaker article?

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Hi there,

Wondering if anyone has the ETI magazine article for these speakers?  

I think they were ETI 4000 or ETI 4001.  Each speaker box has 4 speakers,
12" bass, 7" low-mid, 2" dome hi-mid and 1" dome tweeter.  Box stands a
metre high and the Rod Irving ones are 19mm chipboard.

I built them way back around 1980 or so, from kits by Rod Irving
Electronics in Thornbury, the passive crossovers were by Selectronics
(? I think)  Very expensive at the time and improved a great deal a
few years ago when I replaced the bipolar caps in the thing.  Bass
was always a bit low response but nicely defined since they're sealed
enclosures.  

An extra sealed inner enclosure for the 7" low-mid speaker.

I'm interested in seeing the original design specs, like crossover
frequencies.  Reverse working from the circuit is a bit difficult.

I'm considering ripping the passive crossover out, at least for the
bass, maybe go three-way active?  Dunno, all fluffy ideas at the
moment.  Was quite amazed how new higher voltage rated bipolar caps
helped the bass along, been thinking quite some time about going
to active crossovers, get rid of the E core laminated low frequency
inductors and bipolar caps.  I imagine the hi-mid and tweeter are
okay with passive xover, or I could drop something active up there
too, not so much power required?

Ideas welcome :)

So, does anyone have a copy of the articles they could scan?  Last
time I checked there were no library copies available, even our local
uni had dumped their magazines from that era.  Or is there an online
magazine repository?  

Thanks,
Grant.

Re: Electronics Today International ETI 4000 speaker article?


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Any idea of the month/year ? I would be 90% sure of still having mags
from that era but would be quite a search without this

Re: Electronics Today International ETI 4000 speaker article?



"kreed"
 Grant

Any idea of the month/year ? I would be 90% sure of still having mags
from that era but would be quite a search without this


** The ETI 4000 4 way speaker was published in February 1980.

 The PCB is coded  et496.

 A 3 way version was published in June 1980.

 Source is the RCS Radio PCB listing.


.....   Phil



Re: Electronics Today International ETI 4000 speaker article?


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Thanks Phil, you turned hours of work into 5 minutes :)


I do have both these issues, unfortunately my 1980 set are in a
binder, the front and back (glossy) covers of each mag have somehow
glued themselves together and also to the vinyl of the binder so they
can't be removed and cant be laid flat on a scanner. The pages are
also fragile.

The June 1980 article is probably what you want as that has the
details as well as a plotted graph showing the frequency ranges of
each speaker etc.

Will try and photograph the pages and see how well that works, can you
provide an email address please.

Re: Electronics Today International ETI 4000 speaker article?



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Be nice, yes.  There was that earlier technical discussion of the project.

At the time I built the 100W/channel MOSFET amps and that preamp with
the LED level meters.
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OP's addr is snipped-for-privacy@grrr.id.au  The stuff Mark sent is the speaker project
itself.  It's got the crossover frequency info I was after, so knowing
why they loaded / adjusted the crossover network is icing on the cake :)

Thanks!
Grant.

Re: Electronics Today International ETI 4000 speaker article?


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It has been sent.

If it doesn't come today, check your spam folder for "ETI 1980
article"

Hope it is what you need.




Re: Electronics Today International ETI 4000 speaker article?


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**It'll be in one of a couple of dozen boxes, somewhere. I could not lay my
hands on my copy for quite some time, due to time constraints, though I've
promised myself that I'll sort through my back issues next year. Maybe.

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**Not a bad idea, given the low cost of electronic crossovers and cheap
amplification nowadays. The Behringer crossovers are reasonably well
resolved and extremely flexible.

  Was quite amazed how new higher voltage rated bipolar caps
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**More important would be to replace the HF driver with something more
modern, as big advances have been made in recent years. Now I think on it,
replacing the bass driver with a Peerless XLS would be a smart move too.

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**Like I said: Next year. Maybe. Perhaps someone else can locate it for you.
You could try calling RCS Radio. They may be able to supply a copy.


--
Trevor Wilson
www.rageaudio.com.au



Re: Electronics Today International ETI 4000 speaker article?



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I don't hear that much HF.  Though I have another pair of boxes need new
drivers, made of plywood, but the bass is so bad I think the magnets
lost it or something.  Different project that one, just fill the holes
with cheap speakers for a second pair.

Don't think I'd replace the woofers, I had trouble with one of the lo-mids
and a bad solder joint, but it survived my repair from some years back,
that wire up from the voice coil is so fine, compared to the flexiwire
from cone to solder lugs.
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Thanks, Phil pointed at them too.

Cheers,
Grant.

Re: Electronics Today International ETI 4000 speaker article?



"Grant is a Jerk "

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** That is a very fluffy idea.


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** Pure self delusion.


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**  Out of the frying pan and into to fire.


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** So is the damn woofer.

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** Forget going active -  the advantages are grossly overstated.

 Having speakers that are not compatible with a normal hi-fi amplifier is a
real PITA.



....  Phil




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Re: Electronics Today International ETI 4000 speaker article?



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Smooch :)
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Nah, I reckon new 100V bipolars let the bass come through heaps better than
near 30 year old tiny 50V bipolar caps -- besides, after all that work I put
in, they *must* sound better :)
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I tend to agree, if the amp dies, it's another story though.  But yeah,
lots of work for maybe no real benefit.  Certainly being in my fifties
I'm not hearing much from the tweeters ;)  

Once I was close to ripping out the bass xover and run 4 x 50W amps from
PC sound card doing the electronic crossover.  But after I replaced the
bipolar caps the improved bass was enough, lost motivation to complete
the amplifiers, so they're partially built in a cardboard box, for when
the stereo gives up the ghost.

Grant.

Re: Electronics Today International ETI 4000 speaker article?


Grant is a  total Jerk "


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** What flawless logic.

   (  Shite deleted )




...  Phil



Re: Electronics Today International ETI 4000 speaker article?


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If you continue to delete "shite"best lop off your meat smoking head

--
X-No-Archive: Yes

"The problem with Australia is stupidity. I'm not saying there should be
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Re: Electronics Today International ETI 4000 speaker article?



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Possibly the old ones had lost capacitance, obviously it wasn't the higher
voltage rating by itself that made any difference, if there was one.

MrT.





Re: Electronics Today International ETI 4000 speaker article?


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Wrong attrib

--
X-No-Archive: Yes

"The problem with Australia is stupidity. I'm not saying there should be
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Re: Electronics Today International ETI 4000 speaker article?


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Agree, lost capacitance or developed a resistance across them that was
pulling down the power to the woofer.
With 30 year old caps, this is definitely on the cards.

I fail to see how the voltage rating can change anything.


Re: Electronics Today International ETI 4000 speaker article?



"kreed"

Agree, lost capacitance or developed a resistance across them that was
pulling down the power to the woofer.


** Absolute bunkum.


With 30 year old caps, this is definitely on the cards.


**  Insane to assume any such thing in this case.


I fail to see how the voltage rating can change anything.


** You fail to see a lot of things.

 Like the inherent worthlessness of the OP's subjective opinion.



....   Phil



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Ok, I wont discuss it anymore. Getting boring anyway.

Re: Electronics Today International ETI 4000 speaker article?



"kreed"

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Ok, I wont discuss it anymore.


**  Wise move.

 The OP is a blatant troll.



....  Phil






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They're bigger, lower impedance, I had to drill out some PCB holes
for the larger wire.  Besides I added more of lower value in parallel
(for example 3 x 33uF instead of original 2 x 47uF), so it's not just
upping the cap voltage rating, it's about lowering ESR.  

Upping the cap V rating is simply because the local Jaycar agent sold
100V bipolars at a decent price at the time.  Quite an obvious thing to
do.  Especially since rereading the articles I received -- Thanks Guys!

Grant.

Re: Electronics Today International ETI 4000 speaker article?



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Exactly my point, plus the fact that you didn't test whether the old caps
were still OK, and have no way to test the real before and after performance
of the speakers anyway. But IF it sounds better to YOU, then that's all that
matters, to YOU, right?

MrT.







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