Another 416-8B lives on

[wilcal]

I thought I would pass on to everyone that I
am the proud owner of a vintage Janus
subwoofer (driven by an equally venerable
bridged Crown D-60). I bought the setup in
78 and it's been flawless ever since. Well,
at least until I recently moved. After
everything was finished moving I finally had
some time to set up and check out the ole
Janus. It came up and woofed just fine but
using the Stereophile test CD there clearly
was some mechanical noises emanating from the
Janus box. Strange whistling and rattling
noises. My mind said that after over 25 years
the old 416-8B had finally bought the farm.
Time to open it up and take a look.

I figured the worse. Recone, rebuild or
replace were all possibilities. After just
a few minutes the bottom was off the 150lb
Janus box and there was the 416-8B. I
carefully removed the stuffing and gently
poked at the speaker cone. Soundless, no
rubbing or scraping. I must be missing
something here? A few more pokes and prods
and sure enough all the mounting nuts had
worked themselves loose over the years. One
of the washers was loose enough that it
clattered like a bell. There was the source
of the rattling noise.

The Janus is a multichambered slot load
enclosure. The 416-8B is mounted in the
sealed lowest chamber and fires into a
second chamber that is slot loaded & ported
into the 3rd & top port that is open to the
room. It takes three men and a boy to haul
this thing around. Over the years the 416-8B
had pushed itself loose just enough that air
was leaking around the speaker frame seal and
that was the source of the whistling sounds
and the loose washer was the source of the
clattering sound. So a gentle twist to all
the mounting bolts resnugged everything back
down and tight. Some new brass wood screws
and the whole monster was back together.
From what I could see the 416-8B, basically
being housed in an almost sealed box, looked
good as new. Would it perform as new was the
next test?

YOU BETCHA....Janus subs are well known for
knocking out windows in living rooms and this
baby was right back to form. 10 watt
electrical in, 100db+ @ 20Hz out. I am back
in business probably for another 25 years.
Do note that the 416-8B is mounted completely
within the Janus enclosure in an optimal
condition. Basically in a sealed enclosure
facing straight up magnet assembly down.

WOOF! WOOF!

Wilcal

[boltupright]

I find this topic very interesting, Is there a plan for this encloser? It wold be great to have a sub that doesnt need a million watts to fill a room. How low can it go?

[boltupright]

I find this topic very interesting, Is there a plan for this encloser? It wold be great to have a sub that doesnt need a million watts to fill a room. How low can it go?

[gearjammer]

I think you are using the wrong driver as the 416B really is not designed as a sub-woofer.
Strap in a jbl 2235H in that box and you will get as close to nirvana as anything out there.

[wilcal]

> Is there a plan for this encloser? It wold
> be great to have a sub that doesnt need a
> million watts to fill a room.

I do not plan on reproducing this thing in
any way shape or form. Janus itself was on
Long Island and is long since gone. I thought
I saw someone using the name somewhere but I
think I was mistaking it with "Jamo" who
also make subwoofers. Yes, it is very
sensitive in that it really only needs a few
watts to fill a room. My bridged Crown D-60
( 2 30W amps, 120W Bridged ) is way too many
watts needed. Typically 10w will shake the
room.

Over the years there have been some pretty
impressive high efficiency subwoofers built.
Janus being one of them, another was
coined "The Coffin". That in that it was
about the size of a coffin, was a dual
transmission line design and used two
10in KEF oval drivers. One driver at each
end. IMO that unit was about twice as
efficient as the Janus units. Also long
since gone.

Cheap easy power simplified subwoofer
design.

> How low can it go?

The 416-8B resonates at 25Hz so it at least
goes that low. The 20Hz test signal on
the Stereophile test CD shakes the windows
of the room but I can't hear it. I have a
recording that claims an 18Hz pipe organ
tone and that has no effect on the room
whatsoever. So the low point is in there
somewhere. Chambered ports like the
Janus design unload very very fast on
the low end. At 20Hz you have room
shaking energy. At 18Hz there is no
output whatsoever even though the
speaker may be pistoning.

The 416-8B will handle 75w and I don't
even want to be in a room feeding that
thing with 75w.

Technical note. The Janus subs were VERY
efficient even up to 400Hz and higher.
So you have to use an electronic 3rd order
active filter to make it work right.
That's a brick wall filter. I have the
roll off starting at 40Hz and by the
time it gets to 45Hz or so there is
nothing coming from the sub.

Wilcal

[Todd W. White]

BLASPHEMY!

Try and ALTEC 3182 or 411A, anything but something from the people at JustBigandLoud!

Actually, the 416, though not an actual subwoofer, is a pretty impressive speaker...anyone interested in new C-types let me know...

[gearjammer]

I am sorry,but on the other hand if altec did not go the way of the dodo bird and was still in business i am sure they would have some current drivers that would be running right up there with the 2235H by ***

[GM]

1) What is the T/S efficiency of the 3182? It's not listed in the table on the Unofficial Website.

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I calc 92.39dB/W/m

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3) Just how much bass do we need for home stereo, anyway?

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There are CD's around with 7-8Hz content, so huge multiple driver IB's are the current ideal. How loud you play it then depends on the number of drivers, their Fs, amp power, and how much house 'rattle' you will tolerate.

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4) I've found that essentially none of the music I listen to has any appreciable content this low. So, do we really need bone-crushing response at 16 Hz?

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Obviously, if your playback signal and/or electronics can't/doesn't go this low or you're a multiple tenant housing dweller, then it's wasted $$/effort, but for those of us who want to reproduce all the signal without worrying about the driver unloading and are fortunate enough to have the required isolation...........

FWIW, back before HT got going good and CDs were for the most part BW limited to 20Hz, the lowest tuned systems I designed for others were usually tuned to ~27.5Hz, the lowest note on a piano, and for vinyl lovers, 32-40Hz depending on the driver/app..

GM

[taudo]

GM wrote:

>There are CD's around with 7-8Hz content
====

What are they recordings of? If 16 Hz is the lowest musical note, are these freq's just HT effects?

I'm fortunate enough to live where even recreational blasting would be tolerated, but I'm honestly wondering if I haven't already reached a cost/performance optimum for listening to _music_. Currently the "rate-limiting-step" is the recording. My system is capable of reproducing anything my existing recordings have on 'em, and of highlighting the large differences between recordings.

The self-powered, high Xmax HT subs I experimented with were capable of out-driving my A7's, but the result was NOT musical. When turned way down, however, they sounded surprisingly good [the 2235's are even better and more musical as well]

In a way, I guess I'll never know until I try a pair of "bone-crushers" and see how I like them.

taudo

[GM]

You ever noticed how there's something you can't quite put your finger on when listening to a reproduced drum solo, no matter how 'live' in SPL it is? The kickdrum has ~7, 14Hz sub harmonics that's felt, but precious few systems can reproduce if it's on the recording, and a few are. Then there's the organ's 16Hz, piano's 27.5Hz, etc., rolloff that subtly brings us closer to 'live'.

Sure, your system is at the ~95th percentile of reproducing the signal, so like anything else, getting the last ~5% becomes exponentially harder/more expensive to achieve. You'll just have to decide if you've already reached your personal point of diminishing returns. For some folks though, getting some semblance of the impact of cannon fire in the 1812 Overture or gut wrenching feel of a space shuttle launch alone is worth the price of admission.

Me, I've been almost to the 'top of the mountain' and it was a really sad day for me to have to give up both the quest and the performance I had, but I for sure don't regret the time/$$/effort.

GM