View Full Version : Janis w-1 withjanis cross over amp setup

Gent gerard
12-03-2012, 06:22 PM
I have a JANIS W-1 subwoofer with the Interphase 3-a electric crossover amp.I need to connect to a HEATHKIT AP 1800.I have never hooked up a sub before.Connections on the back are left and right RCA plugs marked input and left and right RCA plugs marked to the main amp.Any help would be great.

12-03-2012, 07:33 PM
Pictures are worth a thousand words.

12-04-2012, 07:19 AM
This might help:


Already in 1970 John Marovskis from the Bronx (New York) designed his extraordinary Janis W-1 subwoofer. The story goes that he made some 50 cabinets before he arrived at the excellent sonic performance of his system which has a flat frequency response from 30 to 100 Hz. (-3dB). He designed an electronic crossover module with a 60 Watt amplifier to go with the handsomely finished cabinet. He called this elelctronic crossover unit with amplifier, Janis Interphase with a fixed crossover frequency of 100 Hz. Both low pass and high pass sections filtered with 18 dB slopes. Later he designed a smaller Janis W-2 to add to his catalog, and also another version of the Interphase. The crossover frequency was fixed at 100 Hz. The Janis Interphase filtered the low pass section (Janis W1 or smaller W2) and the high pass section (satellites) with slopes of 18 dB per octave.
Another, most important feature of the Interphase modules was the continuous variable phase adjustment of the subwoofer (0-180) in order to achieve a seamless and harmonious integration of subwoofer and satellites, independent of the subwoofer's position in the room.
Dutch importer Jan Endenburg told in an interview that he had read about the Janis W-1 system in 1970 in an article written by Bert Whyte (published in AUDIO) and when he was in New York he called John Marovskis asking where he could hear the Janis subwoofer. Marovskis asked Jan Endenburg where he was calling from. "I am in New York", Endeburg said. John Marovskis invited him to his home and demonstrated the systems set up with Quad ESL loudspeakers. That is how Endenburg's firm Engasound became the importer for the Netherlands. It was Jan Endenburg who explained to me the importance of phase and he pointed out to me that optimum phase coherence could also be obtained by using a 12dB low pass for the Janis W1 and a 6dB high pass filter for the satellite speaker as was achieved by the than cherished and famous Symmetry Electronic Crossover. But I found that the 18 dB slopes were much cleaner and also the Symmetry did not have this variable phase.


Once in a while you read a rather negative review about the Janis subs. But these are always written by people who do not know how to use the Janis sub woofers. They make the mistake of using high current amplifiers (NAD, Rotel, Bryston, etc.) that get their power out of the large toroidal transformer instead of large capacitors. Toroidal transformers cannot deliver enough current and are soon exhausted because they need to deliver current directly out of the AC mains. In the past I have tried a Tandberg power amplifier for the satellites. They did not match at all. The sound of the Janis Woofers became realistically impressive only when using amplifiers that really go with the nature of the Janis Interphase. For instance when an Amcron power amplifier was used to furnish the power to the satellites. The Janis worked also perfectly well with mono blocks from French manufacturer Elipson. Just to mention some historical units. If you combine the Janis Interphase with the right amplification then the music will get its impact and slam. Not only when playing Tchaikovsky's 1812, but any record from your collection.
In recording studios in Hilversum (The Netherlands) Janis Subs were used in the nineteen seventies en eighties. Below the frequency response curve of the Janis W-1 (from the literature provided by John Marovskis).

Another favorite bass system from the past was the Hartley sub woofer which was combined with de Decca Ribbon high frequency unit and the Quad electrostatic speakers (ESL). Impressive as well. (See: The Decca London Ribbon Horn Tweeter.)


12-04-2012, 07:44 AM
I've got the instructions for the Interphase 1a, but I'm guessing that might not help you ??

If you think it might, send me a PM.

12-04-2012, 08:37 AM
Wiring them up is pretty straight forward. The Interphase amp/crossover has four RCA connections, two in from the preamp/tape out, and two for return to the amp in or tape return. The Interphase unit also has a pair of speaker terminals to feed the sub. The Crossover is incorporated into the sub amplifier assy. so there really isn't anything else to it. Play with the phase adjustment until the sub seems to most sonically "disappear"...there is no "right" adjustment, it's right when you think it sounds best.

12-04-2012, 09:57 AM
I have that sub as well and it is a very good one IMHO.

Gent gerard
12-04-2012, 10:16 AM
So basically tape out on pre amp to the woofers amp in. Tape in to woofer RCAs marked TO MAIN AMP.If so I got nothing.The woofer says it has a fuse.It is my understanding the bottom is sealed and very hard to get in to.The woofer says their is a fuse on the bottom.

12-04-2012, 11:16 AM
It sounds like you might have to select Tape Monitor on the preamp in order to listen to the signal coming back from the sub. But even if you haven't done that, the sub should work but nothing else. If your sub isn't working it does sound like there is something hinky going on.

+1 on the pics of the jack panels.

12-04-2012, 11:45 AM
If he uses tape out how is the volume of the sub controlled? He would need a pre out signal, which it sounds like he doesn't have. Sounds like those pieces are not compatible.

Gent gerard
12-04-2012, 01:41 PM
Here are pics of the woofer amp and some of the back of my heathkit ap-1800.The 1800 is connected to a ADCOM GFA 555.Bad pics of my pre Ididnot want to totally disconnect it.

12-04-2012, 01:44 PM
Never seen a setup like this, it's very unusual.

12-04-2012, 03:02 PM
If you're using a preamp & amp, it couldn't be simpler. Just run one RCA cord (stereo paired R&L) from the preamp OUT to the IN on the Janis amp, then run another RCA cord from the Janis amp OUT to the amp IN. In affect you are just putting the Janis crossover/amp unit BETWEEN your existing preamp, and amplifier.
If you are using an integrated amp, or receiver, you will wire it into the TAPE IN & OUT, the same way. Once it is wired into the tape IN/OUT of your receiver, you will then need to push in the "tape monitor" button. Just remember to always connect one "out" to another "in", never IN/IN, or OUT/OUT!

This sub is wired exactly the same as any other powered sub, the only difference is that the woofer happens to be in a separate box from the amp/crossover so there is also a speaker wire to connect the two.

Gent gerard
12-04-2012, 03:30 PM
There is not a pre amp in on the heathkit ap-1800.There are two pre amp outs.There is an adaptor in and out with a switch on ther front.Tried the tape in and out no luck.I really would like to hear this sub. Thanks

12-04-2012, 03:42 PM
So, if I understand this correctly, you are using the Heathkit (receiver with a "pre out") to drive an Adcom 555, and it is working fine without the sub. OK, then all you have to do is take the RCA that is currently going into the Adcom, and put it into the "amp in" location of the Janis instead. Now, run another RCA from the Janis's "amp out" to your Adcom... simple! If it doesn't work that way, there is something wrong with the Janis Interphase unit.

...I just looked up that Heath preamp, and it is an interesting bird - I've seen similar, but not many. It appears to have speaker inputs & outputs so that you can run the amp output back into the preamp so that you can control speaker selection. The reason you don't have a "pre-in" is because it's a preamp, not an integrated, even though it has speaker outputs! Wiring the Janis between the Heath's pre-out, and the Adcom's input is still the simplest & best sounding way to go. You could also just connect the Janis "in" to the second "pre-out", and not bother with the Janis's RCA "out" at all, but that would leave your mains to run full range along side the sub. Such a set up usually creates more upper bass than you want, and limits the system's peak output to what the main speakers were capable of without the sub. Like most things in audio, simpler is better, so try just putting it inbetween the Heath & Adcom first.

Gent gerard
12-04-2012, 04:16 PM
O.K got the sub running though the tape 2.Opened the JANIS crossover/amp bad fuse all lights where on.Got everything working but the sub is rattling inside.SOUND,but sounds like the woofer needs refoamed or shot.Should I brake the seal on the bottom and have a look? I have nothing to lose. Thanks for all the info

12-04-2012, 04:50 PM
I would definitely have a look inside that sub before running it any more. It does not have a grille that can be removed?

12-04-2012, 06:28 PM
I would definitely have a look inside that sub before running it any more. It does not have a grille that can be removed?

the bottom comes off. the driver is up firing into the top slot.

Gent gerard
12-04-2012, 07:00 PM
Got the bottom off.The woofer seems fine nothing is shaking or loose.Hooked the woofer up like a regular speaker,sounded fine.Thanks for all the help. Moving on to have the amp checked out. Thanks Gent

12-04-2012, 07:31 PM
If you connect the sub woofer to a tape monitor loop you have to separately adjust the subs volume. The best way to connect it is as frommerstop suggested.

12-05-2012, 04:57 PM
O.K got the sub running though the tape 2.Opened the JANIS crossover/amp bad fuse all lights where on.Got everything working but the sub is rattling inside.SOUND,but sounds like the woofer needs refoamed or shot.Should I brake the seal on the bottom and have a look? I have nothing to lose. Thanks for all the info

Can you describe the problem with a little more detail? I can't think of any amp or crossover issue that would cause, what I would describe as, a "rattling sound". My experience with Janis subs is that they are pretty reliable. Maybe you could try running it simply off the second pre-out to see if the noise goes away.

BTW, I know there are a lot of folks that think the Janis used a "cheap" woofer, and there are a number of threads on line about replacing the driver with something "better". IME the original woofer is perfectly suited to it's job, and at best, most replacements are just as good... often worse! It does have a small magnet, but it was chosen for that cabinet & loading, and it works well enough to achieve 30-100htz +/-1db! That's pretty darned good, even by current sub standards, much less a sub designed in the sixties!