, Various, Spectra 2200 and 1100 make a 3300?

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Erik Klijnsmit2004-02-23 22:21

Hi Andy, I have a pair of Spectra 2200. Now I have also a pair Acoustat panels from the 1100. Can I put them together to make a Spectra 3300? I have read the schematics from the 2200/3300 and it is almost the same.

And now the question. Which panel must have the high, which panel must have the mid and which panel must have the low tones ? The Spectra 2200 have one strip high ,one strip mid, and then two strips low but how must i fix the 3300 panels. Greatings, Erik Klijnsmit, Holland.


Andy Szabo2004-02-23 22:21

Converting a Spectra 2200 into a 3300 is certainly possible with the addition of two more Spectra panels and a new frame. The 3300 is merely a 2200 with extra area for bass reproduction. Panels from any Spectra model may be used: they are all the same.

Complete frame drawings for the Spectra 3300 are available from this site. The frame is very similar to the 2200, only wider. Use your existing 2200 frame as a guide. The decorative wood & brass strips from the 2200 may be reused on the new speaker. You\'ll also need to construct a wider base, and make a longer metal plate for the top of the speaker. This site lists a source for new grille socks.

The two original (2200) panels are mounted towards the inside edge of each new frame. That is, towards the right side of the left frame, and towards the left side of the right frame. All four sectors of the original panels are wired the same as in the 2200.

The new panel is mounted at the outside edge of each frame. Both sectors will be connected to the ”low frequency only” outputs. These are the blue/black and white/black output terminals on the interface. See the diagram for clarification on the sector wiring, and the relationship between the different models.

The wire leads on a panel from an 1100 may be too short to reach down to the interface. I suggest using high-voltage wire to extend the leads, insulating all splices with a double layer of heat-shrink tubing.

Due to the added area for bass-only reproduction, less bass boost is required from the interface. This is accomplished by changing the low-frequency tap on the two audio transformers. The 2200 uses the red tap, and the 3300 uses the orange tap. Considerable disassembly of the interface is necessary to access these wires: they are underneath the transformers. Some of the wires will need to be unsoldered from the pc boards before the transformer assembly may be unbolted and lifted from the chassis.

Good Luck: this sounds like a fun project!

Mat2012-03-04 18:12

I wonder if Erik is still around to comment on this project, did it work for him and how did it sound? Great idea!


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