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AR6 crossover for AR7


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Something I'm considering as an experiment, here's why:

Over the years it becomes apparent that the classic 2 way paper driver ARs adopted an ultra-simple crossover with just a single tweeter capacitor of around 6uf.

One has to ask why, and I can come up with a couple of reasons but primarily I keep returning to questions of cost and simplicity, particularly in the lower priced smaller models.

But there is a price to pay IME, since all of the capacitor only 8" bass driver models suffer some upper mid energy excess and cupped-hands colouration on vocals. This is the inevitable result of running the bass unit high, and a less than optimal power response from this relatively large driver operating into the upper mids, then crossing to the much smaller tweeter cone.

So I'm wondering if the older designs which rolled down the woofer earlier and crossed the tweeter a little lower were in fact superior from a pure performance POV, though obviously more costly to produce.

Therefore, given the AR6 and AR7 in their later mid 70s incarnation used the same drivers, I'm going to experiment with the AR6 type B crossover on the AR7.

Anyone else tried this, or interested in the project which I'll happily document with measurements?


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I seem to remember some excellent work you did with a pair of AR-4xa's maybe a year or two ago, which included some interesting tweeter level controls which were unfamiliar to me. That said, I'll be very interested to see where you go with this study with these other small two-way speakers, as well as what sort of discussion arises. If I understand you correctly, you intend to install the second AR-6 crossover [version B] into AR-7 cabinets with original drivers. See attached schematics.

Looking thru the various bits of published material I have collected, I see that the AR-7 had a x-o freq. at 2000Hz, and I am pretty certain this model never underwent any changes in driver selection (except that the 8" universal replacement woofer was indeed different from the factory flat-cap original). For the 4xa, I have only seen its x-o freq. reported as 1600Hz, even though this model most certainly employed at least two different woofers (cloth-alnico and foam-ceramic) throughout its production run. Not sure if the tweeter part number or construction ever changed on the 4xa.

As you know, the AR-6 has a more complex history with greater variation in components throughout its production. Drivers, coils, capacitors, switches and driver phasing all appear to have been revised at various points of production. For some time I had been led to believe that these parts changes still resulted in a speaker which was designed to perform to the same engineering standards, but I can no longer be convinced of that. Different drivers, different crossover circuits and now I see different x-o frequencies. Various published documents for the AR-6 list this as: 1500Hz (1971 AR lit.); 2000Hz (1972 review); and 1800Hz (1973 and 74 AR lit.).

Based on your past project, I would have thought your first inclination might be to try to adapt the AR-7 crossover more closely toward the simpler AR-4xa rather than the more complex AR-6, but nonetheless, I'll be interested to see where you go with this study.


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Many thanks for the comments.

I don't intend to the change the tweeter attenuator, just the filter network.

I can certainly try the 4xa filter, though given the 7 and 6 drivers are effectively the same (very early 6 excluded) I would expect the revised 7 to perform much like the mid 70s AR6 but with less low bass due to the smaller cabinet.

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  • 5 years later...

I own both AR6 and AR7 speakers. The AR7 speakers sound better than my AR6 speakers in original configuration. 

My AR6 speakers now have a crossover similar to the AR7. The AR6’s  now have the combined attributes of both: openness and natual sound with a better (AR6) low end  

To go the other direction (replace the original AR7 crossover with the original AR6 crossover) is a step backwards. 

It is also very presumptuous to think that AR would place cost at the forefront of proper design and a well established reputation for sound reproduction accuracy and product quality, at least at the time of the AR7 introduction. 

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  • 1 month later...

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