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Peter Wieck[_2_] Peter Wieck[_2_] is offline
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Default Attenuate highest highs?

Please note the interpolations.


so there might be relevant info there. I'm using a very basic pre-amp with no tone controls and a certain Dynaco ST120 power amp. There is a pass-through crossover between the two taking everything below 70Hz to a 10" subwoofer as described in another post.


I see that. And you mentioned that the Sub amp has a level-control. Have you tried boosting that just a bit?


Were I to run the system "flat", I would have exactly the problem you describe. The 3x has a 'loudness' switch that boosts the bass relative to the treble, just a bit. That allows a more balanced perceived sound at the low levels I use. That capability went out of style more-or-less in the 1980s.. The other option would be an outboard equalizer - overkill certainly, but an option.


I've been watching auctions for good quality EQs but unfortunately anything other than used
gimmicky plastic 90s things (that people seem to ask new prices for) are well beyond my price range.


The SE-10 I mentioned came my way for $0, as it was perceived as totally dead from the BIN (Buy-it-Now) pile at Kutztown. You will notice that the fuse is inside... and missing in the example I found. As I have my original example purchased as a kit, I do not need two. So, to you it would be cost-of-shipping, not inconsiderable.


The 'disrupter' method, while cute, may require you to try many sorts of materials before you are satisfied and/or may require different materials based on the signal at hand. It does *work* however.


Getting back to your sub-amp. I am assuming that it is strapped for a single output at 300 watts into 4 ohms. For the record, driving 2N3773s in that configuration to 300 watts is wildly optimistic. Much as one *can* operate a Ford Focus engine at 6,000 RPM - just not for very long. All that aside, I also understand that particular amp sometimes has a problem amplifying mains current hum? When I looked it up, I saw no associated power-supply (or, to be fair, no transformer) or diode/capacitor block. Just a "suggested power supply" http://home.alphalink.com.au/~cambie/PM300/PM300.htm I would also 'fix' the bias (replace the pots) for stability, once you are sure of the proper value(s). A number of US manufacturers used pots back in the day - and as the pots went open, all that magic smoke escaped. And given that device was designed c. 1980, that may be a consideration.

Cutting to the chase, try playing around with the bass output levels, and keep in mind that pretty much anything below 500 HZ is non-directional in any case - such that distance between the treble source and bass source (and you) are the governing factors, not direction. Leading to having the bass source, ideally, the same physical distance from your ears as the treble source. Do also verify phasing - speakers out-of-phase give all sorts of unhappy effects.

Some "stuff" on that: https://us.kef.com/blog/how-to-get-t...nd-positioning

Some further experimentation with placement may be in order.

Peter Wieck
Melrose Park, PA