Hedd Type 05 mk2 with a sub (JL Audio d108)
Here are a few more observations of the Hedds, paired with a (JL Audio) sub and there were a few surprises!
First off, I initially switched the Type 05s to ‘Sub (80hz)’ using one of the 3 position switches on the rear panel. I then switched the JL sub so that it was using its own internal filters (set to approx 80hz low pass filter).
The sound was different, but surprisingly, not the change I was expecting - a touch muddied in the bass register. Weird, I thought. After listening for an hour or two, I thought I’d leave it, and return to listen/fiddle around some more the following day.
Next day, I re-connected my Behringer active filter that I thought would become redundant with the Hedd type 05s. I also switched the ‘sub’ setting on the Hedds back to the off position (as I thought that leaving it on would create a double high pass filter). Voila! - the sound was now clear as a bell with no more smearing of sound caused by overlapping (<80hz) bass frequencies. I now strongly suspected that the ‘sub’ switch on the Type 05s was NOT acting as a high pass filter. So what does it do?
Having re-read the review on the Soundstagesimplifi.com site (see above), I think the reviewer made the same mistake. It appears (I may be wrong and I’m going to contact Hedd on this) that the ‘sub’ switch produces a small delay from the Hedds to linearise the sound from the main speakers to match that of the sub (irrespective of make and model). Earlier on tonight, I switched the ‘sub’ setting back on. Another audible improvement!
The sound had improved yet again. I am very impressed by the sound quality this combination (Hedd 05 + Sub) is now producing. Sounds literally appear from an expansive soundstage with crystalline clarity. Lyrics can be made out easily and decay of notes linger longer (e.g. a better ring at the end of a symbol hit), drum hits are easily distinguishable from the rest of the mix. Bass notes, are of course, distinct and well rounded - the Hedd is no longer having to do any of the <80hz work so it's free to produce effortless mid/treble ****
I could go on and on waxing lyrical (but won't!). Needless to say, I’m very (very) impressed. The Hedds are a great little speaker when used on their own. When combined with a sub + a method of high passing the main speakers, they are tremendous.
**** I have found the filter frequency scales on the sub as well as on the active filter to be less than 'spot on' and some careful adjustment/fiddling is in order to get things right. So far, I have only ever used my ears (+ others in the family with better ones) as well as some basic db readings from my phone. At some point, I might finally get round to some proper room measurements.