Having been contacted by a certain Mr Bernie Candy and his “floppy bottom”, we initially instructed him to run our bass test tone set and report back with his results . However, with the findings a little inconclusive (a lack of bass notes significantly louder than others), a visit was made, during which we measured the reverberation time. It was now obvious why the listening test revealed so little !!.
The room, with it’s 4 x 5.25 x 2.5 dimensions falls well within all 3 of the classical “favorable ratios” studies, and just happens to be, exactly No 9 of Louden’s “top twenty” room ratios for “best bass”. This means that the rooms resonances are quite evenly spread, resulting in (from, say 40 Hz) more than 2 octaves of low frequency resonances, all playing their part in making bass take, almost forever to decay.
The graph shows:
In RED:- The Reverberation time in Bernie’s room (RT60), and it’s 3 distinct peaks. The issue with well spaced resonant frequencies though, is the large number of resonances between the more obvious peaks. This adds up to a relatively large frequency range of long decay time, and makes targeted “single frequency” treatment, with devices like RaTs impractical. With different room dimensions however, the peaks are often more “stand alone” and therefore easier to treat in a targeted manner.
Our own evaluation room’s reverberation time for comparison.
Bernie’s own complaint (if that’s the right word) was that “more modern” or significantly “bass heavy” recordings were unplayable, due to a seriously overwhelming and uncontrolled amount of bass. In subjective listening, the sheer amount of bass and it’s extended decay time were certainly ridiculous and totally “musically destructive” – rendering any recording with “a bit of extra” bass completely void of dynamics and swamped by bass rampaging around the room !.
This is typical of the rooms reaction (or lack of) to music with a reasonable bass content … We’ve deliberately stopped the track a few times “mid bass note” …
Here, we’ve put in a little lump of silence, at the point in time, where the bass note recorded has all but died away, so, what you hear after the lump of silence is all down to the room !
Even so, these recordings can’t do real justice as to just how long, heavy and loud the bass overhang is in reality !!!
This is what the sounds waveform look like, showing the point where the sound itself stops, and the room takes over ..
The answer, as I recommended, and was agreed, was to introduce our DSP1 controller to give low frequency room correction, ahead of any physical bass trapping in future . As you’d need so much physical bass trapping to do the job on it’s own, it seems only fair and sensible to give the room a head start with treatment that really has no aesthetic or space issue and a much reduced cost issue. Then, far less actual physical trapping can complete the treatment to a point where both the room itself, and the reproduced music within, are on the same “aural planet” and music sounds, well … musical !
The “purest’s” among us would argue that adding anything in the way of system components, and increased cable/s and connectors is definitely not the way to go, but in this case, there’s a really strong argument for : Any insertion losses, due to added components, will be seriously overshadowed and negated by the overall gains achieved. Effectively, it’s the wrong kit – in the right place !
Which, as predicted, is actually the case, having turned a system from basically unusable to very usable, and sounding, overall, far better, with increased dynamics, better bass detail and musicality, a cleaner, more “airy” mid and top, with a more “holographic” image.
In short, a system that actually makes music, rather than one that’s only switched on with trepidation !!
We did try …
We did try to minimise insertion losses and keep signal path lengths to a minimum, but Bernie’s much loved Cyrus, unfortunately, isn’t blessed with a “pre out” / “power amp in” loop, so, some how or other we were forced into effectively creating an insert point to get our signal into and back out of the DSP. We even went as far as a chat with Cyrus, who, for their own reasons, were not in the mood to offer circuit details that would have allowed a modification, in much the same way as we, were not entirely in the mood to conduct a modification, without their blessing. As an aggregate effect then, the insertion loss is more than, in an ideal world, it could have been. But, in practice, still of absolutely no real consequence given the massive improvement. An improvement, that in itself is only likely to keep improving, as more and more “digital era” bass heavy music adds to the record collection.