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In the Forum: Melquiades Amplifier
In the Thread: Planning my DSET
Post Subject: Many variables in playPosted by Romy the Cat on: 3/3/2019
I do not care about the room treatment at this point. The treatment
you use looks like very effective but it is very premature in my mind to think
about it. It is not to mention that the
contribution the treatment has to LF frequency response is usually dubious as
it frequently shorter reverberation time very unproportionable and more effective
at upper bass then lower bass.
What strikes me most is not you response, that might be worked
anyhow, but rather the fact that you use your 60Hz low pass filter and you looks
like do not have a good roll off. I was expecting that you upper knee of you LF
will roll of much sipper. My tower with the very same drivers do decay much
faster with the same filter. I do not know what cause of it. It might be enclosure
that looks like “beaming” too much and the way how you room is you have no
option to toe out your woofer tower away from you listening position. I am not
sure it would be even effective at 200-400Hz…
Anyway, you might consider going with second order in you
bass tower. It is not something the you need to do now but keep it in your mind
as an option. It would not be hard to do. The final design you will be making what
you have your upperbass horn in place. You might use the decay of you woofer toward
as some sort of pedal point that will have a foundation of your third octave,
what they call drone, but your upper bass should ride atop as a alien dissonant
harmony.
The setting I describe above This requires some very precise
tuning and no measurement will help you, you need to do it by ears. You see, the sonic output of your woofer towers
above 100H is very bad quality in my view. Hone is much more interesting, but
it might not be “enough”. To run the woofer tower’s long tail is good way to
beef up you above 100Hz but it needs to be done in proper balance. You run the woofer
towers above 100Hz too hot, and you will make your very lower MF too impersonalized.
If you run your woofer towers too shallow above 100Hz then you will use too
sharp filter in you A-channel and you might lose some imaging at lower octaves.
So, it is delicate game that you will need to play and ultimately you will make
your own design based upon what you room can tolerate and demand.
Generally, I do not think you are ready now to think about
it and there are other things that very much mask your ability to make the
final decision about idiosyncrasies of LF and upperbass integration. Here is
the methodologically proper sequence that I recommend.
1)
Make the speakers and amps fully operational.
2)
Use default Upperbass configuration
3)
Find an approximate LF configuration,
not perfect but listenable, use digital crossover is fine at this point.
4)
Spend at least a week to listening
and get comfortable with sound, not truly conformable but rather well familiar
with the problem you have sub 500Hz, catalog the problem, literally write them
down.
5)
Connect the upperbass horn to C channel
(full range) and begin to play with volume and filter.
6)
Get the “feeling” how much you want
the upperbass to ride over the LF
7)
Begin to fine tune your LF section
8)
After the LF is done then reapply that
comfortable to you the “feeling” of upperbass to ride over the LF
When you begin to play with upperbass in my view the main dilemma
that you need to decide for your is now to roll off the volume of the upperbass.
You can do it with voltage divider at the “B” channel as I did in my case or
you can do it by change the loading of output stage of your “B” channel. Unloading
the output stage more will give you less distortions, faster sound, more transients,
more dryness and less lash sound. It is not necessary too good but if you have
the upperbass well supported by your LF at let say minus 8-9dB then you might
like it. Eventually you will find the balance you like. I have found mine running
the OPT in “B” configuration and burning some volume in resistors but you have
a different OPT and different upperbass penetration by your lower bass. You might
find a different configuration that you feel conformable.
Also do not forget that I run now a dedicated midbass channel,
it means the I felt that to have LF and upperbass was not enough…, but it was
not enough ONLY in context of my current room… so as you see there are many variables
in play…Rerurn to Romy the Cat's Site