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In the Forum: Melquiades Amplifier
In the Thread: Planning my DSET
Post Subject: Not exactly flat to 18Hz...Posted by anthony on: 3/2/2019
There are still room modes to contend with the first starting at about 41Hz.
Here is an impedance plot of the left Bass Cannon as seen by the amplifier, so including speaker cable.
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As you can see I managed to get Fs down to about 44Hz and it turns out and an impedance range of about 1.1R to 3.15R, which apart from the unavoidable resonance peak is pretty flat from 5Hz - 1kHz. Due to their dimensions I've had to use a very particular damping scheme of the Cannons to get this 'flatness'. I also made quite an effort to seal up my room to get best use of 'room gain'.
The left Bass Cannon measured at the listening position in my untreated room gives the following graph:
So not exactly flat, but conforming quite closely to expected room behaviour. I am confident that I can greatly flatten those hills and fill those hollows and have run a few tests with just a couple of bags of wall insulation brought into the room and have had improvements in all of the hollows of up to 15dB and the peaks have come down a few dB each. 41Hz, is the biggest challenge, but I think I will be able to knock a fair bit from it without too much treatment.
The Upperbass Horns are still a ways from finished, but I am certainly trying to get them finished. In the meantime I will work on the second DSET and perhaps take some measurements and give this first one a thorough check-over now that it seems to be reliable.
Regards,
Anthony Rerurn to Romy the Cat's Site