I finished a pair of these in time for Frankenfest as described in this thread:
https://audiokarma.org/forums/index.php?threads/rectilinear-iii-econowave.812079/
Here they are at the Oct. 23 2021 Frankenfest in West Boylston, MA this past Saturday:
They played bi-amped with a MiniDSP for the crossover since I've not yet designed a passive version.
It was also interesting that in my home I felt that they needed 4dB of boost at 28 Hz for a subjectively
flat response but in the large room it sounded better with the boost removed.
Anyway, they are tuned low in the bass to 28 Hz for the best compromise between musical deep
low end, box size and MaxSPL.
A few people asked me what tracks I was playing, and sorry for repeating these from previous
years but the album was Dig from Boz Scaggs tracks "Thanks to You" and "Miss Riddle" have
bass well below 40 Hz and that's what's needed to demonstrate a system with a very low cutoff.
This is not an audiophile recording so the bass is hyped up a bit and not as tight as it seems it
should be but overall it is overall a nice clean recording, far better than most non-audiophile
recordings. I also used a Telarc track "Use Me" by Junior Wells that is very clean and punchy
in the bass:
Paul McGowan of PS Audio, who I often do not agree with, talks about the album Dig here:
https://www.psaudio.com/pauls-posts/a-simple-test/
Note that most of the people commenting are way off with their statements about the frequencies involved
but McGowan does not state what the frequencies of the low bass notes are. I'm wondering what they are
in case anyone has a reference or has determined them. I have, in the past, pulled the music file into an audio
workstation and counted the cycles to figure out the frequencies involved but too lazy to do it today.
The Econo-Rec s are tuned to 28 Hz Fb which is quite low so I needed material with output
there. A0 (27.5 Hz) is the lowest note on an 88 key grand piano and that is a good reason to tune
there, also while 4 string basses so popular in the past had a lowest open E1 of about 42 Hz
newer 5 and 6 string basses have C1 around 32.7 Hz. See frequency of notes here:
https://www.seventhstring.com/resources/notefrequencies.html
Back in the mid 1990s I designed a floor stander with two 12" woofers on each side tuned to 20 Hz
and I had a list of the usual bass test tracks that I'll have to look up again.
There's also the Boston Audio Society test CD that I have a copy of and need to dig into and also some
Bosendorfer recordings of their 92 and 97 key pianos that go lower than the usual grand:
https://en.wikipedia.org/wiki/Imperial_Bösendorfer#:~:text=Bösendorfer Imperial Concert Grand pianos,computer reproducing system is installed.
Any suggestions for good sounding (well recorded) bass demo tracks with content below 40 Hz?
Not looking for sound effects and explosions.
The HT guys do a lot of analysis of source material that I have to look into again.
https://audiokarma.org/forums/index.php?threads/rectilinear-iii-econowave.812079/
Here they are at the Oct. 23 2021 Frankenfest in West Boylston, MA this past Saturday:
They played bi-amped with a MiniDSP for the crossover since I've not yet designed a passive version.
It was also interesting that in my home I felt that they needed 4dB of boost at 28 Hz for a subjectively
flat response but in the large room it sounded better with the boost removed.
Anyway, they are tuned low in the bass to 28 Hz for the best compromise between musical deep
low end, box size and MaxSPL.
A few people asked me what tracks I was playing, and sorry for repeating these from previous
years but the album was Dig from Boz Scaggs tracks "Thanks to You" and "Miss Riddle" have
bass well below 40 Hz and that's what's needed to demonstrate a system with a very low cutoff.
This is not an audiophile recording so the bass is hyped up a bit and not as tight as it seems it
should be but overall it is overall a nice clean recording, far better than most non-audiophile
recordings. I also used a Telarc track "Use Me" by Junior Wells that is very clean and punchy
in the bass:
Paul McGowan of PS Audio, who I often do not agree with, talks about the album Dig here:
https://www.psaudio.com/pauls-posts/a-simple-test/
Note that most of the people commenting are way off with their statements about the frequencies involved
but McGowan does not state what the frequencies of the low bass notes are. I'm wondering what they are
in case anyone has a reference or has determined them. I have, in the past, pulled the music file into an audio
workstation and counted the cycles to figure out the frequencies involved but too lazy to do it today.
The Econo-Rec s are tuned to 28 Hz Fb which is quite low so I needed material with output
there. A0 (27.5 Hz) is the lowest note on an 88 key grand piano and that is a good reason to tune
there, also while 4 string basses so popular in the past had a lowest open E1 of about 42 Hz
newer 5 and 6 string basses have C1 around 32.7 Hz. See frequency of notes here:
https://www.seventhstring.com/resources/notefrequencies.html
Back in the mid 1990s I designed a floor stander with two 12" woofers on each side tuned to 20 Hz
and I had a list of the usual bass test tracks that I'll have to look up again.
There's also the Boston Audio Society test CD that I have a copy of and need to dig into and also some
Bosendorfer recordings of their 92 and 97 key pianos that go lower than the usual grand:
https://en.wikipedia.org/wiki/Imperial_Bösendorfer#:~:text=Bösendorfer Imperial Concert Grand pianos,computer reproducing system is installed.
Any suggestions for good sounding (well recorded) bass demo tracks with content below 40 Hz?
Not looking for sound effects and explosions.
The HT guys do a lot of analysis of source material that I have to look into again.
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