Hi,
the mouth area of your horn will cut off at about 90Hz if you use both floor and rear wall loading.
The actual mouth area (Sm)=0.27sqm.
Wall + floor loading gives an effective area = 4 * Sm = 1.1sqm.
The circumference of the equivalent area is 3.71m and this equates to 92Hz.
However your length will allow some output down to about 50Hz but because you have truncated the the horn early I think the ripples in the low end response will be quite severe.
If you can achieve corner loading then that will extend the response down to 65Hz. In this case rear exit from the horn could use the corner as part of the horn expansion and could give an effective doubling again in the mouth area. Some experimentation here I think?
the mouth area of your horn will cut off at about 90Hz if you use both floor and rear wall loading.
The actual mouth area (Sm)=0.27sqm.
Wall + floor loading gives an effective area = 4 * Sm = 1.1sqm.
The circumference of the equivalent area is 3.71m and this equates to 92Hz.
However your length will allow some output down to about 50Hz but because you have truncated the the horn early I think the ripples in the low end response will be quite severe.
If you can achieve corner loading then that will extend the response down to 65Hz. In this case rear exit from the horn could use the corner as part of the horn expansion and could give an effective doubling again in the mouth area. Some experimentation here I think?
Thanks, lazy as I am I´m always happy when someone else does my maths🙂
The term "sub" was a bit optimistic in the first place, the idea is to add just a little bit of bottom end to a pair of tiny BL horns with FE107E drivers that I already have (my own design but quite similar to Buschorns.)
I´ve ordered a pair of (cheap) drivers (Qts 0,36 Fs 44Hz) but I haven´t started cutting any wood yet, so there is still time for changes. I must admit that WAF is of major importance here, thats why I bother to design the horn in such a way that it can be used as a TV bench.
Maybe a double horn that couples to both floor and back wall would be better?
The term "sub" was a bit optimistic in the first place, the idea is to add just a little bit of bottom end to a pair of tiny BL horns with FE107E drivers that I already have (my own design but quite similar to Buschorns.)
I´ve ordered a pair of (cheap) drivers (Qts 0,36 Fs 44Hz) but I haven´t started cutting any wood yet, so there is still time for changes. I must admit that WAF is of major importance here, thats why I bother to design the horn in such a way that it can be used as a TV bench.
Maybe a double horn that couples to both floor and back wall would be better?
Fuling said:
when i saw this post, i was having the same thoughts about double horns.
also consider that you will get bass from the sealed box behind the driver
AndrewT said:
through the horn.
i should have been more explicit, .. the volume of air behind the driver loads the driver like a sealed system
HideAway Sub
Hi Fuling (nice name)
I have made a TL sub with a very good SAF, which might give you some ideas. I am writing on an article about this design. The geometry ends up with a tuning frequency of 25 Hz, and as both the opening and the driver is at the floor, I am very satisfied with the performance.
Hi from Wonderful Copenhagen
Hi Fuling (nice name)
I have made a TL sub with a very good SAF, which might give you some ideas. I am writing on an article about this design. The geometry ends up with a tuning frequency of 25 Hz, and as both the opening and the driver is at the floor, I am very satisfied with the performance.
Hi from Wonderful Copenhagen
Just a few basic-guidelines:
A stand-alone hornsub with lack of moutharea largely depends on a large rearchamber.
As a rule of thumb: How low it will actually go, depends on the hornlength. How sensitive it will be at low frequencies is determined by the moutharea. For mouth area; The bigger the better, up to a certain point, few will ever reach, where it will work against you. Play around with the compressionfactor as well. For length (and compressionfactor); Keep it real!! 😉
If you don't have enough moutharea you can give it a larger rearchamber at the cost of excursion and thus powerhandling and maximum SPL.
Always design for 1/4 or 1/8 space and keep the roomgain in mind.
Mvg Johan
A stand-alone hornsub with lack of moutharea largely depends on a large rearchamber.
As a rule of thumb: How low it will actually go, depends on the hornlength. How sensitive it will be at low frequencies is determined by the moutharea. For mouth area; The bigger the better, up to a certain point, few will ever reach, where it will work against you. Play around with the compressionfactor as well. For length (and compressionfactor); Keep it real!! 😉
If you don't have enough moutharea you can give it a larger rearchamber at the cost of excursion and thus powerhandling and maximum SPL.
Always design for 1/4 or 1/8 space and keep the roomgain in mind.
Mvg Johan
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