Bert's Subwoofer/My subwoofer (Off Topic)
Ha Bert,
You are finally taking the big horn out of business? A funny coincidence, I have glue drying on a subhorn. 
My girlfriend has moved in, with All Her Stuff... We have hundreds of books, CDs and DVDs and instead of devoting a wall and a half to my system (
), we need some wall for bookcases. I told my girlfriend I was taking one corner and she could have the other. :wink: Free space in "my" corner is large enough to house an Electrovoice Patrician, so anything smaller will fit as well. Obviously, this is a sub/sat approach. Pros and cons, but in my situation this was the most feasible compromise.
I started off with the corner Schmacks for 12 inch speakers, picture below. There are various reasons, one of them is reputation, another is that it's easy to build. Also, there's an interesting anomaly in this design: it's made of soft fiberboard. I didn't believe it at first, but various builders of the horn confirm that this is the best material. They think it's about damping resonances, worth a try. It can also be cut with a knife, which is handy when you don't have a workshop. The inside panels are finished and glued to the baffle, now it's a matter of glueing on the side and back panels.
[img]http://www.v-2u.dds.nl/30cmschmackstoon.jpg[/img]
Simulated response is somewhere between 30-40 Hz, plenty for now. However, I have never made a speaker out of this material before and I wonder if bass will come out of this horn at all...:confused: We'll just have to wait and see/hear.
Enjoy spring!
Ivo
PS: My system is clearly in a different league then most of the other posters around here. 
Addition, BD-Design subwoofer
Bert,
Are you going to release a subwoofer? I know that you think a full 20Hz is not necessary for good music reproduction. I had a good glimpse of Reality when I heard your Swings while they were still being tuned, so I believe you. But your "wall of sound" seems to suggest you enjoy some good low bass from time to time.
Ivo
Addition, BD-Design subwoofer
by Bert 
, Monday, April 30, 2007, 19:03 (6203 days ago) @ Ivo
Hi Ivo,
Are you going to release a subwoofer? I know that you think a full 20Hz is
not necessary for good music reproduction. I had a good glimpse of Reality
when I heard your Swings while they were still being tuned, so I believe
you. But your "wall of sound" seems to suggest you enjoy some good low
bass from time to time.
No, not yet. The subwoofer I am planning is the one only for me.... it will have a HUGE headroom and easily go down to 5Hz (without sweating) resulting in a very clean subrange.. with that experience I can tell if we need more output below 30Hz or not.
Some records do have output there (Hatsfield, organ, ambiance) and some latest experiments do tell me that there is something to enjoy below. With movies this usually is the case to make that more fun....
Shaking baby...
Bert
--
BD-Design - Only the Best!
Addition, BD-Design subwoofer
Hi Bert,
with that experience I can tell if we need more output below 30Hz or not.
With poor bass systems, I rather listen without low bass, it ads chaos and takes away air. With good bass systems, I enjoy the added space in the sound. Somehow there is more clarity with real deep bass, but only if it's clean. I heard maybe 3 systems where I was happy with the extreme low bass, the rest was a disappointment.
I mostly like the deeper bass response with acoustic recordings.
Ivo
Clean Bass?
by MikeH , Tuesday, May 01, 2007, 05:20 (6202 days ago) @ Ivo
Ivo, in your searching have you listened to one of those servo subs? they have an extra "voice coil" to detect cone position.
they look interesting but I'm a bit old fashioned and I'm wary of non-paper cones.
Sub inserted in my system .
hi all
i finished a subwoofer cabinet for the Aura 1808 sub yesterday, based on original plans from seismic sub's company ( witch does not exist anymore ). The Aura1808 has been replaced with the model NRT18.8. I played the cd bass test $ bass tracks, it shaked all the windows, even a lamp of the ceiling falled down. I heard something similar only with the Eminent propeller sub, witch goes down to 2hz. It is incredible. Not boomy, with explosive impact , very dry and clean, and musical finesse at the same time!
rds Angelo
![[image]](images/uploaded/image39.gif)
Bert's Subwoofer/My subwoofer
by Bert , Monday, April 30, 2007, 18:59 (6203 days ago) @ Ivo
Hi Ivo,
You are finally taking the big horn out of business? A funny coincidence,
I have glue drying on a subhorn.
I have to do that if I want to go deep down under...your smacks will stop below 30Hz rapidly..
Simulated response is somewhere between 30-40 Hz, plenty for now. However,
I have never made a speaker out of this material before and I wonder if
bass will come out of this horn at all...:confused: We'll just have to
wait and see/hear.
The soft material will probably reduce the low midrange colouration (boost) but will also lower the sensitivity in the lowest frequencies a bit...
Bert
--
BD-Design - Only the Best!
Bert's Subwoofer/My subwoofer
Bert,
your smacks will stop below 30Hz rapidly..
I think that will already be an earthquake, compared to the 60Hz I have now.
The soft material will probably reduce the low midrange colouration
(boost) but will also lower the sensitivity in the lowest frequencies a
bit...
A bit? Are we talking 1dB or 12 dB? I don't know what to expect, at all...
Anyway, there will be a PA driver in it, 97dB/1w/1m efficiency and a good power amp driving it, so there is plenty of headroom to boost a little here and there. It will probably be alright.
Ivo
Bert's Subwoofer/My subwoofer
by Bert , Monday, April 30, 2007, 23:11 (6203 days ago) @ Ivo
Hi Ivo,
A bit? Are we talking 1dB or 12 dB? I don't know what to expect, at all...
The weaker the construction the less output in the deeper frequencies. No idea how many bits though...
Anyway, there will be a PA driver in it, 97dB/1w/1m efficiency and a good
power amp driving it, so there is plenty of headroom to boost a little
here and there. It will probably be alright.
A PA driver usually does not have much linear excursion, not that much headroom in the lowest frequencies if you ask me... better use a quick woofer with some more excursion capabilities for deeper bass. Each octave lower or 6dB extra gain will make the cone move 4 times as much in the very low frequencies...
Ciao,
Bert
--
BD-Design - Only the Best!
Bert's Subwoofer/My subwoofer
Hoi Bert,
A bit? Are we talking 1dB or 12 dB? I don't know what to expect, at
all...
The weaker the construction the less output in the deeper frequencies. No
idea how many bits though...
I see. The sections near the throat are quite stiff, the section towards the mouth is weaker. I read reports that the positive effects of the soft fiberboard are mostly preserved even if you glue a shell of particleboard around the horn, so I could always do that. For now, I think it's cool that I can move it around with one hand...
better use a quick
woofer with some more excursion capabilities for deeper bass.
I will when I have money to spend. I'm using a driver that I used in horns before, it worked splendidly then.
Ivo