Scaled Down IB
Nov 24, 2015 6:21:10 GMT -7
Post by machineage on Nov 24, 2015 6:21:10 GMT -7
Hi all!
I am very interested in the IB concept - well done to all here who have realised their designs
I am wondering if there is a way to scale down what is suggested here for a low volume / small room application? I read that 2 x 15” high Xmax / low Fs woofers are suggested with 12 litres displacement mentioned as a minimum requirement. Amplifiers of several hundred watts are also suggested. However there must surely be a case for lesser displacements & power using smaller drivers to satisfy those with a low spl / small room application?
I read for example Colin Pykett’s article describing his experience in the 1980s of using two 12” woofers with a Fs of around 35Hz mounted as a simple line array in a loft hatch. I guess these older drivers likely had limited Xmax compared to what is available & recommended today. You can read his article here:
The Electronic Reproduction of Very Low Frequencies
I quote:
’The results were, to put it mildly, certainly without equal to anything I had previously experienced. Varying the frequency of a sine wave oscillator slowly between 15 and 50 Hz produced the "feel" rather than the sounds of these low frequencies, and at surprisingly low powers. Only 5 watts of electrical power produced results that rattled doors, windows and radiators even in distant rooms, much to the annoyance of my family. The lowest frequencies seemed to permeate the entire house. On the electronic organ itself I had to attenuate the outputs of the pedal stops over the lowest octave to prevent quite deafening results. On the softest 16 foot flue stops I was able to obtain the quiet, breathing bass that had eluded me for so long. In fact, one could hear it rather too well in the garden.’
Now this sounds completely overkill to what I & possibly others would want - even with his minimal 5 watts of power. Granted the drivers being mounted as they were likely accounted for a degree of the mechanical vibration. Nevertheless he obtained the bass he desired.
For example I would like to incorporate an IB in one of my small bedrooms in my bungalow which measures just 12’ x 9’ x 8’. There is no available space for a freestanding subwoofer enclose. I have no desire to reproduce the house shaking results as those described by Colin. Just an extension to the bass at low listening levels. However it seems anything less than what is recommended in the forum is dismissed as if it would be equal to not even connecting the drivers to the amp!
Your thoughts would be welcome.
I am very interested in the IB concept - well done to all here who have realised their designs
I am wondering if there is a way to scale down what is suggested here for a low volume / small room application? I read that 2 x 15” high Xmax / low Fs woofers are suggested with 12 litres displacement mentioned as a minimum requirement. Amplifiers of several hundred watts are also suggested. However there must surely be a case for lesser displacements & power using smaller drivers to satisfy those with a low spl / small room application?
I read for example Colin Pykett’s article describing his experience in the 1980s of using two 12” woofers with a Fs of around 35Hz mounted as a simple line array in a loft hatch. I guess these older drivers likely had limited Xmax compared to what is available & recommended today. You can read his article here:
The Electronic Reproduction of Very Low Frequencies
I quote:
’The results were, to put it mildly, certainly without equal to anything I had previously experienced. Varying the frequency of a sine wave oscillator slowly between 15 and 50 Hz produced the "feel" rather than the sounds of these low frequencies, and at surprisingly low powers. Only 5 watts of electrical power produced results that rattled doors, windows and radiators even in distant rooms, much to the annoyance of my family. The lowest frequencies seemed to permeate the entire house. On the electronic organ itself I had to attenuate the outputs of the pedal stops over the lowest octave to prevent quite deafening results. On the softest 16 foot flue stops I was able to obtain the quiet, breathing bass that had eluded me for so long. In fact, one could hear it rather too well in the garden.’
Now this sounds completely overkill to what I & possibly others would want - even with his minimal 5 watts of power. Granted the drivers being mounted as they were likely accounted for a degree of the mechanical vibration. Nevertheless he obtained the bass he desired.
For example I would like to incorporate an IB in one of my small bedrooms in my bungalow which measures just 12’ x 9’ x 8’. There is no available space for a freestanding subwoofer enclose. I have no desire to reproduce the house shaking results as those described by Colin. Just an extension to the bass at low listening levels. However it seems anything less than what is recommended in the forum is dismissed as if it would be equal to not even connecting the drivers to the amp!
Your thoughts would be welcome.
