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<blockquote data-quote="Brad Weber" data-source="post: 55750" data-attributes="member: 114">Re: Subs Subs SubsI&#039;m surprised it hasn&#039;t already been asked but can you tell us anything about the application and why you are considering that specific product?&nbsp; Whether they may be appropriate or not and what may be a comaprable or better alternative is usually going to be application dependent.It may help to understand how Bag End INFRA subs work.&nbsp; Put a driver in a small sealed enclosure to raise the resonant frequency, then operate it below that frequency and add an &#039;integrator&#039; to apply EQ to compensate for the controlled low frequency roll-off.&nbsp; The compensation EQ applied at lower frequencies can be pretty extreme, look at <a href="http://www.bagend.com/" target="_blank">Bag End Loudspeakers 847 382 4550</a> to see the response curves for some of the Bag End boxes without the &#039;integrator&#039;.&nbsp; Looking at the S18E response in that chart it starts to roll-off somewhere around 65Hz and is 3dB down at about 50Hz.&nbsp; To get flat response at 30Hz means adding 11-12dB of boost at 30Hz.&nbsp; That EQ can then provide extended low frequency response, however it can also lead to limited output capability.The results of that approach are reflected on something like the P-S18E-I datasheet on Bag End&#039;s web site that shows a +/-3dB response of 60-250Hz without the integrator and a maximum 1m output (half space) of 124dB at 80Hz, 115dB at 40Hz and 103dB at 20Hz.&nbsp; Thus limited response without the integrator while with the integrator the lower you want extension, the lower the maximum output.&nbsp; Lang&#039;s example reflects that same situation, the low frequency response shown suggests that no integrator was used while using the integrator would usually result in extended response but lower output.</blockquote>

[QUOTE="Brad Weber, post: 55750, member: 114"] Re: Subs Subs Subs I'm surprised it hasn't already been asked but can you tell us anything about the application and why you are considering that specific product? Whether they may be appropriate or not and what may be a comaprable or better alternative is usually going to be application dependent. It may help to understand how Bag End INFRA subs work. Put a driver in a small sealed enclosure to raise the resonant frequency, then operate it below that frequency and add an 'integrator' to apply EQ to compensate for the controlled low frequency roll-off. The compensation EQ applied at lower frequencies can be pretty extreme, look at [url=http://www.bagend.com/]Bag End Loudspeakers 847 382 4550[/url] to see the response curves for some of the Bag End boxes without the 'integrator'. Looking at the S18E response in that chart it starts to roll-off somewhere around 65Hz and is 3dB down at about 50Hz. To get flat response at 30Hz means adding 11-12dB of boost at 30Hz. That EQ can then provide extended low frequency response, however it can also lead to limited output capability. The results of that approach are reflected on something like the P-S18E-I datasheet on Bag End's web site that shows a +/-3dB response of 60-250Hz without the integrator and a maximum 1m output (half space) of 124dB at 80Hz, 115dB at 40Hz and 103dB at 20Hz. Thus limited response without the integrator while with the integrator the lower you want extension, the lower the maximum output. Lang's example reflects that same situation, the low frequency response shown suggests that no integrator was used while using the integrator would usually result in extended response but lower output. [/QUOTE]

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