Hi LeeC,
you have two choices integrating a sub to your system.
1. Connecting the sub output of your Devialet to the JL using a RCA cable. As your JL only supports low level inputs this might appear as the only way to you now.
2. Connecting the speaker outputs of your Devialet in parallel to the JL. That's a high level connection. Some subwoofers provide extra high level inputs for this scenario. Unfortunately the JL doesn't.
But you can work around this by using a device as in the picture below. It appears to be of low quality but there is only two transmitters inside leveling the signal from high to low level. And it does a very good job when sensitively leveled with the build in potentiometers.
I've used it more than a dozen times to integrate subwoofers very nicely to a system. With a High level connection you get a sub straightforwardly integrated into your system. Connected this way the sub won't bother you with this boomy (out of phase signal) presence many Subwoofer-Configurations are showing. It would integrate just so smoothly and give you a much bigger stage of sound and thrust where it's needed. It's even more likely you can place the sub into a corner out of view using a high level connection.
Some words to positioning of your speakers. It might be necessary to move your speakers (more) out of the corner(s) because the bass (of your speakers) resonates/billows out more in corners and you won't be able to find a matching crossover frequency/level for the sub to integrate into the sound. It's impossible to match to a boomy resonance with a sub. The sub would rather play to loud or it would not be able to support the depth of bass because you have to level it down.
Another trick. Start with the lowest possible crossover frequency you can adjust to the sub. Increase level and find the point where the sub gets to your attention...then pull back a bit and you're done. You might have to adjust the level for some special recordings with very deep bass (London Grammar 'Hey Now' etc.) but that's the game when using a sub
Have fun. Once having a perfectly integrated sub and you will never do without it...it's not because of the bass but the enormous stage you gain
gui
edit:
And trust the words of Vivialet. Don't use the integrated crossover of your D. The Focal speakers should run full range. Sounds the best.
you have two choices integrating a sub to your system.
1. Connecting the sub output of your Devialet to the JL using a RCA cable. As your JL only supports low level inputs this might appear as the only way to you now.
2. Connecting the speaker outputs of your Devialet in parallel to the JL. That's a high level connection. Some subwoofers provide extra high level inputs for this scenario. Unfortunately the JL doesn't.
But you can work around this by using a device as in the picture below. It appears to be of low quality but there is only two transmitters inside leveling the signal from high to low level. And it does a very good job when sensitively leveled with the build in potentiometers.
I've used it more than a dozen times to integrate subwoofers very nicely to a system. With a High level connection you get a sub straightforwardly integrated into your system. Connected this way the sub won't bother you with this boomy (out of phase signal) presence many Subwoofer-Configurations are showing. It would integrate just so smoothly and give you a much bigger stage of sound and thrust where it's needed. It's even more likely you can place the sub into a corner out of view using a high level connection.
Some words to positioning of your speakers. It might be necessary to move your speakers (more) out of the corner(s) because the bass (of your speakers) resonates/billows out more in corners and you won't be able to find a matching crossover frequency/level for the sub to integrate into the sound. It's impossible to match to a boomy resonance with a sub. The sub would rather play to loud or it would not be able to support the depth of bass because you have to level it down.
Another trick. Start with the lowest possible crossover frequency you can adjust to the sub. Increase level and find the point where the sub gets to your attention...then pull back a bit and you're done. You might have to adjust the level for some special recordings with very deep bass (London Grammar 'Hey Now' etc.) but that's the game when using a sub
Have fun. Once having a perfectly integrated sub and you will never do without it...it's not because of the bass but the enormous stage you gain
gui
edit:
And trust the words of Vivialet. Don't use the integrated crossover of your D. The Focal speakers should run full range. Sounds the best.
"Oh, you can buy the other. But then it is a cost intensive learning process"
berlin
