30-Jan-2023, 08:09
@Pim may have identified the issue when he said it could be a room problem. The louder the bass, the longer it takes to decay. At the modal frequencies of your room you get standing waves and the bass notes are exaggerated more than at other frequencies so they sustain even longer. Instead of hearing an attack when the bass note occurs followed by a decay before the next note occurs, you lose the decay, the note sustains and the next note occurs before there has been sufficient decay for you to hear a decent decay on the previous note. Instead of hearing note, note, note as the bass notes are played, you just start to hear a long, sustained, even bass level which, while loud, lacks the clarity which allows you to hear the separate notes clearly. The solution is not to play things loud enough to lose the clarity you need in the bass.
Since you're using a sub, if Pim's idea is correct then, depending on the modal frequencies of your room, the problem may be due to your Dalis producing bass too loudly above the sub's crossover frequency in which case you should turn the Devialet's problem down or, if the problem relates to frequencies below the sub crossover, then you need to turn the gain down on the sub, or it could be a problem with both. You'll need to experiment with turning the amp's volume down and turning the sub's gain setting down in order to sort out where the problem is occurring if Pim is correct.
There is another possible cause. Are you using SAM? If you're using SAM, the Devialet "watches" the bass levels and turns them down in order to protect the speakers if the woofer excursion exceeds a certain amount. The higher you set the % level for SAM, the more likely it is for the woofer protection to be activated so if you're using SAM I'd turn the SAM % down to zero since you have a sub to provide the extra bass extension that turning the % setting up is intended to provide. SAM is still active when set to zero % and it will still deliver phase correction below 150 Hz to the Dalis. You should have no need to use SAM for bass extension if you're using a sub with your speakers.
If you're using SAM and have the SAM % set to something above zero then I'd turn SAM down to zero first before experimenting with turning the volume down for the speakers and/or the gain down on the sub.
I just looked up the details of the SAM profile for your Opticon 6's. The woofer protection applies once the volume setting will cause the woofer excursion to exceed 4mm. The profile indicates that with SAM set to zero your bass will extend down to 34 Hz but with SAM set to 100% bass will extend down to 21 Hz. I don't know what sort of music you like,r how low the bass on the recordings you play goes, how loud you like to play it, or what your room is doing to the bass response at your listening position, but given that with SAM active you can extend the bass response of your Opticons down to 21 Hz you may be able to better get the sort of bass response you want with the Opticons alone without the need for a sub to supplement their bass response. There isn't all that much music which contains bass down to 21 Hz. The bottom note of a standard double bass or electric bass is 41 Hz, the bottom note on a piano is around 29 Hz and there are some wind instruments used in classical music which go down to around 24 Hz. About the only instruments which go below that are synthesisers and pipe organs. Just because the piano and some wind instruments go below 30 Hz doesn't mean that the musicians will play those notes frequently and in the case of some instruments the sound of the first overtone of the lowest note (that overtone occurs at twice the frequency of the actual lowest note) can be as loud as the sound of the actual lowest frequency so you may very well not notice that the level of some of the very lowest notes in music isn't as loud as it should be. Disconnecting the sub and using the bass extension provided by SAM may well be the best solution but if you're going to try that, do so by increasing the percentage level slowly and listening to the effect it provides as you turn the volume up.
I have one other possible diagnosis for your problem. Bass nulls, a cancellation of the bass frequencies, occur at some locations in a room and bass peaks occur at other locations. I was once auditioning a speaker in a dealers showroom and sitting in the listening seat at the position the dealer had placed it, I noticed the complete absence of a repeated low note on a recording I knew very well. When I stood up and moved forward a step or two towards the disc player to change discs I suddenly heard the missing note loudly and clearly. The listening chair has been placed at a location where a null was occurring and when I stepped forward I stepped into an area where there was a bass peak. Solving your problem may actually be as simple as moving your listening position forward or back a bit.
Good luck exploring the options above.
Since you're using a sub, if Pim's idea is correct then, depending on the modal frequencies of your room, the problem may be due to your Dalis producing bass too loudly above the sub's crossover frequency in which case you should turn the Devialet's problem down or, if the problem relates to frequencies below the sub crossover, then you need to turn the gain down on the sub, or it could be a problem with both. You'll need to experiment with turning the amp's volume down and turning the sub's gain setting down in order to sort out where the problem is occurring if Pim is correct.
There is another possible cause. Are you using SAM? If you're using SAM, the Devialet "watches" the bass levels and turns them down in order to protect the speakers if the woofer excursion exceeds a certain amount. The higher you set the % level for SAM, the more likely it is for the woofer protection to be activated so if you're using SAM I'd turn the SAM % down to zero since you have a sub to provide the extra bass extension that turning the % setting up is intended to provide. SAM is still active when set to zero % and it will still deliver phase correction below 150 Hz to the Dalis. You should have no need to use SAM for bass extension if you're using a sub with your speakers.
If you're using SAM and have the SAM % set to something above zero then I'd turn SAM down to zero first before experimenting with turning the volume down for the speakers and/or the gain down on the sub.
I just looked up the details of the SAM profile for your Opticon 6's. The woofer protection applies once the volume setting will cause the woofer excursion to exceed 4mm. The profile indicates that with SAM set to zero your bass will extend down to 34 Hz but with SAM set to 100% bass will extend down to 21 Hz. I don't know what sort of music you like,r how low the bass on the recordings you play goes, how loud you like to play it, or what your room is doing to the bass response at your listening position, but given that with SAM active you can extend the bass response of your Opticons down to 21 Hz you may be able to better get the sort of bass response you want with the Opticons alone without the need for a sub to supplement their bass response. There isn't all that much music which contains bass down to 21 Hz. The bottom note of a standard double bass or electric bass is 41 Hz, the bottom note on a piano is around 29 Hz and there are some wind instruments used in classical music which go down to around 24 Hz. About the only instruments which go below that are synthesisers and pipe organs. Just because the piano and some wind instruments go below 30 Hz doesn't mean that the musicians will play those notes frequently and in the case of some instruments the sound of the first overtone of the lowest note (that overtone occurs at twice the frequency of the actual lowest note) can be as loud as the sound of the actual lowest frequency so you may very well not notice that the level of some of the very lowest notes in music isn't as loud as it should be. Disconnecting the sub and using the bass extension provided by SAM may well be the best solution but if you're going to try that, do so by increasing the percentage level slowly and listening to the effect it provides as you turn the volume up.
I have one other possible diagnosis for your problem. Bass nulls, a cancellation of the bass frequencies, occur at some locations in a room and bass peaks occur at other locations. I was once auditioning a speaker in a dealers showroom and sitting in the listening seat at the position the dealer had placed it, I noticed the complete absence of a repeated low note on a recording I knew very well. When I stood up and moved forward a step or two towards the disc player to change discs I suddenly heard the missing note loudly and clearly. The listening chair has been placed at a location where a null was occurring and when I stepped forward I stepped into an area where there was a bass peak. Solving your problem may actually be as simple as moving your listening position forward or back a bit.
Good luck exploring the options above.
Roon Nucleus+, Devilalet Expert 140 Pro CI, Focal Sopra 2, PS Audio P12, Keces P8 LPS, Uptone Audio EtherREGEN with optical fibre link to my router, Shunyata Alpha NR and Sigma NR power cables, Shunyata Sigma ethernet cables, Shunyata Alpha V2 speaker cables, Grand Prix Audio Monaco rack, RealTRAPS acoustic treatment.
Brisbane, Qld, Australia
