Quickie for the comments, The receiver's crossovers stack on the natural rolloffs of your drivers. Shoot for LR4 final slopes. (using REW and a microphone to verify). Take sweeps with REW using acoustic or loopback reference. Play with the alignment tool to align phase (using delays or inversion if necessary). Enjoy the bass.
Super grateful for the answer! Already gave me a lot of think about and tinker with. REW time! As some added context (feel free to just answer in comment form if it's not a good video topic to get deeper into, as it might be too specific to me, also I'm happy to simply be pointed in the direction of research I can do on my own if you don't have time to get into a detailed answer) -- I have 4 sealed subwoofers (2x SVS 3000Micro and 2x SVS SB-2000Pro) in my environment currently, arranged mid-wall square, most similar to Harmon multi-sub placement research number 12 or 13, at least in the paper I've read. (Investigation 4: Practical Subwoofer Locations) This arrangement already helps a lot in my initial measurements. My AVR is an Integra DRX 3.4, full range Dirac Live available, but no DLBC license possible. (Would need to upgrade to a DRX 8.4 or similar AVR) I recently acquired a MiniDSP Flex and have turned off all the on-board DSP I could from the SVS app for each sub and set crossover to OFF/LFE. I understand SVS retains some DSP that is undefeatable, but I also assume that's mostly to protect the sub and isn't necessarily of concern for listening quality. So now, I'm curious as since I'm able to control so much independently from the Flex, should I also be turning off crossovers from my AVR as well and sending full LFE, highest crossover possible from the AVR to the Flex and then letting the Flex actually do all the work after I've measured from REW? If I do that and then run Dirac Live at the end, should I make sure the DL filter stops at my crossover points setup in my Flex, or let DL run full range and potentially put additional adjustments into the AVR via DL which then are getting fed into my Flex from the AVR, presumably tuning the response further from DL perspective, or would that just muddy the waters and it's better to let the Flex control everything and only let DL run on frequencies above the Flex? Thanks again for your expertise and any assistance you have time to give.
@@Echo-jg8is The AVR Subwoofer outputs (in my case, 2 but they are actually just a bridged .1 signal still) go into the Flex RCA inputs 1 and 2, respectively. Then it has 4 subwoofer Outputs that I have running cables to each of my subwoofers LFE-In. -- It depends on which MiniDSP Flex you get, in my case I stuck with the unbalanced RCAs, but it comes in balanced and other configurations, as well.
I would consider trying it both ways. Prefixing the bass gives Dirac less to do. Done correctly, live on top of it can be good. A few things about your other points. All subs generally have some signal processing you can’t And shouldn’t defeat. SVS subs have highpass filters to protect against infrasonics and damaging low frequencies. It also has a multi band limiter that prevents the sub from exceeding its limits. You want that. All systems hit their limits from time to time.
Hi Matthew. Always enjoy the videos. Hope that it's as worth it for you as it is for us! Anyway, general question about basic theatre setup I think might be helpful to other viewers. I noticed in your video about your own theatre that you have 7 bed channels. Anthony Grimani, who your work with, is a strong advocate for adding wide speakers, for a total of 9 bed channels. Was your decision not to use wides in your own theatre due to your design preference? The size of the room? Number of available processor channels and how you prioritize them? Keep up the great work but you should still take the summer weekends off.
So I’ve had this discussion on Genes channel before. It’s not a design preference exactly but that is probably the closest approximate category. It’s a budget issue. In order for me to run a 9.1.6 system, for example, I would need to have 9 high quality bed channel amps and 6 adequate if not equal quality top amps. I would need another set of aimable or aimed S series Perlisten speakers. The cost wasn’t small. I had entertained the idea of going down to R series for the surrounds and doing that extra channel. But my own design belief is that speaker quality matters more than channel count. When budget limits the speaker count, you are better off going with the better speakers. Now having said that. It’s been hard to do good comparisons. Anthony and I both like to add wides. But until recently a lot of content didn’t necessarily support the wides. Setting up a system with presets for different channel counts is tricky. I’ve not personally done it. Do I consider this something I would like to play around with more in the future. In my own system, the wires exist for the added two channel sets I left out. I will upgrade my amps again to get enough channels and add the other speakers. I suppose a follow up review will be in order they includes that test.
Thanks! I'd like to see that sealed vs ported video. I currently have 2 18" ported subs tuned to 17hz and 2 12" subs tuned to 21hz. Im going to be replacing the 2 12 with 2 more 18 but do not know if I want to stay with ported. (If I go sealed Id be changing the existing 18's as well). My room specs are 19x19x9 in a 2nd floor bonus room above the 2 car garage. Subs will be in the corners. Would I get better infrasonic bass from sealed? How much power do I need to reach the same levels as my ported? Ive always been under the impression that a sealed sub requires more power to reach the same SPL as a ported?
So yes ported subs are more efficient in the port tuning region. But same efficiency above that region and no significant output below port tuning. Sealed subs have a shallower rolloff and more benefit from room gain. There is 12dB per octave of boost in a totally rigid sealed room below the lowest mode. In real rooms it’s still 6-10dB. A ported sub has a 24dB rolloff so that boost is of little use. We’ve done a number of comparison tests or sealed and ported subs. When the sealed vs ported subs are similar capability, we find the noises from ports often is as bad or worse than the rising distortion with sealed. Further, the inharmonic nature makes them far more noticeable. It doesn’t mean you can’t get great sounding ported subs. But in my experience, after decades of going back and forth, I abandoned ported subs in favor of big sealed subs. I just add more subs. Makes up for the loss of efficiency.
@@PoesAcoustics Thanks for the informative reply. I forgot to mention that Im limited in the room to a single 20amp circuit to run everything. Running my amplifiers too hot would spell doom for my projector. After reviewing several other videos on the subject, I think Ill play it safe and stay with ported. Im really happy with the ones I have, so going square with 2 more of them and putting them in the corners should be perfect.
Do you have any experience using the PSI Audio AVAA C214 Active Bass Traps? Not sure I fully understand how they work, but they seem like an interesting (though expensive!) product that could work well in compromised home theatre setups (e.g. livings rooms). Keen to hear your thoughts on them
I watched the whole thing but didn’t understand any of it, glad I can enjoy my home theater anyway.😅
Love the details in the videos!
What a great and informative video, just brilliant. Really not come across any other videos that explain all of this.
Quickie for the comments,
The receiver's crossovers stack on the natural rolloffs of your drivers. Shoot for LR4 final slopes. (using REW and a microphone to verify). Take sweeps with REW using acoustic or loopback reference. Play with the alignment tool to align phase (using delays or inversion if necessary). Enjoy the bass.
Would love a video on how you use REW to align the sub and main speaker and then to determine the slopes in crossover point.
Super grateful for the answer! Already gave me a lot of think about and tinker with. REW time!
As some added context (feel free to just answer in comment form if it's not a good video topic to get deeper into, as it might be too specific to me, also I'm happy to simply be pointed in the direction of research I can do on my own if you don't have time to get into a detailed answer) -- I have 4 sealed subwoofers (2x SVS 3000Micro and 2x SVS SB-2000Pro) in my environment currently, arranged mid-wall square, most similar to Harmon multi-sub placement research number 12 or 13, at least in the paper I've read. (Investigation 4: Practical Subwoofer Locations) This arrangement already helps a lot in my initial measurements. My AVR is an Integra DRX 3.4, full range Dirac Live available, but no DLBC license possible. (Would need to upgrade to a DRX 8.4 or similar AVR)
I recently acquired a MiniDSP Flex and have turned off all the on-board DSP I could from the SVS app for each sub and set crossover to OFF/LFE. I understand SVS retains some DSP that is undefeatable, but I also assume that's mostly to protect the sub and isn't necessarily of concern for listening quality. So now, I'm curious as since I'm able to control so much independently from the Flex, should I also be turning off crossovers from my AVR as well and sending full LFE, highest crossover possible from the AVR to the Flex and then letting the Flex actually do all the work after I've measured from REW?
If I do that and then run Dirac Live at the end, should I make sure the DL filter stops at my crossover points setup in my Flex, or let DL run full range and potentially put additional adjustments into the AVR via DL which then are getting fed into my Flex from the AVR, presumably tuning the response further from DL perspective, or would that just muddy the waters and it's better to let the Flex control everything and only let DL run on frequencies above the Flex?
Thanks again for your expertise and any assistance you have time to give.
How does the Flex get wired into the AVR, thanks.
@@Echo-jg8is The AVR Subwoofer outputs (in my case, 2 but they are actually just a bridged .1 signal still) go into the Flex RCA inputs 1 and 2, respectively. Then it has 4 subwoofer Outputs that I have running cables to each of my subwoofers LFE-In. -- It depends on which MiniDSP Flex you get, in my case I stuck with the unbalanced RCAs, but it comes in balanced and other configurations, as well.
I would consider trying it both ways. Prefixing the bass gives Dirac less to do. Done correctly, live on top of it can be good.
A few things about your other points. All subs generally have some signal processing you can’t And shouldn’t defeat. SVS subs have highpass filters to protect against infrasonics and damaging low frequencies. It also has a multi band limiter that prevents the sub from exceeding its limits. You want that. All systems hit their limits from time to time.
Hi Matthew. Always enjoy the videos. Hope that it's as worth it for you as it is for us!
Anyway, general question about basic theatre setup I think might be helpful to other viewers.
I noticed in your video about your own theatre that you have 7 bed channels. Anthony Grimani, who your work with, is a strong advocate for adding wide speakers, for a total of 9 bed channels. Was your decision not to use wides in your own theatre due to your design preference? The size of the room? Number of available processor channels and how you prioritize them? Keep up the great work but you should still take the summer weekends off.
So I’ve had this discussion on Genes channel before. It’s not a design preference exactly but that is probably the closest approximate category. It’s a budget issue. In order for me to run a 9.1.6 system, for example, I would need to have 9 high quality bed channel amps and 6 adequate if not equal quality top amps. I would need another set of aimable or aimed S series Perlisten speakers. The cost wasn’t small. I had entertained the idea of going down to R series for the surrounds and doing that extra channel. But my own design belief is that speaker quality matters more than channel count. When budget limits the speaker count, you are better off going with the better speakers.
Now having said that. It’s been hard to do good comparisons. Anthony and I both like to add wides. But until recently a lot of content didn’t necessarily support the wides. Setting up a system with presets for different channel counts is tricky. I’ve not personally done it. Do I consider this something I would like to play around with more in the future.
In my own system, the wires exist for the added two channel sets I left out. I will upgrade my amps again to get enough channels and add the other speakers. I suppose a follow up review will be in order they includes that test.
What are your thoughts on port plugs?
Thanks!
I appreciate your support!
Hmmm Butterworth 🤤
You completely lost me after "Hi everybody" 😅, obviously I still have a lot to learn.
Thanks! I'd like to see that sealed vs ported video. I currently have 2 18" ported subs tuned to 17hz and 2 12" subs tuned to 21hz. Im going to be replacing the 2 12 with 2 more 18 but do not know if I want to stay with ported. (If I go sealed Id be changing the existing 18's as well). My room specs are 19x19x9 in a 2nd floor bonus room above the 2 car garage. Subs will be in the corners. Would I get better infrasonic bass from sealed? How much power do I need to reach the same levels as my ported? Ive always been under the impression that a sealed sub requires more power to reach the same SPL as a ported?
So yes ported subs are more efficient in the port tuning region. But same efficiency above that region and no significant output below port tuning.
Sealed subs have a shallower rolloff and more benefit from room gain. There is 12dB per octave of boost in a totally rigid sealed room below the lowest mode. In real rooms it’s still 6-10dB. A ported sub has a 24dB rolloff so that boost is of little use.
We’ve done a number of comparison tests or sealed and ported subs. When the sealed vs ported subs are similar capability, we find the noises from ports often is as bad or worse than the rising distortion with sealed. Further, the inharmonic nature makes them far more noticeable. It doesn’t mean you can’t get great sounding ported subs. But in my experience, after decades of going back and forth, I abandoned ported subs in favor of big sealed subs. I just add more subs. Makes up for the loss of efficiency.
@@PoesAcoustics Thanks for the informative reply. I forgot to mention that Im limited in the room to a single 20amp circuit to run everything. Running my amplifiers too hot would spell doom for my projector. After reviewing several other videos on the subject, I think Ill play it safe and stay with ported. Im really happy with the ones I have, so going square with 2 more of them and putting them in the corners should be perfect.
Do you have any experience using the PSI Audio AVAA C214 Active Bass Traps? Not sure I fully understand how they work, but they seem like an interesting (though expensive!) product that could work well in compromised home theatre setups (e.g. livings rooms). Keen to hear your thoughts on them
Less than .01% understood this.
Pretty sure his intended audience is that 0.01%.
Let’s call it 5%
Not the best teacher out here…