Poleepkwa

This has been a interesting experiment. I have tried both. I have now tried both ways. - use LT to extend low-end and use PEQ to flatten response. ( boosting and cutting) - no LT and PEQ to flatten the response. (just cutting). Strangely enough they sound a bit different! After pondering about it a bit I realised that it could be the Q of the subs. My current Q according to the simulator is 0.5. I used the LT is set it to 0.707. and 20hz. Could this be the reason that (even with EQ and similar frequency response) it sounds different? The 0.5 seems drier and faster than the 0.707 alignment. It seems that the LT is usually used to lower the frequency response AND lower the Q of a subwoofer in a too small box. Currently I am increasing the Q instead of lowering it. ( Some other people that have the same elements have increased the Q even more) Does it make any sense to use a LT if the element it is optimal sizes sealed case?

I will go through that. It seems those JBL can be bought here as well and it's pretty inexpensive too. There seems to be no spec sheets for those thought. What would be the requirements for a subwoofer to be used in this kind of build?

While this forum this seems to cater to subwoofers for pro-use, folks have been very helpfull and welcoming. Much appreciated. You have a build somewhere on another forum? I tried to decouple the subs but since my whole backwall is open(and second floor), it did not help much. This also makes it very hard to really pressurise it properly. The sealed Faitals do a good job, but it still lacks that "chest compression". That said I am still learning about EQ and setup so that might also be apart of it. I first. I usually do not listen very loudly, so this Boss platform seems very promising for not much money.

Thanks. Good point about the pro-woofers. I will start to keep my eyes open for some used Peerless XLS drivers. That wall is not solid. Just studs and gypsum board. So might have to keep that in mind.... I will check it out. That seems like another good option.

This will probably work out the easiest, or least time-consuming. Just measur them in-room and EQ to flat, without any need for Linkwitz transforms. It has been pretty informative to test the different Q settings with that though. EQ them flat in-room to flat in room. Getting the rest of the room done, so hopefully I can start to test so REW EQ settings soon. @Ricci I have a small "half wall" right behind my listening position. It's a stairway that goes down to the groundfloor. This is a open area so, cannot listen very loudly when kids are in bed. Some one suggested that so could build in some smaller subwoofers on that wall to provide "tactile" response. That wall is roughly 5 inches thick so That would be the max depth. One of the few options that could work in such a small spaces (at least her in Europe seems to be the old Peerless XLS 12/10 series and a few pro drivers that could work in about 40 liters sealed( Faital Pro 10RS350, Sica 10SR2,5CP). Al of these will be about 100-130€ euros. Peerless can be had pretty inexpensively when buying used. 15" pro driver might work too, bit it will need quite a a bit of EQ. I seem to remember that you like the Peerless XLS for what it was. Would you still recommend them? Not sure if it is even a good idea considering I have the 18" Faitals upfront.... Any thoughts and suggestions?

@RicciThanks. I manage to apply a Linkwitz transform to my subs. So after this the steps would be: 1)measure subs combined in-room response with no filters or crossovers with REW 2) use REW Auto EQ to flat like in this example. https://www.minidsp.com/applications/auto-eq-with-rew 3) Apply filters and crossover if needed in MiniDSP. 4) Experiment with housecurve if needed. Does this seem like a good procedure? Anything else should I keep in mind? Is it good to apply the Linkwitz transform first (boost), and then the room EQ (cut)?

Yes. I think you understand. I am asking in a rather long-winded way how does JTR get their subs frequency response looking like it does (flat from 20-160 Hz and then a steep rolloff after that). Meaning that any sealed subwoofer will start to roll off towards the lower end without any EQ, right? Could it be that they are using a Linkwitz transfor to improve the low-end extension?

Hello! I am looking for some help in "baking" in some EQ for my DIY subwoofers, before doing bass management in my processor. I currently have a pair of sealed 150liter cases with Faital 18XL1800 elements. These are EQ by a MiniDSP 2x4 HD and powered by bridged Pascal amps. These are inspired by the sealed subs from Grimani, Procella and of course JTR. I have REW and UMIK and some basic understanding of the steps involved, but I am unsure as to what will be the " correct" way to proceed. In the JTR Captivator S2 review their is stated that "S2 is still employing significant low frequency boost in order to extend and flatten the response down to below 20Hz" The way I see it is too: a) use a Butterworth 6db LPF@25hz to bring out the low bass Or b) add bass boost where the room gain starts to drop off. How should I proceed to design and implement that freq shaping for my subwoofers? I am unsure why most people seem to be using option (b) and not (a)? Anyone able to explain the theories behind these methods?