Subwoofer Advice

@mijostyn I understand the principle behind dual opposing drivers. There are many ways to get good sound, with some better than others. That doesn't mean all other options are "wrong". I rarely listen at loud volumes and have 4 subs. They are never straining, which leads to distortion. They all have their volume at around 20 - 30 percent of maximum. They are well integrated, so that with most music, you wouldn't detect their presence. The same results can be achieved in a small room with a couple of smallish sealed subs if setup correctly, with great results and little or no distortion.

+ big_greg, well said.

mijostyn continues to take the time to share a great deal of his practical experience gained from his interesting system and room relationship. Also well done. I have great admiration when it comes to his immaculately dust free well appointed shop. Absolutly stunning. 

IME, if one uses the simple crawl test and low frequency test tones to locate their rooms best sounding room mode. Positioning even a modestly priced -3dB subwoofer with basic controls in, can have quite an entertaining low frequency presentation at least at the listening position. Cost? A long pair of economical interconnects.

With the exception of a four sub array, I've found poor room positioning to be the most common reason for poor subwoofer performance. 

@big_greg you think? Just because your subs are not at max volume does not mean they do not resonate. Some enclosures are better than others, but the only commercial subwoofer that are virtually resonance free is the Magico Q series subwoofers and they are balanced force. There is no other commercial subwoofer you can integrate with ESLs satisfactorily. They all stick out like a sore thumb. All the subwoofers I have ever made except the final model have stuck out like sore thumbs. In addition you can not satisfactorily integrate subwoofer with a 2 way crossover and digital signal processing.

What you are use to hearing is satisfactory to you. My problem is that the sound I was and am getting is never satisfactory to me. That is a curse that nobody needs. Look what it did to me https://imgur.com/gallery/building-resonance-free-subwoofers-dOTF3cS

Making deep bass accurately is very difficult because the laws of physics are stacked against us. Bass is also vague relative to midrange, it not as easily localized if at all and the timbre of bass instrument is determined by their contributions to the midrange. I cross to my high frequency transformer 500 Hz 2nd order and with everything else turned off you can still clearly make out most bass instruments. Synthesizers are the only exception I know of. A great subwoofer system is felt rather than heard. To get the maximum "feel" out of a subwoofer system you have to run it up to 80-100 Hz, painfully close to it becoming obviously audible. Doing so requires very steep slopes, above 10th order to minimize the subwoofer systems contribution to the midrange. Such steep slopes are only practical digitally. You can cross to the sub much lower and use a shallower slope, but you miss out on a lot of the feeling that goes with percussion and bass instruments. Anyone who has been to a live performance in a smaller Jazz club like the Blue Note or Birdland in NYC knows what I am talking about. Recreating that kind of bass in a residential environment takes a lot of power, a lot of subwoofer and digital equalization. Most systems are down by at least 6 dB, usually much more when they get down to 20 Hz. This is at the listening position, not one meter. To get realistic bass in most rooms requires adding at least 10 dB sloping up going down to 20 Hx. That requires 10 times the power! Another big problem occurs in the time domain. It is important that the signals from the various speakers arrive to you at the same time and in phase if that "feel" is to remain intact. You can move speakers around till you are blue in the face,you will never achieve the accuracy of a measurement microphone and digital delay capability. In many cases the correction is done by computer, even better. All this tech is now readily available and at a reasonable price. A $950 MiniDSP SHD Studio and two good quality DACs like Benchmark Media Systems will do the job for most systems. Such a set up will turn a run of the mill Mid Fi system into a stunning performer. Going up the ladder is Anthem and ARC followed by Trinnov and finally DEQX. 

@mijostyn That's really neat that you like going down rabbit holes in pursuit of what you consider perfection, but that doesn't sound like what the OP was asking about.