Do you think you need a subwoofer?

Dear friends: I started this thread almo9st 20 years ago but things are that as many other audiophiles I followed learning not only in this subs issue but in the audio world genral subjects.

Well, in the last 2 years I made it several chnages/up-dates/up-grade to my room/system and mainly to my speakers crossover parts.

So and thank's to a thread dialogue in Agon where I 'm participating last nigth I decided to try different changes in my subwoofers PHASE that's a subject that not only in this thread but in no other thread or audio forum never read in deep the critical importance of Phase in the subs to stay sure that's room/speakers integration is " optimal ".

Started listening to Original Motion Pictures  CDs source with MUSIC as Day After Tomorrow, Gladiator, Thin Red ine and the like. Almost all goes deep in the bass through synthesisers. During my late nigth session I left the PHASE at the best position my ears told me and I gone to sleep with some doubt about.

So, early this morning I come back to my system to continue testing PHASE in the subs and this time with acoustic instruments in several LPs I own and used mainly the Telarc 1812 recording that comes with several kind of bass at diferent frequency bass ranges and my last nigth doubt came out: the choosed Phase was wrong and when finally my analog Phase tests session I achieved a quality level I was not prepared to attain, it was something unexpected and the best it happens to me in many ytears with my audio system.

That's why I urge all of you that already own subs in your systems to " play " seriously with the Phase control in your subs and if you already do it then try it again to confirm is ok for you.

Patience is only what we need but the rewards are huge on this Phase critical subject.

I never imagined its crucial importance.

My findings where confirmed in an Agon thread by a true Agoner expert in that and other audio subjects as is : @deep_333  ..

R.

Wow...this thread has lived for 20 years. And in the wrong category.

Raul, I assume you’re referring to the electrical phase of the signal delivered to your subwoofers with reference to the electrical phase of the signal delivered to your main speakers. This is known to make a difference. But usually one can only alter the phase relationships by 180 degrees, by reversing leads or inserting a phase switch. Are you able to test differences in phase that are >180 or <180 degrees but more than zero degrees? If so, how?

@rauliruegas It is phase and time. The Australians call it " launch time"  The sub has to be in phase with the main speakers and the signal from the main speakers and subwoofer have to reach your ears at exactly the same time. Changing only the phase angle of the subwoofer is going to change the amplitude response of the system is unpredictable ways. The system may sound better or worse depending on taste and even the music you are playing. It can drive you crazy. One minute you think you have it sounding great, the next minute not so much.

@lewm  Many subs have continuously variable phase angle over 180 degrees, but without the ability to match arrival times the phase angle control is a real double edged sword. Once matched in time and phase everything sounds great. You REALLY need to try subwoofers with your SLs. Get an inexpensive MiniDSP  crossover to start. This will give you a good idea what the advantages are, then you can get a more elaborate unit down the road. Benchmark Media Systems uses a MiniDSP SHD studio and two of their own DACs.

I just finished the first pair of model 4 subwoofer. I'll be putting a picture on my system page.