Do you think you need a subwoofer?

Dear friends: from my last sub changes I confirm that that doppler developed characterisc in woofer main speakers must be should be at absolute minimum.

The issue is that the bass range is all about MUSIC room/system quality level reproduction and the bass rage must be perfectly blended inside the bass range. This is high mid-bass, mid-bass, low mid-bass, low bass and deep bass.

That blend must permit that we be aware of eacg bass frequency range with out a bass frequency range " leader " or " leaders " and all those is the true challenge we have with the subwoofer room/system integration.

That bass frequency ranges blend will gives me the best MUSIC rythm ever and the perception of dimensional MUSIC presentation where each track performs in its each territory that’s our room seat position.

With out all those we can’t really have true MUSIC enjoyment and only " something " that we like it..

Not an easy task that bass range frecuencies blend because it’s as complex as a speaker design where the designer needs not only to choose the rigth drivers but the rigth crossover frequency for each driver and the crossover filter shape that permits a seamless blend that’s what makes the differences between a good speaker and a very good or excelent speakers.

Here mijostyn  looks as he knows about and maybe could share his point of views.

R.

@rauliruegas is right in many ways with a few caveats. 

In a normal point source system two subwoofers is fine and more does not add much. Line source systems require a driver every 4-5 feet along a wall to form a line source subwoofer to match the main speakers.

I would not bother with subwoofer drivers smaller than 12". 10" drivers are fine if you use two of them per enclosure. Most big point source systems require two 15" subwoofers. The smaller the driver the greater the distortion levels at a given volume.

Blending the subwoofers into the main speakers using second through 4th order slopes is appropriate for all subwoofers except a small number of truly excellent units. Subwoofer enclosures are extremely hard to make. Most of them are musical instruments and have a particular sound. If you use a steep slope with these subwoofers the cross is very noticeable. Turn the volume up and place your hand on the sub enclosure. If you feel any vibration you have a musical instrument. Subwoofers that have no sound of their own (do not vibrate at all) can be run higher up using very steep slopes 8-10th order (digital only) as there is little sonic difference between the subs and the main speakers at the crossover point. Here the important factor is keeping the sub out of the midrange where you will hear it. Subs are integrated correctly when you can't tell they are there. Using a low pass filter only on subwoofers is a sad proposition. Easily 1/2 the benefit of using a sub is cleaning up the midrange of the main speakers. You have to use a high pass filter on the main speakers to do this. It is not done because of the added expense of electronics and cables. 

I believe all subwoofer systems should run down to 18 Hz. Music does not go that low but venue clues do. Large venues breath at very low frequencies. With some live recordings you can feel the venue. Subwoofers should be felt more than heard. This is the difference between a live and reproduced performance. Proper subwoofers give you the feeling and excitement of a live performance. 

In my mind there is no difference in the requirements of a theater vs music system. A great music system will sound just fine in theater mode and is quite capable of rattling your teeth.

These are some important concepts to keep in mind when buying subs. Balanced force design. Some of the vibration you feel is the enclosure shaking in opposing response to cone movement. Placing a driver at opposite ends of the enclosure cancels out these forces lowering the musical instrument factor. Smaller enclosures are better because they are easier to control lowering the musical instrument factor, but they will require more power and possibly EQ. A box is the worst shape for a subwoofer. The best shape would be a sphere, but this is impossible to make. The next best shape is a cylinder. Cylinders have inherently stiff walls and are less prone to resonance than flat walls. Cylinders are relatively easy to make and I am surprised that nobody is making cylindrical subwoofers. Open baffle subwoofers are IMHO a silly concept and a florid waste of power. Why some people think they are great is more an indication of how poor many enclosed subwoofers are. There are many excellent subwoofer drivers out there. Dayton makes a Reference sub driver for any situation and I do not see how you can do any better. DIY by all means. Think big pipe with a driver in each end. You can get aluminum pipe in almost any dimension, cap the ends, drivers, binding posts and cleverness. 

Subwoofer drivers take a beating and even the best ones fail on occasion. It is not a bad idea to keep a spare driver handy. The drivers evolve and it is unlikely you will be able to get the same driver after 10 years. Without a spare you will have to replace all of them. 

I'm happy with my Genelec 8351Bs that reproduce accurately down to 32 Hz with no subwoofer. Most of what I listen to, i.e. recordings of acoustical instruments and ancient 78 RPM records, isn't recorded below that, anyway, so I don't care. It would be nice to have one, but the amount of expense and trouble I'd have to go to to get something appropriate would be far disproportionate to the amount of enjoyment I'd get out of hearing the handful of recordings I listen to with crazy-low notes. I have better things to worry about.

Dear @mke246: Well, your powered 3-way monitors are really good ( I had the opportunity to listen it. ) specially at near field position.

The weakness ( if any ) is when you have a greater room and don't listen at near field position where the bass range at higher SPL just distorts, nothing is perfect and in my case even that normally I listen at near field position my room is to big and I listened to evry kind of MUSIC with low bass content. I don't know how you considere Organ instrument as an acoustic o0ne or not but not only the organ scores but what mijos posted about the venue breaths.

I don't know the kind of room you have and your seat position but maybe you are acandidate to integrate a pair of subs using only low-pass filter, using the subs as a low bass reinforcement crossover30hz-40hz 8th order filter shape. Just thinking " loud "..

R.

Good points, I may think about getting a pair of Genelec 7360s in the distant future. Not something I really need but might be fun to have. I mostly work on ancient acoustical and early electrical recordings from the 1910s through 1933 or so, and the bass response on those cuts off around 100 Hz on the acousticals and maybe 50 Hz on the really well-recorded electricals. Even 100-year-old records are often surprisingly high-fidelity if restored properly. I have a few Fats Waller organ records which are very well-recorded for the 1920s with big luscious room tone, but they don’t test the monitors’ capabilities in the least. I do listen to modern music on streaming on rare occasion and remember just how great my equipment is! I’m almost always in my office in the near field restoring old records. If I have a listening party I can use a different GLM setup and tilt the monitors a bit to move the sweet spot back. Subs would be overkill for my needs, but I guess I’ll keep them in the back of my mind. It may be a while--there’s always a more pressing need like getting more custom stylii made or a rare record. Down the road, I could see squeezing them into the budget.