Is There A Big Difference Between Subwoofers From Different Manufacturers

@lalitk , it in not prejudice or hatred , just an analysis of the problem of making subwoofers you can distribute and sell in this market. Pitifully few of us are going to spend $36K per sub on Magicos. Being cost effective and competitive means compromises a DYIer does not have to make. There are all sorts of drivers available for reasonable money. The problem is the enclosure. As an example most woofers are constructed with an MDF base in a box format. Cabinet grade plywood is twice as stiff but 4 times as expensive. A box is perhaps the worst shape to use for a subwoofer enclosure and a lot of bracing has to be done to get resonances above the frequency range of the woofer but these resonances can still be excited. The perfect enclosure would be a sphere as it is self supporting. Try crushing an egg cupping it in both hands applying even pressure. Unfortunately spheres are very difficult to make and work with. Next is a cylinder. It would be much stiffer than a box and could be machined in aluminum but it would be very expensive. Making it out of wood would require multiple laminations around a form with the seams staggered again a very expensive, labor intensive process. It might be cheaper to machine it in aluminum! There are other more complex forms that could be used such a  Decadron cylinder. 

As far as integrating subs into a system is concerned the same factors apply to all subwoofers. Many commercial subs Like some of the JL Audio units have room control and adjustable delays which is great but you have to adjust the delay by ear a very difficult way to do it but a $300 measurement microphone would cure that problem. A dedicated 2 way crossover is for all intent and purposes mandatory if you want the best performance. IMHO and that of many others using a low pass filter on the sub and crossing it in under the main speaker is a half baked at best solution.

@lalitk --

May I remind you that this thread is about seeking differences between commercially build subwoofers. If you and @mijostyn wish to further portray the superiority of DIY designs then I suggest you start a new thread. Thank you for your consideration and understanding.

... One can always contribute here objectively without showcasing their own prejudice or hatred for commercial builds.

As I said, "If you ask me" and "to my mind" - these are merely my assessments, and I'm in my right to express them. Instead of conveniently asking a few guys to enter elsewhere because what they're saying rubs you the wrong way, not to mention that you feel the need to act like an admin, why not address the matter without throwing "prejudice" and "hatred" into someone's shoes?

'Objectively' is certainly not off-base when the emphasize is physics more than brands, hence why speaking of the design aspect (or their variations) - whether it's DIY or commercial - is a primary focus that implicitly connects to what the OP is inquiring about. 

@mijostyn --

Right now it is two per channel and going to 4 drivers in two cabinets for a total of 8.  All the drivers are set to form a linear array so they all work as a unit as most bass is center channel. They are however hooked up stereo because I cross up at 100 Hz. As for overdoing it the limiting factor is space. I would use 15" drivers but the enclosures would have to be so big it would be impossible to fit them in.

Makes sense. Doubling the capacity from 4 to 8 units should see worthwhile results, not least also forming a linear array this way. Is avoiding the traditional approach of DBA distributing the subs throughout the listening space due to the higher cross-over frequency? 

@phusis

I see no sense in arguing with you further, nothing good is going to come out of it. Remember it was you who engaged me, it was you who felt the need to advocate and pitch the superiority of DIY designs. I couldn’t care less or more, cause I already expressed where I stand when it comes to commercial vs DIY subs. Next time you chose to engage someone here or another forum, learning first what they have posted and their beliefs will help you save time and embarrassment. It’s also called ‘knowing your audience’ which involves identifying the audience and adapting a speech to their interests, level of understanding, attitudes, and beliefs.

How far do you think I’m going to succeed by pitching an idea of DIY cables to a guy who has a full loom of Nordost Odin or Synergistic Research SRX?

My suggestion to start your own thread was based on your posts here and after reading your system bio. I knew exactly which camp you belong to and I respect your chosen path. It’s time that you open your mind to the fact that not everyone out there is inclined to build their own subs. Some of us are just happy with our choice of commercially build subs, irrespective of brand and price of admission.

Ryder, what kind of speakers are those.  They must cost a fortune.  What are you driving them with?

Hi OP, I have a small SVS SB1000 PRO and a REL S2. The SVS is, in my system, superior. The REL is more expensive and this reinforces my opinion that RELs are overpriced and overrated and they are certainly not unique in accepting high-level input. REL's oft quoted ability to take on the sound of the main amp would require a sub amp that is completely without colouration, totally neutral and zero distortion, in other words: a wire with gain. There are many disagreements on these forums but all will acknowledge that such an amp as I have just described does not exist.

The S2 is also country specific meaning it is not dual voltage. I emailed REL about this and received a prompt and polite reply. "It will need to go back to the factory for a new amp" Apparently the newer models now address this issue. The phase can only be swapped 180 degrees which makes finding the best place more difficult.

The SVS has continuously variable phase and this together with volume, XO frequency and slope, also presets for movies or music and a band of PEQ with adjustable Q, all remotely done from your listening position via cell phone.

My ongoing house repairs precluded me from building the subs I wanted which are the servo units from Rhythmic/GR Research.

Ignore the joker who claims ported is better than sealed, he has that bass ackwards.

To the poster claiming 4 subs will fix all room problems, they will not. What they do is smooth out the nodes rendering the peaks less severe and filling in the nulls providing a very much improved top to bottom performance and I am a strong proponent of multi-subs..but..what about the time it takes for the sound to decay? To manage the decay time room treatment is necessary, there is no workaround and EQ can't help.

If you treat the room and employ at least 2 subs or 3 or 4  you will realise optimum performance at a level you probably did not know was possible.