Should I upgrade from REL/510 subwoofer to REL/812 subwoofer?

I went from 1 to two SVS sb1000Pro subs in a 14wx16L room with a vaulted ceiling going from 8 to 16 ft in  a well damped room  opened at one end. I sit 8 ft from speakers.The second sub added to the sound stage and imaging and filled in  the bass ie more meaty and detailed. I integrated the  two subs with my Canton 9k stand mounted 2 ways  and they play seamlessly together. If you have resources go for it.

I agree with the two sub approach, but if you are staying with just one sub there is no reason to move up in size unless your current sub does not have enough power for your needs.

It is counter intuitive, but when you add multiple subs, because of the comb filtering that occurs, which smooths out the frequency response, it also causes overall output power to be reduced. So if you are thinking of adding a second sub and you are currently operating your single sub close to its maximum output, then you may need to move up to the next larger size.

Thanks to all for your comments.  Will make a decision next week.

go for a GR research dual open baffle 12" servo sub kit it is about the best you can get for about $2K avail as kit too an easy build or they have someone who will build it tif you wish/ need it will smoke all the others mentioned considered! ck them out 
 

Open baffle subwoofer kits, particularly those from GR Research, are designed for DIY enthusiasts seeking high-quality, customizable bass reproduction. These kits utilize open baffle designs, known for their spatial sound and reduced room interaction, often incorporating servo technology for enhanced control and accuracy. 

Key aspects of open baffle subwoofer kits:

• Open Baffle Design:

  Unlike traditional sealed or ported enclosures, open baffle designs allow sound from the front and back of the driver to interact, resulting in a unique spatial sound and potentially reduced room modes. 

• Servo Technology:

  GR Research's servo subwoofers utilize a coil feedback system, where a sensor on the driver compares movement to the input signal and adjusts accordingly, resulting in fast, accurate, and articulate bass. 

• DIY Friendly:

  These kits come with all the necessary components, including drivers, crossovers, and sometimes flat-pack cabinets, allowing for a rewarding DIY experience. 

• Customization:

  Many kits offer flexibility in terms of baffle size, driver selection, and amplifier choices, allowing for fine-tuning to individual preferences and room acoustics. 

• Potential Benefits:

  Open baffle subs are often praised for their spatial sound, reduced room interaction, and ability to integrate well into various listening environments. 

• Considerations:

  Open baffle designs can have lower efficiency and may require more amplifier power than traditional designs, and some may find them more challenging to integrate into a room than a sealed or ported box. 

• Kits from GR Research:

  GR Research offers a range of open baffle subwoofer kits, including their "Double Trouble" and "Servo" series, known for their high performance and customization options. 

I realize I am talking about old equipment from 25 years ago, but I think it is still appropriate.  We had a home theater room (roughly 20x20) with Linn speakers, Marantz power, and a 3 gun Runco projector.  For the bass we used a 15in downward firing Mirage 500 watt sub.  The was on the second story with wood subfloor.  We insulated the 'hell' out of all the walls (double offset studs) and floor.  The power of this system was unbelievable, while barely hearable downstairs in the family room.  This thing rivaled any movie theater in realism and effect.  Keep in mind though that this was for movies only as we had a separate system in the family room for 2 channel.