I feel like I should contribute SOMETHING since so many people helped me with this decision back in 2015 when I had to replace an older, quality Klipsch sub. I dug around a bit and discovered that Bob Carver now made subwoofers. Audiogonites HEAVILY recommended the REL T9 over the Sunfire SDS-12 but a T9 was three times the price. $650 was suddenly $1900 so I went with the Sunfire.
That was background. Where this may apply to you is literally EVERYONE told me, regardless of brand, if you want to add another subwoofer, make sure it's the same brand and model. Don't spring for a REL T9 for the right channel then realize you're short and buy a REL T5 for the left channel. Do the smart thing and just by 2 REL T5's.
That makes A LOT of sense to me and it did then 6 years ago to everyone else so I assume it's still true today.
That was background. Where this may apply to you is literally EVERYONE told me, regardless of brand, if you want to add another subwoofer, make sure it's the same brand and model. Don't spring for a REL T9 for the right channel then realize you're short and buy a REL T5 for the left channel. Do the smart thing and just by 2 REL T5's.
That makes A LOT of sense to me and it did then 6 years ago to everyone else so I assume it's still true today.