Different Subwoofer sizes in my home theater but same brand and type ok?

[Outatime]

Hello All! I am currently running two Monolith THX 12” subs in my home theater room and was thinking of adding a 3rd for now. However I’d the to add the Monolith THX 15” instead of getting another 12”. I know the recommendation is to always stick with the same sub if possible so in this case it’s basically the same exact sub but just the larger version. I know the easy answer is to just get two more 12s to have four total but I’d prefer to just get one more if possible. Can this work? My current setup is one at the front almost mid wall and one at the back mid wall behind the seating area. I’m thinking that I would put the 15 inch at the front mid wall and take of 12 inch subs and move them to each corner in the back.The two subs running currently sound great and you can feel them but I was hoping to get a little bit deeper punch by adding the 15 inch. I don’t want to replace the 212s I currently have just to turn around and have to buy all 15s so I was hoping to go this route. The room is 22 feet long by 13 feet wide. It is basically a rectangle however on the left side of the room there is an open area to the wall that leads to the steps to the floor above that I cannot close off. The current performance however seems very good as I mentioned. I have a 7.2.4 set up with all Klipsch reference speakers and a Denon receiver and an Emotiva 3 channel amp For the front 3 channels Any thoughts and input would be greatly appreciated. Thanks!

 

[shadyJ]

Having different subs can work, but not all the time, and care has to be taken in selecting the subs. The problem is that if you pair a weak sub with a powerful sub, at higher drive levels the weak sub may run into heavy distortion which degrades the overall sound, so it would have been better not to add the weak sub at all. You need to ensure that the weak sub is strictly limited so that it doesn't run into heavy distortion at high drive levels. The good news for you is that the Monolith subs do just that. The 12"s can not be pushed into heavy distortion, and that is mandated by their THX certification. If you drive the full throttle, they just stop getting louder. So yes, you can mix the Monolith 12" and 15" subs, and it will work just fine.

 

[Hetfield]

I have 2 different size subs working on my HT. Two SVS subs, PB 2000 Pro and regular PB 1000. It's working, I'm not really sure how much the PB 1000 is contributing or what exactly I'm feeling but it does overall sound good. The PB 2000 Pro is extremely impressive to me, I'm having fun with it.

Sent from my Pixel 4 XL using Tapatalk

 

[William Lemmerhirt]

The thing I would be worried about aside from the limitations of the lesser sub, which shady already covered. Is that they’re not the “exact same sub just a larger version”. The phase responses of the drivers and ports are going to be different and you could run into cancellations, and undo everything your trying to accomplish. It’s possible to add the 15 and you’d get ok results, but IMO you should already be measuring with REW, and especially if you add a single 15 or another pair of 12’s.

 

[Outatime]

Thanks for the responses I’ve received so far. I figured I’d get some different opinions So Im still not sure what to do. Gene has always stated that it’s better to get subs in pairs and not do odd numbers unless you have an odd shaped room then you can throw that out the window. My room is basically a rectangle as I mentioned. Perhaps I should just get 2 more 12s. I was just trying to get a bit lower frequency response and a bit more power by adding the 15 on top of what I already have. Plus one additional unit instead of 2 so taking up less space. I’m not in any way unhappy with how it currently sounds but always wanting to get better if possible.

 

[lovinthehd]

You could also review Geddes' sub setup recommendations....

 

[Outatime]

You could also review Geddes' sub setup recommendations....

I’ve read it or at least some of it. It goes against most peoples approach of setting your crossover and your receiver at 80 Hz and running your man’s at full. I’m not sure that’s the best approach here.There’s also the Welti approach which is completely different. I realize there are so many factors that can come in to play. At the end of the day all I’m trying to figure out is if I’m making a mistake by purchasing another subwoofer from the same company that is a 15 inch sub as opposed to purchasing two additional 12 inch subs. if I purchase the 15 and it doesn’t make a big difference it’s not very easy to just send it back without spending hundreds of dollars to ship it even if they will honor the return. And from an earlier response I do realize that the 15 inch sub while the same brand and type will still not be exactly the same because it is a larger sub and therefore the range is naturally different. I just am trying to get input on if I’m going to be defeating the purpose or is there actually a chance that it will make it better and give me what I am hoping for. Everything I read says try to stick with the same subwoofers. I’ll ported subs or all sealed subs. All the same manufacture. I get both of those. What I don’t see a lot of information on is if two of my subs are 12 inches and the third sub is a 15 inch Will that create an issue negatively and therefore am I stuck with getting two additional 12 inch subs. I wouldn’t be adding two additional subs because I felt like there are too many areas other than the money seat that are lacking bass. Where I previously mentioned that I have my subs placed at the moment I don’t seem to have that issue. The bass is pretty consistent. I’m just looking for it to go a little bit lower, a little bit louder, with a little bit more “feel” in your body. I hope this makes sense.

 

[kini]

Hello All! I am currently running two Monolith THX 12” subs in my home theater room and was thinking of adding a 3rd for now. However I’d the to add the Monolith THX 15” instead of getting another 12”. I know the recommendation is to always stick with the same sub if possible so in this case it’s basically the same exact sub but just the larger version. I know the easy answer is to just get two more 12s to have four total but I’d prefer to just get one more if possible. Can this work? My current setup is one at the front almost mid wall and one at the back mid wall behind the seating area. I’m thinking that I would put the 15 inch at the front mid wall and take of 12 inch subs and move them to each corner in the back.The two subs running currently sound great and you can feel them but I was hoping to get a little bit deeper punch by adding the 15 inch. I don’t want to replace the 212s I currently have just to turn around and have to buy all 15s so I was hoping to go this route. The room is 22 feet long by 13 feet wide. It is basically a rectangle however on the left side of the room there is an open area to the wall that leads to the steps to the floor above that I cannot close off. The current performance however seems very good as I mentioned. I have a 7.2.4 set up with all Klipsch reference speakers and a Denon receiver and an Emotiva 3 channel amp For the front 3 channels Any thoughts and input would be greatly appreciated. Thanks!

I run 2 very different subs an SVS PC12+ and a Def Tech Super Cube 8000. I don't measure anything as I'm not one to want to dive down that hole. But I do know that my system sounds better with both subs on than with just the PC12+. Only at very loud levels does the SC call attention to itself by maxing out before the PC12+ does. I don't hardly ever listen that loud anymore and if fact haven't in well over a year so I have a better sounding system pretty much all the time now.

 

[lovinthehd]

I’ve read it or at least some of it. It goes against most peoples approach of setting your crossover and your receiver at 80 Hz and running your man’s at full. I’m not sure that’s the best approach here.There’s also the Welti approach which is completely different. I realize there are so many factors that can come in to play. At the end of the day all I’m trying to figure out is if I’m making a mistake by purchasing another subwoofer from the same company that is a 15 inch sub as opposed to purchasing two additional 12 inch subs. if I purchase the 15 and it doesn’t make a big difference it’s not very easy to just send it back without spending hundreds of dollars to ship it even if they will honor the return. And from an earlier response I do realize that the 15 inch sub while the same brand and type will still not be exactly the same because it is a larger sub and therefore the range is naturally different. I just am trying to get input on if I’m going to be defeating the purpose or is there actually a chance that it will make it better and give me what I am hoping for. Everything I read says try to stick with the same subwoofers. I’ll ported subs or all sealed subs. All the same manufacture. I get both of those. What I don’t see a lot of information on is if two of my subs are 12 inches and the third sub is a 15 inch Will that create an issue negatively and therefore am I stuck with getting two additional 12 inch subs. I wouldn’t be adding two additional subs because I felt like there are too many areas other than the money seat that are lacking bass. Where I previously mentioned that I have my subs placed at the moment I don’t seem to have that issue. The bass is pretty consistent. I’m just looking for it to go a little bit lower, a little bit louder, with a little bit more “feel” in your body. I hope this makes sense.

Just like you say, there are many factors and different approaches will work differently in different rooms to an extent as well. Because I've procrastinated a lot I run a dual opposed 15" with three single 18"s (I have the 18" drivers for a dual opposed build too). Not an issue but they have similar response characteristics (as measured at data-bass.com). I've also run mismatched subs in other rooms at times without particular issue, with a bit wider variation in response. You will be limited by the less capable sub, too.

Since shadyj says they should work together well I'd take his word for it, you might check shadyj's reviews:

Monoprice Monolith 15” THX Ultra Subwoofer Review

At last! It's here! Our review of Monoprice's monster subwoofer, the Monolith 15" THX Ultra! This 130 lb. beast might look like it's all muscle, but there's at least as much brains as there is brawn.

www.audioholics.com

Monoprice Monolith 10” THX Select and 12” THX Ultra Subwoofers Review

In this review, we look at two high-powered but affordable Monoprice subwoofers, the 10" THX Select and 12" THX Ultra. Continue reading to find out if your home theater room can handle these beasts.

www.audioholics.com

 

[Outatime]

Just like you say, there are many factors and different approaches will work differently in different rooms to an extent as well. Because I've procrastinated a lot I run a dual opposed 15" with three single 18"s (I have the 18" drivers for a dual opposed build too). Not an issue but they have similar response characteristics (as measured at data-bass.com). I've also run mismatched subs in other rooms at times without particular issue, with a bit wider variation in response. You will be limited by the less capable sub, too.

Since shadyj says they should work together well I'd take his word for it, you might check shadyj's reviews:

Monoprice Monolith 15” THX Ultra Subwoofer Review

At last! It's here! Our review of Monoprice's monster subwoofer, the Monolith 15" THX Ultra! This 130 lb. beast might look like it's all muscle, but there's at least as much brains as there is brawn.

www.audioholics.com

Monoprice Monolith 10” THX Select and 12” THX Ultra Subwoofers Review

In this review, we look at two high-powered but affordable Monoprice subwoofers, the 10" THX Select and 12" THX Ultra. Continue reading to find out if your home theater room can handle these beasts.

www.audioholics.com

 

[Outatime]

Yes, I had already read that review which is why I bought the two 12s in the first place. Based off of ShadyJ’s original response, which I value highly I think I feel comfortable getting the 15 as a third subwoofer and trying out both of the 12s in the rear of the room. I of course know I will most likely need to play around with it or try REW but based on how it already sounds I think it should work nicely. I just wanted some confirmation and input from others just to get a better feel for my decision. Like I said it was either going to be two more 12s for a total of four subwoofers or the one 15 so I can stick with three. Thanks!

 

[lovinthehd]

Then again four of the same....

 

[Outatime]

Having different subs can work, but not all the time, and care has to be taken in selecting the subs. The problem is that if you pair a weak sub with a powerful sub, at higher drive levels the weak sub may run into heavy distortion which degrades the overall sound, so it would have been better not to add the weak sub at all. You need to ensure that the weak sub is strictly limited so that it doesn't run into heavy distortion at high drive levels. The good news for you is that the Monolith subs do just that. The 12"s can not be pushed into heavy distortion, and that is mandated by their THX certification. If you drive the full throttle, they just stop getting louder. So yes, you can mix the Monolith 12" and 15" subs, and it will work just fine.

Having different subs can work, but not all the time, and care has to be taken in selecting the subs. The problem is that if you pair a weak sub with a powerful sub, at higher drive levels the weak sub may run into heavy distortion which degrades the overall sound, so it would have been better not to add the weak sub at all. You need to ensure that the weak sub is strictly limited so that it doesn't run into heavy distortion at high drive levels. The good news for you is that the Monolith subs do just that. The 12"s can not be pushed into heavy distortion, and that is mandated by their THX certification. If you drive the full throttle, they just stop getting louder. So yes, you can mix the Monolith 12" and 15" subs, and it will work just fine.

Thanks for your response ShadyJ. I think I’m going to pull the trigger on trying the 15 instead of adding two more 12s. My plan is to put both of the 12s in the back of the room and put the 15 upfront and go from there. I know I will most likely need to play around with placement and possibly use REW but based on how it currently sounds with just the two 12s I am anticipating that it should give me what I’m hoping for.

 

[Outatime]

Thanks for your response ShadyJ. I think I’m going to pull the trigger on trying the 15 instead of adding two more 12s. My plan is to put both of the 12s in the back of the room and put the 15 upfront and go from there. I know I will most likely need to play around with placement and possibly use REW but based on how it currently sounds with just the two 12s I am anticipating that it should give me what I’m hoping for.

Having different subs can work, but not all the time, and care has to be taken in selecting the subs. The problem is that if you pair a weak sub with a powerful sub, at higher drive levels the weak sub may run into heavy distortion which degrades the overall sound, so it would have been better not to add the weak sub at all. You need to ensure that the weak sub is strictly limited so that it doesn't run into heavy distortion at high drive levels. The good news for you is that the Monolith subs do just that. The 12"s can not be pushed into heavy distortion, and that is mandated by their THX certification. If you drive the full throttle, they just stop getting louder. So yes, you can mix the Monolith 12" and 15" subs, and it will work just fine.

Now I have a new dilemma James. Add the 15 inch or Add the new 13 inch they just came out with that you just reviewed instead? I read your review and saw your latest videos including Gean’s review tonight and it’s obviously a better sub even though it’s a bit smaller but for my original question should I pay the extra few hundred dollars for the 13 inch or just stick with my original thought and save a little money and I had the 15?

 

[shadyJ]

Now I have a new dilemma James. Add the 15 inch or Add the new 13 inch they just came out with that you just reviewed instead? I read your review and saw your latest videos including Gean’s review tonight and it’s obviously a better sub even though it’s a bit smaller but for my original question should I pay the extra few hundred dollars for the 13 inch or just stick with my original thought and save a little money and I had the 15?

I would probably just stick with the 15". It's at such good pricing right now, and it is a great sub. You can always talk yourself into a higher price bracket, so you have to draw the line somewhere.

 

[}Fear_Inoculum{]

Just piggy backing off of this thread/conversation. I have the chance to pick up a Defiance X15 for a great price to go along with my 2 X12s, yay or nay?

@shadyJ @lovinthehd @William Lemmerhirt

 

[lovinthehd]

If the price is good, sounds like a plan.... but do you have two Defiance X12s already or the Monolith 12"s? https://www.audioholics.com/subwoofer-reviews/paradigm-defiance-x15

ps nm thought you were the OP

 

[shadyJ]

Just piggy backing off of this thread/conversation. I have the chance to pick up a Defiance X15 for a great price to go along with my 2 X12s, yay or nay?

@shadyJ @lovinthehd @William Lemmerhirt

If the price is great, that is a bigtime yay.

 

[}Fear_Inoculum{]

If the price is good, sounds like a plan.... but do you have two Defiance X12s already or the Monolith 12"s? https://www.audioholics.com/subwoofer-reviews/paradigm-defiance-x15

ps nm thought you were the OP

If the price is great, that is a bigtime yay.

The guy is asking 1200$ Canadian for the X15, could probably get him down a bit more even