Dual Monolith 15" Ultra's

408Revo

New Member
Thread Starter
Joined
Dec 25, 2023
Messages
17
I decided to upgrade my dual 12" monolith subs and got dual 15" subs, I got to say that it's a night and day difference. Can't compare the sound dual 15"s give over the 12"s. Unfortunately it did not work for MLP. Almost everywhere else the sound was amazing. Through out the entire house I had bass but not where I sit down. I basically tore my entire room apart moving everything around trying to get these 15" to work with my room but was unsuccessful. I tried placing the 15" in every location possible in my room but my MLP was lacking sound. I'm trying to understand why this happened if my dual 12"s sounded great at my MLP. Also, I placed the 15"s woofer at the same location as the 12"s but did not work for me. Did I do something wrong or can this happen?
 

Sonnie

Senior Admin
Staff member
Joined
Apr 2, 2017
Messages
5,148
Location
Alabama
More  
Preamp, Processor or Receiver
StormAudio ISP Elite 24 MK3 Processor
Main Amp
McIntosh MC1.25KW Monoblock Amps
Additional Amp
StormAudio PA 16 MK3
Computer Audio
Intel NUC w/ Roon ROCK
Universal / Blu-ray / CD Player
Panasonic UB9000 4K UHD Player (for media discs)
Front Speakers
RTJ 410
Center Channel Speaker
MartinLogan Focus C-18
Front Wide Speakers
JTR Neosis 110HT
Surround Speakers
JTR Neosis 210RT
Surround Back Speakers
JTR Neosis 210RT
Front Height Speakers
JTR Neosis 110HT-SL
Rear Height Speakers
JTR Neosis 110HT-SL
Subwoofers
JTR Captivator 2400 x6
Other Speakers or Equipment
VTI Amp Stands for the Monoblocks
Video Display Device
Sony 98X90L
Remote Control
Universal MX-890
Streaming Equipment
Kaleidescape | FireCube | Lenova Carbon X1 and Intel NUC for Roon
Streaming Subscriptions
Lifetime Roon Subscription
Tidal
qobuz
Netflix
Amazon Prime
Satellite System
Dish Joey 4K
Other Equipment
Zero Surge 8R15W-1 | Salamander Synergy Equipment Stand
Typically you get fairly close to the same response if the front of the sub is at the same location. You may get more extension in both directions with a more capable sub, but otherwise I don't think it would be that much off, unless they are ported and tuned to a different frequency.

Have you reconnected the 12" sub in one location to see if it measures as it used to measure?
 

408Revo

New Member
Thread Starter
Joined
Dec 25, 2023
Messages
17
Yes, I just reconnected the 12”s instead for now and put my living room back together. A little bummed out that I couldn’t get the 15”s to work for my MLP. I know that my room is not ideal as it opens up to the kitchen and opens up to two other hallways. Going to keep doing research and see what I’m doing wrong or the reason why this is happening. I might just get a third 12” and call it good.
 

Sonnie

Senior Admin
Staff member
Joined
Apr 2, 2017
Messages
5,148
Location
Alabama
More  
Preamp, Processor or Receiver
StormAudio ISP Elite 24 MK3 Processor
Main Amp
McIntosh MC1.25KW Monoblock Amps
Additional Amp
StormAudio PA 16 MK3
Computer Audio
Intel NUC w/ Roon ROCK
Universal / Blu-ray / CD Player
Panasonic UB9000 4K UHD Player (for media discs)
Front Speakers
RTJ 410
Center Channel Speaker
MartinLogan Focus C-18
Front Wide Speakers
JTR Neosis 110HT
Surround Speakers
JTR Neosis 210RT
Surround Back Speakers
JTR Neosis 210RT
Front Height Speakers
JTR Neosis 110HT-SL
Rear Height Speakers
JTR Neosis 110HT-SL
Subwoofers
JTR Captivator 2400 x6
Other Speakers or Equipment
VTI Amp Stands for the Monoblocks
Video Display Device
Sony 98X90L
Remote Control
Universal MX-890
Streaming Equipment
Kaleidescape | FireCube | Lenova Carbon X1 and Intel NUC for Roon
Streaming Subscriptions
Lifetime Roon Subscription
Tidal
qobuz
Netflix
Amazon Prime
Satellite System
Dish Joey 4K
Other Equipment
Zero Surge 8R15W-1 | Salamander Synergy Equipment Stand
That is quite odd for sure, and a third sub could be a good option for you... or just see what adding the 15 might do for you. It may interact well with the 12" subs.
 

408Revo

New Member
Thread Starter
Joined
Dec 25, 2023
Messages
17
I agree.
I went at it again today. Tried different variations and no luck. My (2) 12s sound better at my MLP over the (2) 15s. Sending them back and ordering another 12. Hopefully with the third, I’ll get a flatter curve.
 

Gerry Iaria

Moderator
Staff member
Joined
Nov 10, 2018
Messages
119
Location
Portugal
More  
Preamp, Processor or Receiver
Marantz Cinema 50
Universal / Blu-ray / CD Player
Sony X800
Front Speakers
Arendal 1961 monitors
Center Channel Speaker
Arendal 1961 centre monitor
Surround Speakers
Altec c1
Surround Back Speakers
Totem Acoustic Dream catcher
Subwoofers
Arendal Sub1- Ken Kreisel 800
Screen
Samsung S95C 77inch
Remote Control
yes, L.O.L
Streaming Equipment
Apple
Streaming Subscriptions
Apple,Netflix, Prime, Skyanytime
I agree.
I went at it again today. Tried different variations and no luck. My (2) 12s sound better at my MLP over the (2) 15s. Sending them back and ordering another 12. Hopefully with the third, I’ll get a flatter curve.
That's very strange, you would think that with the 15's you'd get better, did you try one of the 15 as a 3rd sub, to see if it works before buying anoter 12??
 
Joined
Mar 3, 2019
Messages
41
I decided to upgrade my dual 12" monolith subs and got dual 15" subs, I got to say that it's a night and day difference. Can't compare the sound dual 15"s give over the 12"s. Unfortunately it did not work for MLP. Almost everywhere else the sound was amazing. Through out the entire house I had bass but not where I sit down. I basically tore my entire room apart moving everything around trying to get these 15" to work with my room but was unsuccessful. I tried placing the 15" in every location possible in my room but my MLP was lacking sound. I'm trying to understand why this happened if my dual 12"s sounded great at my MLP. Also, I placed the 15"s woofer at the same location as the 12"s but did not work for me. Did I do something wrong or can this happen?
This could be an issue of: inversion, incorrect crossover points or delay issues that are causing your subwoofers not to integrate with the rest of your system.

In our tech blog we explore how to reach the goals of proper subwoofer integration:

Goals:
  • Optimization of level, crossover and delay settings
  • Seamless integration of the last audio spectrum octave
  • Elimination of excessive driver excursion and heat dissipation in full-range speakers
  • Maximizing clarity and impact
Room EQ Wizard (REW) is used as a tool during the miniDSP Device Console setup. Hopefully some of these methods will help you discover a remedy for your situation.
 
Top Bottom