Looking for advice on new subwoofer purchase

[Snowskate]

Hello all. This is my first post as I've just purchased a house with a home theater system already installed. Well, not exactly complete, but here's the setup:

Already existing when I bought the house:
Front: (2) Polk Audio left & right speakers (unsure of model's), (1) Polk Audio center speaker (unsure of model)
Rear: (2) Pol Audio left & right (same as the front's I believe, still don't know the models)

Purchases I've made:
Subs: (2) Klipsch 12" 400 watt peak, 200 watt continuous RMS (Model: R-12SW) Just picked these up on a black Friday deal for 1/2 price ($225 each)
(Link: http://www.bestbuy.com/site/klipsch-reference-12-400w-powered-subwoofer-black/6228076.p?skuId=6228076)
Receiver: Denon AVR 3313ci (125 watts per channel, 7.2 channel)
(Link: https://usa.denon.com/us/product/refurbishedprocat/avreceiversref/avr3313ci)
*****I do not have side speakers..... *sad face*....

The room:
- 24'x24'
- Vaulted ceilings
- Roughly 6-7 windows in the room?
- Many shapes and windows for reflection, bladie bladie blah, not that important for this discussion.

What will I be listening to/watching:
- Pandora
- I like classic rock, 50's music, todays hits etc.
- I like all types of movies. Typically watching ripped movies on a 65" 4k tv. Mostly 720P movies. They look and sound alright (to me anyway, I'm sure everyone here would disagree, and thats ok)

Anyway, my question(s).

1.) Will I need (2) subwoofers for this 24'x24' room?
2.) Are (2) 12" 400 watt overkill for my application?
3.) Will these subs work well with my setup?

I believe the subwoofers I've purchased are fairly overpowered for my application, but I figured I'd ask the question to highly educated enthusiasts, such as yourselves, as my knowledge is at the beginner level. I have a feeling there is a ton of information that I have not provided so please feel free to ask questions. I'm sorry if my response time is slow in advance. My free time is usually at night, but I will try to look every now and then during the day to respond with any information I've left out.

Thank you in advance!

 

[cel4145]

You have a very big space, and subwoofers see the whole room. So no. Not too much for your room. You'll calibrate them with your receive to integrate them well.

Dual subs, when well placed, also have the benefit of providing a smoother frequency response through a wider seating area. So a plus in that regard, too.

 

[shadyJ]

Two subs are not too much for the room. What they can do is smooth out the frequency response better since the kind of response that is almost always had with a single sub is very bad, as the long waves of low frequency sound bounce over itself and creates peaks and nulls. If you want really good bass, look into a USB microphone that can allow you to see how the subs are acting.

 

[Snowskate]

Thank you for the responses.

In regards to fine tuning the sub woofers (now that I'm more confident that I'll keep them both), what is a good beg fine r a guide that I can follow to adjust the levels and explain different placements? I've seen the sub woofer shuffle video which was a bit funny, but I don't think that's the best way? the USB microphone sounds like a good idea. Would someone mind providing a link for a recommended mic?

Also, my receiver has audyssey capabilities. I would assume this is a good testing device? Or is this just for the speakers and the sub is a different animal?

 

[shadyJ]

Audyssey EQs the subs as well as the speakers. What yo can do is make sure the subwoofer placement is optimal. One thing you can get is a UMIK-1 microphone, and hook it up to your laptop. Use Room EQ Wizard (its free) to measure varies placements for your subwoofers, and keep the placement combination that has the flattest overall response. Here is a very simple guide to using the software.

It will take some time to figure out the best placements for your subwoofers, but you will learn how low frequency sound waves interact with your room and how much better things can sound with a flat frequency response. After you find the best placement, then run Audyssey, and then do a final measurement to see how flat things are. Audyssey is good at cutting peaks, but it can't really shore up dips in the response: only good subwoofer placement can do that.