Need Help With New System Including Selection of In-Wall Passive Sub and Amplifier

[WaltJohnson]

Please Help,

I've been collecting the pieces for our home theater/music system for the last year and now it is down to the subwoofer/amp before I start installing. I have put this system together on a tight budget off ebay (as you can probably tell from the equipment list below) The system is primarily going to be used for my two teenagers and their friends for television/movies, xbox, and music (mp3s from a PC through an optical toslink cable).

Acoustics: The room is 12' by 23' with french doors and windows at each end. Of the remaining two walls, one is solid drywall since it faces the garage. The other wall faces the main portion of the house and has two doors. The wall that adjoins the garage will be the "rear" of the system and I plan on installing the subwoofer on this wall. Since it shares a wall with the garage, space is not an issue for the amplifier.

Current equipment (still in boxes) and how I believe they will be used:
A/V Receiver: Harman Kardon AVR 635
Front Speakers: JBL Soundpoint SP6CII
Center Channel: Infinity ERSH V250
Surround Speakers: JBL Soundpoint SP6CII
Rear Speakers: JBL Soundpoint SP8CII

I'll be running 12 gauge speaker wire for all the connections
I'll run RG6 with RCAs for the subwoofer amp connection

Questions: I would like to stick with the in-wall configuration and install an in-wall passive sub with separate amplifier. I can only afford to purchase "pre-owned" equipment and have been looking at eBay to try to find compatible equipment. I have tried to do as much research as possible but now need answers to some questions that may seem basic, but I just don't know.

 Should I be looking for a subwoofer in the 12" range powered by a 200 wall (or higher) amplifier?

 Should I build an enclosure in the wall and install the sub driver in the enclosure to save money, or am I overthinking this? If I do build the enclosure, what should I do for the grill?

 Many people are selling plate amplifiers for either DIY kits or that have been removed from free standing subwoofer boxes. Is there an advantage/disadvantage to using a standard subwoofer amplifier over a plate amp? What are the pros/cons of each?

 When looking at amps and passive subs, I see that the impedance of different subwoofers can be either 4 ohm, 6 ohm, or 8 ohm. The amplifiers' will list 8 ohm and 4 ohm. This is the question that will make me sound stupid, but will any subwoofer amplifier run any subwoofer, or do you have to match them up based upon the Impedance rating of the subwoofer?

 I need to stay under $300 total for the amp and subwoofer. I've been looking at used Dayton, JBL, Velodyne, NHT, Eosone Polk, and M&K amplifiers. I've seen several of the Eosone Polk and M&K surplus plate amps lately on eBay. As far as subwoofers, I'm staying away from the low budget stuff and just waiting it out for a higher quality used one to show up at a good price.


Please help. Also, please offer suggestions if you feel I am doing something wrong with the equipment I currently have.

Thanks,

----Walt

 

[lsiberian]

an IN-wall sub on your budget doesn't seem feasible. honestly.

For an Amp just get a Behringer a500 or something similar.

 

[WaltJohnson]

Infinite Baffle Sub has been recommended - Thoughts or Designs ???

Hey everybody,

On a separate post, it has been recommended that I construct and IB (Infinite Baffle Sub) to complete this project.

Do you have and thoughts or designs for this IB? Any recommendations on specific equipment for this DIY?

It will probably be installed in my garage with the opening towards the entertainment room.

As they mentioned, Quality depends entirely on the quality of the equipment used. Having two opposing drivers also cancels any mechanical vibrations of the cones moving.

As it was mentioned, IB subs go from simple to extreme. But the concept is all the same. By using large drivers, they don't have to work as hard. Not working as hard equals less distortion. Less distortion equals quality bass. With my $300 budget I can build a simple IB with dual 15's and a plate amp.

Thoughts everybody?????????

Thanks,

----Walt

 

[AVRat]

The IB was my first thought for your situation since you’re using the garage wall. For more serious discussion I suggest you head on over to the cult. You’ll need to register to get in but it’s painless. Members there are more than willing to help and some have done simple implementations like yours. http://ibsubwoofers.proboards.com/index.cgi?

 

[TLS Guy]

Hey everybody,

On a separate post, it has been recommended that I construct and IB (Infinite Baffle Sub) to complete this project.

Do you have and thoughts or designs for this IB? Any recommendations on specific equipment for this DIY?

It will probably be installed in my garage with the opening towards the entertainment room.

As they mentioned, Quality depends entirely on the quality of the equipment used. Having two opposing drivers also cancels any mechanical vibrations of the cones moving.

As it was mentioned, IB subs go from simple to extreme. But the concept is all the same. By using large drivers, they don't have to work as hard. Not working as hard equals less distortion. Less distortion equals quality bass. With my $300 budget I can build a simple IB with dual 15's and a plate amp.

Thoughts everybody?????????

Thanks,

----Walt

No you won't come out for $300. xmax X driver area needs to be at least 12 lt, or the drivers will self destruct. This type of project will require four 15" long throw drivers or two 18" long throw drivers. The drivers need low Fs also.

An IB project is an expensive proposition.