AVS Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
64 Posts
Discussion Starter · #1 ·
I'm putting together my first HT and on a very tight budget (single income + family of five = little disposable income). I have picked up most of the components needed to put it together but the sub I currently have is too weak for the space. As outlined in the stickied thread, my conditions can be summarized as follows:

1. Budget

Definitely need to keep the cost below $500. I would like to try and get something for around the $250 mark. My preference is to buy used equipment over new to try and reduce costs and still get good quality components.

2. Size requirements/limits

Form factor of sub does not matter. I have a giant space to put it in (see next point). I was thinking about running a single 10" or 12" with the possibility of upgrading to dual subs in the future but I'm not an expert and will rely and whatever feedback I can get from you guys.

3. Room dimensions

The HT is going in the basement which has a fairly open floor plan. The entire open space comes to about 6,000 cubic feet. I intend to leave this space and develop the entire basement into a games room / bar / HT so the sub needs to be able to fill this volume.

4. Primary uses

Once completed, I will use the HT for gaming and movie watching primarily and little bit of music listening (and Rock Band!). If I were to guess the useage I would go: Gaming 40%, Movies 40%, Music 20%.

5. Listening habits

The main point is being able to hear all of the sound effects present in the source material. I won't be able to crank it that often as I have kids that will be sleeping upstairs, but when I get the chance, I want it to deliver. I understand that my budget isn't exactly going to knock the socks off of anyone so I'll just have to do the best that I can with the constrainst that I have.

6. Appearance requirements

Appearance doesn't matter. I will probably be framing it in and then putting some AT material over the front of it. If it doesn't make sense to put the sub in an enclosure then it can be placed anywhere in the room (pretty flexible).

7. Timeframe

The sub I presently have is "functional" so timeline isn't that critical. If I do frame it in then I do need dimensioning soon as I intend to start framing this the PJ screen area this weekend.


One other question, the sub I currenlty have is part of the Athena Point 5 MkII 5.1 speaker system. It is supposedly matched to the surround speakers so that it provides "seamless" coverage of the frequency spectrum when used with those speakers. Should I run dual subs and keep this sub in system to compliment the satellite speakers while using a larger sub to fill the room with LFE or just get rid of Athena sub?
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #2 ·
I forgot to add that I was leaning towards the PA-120 subs as they appear to be getting good feedback on these forums particularily regarding their cost/performance. I was thinking of starting with a single PA-120 ($230) and then upgrading to dual PA-120s ($460) if I was unsatisfied with the performance coming from just running one.
 

·
Registered
Joined
·
191 Posts
Wow, your situation sounds real similar to my thread . Even both looking at the PA-120's in a possible dual set-up (although I don't intend on framing mine in). Hopefully between the two of them we can get some good recommendations.
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #4 ·

Quote:
Wow, your situation sounds real similar to my thread. Even both looking at the PA-120's in a possible dual set-up (although I don't intend on framing mine in). Hopefully between the two of them we can get some good recommendations.

Yeah, I did read through your thread but I think the big difference between our situations is the room size. You have a comparatively small space to fill with sound (1250 cu.ft. if I recall correctly) compared to the 6000 cu.ft. I'm trying to fill. I'm guessing you can probably buy a better sounding sub than me and still be able to fill the room with sound. I'm probably going to have to compromise a bit on the sound quality and go for sheer SPL to get decent LFE in an area this large.


I'm not an expert though and hopefully someone will chime in with some good advice. Good luck with your setup!
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #6 ·

Quote:
Originally Posted by gtpsuper24 /forum/post/17029706


Is DIY out of the question, your best bang for the buck is diy. A kit like this http://www.creativesound.ca/details.php?model=QUARTET12 all you have to do is build a 20" cube out of 3/4 mdf about $20 at home depot or lowes, they even give you a guide to build the box http://www.creativesound.ca/pdf/Quar...woofer_Kit.pdf

I hadn't given DIY much thought but I suppose that is an option. The only issue is that I'm busy with the rest of the home theater construction at the moment so if I do decide to go the DIY route I won't be able to start the sub construction for at least a month if I'm being realistic. Is a single sub the best option for a large space like this or should I be looking at building/buying two smaller subs to smoothen out the bass for the entire space?


Also, I was framing in two locations for subs when building the projector screen stage area. If I use framed in locations, should I stick with forward firing subs or does that not really matter?
 

·
Registered
Joined
·
3,995 Posts
If you're building a dedicated space, better to slow things down a bit and do it right the first time. If you're in the construction/framing phase now's the absolute best time to impliment/design a built in DIY subwoofer. Wall cavities if done properly can make for excellent ported enclosures but it's going to take some patience and work on your part. Definatley worth while considering the advantages over a Pa-120. One of the easiest and best performing subwoofer alignments is an infinite baffle where the subwoofer(s) face inot the listening space and the rear of the subs are loaded into a seperate room that acts as the actual enclosure. Very simple to build and fairly inexpensive with low frequency extension iinto the sub 10Hz region....making even multi SVS Ultra owners jealous. So if you have an adjoining utlily/laundry room that's not a living space, post some pics and i'll help you outline a design.
 

·
Registered
Joined
·
2,069 Posts
+1 on the infinite baffle, very good choice if you are building/remodeling a room for HT. Since your budget is so tight, don't spend most of it on a cheap sub thats not going to get the job done just so you can hurry up and get a sub. If the infinite baffle is something you can't do, the Creative sound quartet 12 is one hell of a sub, I think you would be really surprised at how loud and low and clean it will play. $419 plus $20-25 for .75inch MDF and your good to go. It would be as good as some subs costing twice maybe three times as much. Just use your current sub for now and what ever way you decide to go just piece things together a little at a time.
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #9 ·

Quote:
Originally Posted by mayhem13 /forum/post/17030647


If you're building a dedicated space, better to slow things down a bit and do it right the first time. If you're in the construction/framing phase now's the absolute best time to impliment/design a built in DIY subwoofer. Wall cavities if done properly can make for excellent ported enclosures but it's going to take some patience and work on your part. Definatley worth while considering the advantages over a Pa-120. One of the easiest and best performing subwoofer alignments is an infinite baffle where the subwoofer(s) face inot the listening space and the rear of the subs are loaded into a seperate room that acts as the actual enclosure. Very simple to build and fairly inexpensive with low frequency extension iinto the sub 10Hz region....making even multi SVS Ultra owners jealous. So if you have an adjoining utlily/laundry room that's not a living space, post some pics and i'll help you outline a design.

Thanks for your help. When I get home (at work now) I will draw up a floor plan of the space and how I intended to layout the home theater and get your feedback. There is a staircase right next to the area I am going to put the home theater in that might work for this (the cavity underneath the stairs that is).


As far as current progress, I am just laying out and preparing the space at the moment and haven't actually got into full construction yet so there is time to make adjustments still. I was going to start building this weekend as my sheet of Wilsonart DW laminate just arrived (for the screen).
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #11 ·

Quote:
Originally Posted by gtpsuper24 /forum/post/17033218


Under a stair case is perfect depending on what size the area is and if the stair case is sealed.

Actually, I was thinking about this some more and the other side of the stair cavity is adjacent to a cool room. If I needed more volume, I could take the sheet rock off of this wall so that the stair cavity and cool room are all one space and then seal them up. The cool room is vented to the outside however and this can't really be sealed up or it will no longer work as proper cold storage. Maybe this is a good thing as open to the outdoors should really make it an infinite baffle! (although the opening is only about 1' x 6")


I spent the last few minutes looking into other IB setups and these things look crazy (in a good way)! This is definitely something that I would be interested in doing even if it means limping along with my little sub for a while longer. Are these IB setups strictly for massive low frequency effects or do they produce decent SQ as well? What do you figure I would need as far as drivers and an amp? If I know what components I need I can keep an eye out over the next few weeks and see if any deals show up (on eBay or whatever). I suppose the sky is the limit but a modest start would be fine.
 

·
Registered
Joined
·
2,069 Posts

·
Registered
Joined
·
64 Posts
Discussion Starter · #13 ·

Quote:
Originally Posted by gtpsuper24 /forum/post/17033525


Not all subs will work in a IB setup, your also going to need a amp and a hi pass filter.

Excuse my ignorance, but what is the purpose of installing a high pass filter? If I'm thinking correctly, I would run the pre-amp sub output from my AVR to the sub amp but I would expect that signal to already be properly filtered by the AVR. Also, what is the proper process of selecting components? I'm guessing the proper way would be something like...


1) Determine the sub displacement required to fill the area in question.

2) Select sub drivers that will meet required displacement.

3) Select amp that will adequately power the selected drivers.


But the budget minded part of me says something more like...


1) Select an amp that I can afford ($250)

2) Buy as many drivers as I can afford but without exceeding the amps capacity ($400)

3) Live with the performance I get based on the price that I spent


Thoughts?
 

·
Registered
Joined
·
2,069 Posts
You need a high pass filter to keep the driver from destroying itself. Theres nothing stopping a IB sub from going beyond its excusion limit, hence the need of a high pass filter, depending on the driver you get you would set the HPF to 20hrz or so maybe lower and then the AVR does the low pass filter 80hrz. Some amps have a hpf but some do not and you'll have to buy one. With a normal sub like sealed theres pressure in the box keeping the sub from going lower than the driver will allow, but there is no pressure in a IB setup, and the sub will keep playing until it pulls apart the voice coil or the rubber surround gives out. http://www.hometheatershack.com/foru...er-system.html
http://www.hometheatershack.com/foru...ts-photos.html heres a forum dedicated to nothing but IBs, you can post in the AVS diy speaker/sub forum here to get more advice from people who have done this kind of setup or the Hometheater Shack ib forum too, post your budget, pictures, layout, and they can tell you the best stuff.
 

·
Registered
Joined
·
3,995 Posts
IB subwoofers by design will have the best SQ of all of the alignments as there's no port issues, group delay or cavity effects from box loading to worrk about. The reason you don't see many is purely logistics as not everyone has an adjacent room or space for one.


As for the high pass filter, that's a filter to protect the driver from very low freq material where the drivers excursion will be out of limits. But since the goal of an iB is extremely low FR, the highpass becomes more of a default by design.


Considering your budget, the Acoustic Elegance IB15 15" driver is the sensible choice at $149. You'll need two minimum for $300 of your budget




They're available here http://www.aespeakers.com/drivers.php?driver_id=8


A quick simulation with a pair of these in IB formation and 100w per driver shows nearly flat response to 15hz at 110db. Given your budget and the ease of the build, you simply can't outperform this setup...no way no how.

Attachment 150606


Now keep in mind that's with only 100w per channel of amplification which really helps with your budget. Wiring these in series gives you an 8ohm amp friendly load....and with an adjustable high pass filter and built in eq, a perfect use for the Oaudio Bash 500 amplifier.

http://oaudio.com/500W_SUBAMP.html

You can mount it in the wall for easy access to the controls, has an auto on feature and the needed eQ to help flatten the response in your room. With the cost of the amp and drivers, total cost is around $580 inc shipping.
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #16 ·

Quote:
If you're building a dedicated space, better to slow things down a bit and do it right the first time. If you're in the construction/framing phase now's the absolute best time to impliment/design a built in DIY subwoofer. Wall cavities if done properly can make for excellent ported enclosures but it's going to take some patience and work on your part. Definatley worth while considering the advantages over a Pa-120. One of the easiest and best performing subwoofer alignments is an infinite baffle where the subwoofer(s) face inot the listening space and the rear of the subs are loaded into a seperate room that acts as the actual enclosure. Very simple to build and fairly inexpensive with low frequency extension iinto the sub 10Hz region....making even multi SVS Ultra owners jealous. So if you have an adjoining utlily/laundry room that's not a living space, post some pics and i'll help you outline a design.

As promised, here is a rough layout of my basement that I measured up tonight and drew using Visio (that's the only draft-like program I have installed and somewhat know how to use). Hopefully you can open the attached file to view it. The items in green are my plans for the space and don't actually exist yet (can be modified as needed). Based on these measurements the volume of the open space (Bar Area, Home Theater Area and Pool Table Area) actually only comes to 5405 cu.ft. with my 7.5' ceiling so it's not quite as large as I initially stated.


As far as an IB sub goes, the only good options that I can see is putting the sub in the stair cavity or the cold room. The problem that I see with the stair cavity is that the sub will be firing beside and possibly slightly behind the couch which may be an issue. The problem with the cool room is that it will be firing at the bottom of the stairs which probably isn't the ideal position. I could make a small enclosure at the stair landing which directs the sound front from sub into the home theater space.


Anyway, please let me know what your thoughts are on the space and if an IB sub looks like a possibility hear. If it would be helpful to get some photos of any areas in particular let me know and I would be happy to oblige. Thanks for your help.
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #17 ·
I think the other option for DIY sub in my case would be to use the stage area as one big sub box. This stage should end up with about 72 cu.ft. of space inside and that would allow me to position the drivers in the best location. This probably doesn't count as being an IB install but I'm guessing I could get decent results from that as well. Rough guesses on the volumes of each of the spaces under consideration...


Cold Room - 580 cu.ft. (*This room is vented to the outside)

Stair Cavity - 154 cu.ft.

Projector Screen Stage - 72 cu.ft.
 

·
Registered
Joined
·
64 Posts
Discussion Starter · #18 ·

Quote:
Originally Posted by gtpsuper24 /forum/post/17035788


You need a high pass filter to keep the driver from destroying itself. Theres nothing stopping a IB sub from going beyond its excusion limit, hence the need of a high pass filter, depending on the driver you get you would set the HPF to 20hrz or so maybe lower and then the AVR does the low pass filter 80hrz. Some amps have a hpf but some do not and you'll have to buy one. With a normal sub like sealed theres pressure in the box keeping the sub from going lower than the driver will allow, but there is no pressure in a IB setup, and the sub will keep playing until it pulls apart the voice coil or the rubber surround gives out. http://www.hometheatershack.com/foru...er-system.html
http://www.hometheatershack.com/foru...ts-photos.html heres a forum dedicated to nothing but IBs, you can post in the AVS diy speaker/sub forum here to get more advice from people who have done this kind of setup or the Hometheater Shack ib forum too, post your budget, pictures, layout, and they can tell you the best stuff.

I followed your advice and started a thread in the AVS DIY Speakers and Subs forum to try and solicit some advice there as well. Thanks for the suggestion.


DIY Speakers and Subs thread:
http://www.avsforum.com/avs-vb/showthread.php?t=1172867
 
1 - 18 of 18 Posts
Top