Not surprising. Most of the guys over there are very serious about bass and their subs... To the point that it can be hard for the more casual DIY'er to get any useful help sometimes. 4x 12's is an option, but you might need more than one of those amps to power them all? Everyone is different but I have two 18's and have been happy with them.
The subs would get 250 watts each with that amp & they can handle 300 watts rms. You can definitely get a more powerful amp to push them but it would cost you a little more.
Smaller subs cant go as low and larger subs are less detailed. I think 12's give you the best of both worlds. They can go pretty low and still have some detail. The article you posted kinda talks about this as well.
I got to thinking that there must be a way to quantify a goal specific to the size of my room, which is approximately 6,000 cu. ft.. I am still learning more as I go on this but I found this website which has a pretty lengthy qualification for how they arrive at an extreme 'bassaholic' rating for rooms over 5,000 cu. ft and that is >/= 117db @ 25hz and >/= 123db @ 31-63 hz.
I then went back and looked for the winisd graphs that someone did (credit: LTD02) for the last two sub configurations I was looking at to see if one or both met this standard.
Here is the Dayton HO 18" in a 11 cu. ft. vented box powered at 1100W:
So it looks like 118db @ 25hz and 119db @ 31-63hz
It hits the first standard but not the second. If I add a second sub though I get +3db for doubling the area and + 3 db for doubling the power and that pushes it to 125db @ 31-63hz and hits the benchmark and exceeds it.
Now for the Infinity 1260 I found a winisd graph someone did (credit: gperkins1973) for a 6 cu. ft. ported box powered at 300W:
It looks like 108 db @ 25 hz and 109 db @ 31-63hz. But with four equal subs giving +12db that boosts the totals to 120 db at 25hz and 121db @ 31-63 hz.
So in that option its not 'basaholic' but I am only 2db short of the benchmark. My understanding is that the subs need to be in close proximity to get the +3 db effect so if I would decide to place two of the subs in the back of the room so then I would be at 117/118db. But I could get lucky and it could sound great with all four subs up front.
One question: I skimmed your thread so perhaps you already addressed this, but what is your plan for finishing that ceiling alcove? Seems like a perfect opportunity for a painted star ceiling. Have you seen what can be done using this approach?
Some progress to report, rough-ins are complete and wall insulation installed.
Right now I am working on some of the stonework on the fireplace wall and walls flanking the projection screen wall. This dry stack stone is mortared onto the concrete board and the smaller pieces of slate come pre assembled in 6"x24" modules. That is one days work shown there:
The fireplace box will use bio-ethanol fuel and will be set into a cast stone lintel built with a concrete mix used for counter tops.
Casting the firebox lintel:
that took a long time but finished all of the stone and tile work in the areas adjacent to the main screen area.
Fireplace slate wall with concrete hearth and lintel:
The flames will actually get about twice as high after the fire burns for about 15 minutes.
Kitchenette porcelain floor:
walls on each side of screen have the same slate as the fireplace wall:
bathroom tile floor:
Next step is more insulation and drywall then installing casework and fixtures.
LOL that is eaxctly what I said! I think this one is going back downstairs but maybe a new build for upstairs eventaully. After buying thirteen speakers for the basement I am on a 'no more speakers' moritorim for now. Need to focus on finishing the basement.
Keep the pics coming!
I'm confused too.
Looks like your basement is coming along too and sounds like you are enjoying it like I am.
Now that it is warming up and soccer season is full swing it is harder to find solid time to work on it.
I am putting up drywall so I thought I would mention what I am doing for wall construction before it gets covered up. The method of building and insulating and finishing basement walls varies depending on regional preferences and local climate so you might want to just talk to local builders to see what they have been doing with success. I had a very dry basement but did not want to take any chances with moisture since adding the insulation does change things creating a cold side against the concrete and then of course the interior space will have humidity as well. The studs are placed 4" from the face of concrete so there is a 1/2" air gap for variance in the concrete face and so that the wall will not be in contact with the concrete. The insulation batts are un-faced so the paper will not act as a vapor barrier. Before the drywall I then put a new product called membrain. The way I understand it is that in dry conditions the sheeting stops moisture vapor from passing through which is what you typically want. If however water gets inside the wall then the pores of the membrane open up larger so that the inside of the wall can then dry out. It is quite a bit more cost than regular poly vapor barrier but at $100 a roll I can do all my outside walls and have peace of mind. There are other great systems such as sprayed closed-cell foam but I think the system I chose will perform at a good value.
The kitchenette cabinets are in now, they are re-purposed from a former office break area. I had to reconfigure them to fit the space, I cut the solid surface counter shorter by a few feet and I used 3/4" black shelf boards to build out the base cabinets to the new configuration. The empty space under the counter are for microwave and toaster oven. The maple filler piece on the far right of the wall cabinet doors was from a side panel we did not use. The accent lights in the bulkhead look pretty good, there will be quite a few of them around the theater space too. They have a MR16 lamp that can be swapped out for LED versions eventually. We are also going to add under cabinet lights to highlight the yet to be determined tile back splash.
This is the space just to the right of the kitchenette, an alcove for the refrigerator. You can see the back side of the Klipsch tower speaker, it has a rear port but there will be quite a bit of volume behind the fridge so I don't think it should effect the sound being built into the wall in this manner.
I love the marty sub. It really makes music sound like the band is right in the room. My experience is that the content has to have low base to really get the powerful room shaking sound, like the movie Pacific Rim does. I also think maybe my current AVR line out is not sending enough power to the inuke, even with the subwoofer speaker level turned way up.
I debated on the placement of the marty subs, built them and placed them in the front of the room, then decided that they were visually going to compete with the screen so ultimately I decided to locate them elsewhere. I am wanting to get a new receiver with Audessy XT32 to help balance out the odd shaped room and manage the base since they will be somewhat asymmetrically placed.
I know there are many configurations with the placement of the driver and port slot and the guys over on the DYI speaker boards are very helpful. I think the key to the port is both the area of the opening and the length of the port so if you have it on the long side it would have to extend back and turn up the back side inside the box if that makes sense, but I am sure you know that.
Design change, but I think it will be cool. I was under the impression that the port on the back of the tower speakers was for venting the negative pressure of the drivers but I noticed a lack of base when I moved the fridge into position behind it. I talked to the Klipsch rep and he confirmed there is mid and low range sound loss if that port is blocked. I cut a slot above the tower and below where the RBH in-wall front height speaker will go, so I will just have full height speaker grill connecting all three sections. Sounds much better too.
Now I am thinkging that I might go ahead and block the port on the back of the towers in the original configuration, set the speakers to crossover at 80hz (or whatever Audyssey sets it at) and let the subwoofer handle the bass.
I saw this on a really old thread:
Originally Posted by Dr. Earl Geddes
"I don't port my main speakers because the lower roll off of the mains when closed box integrate better to the use of multiple subs."
And on another forum:
"First, most subs have a 2nd order low-pass filter. Vented main speakers have a 4th order acoustic roll-off on the low end, while sealed mains would have a second order roll-off. As a general principle of crossover design, you want the same rolloff rate on either side of the crossover."
plus the center channel has a front firing bass reflex ports to fill in the mid range.
Last edited by 4seahorseman; 07-26-2014 at 09:25 AM. Reason: added photos
Luckily I can afford it, but I'd rather do it myself.
Awesome stuff BTW! Looking forward to seeing it finished.
Also, how much did that fireplace cost. I'd like to do something similar! That is awesome!
You can get complete fireplace inserts that cost a lot more but I found the stainless steel box insert on Amazon for about $400 and built it into the wall. The back panel is a sheet of steel from the Ductwork section at menards with high heat black spray paint on it.
Last edited by 4seahorseman; 08-17-2014 at 07:57 AM.
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