# home sub



## humandrummachine (May 17, 2010)

Previously posted in the wrong section but anyway...

Putting a subwoofer in my room. What F3 should i shoot for?

Also, been looking at PA subs recently, at Xmax and Fs mainly, a little Qts. 

What is the recommendation for specs?


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## generalkorrd (Jan 10, 2009)

How big is the room? I wouldnt use a PA sub, unless I had a HUGE room to fill, as the enclosure for that sub will be much larger than a regular HT sub.


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## humandrummachine (May 17, 2010)

room is 10ft^3 at most. How important is it to have a total F3 of 30hz compared to 50hz or even 70hz? 

Wouldn't there be some frequency response down to 30hz even if the F3 was a little high? But would that be sufficient for the room?


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## generalkorrd (Jan 10, 2009)

You need to remeasure your room as it is not 10 cu. ft. You want response down below 30 hz, so you need to tune lower in a home than in a car( no cabin gain). I have a fairly large living room, with a pair of 15's tuned @22 hz, and I still am not getting all the 30 and down that I want. If you have a small room, that prolly means you have small speakers, which in turn would dictate that you don't need a huge sub. It seems a deep digging 10 would be perfect in a small room like that. Benefit to the small room is that you will get some gain from it, so that will help to keep your sub small(inexpensive), and your wattage down(also cheaper).


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## humandrummachine (May 17, 2010)

Sorry i meant 10^3 cu. ft. But anyway a deep digging ten, ill look into it. Thanks


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## generalkorrd (Jan 10, 2009)

Remember, thats just a "from the hip" recommendation and some extrapolation on my part due to a lack of info from you. Without knowing what your main speakers are, and still not knowing how big your room actually is, thats about as good as it's gonna get. 

"10^3 cu. ft"- is this supposed to mean 1000 cu ft? What are the actual measurements of the room? 8 foot ceilings? If you really are working with 1000 cu ft, then a 10 will probably not be able to energize the room enough for your tastes. Look at 1 high power 15(1kwatt or more) or 2 low power 15's. I am running mine at 200 watts per channel, with a larger than recced box tuned low, and it sounds quite amazing. If money is an issue, go with the low power 15 pair, and build the box larger than recommended, that will increase the sensitivity, allowing you to run a lower power amp. This is assuming you are going to build your own, if not, there are many HT subs out there to shop among.


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## humandrummachine (May 17, 2010)

yeah im sure its not quite that so whatever. Any suggestion for the type of 15(s)?


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## Ray21 (Oct 19, 2009)

Movies or music? 

A single 12 should be plenty. If mostly movies, then ported low... if music, then sealed.


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## radarcontact (Oct 28, 2010)

I use 2 JBL (automotive) 12" woofers driven by 500 watts for a 17 ft square room with one wall that only extends halfway down, the other is non-existent. It'll blow you away. 


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## humandrummachine (May 17, 2010)

Music. 

Cool I have a 15" 2001 Pioneer auto. Sub sealed already in too


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## bdelsy (Aug 10, 2011)

If primarily for music, then F3 does not need to be into the 20's unless you like to listen to symphony/orchestral type stuff. 

Placement in the room is important. Google "sub crawl". 


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## generalkorrd (Jan 10, 2009)

Ray21 said:


> Movies or music?
> 
> A single 12 should be plenty. If mostly movies, then ported low... if music, then sealed.


This makes zero sense btw. Port low for everything, not just movies. Thats why you port low, as to try to avoid any large freq. bumps around tuning. If done right, you can easily gain 6 db or more across the freq range by porting( same effect as adding 3 more woofers)


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## humandrummachine (May 17, 2010)

How correct does it have to be to gain 6db's?


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## Ray21 (Oct 19, 2009)

generalkorrd said:


> This makes zero sense btw. Port low for everything, not just movies. Thats why you port low, as to try to avoid any large freq. bumps around tuning. If done right, you can easily gain 6 db or more across the freq range by porting( same effect as adding 3 more woofers)


When I meant tuned low, I meant LLT... ~16hz. Great for explosions and a more visceral experience... just a huge enclosure is required. I wouldn't go through the hassle of building a LLT enclosure if I were going to just play music with my setup. With most ported setups I find an EQ more necessary than with sealed setups... its all IMO so take it or leave it.


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## generalkorrd (Jan 10, 2009)

humandrummachine said:


> How correct does it have to be to gain 6db's?


Make sure the enclosure isnt too small, make sure you have enough port area( doesnt affect output as much as it does port noise). It's not rocket science, here's some calcs:
Car Audio - PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES

I used this to build my subs and they sound amazing.


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## generalkorrd (Jan 10, 2009)

Ray21 said:


> When I meant tuned low, I meant LLT... ~16hz. Great for explosions and a more visceral experience... not so great for efficiency really. I wouldn't go through the hassle of building a LLT enclosure if I were going to just play music with my setup. With most ported setups I find an EQ more necessary than with sealed setups... its all IMO so take it or leave it.


I have my subs in my house tuned to 22 hz, and they are very efficient. Not too much difference from 16hz. Don't get me wrong, I love sealed setups, but if you want more output, you just wont get it from a sealed setup. I don't know what LLT means.. low long tube?low low tune?


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## FartinInTheTub (May 25, 2010)

I built this bad boy for my home theater... 2 Peerless XXLS 10s in seperate sealed chambers. I have it being powered by a Dayton 1000 watt amplifier. This can literally make my pictures fall off my walls.


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## Ray21 (Oct 19, 2009)

I was actually incorrect saying LLTs weren't good for efficiency, must of got mixed up when posting. I built two home sub setups, low tuned @ 16 and 20. I found a sealed 12 to be more to my liking for strictly music though... all depends on the room size, layout, etc of course.


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## humandrummachine (May 17, 2010)

generalkorrd said:


> Make sure the enclosure isnt too small, make sure you have enough port area( doesnt affect output as much as it does port noise). It's not rocket science, here's some calcs:
> Car Audio - PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES
> 
> I used this to build my subs and they sound amazing.


Alright for sure Ive used that calculator myself probably once or twice for boxes, but anyway I was just seeing if theres any kind of hidden clues to making it better. I guess ive never been quite impressed with anything ive built yet, completely. As in satisfactory awesome loud. Lately ive gone through a lot of random sub-woofers too. Maybe I should should just stop now, I think im looking for an awesome smooth loud system of sub-woofer.


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## humandrummachine (May 17, 2010)

FartinInTheTub said:


> I built this bad boy for my home theater... 2 Peerless XXLS 10s in seperate sealed chambers. I have it being powered by a Dayton 1000 watt amplifier. This can literally make my pictures fall off my walls.


Looks sweet man


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## generalkorrd (Jan 10, 2009)

humandrummachine said:


> Alright for sure Ive used that calculator myself probably once or twice for boxes, but anyway I was just seeing if theres any kind of hidden clues to making it better. I guess ive never been quite impressed with anything ive built yet, completely. As in satisfactory awesome loud. Lately ive gone through a lot of random sub-woofers too. Maybe I should should just stop now, I think im looking for an awesome smooth loud system of sub-woofer.


Remember, the enclosure is just as important, if not more so than the sub itself. I think you need to save up some money, and just buy a nice bigass premade, something like this:
Welcome to Epik Subwoofers

Or that premade Dayton I linked from PE earlier in this thread. I would be willing to bet that there may be somebody here who would be happy to design a subwoofer for you, and then you just follow instructions on purchasing/building.

Edit: Or you can make it easy, and buy a couple of 12's or 15's and make a sealed box around 3cu ft(12's) or 6-8 cu ft(15's). Buy a couple of these subs:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-190
and this amp:http://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-6560

Run one sub @ 4ohms to each channel of that bad boy and you will be loving life.


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## humandrummachine (May 17, 2010)

Yeah that could work, I do got an 18" Dayton Classic Sub-woofer too. You think that would sound similar? I do like the 15mm of xmax those 15" Daytons have.


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## generalkorrd (Jan 10, 2009)

humandrummachine said:


> Yeah that could work, I do got an 18" Dayton Classic Sub-woofer too. You think that would sound similar? I do like the 15mm of xmax those 15" Daytons have.


This one:
Dayton Audio DCS450-4 18" Classic Subwoofer 4 Ohm 295-475
?

If so, you may be hard pressed to get it to sound like those 2 15's would, due to cone area, and power handling. The 18 is only good for 300 rms( which I would not go past if you want things to last), while the 15's are good for 600 rms each. If you want to use that 18 and get big output from it, you have to port it. I would go for around 10 cu ft net tuned to 20 hz, that should be lotsa fun. Or, since you already have 1 of those, buy another to match, build 2 seperate 10 cu ft enclosures and run them in stereo off this amp:
Behringer A500 Reference Power Amplifier 2 x 300W 248-749

That should be a great low power system. Make the port nice and big, it can't be too big, but it can be too small. I used about 46 sq inches for each of my 15's in 3.4 net(each). You should have somewhere around 160 sq inches of port per box if you go with 2 seperate 10 cu ft enclosures. I actually went with the rule of thumb of approx. 16 sq inches per cube, and my velocity came up just fine with that calc I posted earlier. As you can see, the dual 15 system will be much smaller than that, but if you have the room, and no wife to ***** at you, then save some money and go with the 2 18 setup that you already have a start on.


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## generalkorrd (Jan 10, 2009)

BTW, the thing with velocity is that if it is too high i.e too small of a port, you will have port noise, and it does get quite irritating, especially with a big sub/big enclosure


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## generalkorrd (Jan 10, 2009)

I just ran the vent calc with that 18, and it says 25 sq inches of port for that particluar driver. I would not go that small, I would do at least 70 sq inches, and you would be good for a driver up to 23mm xmax( incase you want to replace it later and go higher power). If you went with a 10 cube net box with 72.25 sq inches of port(8.5x8.5), the port would only need to be 37.41 inches long to hit 20 hz tuning.


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## subwoofery (Nov 9, 2008)

We still don't know how big your room is... It really can help us decide which sub is better for your needs... 

Kelvin


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## humandrummachine (May 17, 2010)

subwoofery said:


> We still don't know how big your room is... It really can help us decide which sub is better for your needs...
> 
> Kelvin


Ill get on it, I don't really have a good way of measuring it right now. It's looking like 8ft. ceilings, by 10x10ft. sides, With small 2x2ft. indents kitty corner from each other in the room. Ill let you know once i measure it better.


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## subwoofery (Nov 9, 2008)

humandrummachine said:


> Ill get on it, I don't really have a good way of measuring it right now. It's looking like 8ft. ceilings, by 10x10ft. sides, With small 2x2ft. indents kitty corner from each other in the room. Ill let you know once i measure it better.


With those dimensions, you don't need a whole lot: 









Their level 1 sub is an 8" ported down-firing sub with 150rms on it... 
Go with more power and @ least a 10" (or a 12") and you'll be golden. It's up to you to decide where you want to tune your enclosure if you go ported but I would shoot for a tuning around 25Hz. Similar to a car, a small room will boost lower freqs more than a big room. 
You can go 15" or 18" but you're just going to make a bigger box not really necessary for your application... My 0.02 cents 

Kelvin 

PS: model your subs so that it can work without subsonic filters... Therefore you need a sub with some healthy Xmax


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