# Is one sub enough?



## Finleyville (Jun 17, 2005)

Anyway...

I have only owned hatchbacks throughout my life until now. In the past a single 10" in a sealed box was sufficient for my needs. However, that was with an active 3-way up front so the sub only needed ~60Hz on down. 

Now I am looking to to build an active 2-way system in a 2000 Civic sedan. I never had to deal with a full back seat and rear deck before. 

My current plan is to use a single Dayton Audio 12" HO DVC sub (here) seeing around 1000W in a 2.5 ft^3 box ported tuned to around 22Hz. Will this single 12" be enough to blend well with a 6.5" mid up front? Will I need more LF output to get through the trunk and mate well with a 2-way?

Any help in this matter is much appreciated.


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## Chaos (Oct 27, 2005)

Difficult to say. For a well balanced system, that should be plenty of output to mate with the front stage, but everybody has different expectations.


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## minbari (Mar 3, 2011)

really depends on how much output you want. I think a single good sub is the way to go. if you have $300 to spend on subs, I would rather spend it on one really good sub then 2 $150 sub. the single sub will perform better. the only thing you gain with 2 subs is 3-6db of SPL. (depending on if you double power at the amplifier or not)


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## thakid287565 (Aug 3, 2012)

both are true. it all really depends on the box, sub, and amp. any bad component in this group will hurt output. i ran an eclipse 12" aluminum series sub, with a jl 500/1 amp years about. it pounded hard, and sounded great. the benefit of some amps like jl audio, its the let you choose 12db or 24db slope. generally u use 24db in a hatchback, or 12db if ur fighting through a trunk. dayton is a good sub, but ive hard many examples of them burning out. dayton is usually for home audio. which doesnt have the play time a car audio system might. so id say use caution. there are a lot of great subs in the 200-300 dollar range. brands like jl audio, diamond audio, skar, re, and rockford fosgate are usually a pretty good bet. 1,000 watts is kinda stong for that sub. what kind of amp are you using?


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## ZAKOH (Nov 26, 2010)

It's funny that some posters here have doubts about whether a 12 inch subwoofer seeing 150% of its rated power and placed in a vented box inside of a small car will have issues keeping up with the front stage. Don't worry. It will be fine. Also, if you're worried about getting loud, why buy Dayton subwoofer? I have no doubt it will blend beautifully but if you want even more subwoofer headroom, there are better subwoofers. First, its power rating is less than the power you have. Next, it's considered to be a relatively low sensitivity subwoofer. Finally 12.5mm one way xmax is a lot less than what many other subwoofers. If you want to stay in this price range, I would have bought Infinity Kappa 120.9w and run it in 4 ohm mode (this subwoofer has 2ohm/4ohm switch) since 500watts RMS should be plenty for it. It has more xmax than Dayton and better sensitivity. On the other hand, if you want a subwoofer that will take full advantage of the power you have, consider Sundown SA-12 (a little more expensive) in a ported box or Image Dynamics IDMAX (a lot more expensive). These are considered weapons-grade subwoofers.

Also check your box specs. Dayton subwoofers have reputation for working well inside of small sealed or ported boxed. 2.5cu ft seems kind of big. I happen to have the parameters for Dayton HO 12DVC saved in WinISD. WinISD recommends 0.935 cu ft sealed box. If you ask for for vented box specs, it recommends 1.8cu ft tuned to 21Hz or so.


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## analogrocker (Aug 1, 2009)

I'd say it really depends on the size of sub you plan on using. I used to run a single 10 and came to the conclusion that it wasn't enough. The only way I'd run a single sub is if it was a 15 or larger.

I look at it this way: the more subs, the less distortion. By using multiple subs you aren't over stressing anything.


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## Finleyville (Jun 17, 2005)

ZAKOH said:


> It's funny that some posters here have doubts about whether a 12 inch subwoofer seeing 150% of its rated power and placed in a vented box inside of a small car will have issues keeping up with the front stage. Don't worry. It will be fine.


Thank you. Like I said, I never had to use a sub thru a traditional back seat and blend well with a 2-way. I am in uncharted water here.




Zakoh1684261 said:


> Also check your box specs. Dayton subwoofers have reputation for working well inside of small sealed or ported boxed. 2.5cu ft seems kind of big. I happen to have the parameters for Dayton HO 12DVC saved in WinISD. WinISD recommends 0.935 cu ft sealed box. If you ask for for vented box specs, it recommends 1.8cu ft tuned to 21Hz or so.


Alright then. I just double checked my WinISD parameters and fixed some specs that were wrong. My bad. Now my computed box requirements are more in line with yours. 


Just looked at the specs of the JL 12W6. Higher sens & lower power requirements. Here is the plot with the DA vs JL. 

Graph is SPL tab
Green=DA 12HO DVC ported 1.7 ft^3 //Yellow=JL 12W6 sealed 1.9 ft^3// Blue=JL 12W6 ported 2.5ft^3
both ported boxes tuned to 22Hz









So if I am reading this right the JL will output 3dB higher than the Dayton with 100W less power. Hmmmmm.....


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## thakid287565 (Aug 3, 2012)

if you have 1,000 watts rms to play with, thats a lot of power. way too much for a jlw6v2. thats more then enough for 2. like "zakoh" said, ur more in the area of a idmax sub by image dynamics. kappa's are great because the let you select your impedence. and they sound great, always have. which amp are you running again? and ur chart shows it, sometimes less is more. in the case of jl vs dayton.


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## cruzinbill (Jul 15, 2011)

A good ported box with a well chosen sub, you can easily pull 130db, so if thats enough volume wise then ya stick with one. I have a single hertz hi energy 12 running off 1k watts and its more than enough for my setup. 

Its gonna come down to what you want. I would try to hears some peoples stuff that have similar to what you want to get an idea.


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## molsonice (Jul 15, 2012)

I have dual JL 12" subs in the trunk of an e36 m3 running off 500watts, 2-way front stage with 6.5" woofers, 100watts/channel up front.

My experience getting things to blend:
1) Volume-wise I have to turn the subs down on the deck quite a bit.

2) The smoothest blending I have found for xover was subs at 60hz 12db/octave, 6.5's at 80hz 12db/octave. For more power handling I can bump the sub up to 80hz and 6.5's to 100hz, which was good for really cranking it but I did lose a noticeable amount of front stage bass output at lower levels which I normally listen.

3) I measured and set time alignment between 6.5's and subs. This helped a lot. For me I had 2ft of delay which I later confirmed with a mic. You will probably be anywhere from 1-3ft.


thakid287565: I think thats an interesting point about the hatch vs trunk. I never really could get 24/db xovers to transition very smoothly.


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## thakid287565 (Aug 3, 2012)

ive never had luck with 24db xover until i got a hatchback. its always been 12db xover. my other cars were 4 door cars, so its what my amp was set on. once i got a hatch, things didnt seem right. so i switched back and forth and for 24db for a hatch worked better for me. i later found thats what jl audio suggested as a general rule of thumb. but it all really depends on prefrences. your ear will never steer you wrong


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## adrenalinejunkie (Oct 17, 2010)

That W6 is tempting.


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## Finleyville (Jun 17, 2005)

Well...

Thank you for all of your input. I have just purchased a single JL 12W6v2d4. I am still looking for an amp at this point. 1000W is going to be overkill for this sub. However, I would definitely like some headroom. So I am thinking 600-750W at 2 Ohms.

I have a couple of WinISD box sims figured out, but I think I will save that for another thread.


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## m3gunner (Aug 6, 2008)

With that much power, that sub is going to make you very happy...


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## thakid287565 (Aug 3, 2012)

u can never go wrong with a higher end jl audio sub. good pick. for amp, i like to match companys. jl sub, jl amp. but its not a must. my current setup isnt matching. depending on how much you want to spend, there are a lot of great options. some have listings at 12.5 volts, and 14.4 volts. i go by the 12.5 volts, with the lower numbers, that way im never short changed. hifonics still make some decent amps. great for the money. heres one option that lines up numbers wise:

Hifonics ZRX1000.1D 1000W RMS Class D Monoblock Zeus Series Amp

but you can choose anything really, thats just one of many. just try and stay away from the junk brand like boss, and spl. tho from your sub choice, i dont really think you were looking in that direction anyways, haha


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## tyroneshoes (Mar 21, 2006)

yes. You will be fine

I always use a single sub. Right now a single 8" has no problem keeping up and blending well.

22hz is a little low for a car, could sound pretty muddy with cabin gain. Ive always aimed for lik 27-31


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## thakid287565 (Aug 3, 2012)

agreed. i was gonna say around 30. otherwise u risk the bass blending into....mush is a pretty accurate word. punchy hits, and notes are lost


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## ZAKOH (Nov 26, 2010)

Finleyville said:


> Well...
> 
> Thank you for all of your input. I have just purchased a single JL 12W6v2d4. I am still looking for an amp at this point. 1000W is going to be overkill for this sub. However, I would definitely like some headroom. So I am thinking 600-750W at 2 Ohms.


If you don't have a better application for this amplifier, you could still use it with JL sub, just be careful with setting gains. There are many tutorials about setting amplifier gains. One is this:

Wattage

If you set gains correctly, the subwoofer should not see more than say 700watts.


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## Bobo (Aug 6, 2005)

Just thought I'd suggest a sub if your going with ~1000W. My buddy has the new version of the Alpine Type R 12" in a ported box (think it's around 1.5-2.0 ft^3 at 33hz) on a MB Quart ONX1.1500D. I would maybe go a little lower on the tuning, but the output is definitely not a problem and it plays up to 60 hz fine (starts to die off above 60 hz w/o any eq'ing). From my limited experience, it seems the issue is more about strong midbass for getting a good "blend".


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