# How are some of you getting the most bass with low power high efficiency subs



## carter1010 (Sep 20, 2009)

I was curious is anyone has taken the approach to system design where they wanted to get the most out of the lowest amount of power. I am trying to design a sub system that gets nice and loud off of about 100 to 150 watts per sub using 2 12" subwoofers. Just looking for input from those that have done this successfully. What you used and considerations you took. Space for me is at a premium so sealed is the direction I am headed. But looking for all different experiences.


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## savagebee (Sep 12, 2006)

large ported box, possibly some t-line or horn designs, but it will depend on the space you have available, as well as the speakers


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## Oliver (Jun 25, 2007)

carter1010 said:


> I was curious is anyone has taken the approach to system design where they wanted to get the most out of the lowest amount of power. I am trying to design a sub system that gets nice and loud off of about 100 to 150 watts per sub using 2 12" subwoofers. Just looking for input from those that have done this successfully. What you used and considerations you took. Space for me is at a premium so sealed is the direction I am headed. But looking for all different experiences.


You is pissing in da wind


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## benny (Apr 7, 2008)

Hoffman's Iron Law: "You can have low end extension, high efficiency, or small enclosure size. Pick two."


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## chithead (Mar 19, 2008)

I used low power high efficiency subs in my brother's car. But gave them a good amount of airspace.


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## SomeDonnieDude (Oct 19, 2009)

Go with either 2 subs with a high efficiency that have a larger xmax if going sealed. 

OR (this is what I would do) go with 1 sub ported, keep the box on the bigger part of the manufacturers rec volume and go with big port area. I probably wouldn't tune below 35hz...but that will depend more on the subs and possibly vehicle.

Have room for a single 15"?


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## Brian10962001 (Jul 11, 2009)

Build a large ported enclosure and tune it high (45hz or so) and cut them off steep at the bottom end. Really what I'm saying is, you can get powerful volume out of them, but not much low end extension. The best thing about low power handling subs is that you can afford 3 or 4 of them for the price of 1 decent sub and they still won't need a ton of power so why limit yourself to 2 if you're going cheap low power handling?

BTW what do you mean by successfully? I had 1 12in Sony Mobile ES 12 sealed in my g/fs car on 400 watts and she was happy as a clam with that. Do you have a specific goal for this? My friend has a 89 Jeep Cherokee with 2 10in old school Lanzar's sealed in a down firing box I built him. For what they are I would call it a huge success, BUT if we hit the SLP competition it would be laughable.


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## cubdenno (Nov 10, 2007)

Look at the pro audio stuff. Be prepared for larger enclosures than what is traditionally thought of in car audio. They tend to have much better output with equal power.


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## 94VG30DE (Nov 28, 2007)

Yup, I was thinking a PA 15" with a giant sealed enclosure.


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## Gary F. (Nov 23, 2009)

Large vented enclosure. With alot of port area.


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## Oliver (Jun 25, 2007)

100 watts would be excellent for making your tweeters loud


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## SomeDonnieDude (Oct 19, 2009)

Just remember generally with a bigger ported box the output will be more peaky around tuning. More port area will give you more of the rear wave off the woofer = basically more cone area, but can too much can greatly reduce the transient response or "tightness" of the woofer.


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## JoshHefnerX (Jun 13, 2008)

Any time you want to go loud you're going to balance - power vs box volume vs loud. You've said you don't have much power or volume so it's going to be tough. Look into either lots of cone area w/ as high of efficiency as you can get or maybe a little less cone area (2 drivers vs 1 driver) and maximize the box space you can use and port it. Let us know what you decide.

Josh


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## Pillow (Nov 14, 2009)

>100 watts would be excellent for making your tweeters loud <

LOL!!! That is good stuff.

Big box. That is the only solution I can think of. I would also go with one driver and make the box perfect for it. Try out some of the box design software tools to get a roll off curve that you like. Box size can really peak up bottom end if you like it that way. But in general small boxes require more power.

I was reading an older article in Car Audio mag online about the PG RSd 12" and it is a nice SQ sub that does not require a lot of power to get loud. Xmax is not much though. 1.75 cubes per. 

... If you want SPL... I am not sure what would work for you. Xmax takes power.


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## cubdenno (Nov 10, 2007)

My son uses the RSdC 10 or rather 4 of them. Ported.a cube per woof, tuned at 40. Though for his new car we are building a new box so waiting on the design. 

I would figure the actual volume I have available first. Then decide if I have enough volume to build a ported enclosure based on 1 or if possible 2 woofs. Pro audio woofs usually come in 8 ohm flavors rarely do they go lower. They are usually a bit lower in Xmax than what is now thought of as a sub. That shouldn't matter. I would port around 40-45. let cabin gain take care of the low low stuff.
If space is a premium (you have little) then just go with the one woof. The increased efficiency should make up for the lack of power.


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## carter1010 (Sep 20, 2009)

I appreciate all of your input. The subs I am planning on using are Boston Acoustics G1 subwoofers. They are rated for 200 watts RMS. I am currently running 400 per sub approx in a sealed box. I am planning on doing a 4 cu ft ported enclosure tuned @ 34 hz and running them off a bridged side of a Rockford T400-4. I am hoping that sounds a bit louder than they do off of 400 watts each sealed. They sound good right now, but I want to experiment with lower power instead of more power. I remember installs from back in the day with the CA&E mags where I would see a PGM25 running a whole system. A 2 x 25 watt amp to power everything. Granted, thats a beefy little amp, but still bridged is around 140 watts or so if I am not mistaken. This is the philosophy I want to build on. I will be using two RF T 400-4 to power my system, so there will be around 1000 watts of power, but it will be divided between a 5.25 comp set, a 6.5 midbass, and the subs. Hopefully thats enough space for the drivers to get loud efficiently. If not, my experiment will have failed and I will have to find some place to put the monster T300-2. Its a huge amp, and takes up a ton of space so I would rather not use it.


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## Brian10962001 (Jul 11, 2009)

Tune higher, I would shoot for 40hz. Do you have a subsonic filter? In my S10 single cab I have an older punch 600.4 half running Orion 4X6's stereo and half running a pair of Bostwick HD Pro 8 ohm 10's bridged. They are in tiny little sealed Q Logic truck enclosures and they sound great. Don't be scared, you should be happy with your results.


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## my6x9s (Apr 15, 2009)

i did 135.5 on 125w rms with a diy 12" from ant 
i currently run a single RF 10" with 250w rms of RF power and its much louder than the 12"
but i have a vary vary large long t-line but it rolls out
i had many in my ride they all guessed about the same 2-12" with 500-1200w
and they all drop jaw when thy find out its a single 10"(RF hx2) with a 250w amp 
its fun to show them the efficiency of a small sub
http://www.youtube.com/watch?v=BGhJSY73e6k


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## fish (Jun 30, 2007)

If you're gonna use the BA G1's contact Boston Acoustics, and see if their passive radiators will work with that series woofer. From reading their literature on the PR's you don't need to increase the box size from running standard sealed.

Again, not sure if they're compatible with the G1's though.


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## carter1010 (Sep 20, 2009)

Thats a great suggestion. I will do that. I just put the amp in and ran one channel at 2 ohms and frankly it hits pretty hard. I was pretty impressed by what these subs are doing on low power.


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## Hispls (Mar 12, 2008)

carter1010 said:


> Thats a great suggestion. I will do that. I just put the amp in and ran one channel at 2 ohms and frankly it hits pretty hard. I was pretty impressed by what these subs are doing on low power.


Those are a good sub. If you want more output a passive radiator will help, but do take the advice to tune high and use a subsonic filter.

These days power is cheap and in small packages. You can get a lot of output in a small space that way....as everyone else said, you really have to weigh your priorities and find a compromise.


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