# How much power do Boston Pro 12.5LF subs really need?



## dbphelps (Jun 30, 2006)

Hey guys, a buddy of mine just gave me a gift of a couple of Boston Acoustics Pro 12.5LF 4 ohm subs, so now I am on the hunt for an amp to power these babies, thus I am wondering how much power they 'really' need?

The manual for them states the power 'range' as 50-1200watts per sub, but I am sure I don't need to send them a full 1200 each, but is 500 each from a [email protected] amp enough, or even overkill?

If they would do well with 300 each from a good amp that would be even better... I would have to imagine that 200 watts a piece is pretty low for these and would result in too low of output?

For the application they are each going into a 1cu/ft box (per spec) and are both going into a full size conversion van, which already has installed in it a bunch of Proton old-school amps in it (4 to be exact, 3 2x50/1x200 2 channel amps and 1 2x30+2x60 4 channel amp) with a set of old-school JL Audio 3-way components up front (64cs3 comps) and old-school JL 2-way components out back (6cs1 comps)... Currently have each component set on a 50watts per channel, was thinking of bridging 2 the amps to provide 200watts per channel for the fronts, and then adding an additional amp to power the subs...

Or, I could put the front components on the 2x60 channels and the rear components on the 2x30 channel if 200 watts each is enough for the Boston Pros... That way I wouldn't need to put another amp in...

For reference, I originally planned on the 2x30/2x60 amp and the extra 2x50 amp to be used for left/right/center/surround for a 5.1 system in the back for the kids (already wired in an alpine PXA-H510), but never got around to mounting a DVD changer and widescreen LCD just yet for it, so I have options open to me...


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## AudioBob (May 21, 2007)

I was running two Boston Pro 12.5LF subs in one of my cars a couple of years ago. I had them in a sealed enclosure with both subs in 1 cu. ft. each. I had them running off of a JL 500/1 and they handled all of that and played decently loud. They don't need tons of power to play loud. I would try the smaller amp first and see how you like it.

One of my friends bought them from me and put 1,000 watts to each sub and they lasted all of 10-15 minutes. I think that 500 watts each would work pretty nice. I ran just one off of my 500/1 and it sounded nice as well.


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## dbphelps (Jun 30, 2006)

Yeah, I was suspicious of the 1200watt rating, so I was figuring it was a 'peak' rating, so I figure 600rms is about right for them...


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## Oliver (Jun 25, 2007)

JL's 1000/1 will power those nicely  

http://cgi.ebay.com/JL-Audio-Amp-10...ryZ64570QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

good feedback as seller "Integrity"mentioned !


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## JeremyC (Dec 20, 2007)

Those bostons are some killer subs. I had one in my 99 S10, and it sounded amazing. 

Their actually pretty efficient subs too. I was pushing mine with a little less than 400 watts and it rocked. Sure you can feed them more power without a problem, but 500 should be about perfect.


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## GlasSman (Nov 14, 2006)

It depends on enclosure size. My brother has a 2 ohm SVC 12.5 and I'm not sure if the enclosure was a little small but it didn't have enough output and didn't dig very low.

I want to think it was the enclosure because the previous series kicked some serious ass.


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## dbphelps (Jun 30, 2006)

Yeah, I read the 'ideal' enclosure size is 1cu/ft and anything smaller will seriously affect the low-end output regardless of power and anything larger compromises the impact of the sub...

If you model the sub it shows a Qtc of 1.105 with a 1cu/ft enclosure and would require a 7.5cu/ft to get down to a Qtc of .70, so they obviously engineered the sub for a specific enclosure application... These are sealed apps...

That is why modeling sub enclosures off of a program is good for comparison and all, but a lot of the time it does not show the real-world performance to be seen in a vehicle...


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