for sale earthquake 2.5 amp, 2 chan., bridgeable, x-over
550w RMS@4 ohm mono
275w RMS@2 ohm stereo
175w RMS@4 ohm stereo

 

550 w RMS

would that blow my PG Xmax 10" sub into pieces ? i think my sub is DVC .. not sure

how much

 

power doesn't blow speakers, amp distortion/clipping does

How big is your box? sealed or ported? Depending on your box and speaker specs you might find use for that power.

 

found the specs on my sub
http://www.rkst.com/phoenixsubs.htm

mine is the Xmax10

u experts let me know if that amp is too much for my small stealth box and my big magnetted sub

 

i got the phoniix gold xmax 12's great subs and loud too

 

Bah those aren't specs

I'm talking about the Thiele-Small parameters like Bl, Qms, Qes, etc....

Anyways, it looks like you have an inefficient sub (not necessarily a bad thing) that works best in small enclosures. It has plenty of excursion for it's size.

Based on Hoffman's Iron Law (no I am not making this up), if you want to go loud in the lower frequencies with that inefficient sub in a small box, you need lots of amp power.

I think the amp would be a good choice for your stealthbox. We can try to model the response for ya if we can get the T/S parameters for it.

 

payam this amp would be great for u. i had it on (1) 10" eclipse before that was only rated at 200w RMS and it made it pound. like they said u don't blow it by too much power, u just need clean power. oh yeah and i forgot the price. $200 CND

p.s this is the same amp that P.J. has running his (2) 12" audiobahns in his car

im just getting rid of it cause it won't run all my speakers
(you've seen the setup)

Devan

 

define inefficient .. interested in learning

ps. i wouldnt mind hearing it on the car first .. maybe one of these days i'll come by or "borrow" it and see if it makes a big diff over the amp i already got .. if its sold by then .. then so be it .. i've always wanted a better amp .. but its not THAT big a deal to me

ps. how much does it weight

 

The efficiency of a loudspeaker is the SPL it puts out using a specific amount of power measured at a specific distance. The most common way of measuring this is by applying 1 Watt of power to the sub and measuring the SPL at a distance of 1 meter from the cone, hence your sub puts out 86 DB with 1 W of power at a distance of 1 M. This is an anechoic measurement, meaning the speaker is measured in a room that absorbs all sound (cars and rooms increase the volume as sound bounces off walls).

Your sub is 86 db @ 1W/M. An efficient sub would have a rating of over 90db. Many things affect efficiency including motor strength and cone size (10, 12 15, inch etc.) , but often increased efficiency comes at the expense of less power handling and excursion. This is why an inefficient sub is NOT a bad sub, you just need to design the enclosure and choose an amplifier accordingly. Inefficient subs work great when enclosure size is small and amplifier power is abundant, but this setup tends to cost more.

 

so is my amp have enough power to make is sub pound? i would assume it does.

but what do i know i've only got 4 12's and 1200 watts

 

I think it would get pretty loud.... it still depends on the T/S specs of the sub, and the enclosure.... This can be modelled easily if the specs are found. To make a 10" sub really pound in a small enclosure will take a lot of amplifier power, but I doubt Payam will find a better deal then your amp to drive his sub to its max potential.

 

wow craig, is there anything u DONT know about ???

so an efficient amp requires more enclosure and possibly needs less power .. but a less efficient amp would sound better ?! if my sub sounds the way it does (pounds REAL nice) with my 100 w rms pos amp .. i cant wait to hear it with the big one

 

It's speaker efficiency we are talking about.... but you have the right idea. Efficient subs use less power, and combined with a larger enclosure are able to operate just as deep and loud as an inefficient sub in a small enclosure with thousands of watts of power. This is why my 2 ****ty (but sensitive/efficient) 12's in a moderate size box go very loud with a ****ty 80W kenwood amp driving them.

Even though we are talking about speakers, Amps often produce more (or less) then advertised power at a given impedance. Brands like Kenwood, Jensen, and RCA are famous for over-rating their home theater receivers... which is why you see high-end receivers made by Denon and Marantz with the same advertised power costing 10x more.

Definitely try hooking up this amp and see how it works, if the seller will let you You will be able to tell when you are overdriving your sub... so don't worry about blowing it (as long as you don't stress the amp that is and go into clipping, which WILL kill a sub quickly).

The reason I know about this stuff is that I built all my speakers for my home theater, and had to design and build all the enclosures and crossovers for the 7 speakers that I built. It's quite fascinating to learn, and you can do things SO MUCH CHEAPER when you do it yourself and still end up with amazing sound quality. You also get the satisfaction of telling people that you built the speakers putting out the 5.1 sound...

 

this is what my old sub / box looked like 15" mtx in a 3.5 cu ft box ... running the same amp that i run my 10" Xmax in my stealth box .. for some reason . the 15" sounded a LOT better ... probably due to higher efficiency / bigger cubes

that box was also tuned with 2 x 4" ports too
used to shake the pens on the second floor of my highschool i had to loctite the rear plate in .. it kept falling out ... man .. good ol' days ...

15" sub in my Datsun

 

sounds like a nice amp
i used to have 2 15inch DVC pheonix gold XS subs in my 97 caviler Z24
i hit 140 DB in a competition in North Van
they were powered by xs2500 rated at 562 rms (each amp comes with a certifercate rating each individual one)
i had my sub output on the deck at 4 of 8 so i might have been able to squeeze out a couple of more DB's had i noticed