Hey all this sub bumps hard for a 6.5 inch woofer! I am running a Onkyo TX-8140 receiver. Definitive SM-45 speakers. The speakers are 5 1/4 and they also have amazing bass. I am in a 12x12 room and this modest system digs down low and hits hard!

Great little subwoofer , I purchased this subwoofer because I have a narrow space , for a 6.5" speaker it has a full base sound that fills the room. I use this subwoofer to complete my surround sound .

Where do I begin? Let me start with the technology that is offered in this product...
This Earthquake FF6.5 is pristine example of proper audio engineering, fine tuning and care in a finished product. Let's start with the enclosure;
What you have in the 6.5" model is unlike any offering from other manufacturers out there. The enclosure is an extremely solid(resonance-free) quarter-wave transmission line/horn-loaded hybrid made from a combination of 3/4" and 1/2" MDF. Implementing this technology into a home theater offering is an incredibly wise thing to do. Why? The output and accuracy of low-frequency notes are greatly increased, making this subwoofer not only loud but INCREDIBLY efficient and accurate. Quarter-wave transmission line enclosures, if made correctly, can take a smaller driver(subwoofer) and make it equal in SPL to larger subwoofers with traditional ported or sealed box designs. What this means is if you wanted the true output level of a 10" subwoofer but would like to save some space without compromising anything, this is your sweet spot... This enclosure is built in such a way that the air pressure produced from the subwoofer acts as an efficient cooling setup for the amplifier. This allows the amplifier to be internally concealed as opposed to sticking out the rear end of the enclosure= more saved space!

Second... The subwoofer itself. What you have here is a long-throw 6.5" subwoofer with patented Turbine-Cooled-Transducer technology. This technology forces air in through the holes on the bumped backplate, over the voice-coil and out again with each cycle. This allows the subwoofer to play at high levels for a long time while remaining cool, thus keeping the RMS wattage stable... The linear mechanical X-Max (distance cone can travel front to back) is a FULL 2 inches! This is incredible excursion from such a small driver! When I say this subwoofer matches the output of a traditional 10" subwoofer I'm not exaggerating...
The voice-coil and motor assembly is modeled after Earthquakes MiniMe series with some concepts taken from their Magma subs as well.

Third... Wrap this package up with an extremely efficient Earthquake class A/B digital amplifier, awesome X-over controls and 180 degree phase switching ability and you have something no other company could offer at this price. This amplifier runs at 100 watts RMS with 150 watts peak power output keeping strong power output consistent during the entire time you listen to music or watch movies...

If anyone has had the pleasure of talking with professor Joseph Sahyoun of Earthquake Sound you would know the level of genius this man has in audio engineering. The level of quality craftsmanship and technology he puts into his products are something I greatly admire being an audiophile. Most people who have bought this truly don't know what they have.

A word of advice; when you get this subwoofer, allow 1 week of proper break-in time to exercise the spider and motor assembly before turning it very high. When subwoofers are sent to you new from the factory, the spider is very stiff with very little play. As you break them in properly they loosen up allowing the sound reproduction to increase in SPL and accuracy/sensitivity. Cranking up a new subwoofer fresh out of the gates stresses the stiff spider and can break the seal between spider and speaker cone= blown sub.
Keep the max volume at 65% or so for 4-7 days.
A note on the proper application of this subwoofer. This sub is designed to be implemented a space no larger than 12' x 12' x 8' or similar sized rooms. I noticed a bad review from a gentleman who placed this in a kitchen. This is a misapplication of this product... Most kitchens are "open room" designs. In a vast open area like a kitchen you are going to lose your Sound Pressure Level (SPL) which leads to a flat bass response. This is a product designed for a bedroom home theater where the sound pressure is contained(door and windows closed).

Another reviewer mentioned a "humming" noise from his sub, this is due to a bad rca line-out source. Traditional cheap rca line-out cables are unshielded. Being unshielded they can pick up EMF signals floating around from other cables, power sources, antenas etc... Using shielded high quality cables will help drastically. I use what is called a "power conditioner" on all my audio and video equipment. This reduces or eliminates interference, voltage fluctuations, over-voltage and damage to components from brown/black outs.

If you appreciate a well-balanced audio system and are in the market for a subwoofer 10" or under, seriously consider this 6.5". Many people are afraid to buy a 6.5" for fear of it under-performing. Do NOT fret about this subs size, the technology is there to rival 10" subs...

Small but Punchy and very smooth !!!!
I LOVE IT !!! Just want I needed . Was sick of all the walls shaking from 12's or even 10's.
This is a perfect sub, for it's small size. FF6.5

This little thing is exactly what I needed with the limited space that I had. It paired well with my Audioengine A2+ powered speakers. I get subwoofer hum but an isolator solved that issue.