Efficient=loud, nice overall sound

doesn't play below about 35hz in ported box, only handles about 750 watts

This is a great sub for sq and, within reasonable person standards, spl. I have it in a ported box built to jbl website specs. I can get real loud without a ton of power. It is great for rock, with a real live music sound.

Similar Products Used:

various jbl, cerwin vega, audiobahn, eclipse, audiomobile, more that I can't remember

Very high linear travel.
Super power handing characteristics (600W RMS, 1000W Max)
Incredibly load and clean in the right box.
They are built extremely well. Aluminum frame, 4" edgewound voice coil, parabolic pulp cone, ribbed surround, patented coil vents. If your an AES junky, you know thats the way to build em.

The ribbed cloth surround is acoustically excellent, but not durable. It tends to harden and will crack after a 3 years in a car. These speakers really need a big box. I mean huge. All of my attempts to put them in a small box takes away from the low bass response. But in a big box they're unbelievable. This is a big weakness since they are not very flexible speakers. This has much to do with the origins of the speaker since its a concert driver sitting behind 5-6 cu.ft. each.

Dustcap dry rotted after 4 years. had to replace with a repair 4" cap.
After 7 years of service, the cones are thinning. They're less thick than they were when I bought them in 1993.

For the space requirment, I went with a "free-air" setup. Because its the trunk of my prelude, its not really free-air. Its a 15 cu.ft. sealed box for 2 1500GTi. Sealed off from the passenger compartment with two layers of 3/4" mdf bracketed to the car frame. Running 700W total into 2 ohms. This setup is bone rattling. I have yet to hear any two 15" that can come close to this at frequencies around 30 and below. Why? Cause 1500Gtis have 1.6" of clean travel. You can get about 2.4" max and I can't bottem them out. The motor is built with JBL standards so its clean piston action.

Talking about sound Quality. Well again, Better than anything. This motor that JBL uses in the 1200, 1500, and 1800 has extremely good output vs distortion characteristics. In a nutshell, they were so good, I didn't want to screw up the response characteristics by putting them in a cramped up box with ports and phase shifts. Put them in a huge sealed box, so big that its almost like Free-air. You'll never hear anything like it. A pair of these so configured actually broke the spot welds on the trunk lid, and made my rear view mirror fall off.


As a car speaker, I give it a 4 rating. Thats just because of two things: one, its inflexible in its box options. I wonder if JBL actually ever built a box according to their recommendations and put it in a car, or if they just ran a computer simulation. Cause they're box recipe will make this speaker sound really bad to put it nicely.
And two, the choice of cone/surround material leaves something to be desired. Although the materials used have the best sonic characteristics, their durability in a car just plain sucks.

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All types and brands of 15" Most 15"s give you 3/4" to 1" of travel and the travel linearity goes out the window as the travel goes up.