Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: OK I have started bldg my new system and have to decide on a pair of rear speakers, I have the JBL 4-way powered tower speakers, now will these work?
Document: This is my 2nd pair of 830's. I got my 1st pair (refurbished) from a popular auction site a year earlier. These speakers are supurb for music or a home theater set-up. My 1st pair are the rear surrounds in a 5.0 HT with JBL 880's for the front mains and a JBL LC1 center all connected to a Denon 1610 receiver,(no sub). This system is in a 25X20'room with 9' ceilings.
I purchased the L830 speakers  because they match my JBL system. Great sound from JBL, I use them in my surroundsystem. With a matched system (All JBL) the sound is fantastic, JBL speakers are the best. My system has the L890 towerfor the front, JBL LC2 for the center channel and the JBL L830 for rear. Great sound, great cabinets and great componentsmake for a excellent sound.
I have five small Bose speakers in my family room entertainment system, and found them to lack the volume to carry TV audio effectively. Replacing the two front left and right speakers with the JBL speakers is an easy and effective solution. My Panasonic receiver allows recalibrating for the change so the new speakers blend in.
I remember spending 3k for a 5.1 system some years back. I had an Onkyo receiver, huge JBL fronts, JBL sub, and center. Polk rear speakers. They have long been lost to me but I remember eventualy just using the fronts and sub cause it sounded better. Guess I was more into music then. I recently put out under 1k for a 2.1 system with these gorgeous little JBLs, a Polk sub and a Harmon kardon 120w receiver. This blows away the other system.
My Grandpa bought a pair of L830's for his hifi system, which included a better yamaha home theater receiver to power. I was always amazed how crisp and clear it sounded, compared to my setup: a pair of Klipsch F-3s (big, double 8 inch woofers and a horn loaded tweeter, 150 watt RMS, 600 Peak watts, at 97db) powered by an 80's Carver hifi rig.
I'm 53 and owned JBL's ever since I graduated HS and got some L-26's for Graduation present, it was also the first year I turned professional on the drums. All throughout my career a very large percentage of studios I've worked in used JBL speakers in some way shape or form. I never bought a pair yet that I thought sounded bad so I keep buying them and I have had a boatload!!! !Quite simply these are the finest sounding JBL's I've had the pleasure listening too.
Another good thing about connection adaptors of this pair is that they can be easily connected serial externally in an obvious way to rise up impedance of the pair confuguration 16 Ohms, yet to sound mono. Such a serial connection may also be used for center channel of AVR 5.1s if allowed by DMP. As well, you can make this connection from HK3490 through Speaker System 2 as in Speaker System 1. DMP allows it as well. However this time situation is different.
I purchased this product from Amazon.com as part of a 5.1 Home theater system. The purchasing process at Amazon.com was great as was the product. In combination with JBL L890 front speakers, LC2 center speakers, this speaker pair is great value for the price. Hook up was a bit of a hustle as with the other speakers because I was biwiring without banana plugs, so it took a bit of finger twicking to hook all the speaker cables.
Bought two sets of these JBL speakers for my daughters home theater room from brick and mortar establishment. Sounded so full and clear I tried out the sound of these using my OPPO 105 (PURCHASED FROM AMAZON) attached to Harmon 20 amp amplifier. I was blown away by the tone and clarity coming from these non tower speakers.These had already been broken in for two weeks at my daughters before I borrowed the pair.
Very well suited for placement as surround speakers, in my opinion. I have them mounted on a tiltable/swingable wall rack and pointing down towards the central listening position from the rear corners of 6.5 x 7 meters room. The much larger front speakers are similarly mounted high in the front corners of the room, and the resulting system performs brilliantly
Answer: Your rear speakers don't necessarily have to match your fronts, so with that theory in mind, these should serve you well.  As long as your center matches your front left and right, you're good.