A friend just gave me a pair of LE-14Cs with crossovers in the Apollo C51 cabinets. (The cabinets are beautiful with few flaws and the optional fret work). He has had them since the late '60s and the woofers (labled 16 ohm) have the white cones with the dark grey foam surrounds that are totally shot and half gone.
I am thinking of using these to replace my Cerwin Vega VS-100s currently serving front and rear surround duty (Yamaha RX-Z9). As such, I spent a couple hours today comparing them to the Vegas, and my mains. The mains (LCR) are 130A/LE175-HL91/075/N1200/N8000 in L200 cabinets (two ports).
It was instantly apparent that the LE14s were nowhere near as efficient as the Vegas (let alone the mains) with a difference of approximately 15-17 dBC (actually about 20 dBC on a professional Type 2 noise meter, but the Vegas were closer to the meter). Also, the 10" three-way Vegas have far more bass and lower midrange. The Yamaha reports the Vegas as "Large" when going through auto eq. Interesting that it reports the LCR as "Small."
On the spectrum analyzer (octave band), the LE14Cs have a deep notch centered around 500 Hz that extends about an octave in either direction. However, the LE14Cs were far more revealing of detail than the Vegas. They also had a far brighter top end (almost harsh), though they don't extend as high as the 075s.
When compared to the LCR, the LE14Cs actually show a similar, though more accentuated response curve. Unequalized, both frequency response curves resemble a two post suspension bridge (like the CISCO Logo), just that the LE14s show more "droop" between the "posts" (at the 500 Hz notch). The LCR had more droop than they currently do before I added an L-pad to the horn, which allows me to better tune the three drivers together.
My questions are:
How much bass response is actually lost by having virtually no surrounds to speak of? Certainly this represents a massive air leak, but then these are vented cabinets.
Ultimately, I would change the cabinets to make these into surround speakers that hang from the ceiling. How good were the Apollo cabinets for enhancing the bass response? Could this be part of the difference between the bass response of LE14Cs and the Vegas that are now about 10 years old? (I know different cabinets will not help the 500 Hz point and that Vega builds their reputation on bass.)
Finally, is there a general consensus on whether surround speakers should match the sound (response) of the mains (including their flaws), or be as linear as possible? The Yamaha does have a 1/3 octave eq with auto eq for the fronts and surrounds that would make them even a closer match.