Oval speakers, eh? They take me way back. You don’t see too many of them around, but here is a set from Alpine. Indeed, the X-S69C is the top model in the company’s X Series range of speakers.
So, why oval? Basically, it’s one way to make a big speaker fit in a small, oddly shaped space. And cars are full of small, oddly shaped spaces. If you want a bigger woofer in a home speaker, you just make the box bigger. Not an option with cars. In the auto world, the speakers have to conform, not their enclosures.
The speaker cone is rated at 9 inches by 6 inches (speaker drivers are traditionally measured from their screw holes, not the size of the cone itself) — thus the X-S69C model number. It features what Alpine describes as a ‘Nano-Fibre Woofer Cone’ and its engine uses a neodymium magnet.
Interpreting more of the model number, the ‘C’ stands for component. Which is to say, there’s a tweeter, but instead of being suspended in front of the cone of the larger driver, it’s separate, and so can be placed somewhere on the dashboard. As always, you’re going to get more treble if the tweeter is facing you, the listener, than if it’s firing into your calf from the door or under the dash.
The tweeter is a 25mm unit with a carbon graphite dome and neodymium magnet. It comes with its own enclosure, standing 34mm tall and 58mm in diameter. It’s designed for surface mounting.
There’s also a separate crossover network, which can be put anywhere it will fit, within the range permitted by the speaker cables. Lots of mounting hardware is included.
You can open up the crossover network boxes a little to change some settings, and with little careful squeezing, remove the lid completely. This discloses a PC board with two largish components: a 0.4mH coil and a 100 volt, 3.9 microfarad, 5% tolerance Bennic PMT capacitor. Alpine boasts of using ‘high grade network components’ for the crossover, without going into details. Bennic capacitors certainly have a reputation for high quality in audio applications.
We also noted that the printed circuit board is glued into the case, so it’s not likely to come loose and start rattling around over time.
When you slide back the lid of the crossover, two adjustments are available. by moving little square jumpers from one set of two pins to another set. One set of adjustments is to change the level of the tweeter. As delivered it is preset to a reference 0dB, but +3dB and -3dB are available. Chances are you’ll adjust the level with the EQ in your head unit, assuming that most purchasers will have a head unit worthy of speakers like these.
The other adjustment allows you to reverse the phase of the tweeter compared to the larger driver. This may help deal with cross-over issues, potentially unpredictable given that Alpine has no idea how far from the main speaker you’ll be installing the tweeters. But it’s going to take a fine ear indeed to detect any such issues, so I doubt it will be widely used.
You know how manufacturers routinely, if futilely, ask purchasers to retain the packaging
in case of return or having to move? Less relevant with car audio of course, but there’s no hope of that here. The cutting template for the main speakers is most of the back of the carton, which has a perforated outline, ready to push out. Unfortunately, the instructions are also on the back of the carton and you make a big hole in them when the template comes out. Keep the bits. Or take a photo before pushing out the template.
The wiring diagram, which I managed to read by carefully aligning the templates I’d removed from the box, made it clear that the amplifier is wired to the larger driver, with additional wires going from it to the crossover and thence to the tweeter. Clearly the crossover does not control the range of sound delivered to the larger speaker.
The necessary wires are already attached to the crossover and tweeter, but you may need to add more depending on the layout of the speakers in your vehicle. The wiring included allows up to 830mm between the woofer and the crossover, and 1.04 metres between the crossover and the tweeter.
If you like what you see about the Alpine X Series, but don’t have a place for these speakers for whatever reason, there is also the X-S65 model ($649), with is a component system like this one, but the larger speaker is a round 6.5 inch unit, and the X-S65 ($549), which is somewhat like the X-S65C but with the tweeter mounted as part of the main speaker system.
I started off my listening with some challenging material: Beyoncé’s album ‘Lemonade’. With one omission, the sound was astonishingly good. Really lovely, with great tonal balance and precision, and pretty respectable imaging. The omission was the deep bass on the first track, and there was a definite hole there because there isn’t a whole lot of mid or upper bass on that track. Get rid of the really deep stuff, and there isn’t much left. But then the next track — Hold Up — started and the character changed. This track has plenty of mid bass, and the speakers did a startlingly good job of delivering it. There was a real authority and punch, and even some respectable depth, to the bottom end in this track.
Meanwhile, the vocals and some of the instrumentation was reproduced with a real sense of three dimensions. This was more high fidelity home stuff than car equipment, but there we are.
I pushed the volume hard, to the point of producing some rattles in the right channel. I think the main driver was bottoming out, so I backed off a couple of decibels. Up until that point, even though it was extremely loud, the speakers remained clean and controlled, without any sense of distortion.
Switching genres radically, I played sections of the Sutherland/Pavarotti version of La Traviata. This kind of music is challenging in a car because of the dynamic range, leaving too much of the content lost in a car’s relatively high noise floor. That means the level has to be high, which means the speakers have to cope with the peaks.
Unlike Beyoncé, though, there’s no really deep bass, and consequently no danger of
bottoming out the large driver. And it didn’t. The speakers went loud, and the amazing Sutherland aria near the end of the first Act was delivered at a thrillingly high volume, without any sense of shriekiness, which is what lower quality speakers can sometimes produce, even when not overloaded. Instead, this Alpine system was again in complete
control. Later in the same track Pavarotti lets loose, and the result is the same: controlled, powerful music, and nothing untoward.
Perhaps splitting the difference between those two kinds of music, I played Billy Joel. On the opening of The Stranger the cymbals danced cleanly and precisely in space over Joel’s piano. The kick drum was hinted at by its second and third harmonics rather than the fundamentals, although the toms were fully realised. The bass guitar line, rarely strong with Joel, was discernible at around the right level. And the whole thing was nicely boppy.
I ran a few measurements of the two drivers, chiefly to see where the crossover kicked in. That was relatively easy to do given the split nature of the drivers. I just put the tweeter well away from the main speaker, and the microphone a few millimetres away from it. It was clear that the -3dB point of its output at the bottom end was at 1700 hertz, so you could call that, or perhaps 1800 hertz, the crossover point. At the top end it was still producing plenty of output at 30,000 hertz, so if you think you might get some advantage from high-resolution audio in a car environment, these tweeters are going to be the kind of thing you’ll want to hear.
As expected, the larger driver exhibited no hint of having a low-pass filter applied in the crossover. It just does the best it can with the full range of frequencies. Measuring up close, they appeared to be dropping away by 2000 hertz, although it was hard to tell for sure because the measurement showed considerable variation which, I suspect, was due to differing path lengths given the oval rather than round cone. No matter really, I was only interested in the end points.
At the other end, the output was very solid to 130 hertz, then dropped by around 12dB to a new plateau, which it maintained from around 115 hertz down to 40 hertz. Again, all that was with a close measurement.
Measuring the whole thing together at a distance of a metre smoothed it all out a bit, and put the end points of the response at 28,000 hertz at the top (maybe higher given microphone limitations there), and around 100 hertz at the bottom. The roll-off below that was fairly gentle, but the output was still something like 18dB down at 45 hertz.
Depth lovers may wish to factor in a subwoofer, but the Alpine X-S69C component two-way speaker system certainly produces truly high quality sound, and is well worth a listen at your local car audio retailer.
+ Excellent sound
+ Oval shape may allow a larger cone fit in a difficult space
+ Installation flexibility due to component design