J&M 7.25" HD Batwing Speakers

J&M 7.25" Speakers for Harley Touring Models -- Batwing, in this case (not for you Road Glide types as of this writing, but soon if I hear correctly).
Okay - This one isn't for the weak. That is, it isn't for those who like the weak sound of the stock HD speakers in your Glide. We all know they sort of suck. They're embarrassing. But we didn't buy the bike for the stereo. That isn't to say that after getting used to it, you didn't actually like it - as much as you could... because the speakers suck...

But I digress. As I'm so apt to do. And I'll remind you that I'm a conversational typist and I go with my thoughts. As my thoughts are usually scrambled, I may go back and forth a bit. But do read the whole thing. These aren't cheap speakers for a bike. It's worth the few extra minutes.

Anyway - If you've read much of anything else here or at the MASSIVE Mastering site, you already know that I'm an audio engineer by trade. And a picky one. The speaker chain I work with regularly is worth more than my Street Glide. So, I never expected the bike to actually sound "good" -- But it's nice to make it sound as good as it can.

Starting off -- The J&M speakers (purchased from Dr. V-Twin who was running a special for HDForums.com members) were well-packed with solid instructions. A 2-cigarette (around 1 hour) install from start to finish (not counting that I screwed up my head lamp somehow, but that was my own fault). There's a rather attractive grille that holds the mid driver and the tweeter and an "adapter" that allows the 7.25" speakers to mount inside the fairing. It's a pretty ingenious little kit. No issues (NONE) during installation (save the head lamp mentioned earlier). No missing parts, nothing that wouldn't line up (although the typical "put ALL the screws IN before you actually tighten ANY of them" applies).

The A/B experiment was simple -- Tone, pink noise, music. As I'm a freak about such things, I ran far more tests than I'd want.

I hung a measurement microphone right where my head would be, level with my ears. I used an inverted 1kHz tone to find the exact point between the speakers for both the stock and the J&M speakers (the point where the volume dips considerably is the "dead center" -- As the polarity is inverted on the two signals, they cancel each other out at that intersection). Although perfect cancellation wasn't in the cards (hey, this was in my garage - Not in an anechoic chamber), a sharp dip of around 12dB was plenty for me. For the record, volume was at 50%, bass and treble also at 50% (unity gain, for lack of a better term for this purpose).

After that was simply recording and analyzing the tones. I started with 1kHz (@-15dBFS) mono, left, right and inverted. Simple enough. Both speakers were fine and within a dB or so.

Next was pink noise - For the uninitiated, in non-scientific terms, carefully measured static. All frequencies from 20Hz to 20 kHz, simultaneously (1/f @ -20dBRMS).

On a spectrum analysis, it looks like this: ADDENDUM: Included FFT readout *and* spectrographic analysis images by request. The spectrographs are from 20Hz (bottom) to 20kHz (top).





Notice how the response is very steady all the way from 20Hz to 20kHz - Which is exactly how it's designed to work. The power density (volume) falls off at 10dB per octave. Although it's "just static," even to the untrained ear it sounds "natural" without being harsh and edgy (such as white noise). Notice on the spectrograph, a smooth, steady transition from low to high.

On the stock HD speakers, it looks like this:





"Bam" right off the bat. You were always wondering why the high end on the HD speakers sounded like it was carved out of broken glass. That's a rather nasty dip at 10kHz followed by a rather nasty peak at around 13kHz followed by another dip and another peak up beyond 15kHz. Around 2-3kHz, where the ear is very sensitive (also known as the "ex-girlfriend" frequency range for its grating, harsh nastiness), there's an unnatural buildup also. Not a good place for such a buildup - In the mastering industry, a half dB of 2.5kHz can make the difference between "harsh" and "warm" sounding. This is a difference of around 4-5dB. Also notice that there's barely anything at all below 100Hz. Not unusual for a speaker this size, but if you didn't know where the low end was, now you know. It's not there, period. In the spectrograph, that void at 10kHz and peak at 12-13kHz - with nearly the same sonic energy as the low end - is freakishly apparent.

If that wasn't exciting enough for you, on the J&M speakers, it looks like this:





You'll quickly notice the substantial additional low end below 100Hz, a bit of a "plateau" in the "boxy" area of the mids from around 200-1kHz, a mellow dip in the harsh area of the mids from around 2-5kHz, then a smooth rolloff above 10kHz in the high end. Not the smoothest transitions in the universe on the spectrograph, but not shabby at all for a speaker of this size being driven by a head unit of this class. The dip in the "harsh" areas and smoothness of the top is readily identifiable. I'd bet one could guess the crossover points from that image alone... Keep in mind also that, as decent as this looks, is with the tone settings at unity. I'd imagine that if I would have re-shot pink with the tone controls where they are currently (around 75-80% on both controls) the slope would be even smoother.

[CLARIFICATION POINT] Without getting too scientific - Rooms have "peaks" (where low frequency waves collide and build-up) and "nulls" (where low frequency waves cancel each other out). I read my dBSPL notes (I tested every tone with a SPL meter along with the measurement mic) and they coincide with the readings around 90Hz. *At that point in space* there was indeed a null point. According to a rough formula considering the size of my garage, that null point should have occurred at 94Hz. *One foot away from that point* the measurements followed the typical curve (as the microphone was no longer in the null point). That "dip" between 90 & 100 Hz isn't actually there - It's an anomaly of the space vs. the position of the microphone. The "jagged edge" between 200 & 700Hz is known as "comb filtering" -- Again, frequencies build and/or cancel out. Those are a reaction of the ceiling vs. the floor height and are fairly evenly spaced, just as one would expect from ceiling of that height. So again, the speaker almost undoubtedly reads "better" than the filtering present in the graph. Notice that the comb filtering is present in both graphs - That would probably never happen if it wasn't the room (and again, the formulas fit the filtering). And it's in my SPL notes that there was a dip present in both speakers between 90 & 100 Hz -- Although more extreme in the HD speaker, as there really wasn't much there under 100Hz to speak of....

ENOUGH OF THE SCIENTIFIC CRAP - HOW DO THEY SOUND?!?

Funny you should ask... Like many of you (I assume), I keep the tone controls around half. The stock HD speakers have no low end to speak of (and they bottom out readily if you try to push the lows) and the high end sounds like a dog urinating in your ear. They're "reasonable" to listen to at unity on the tone controls. Reasonable. They're also allergic to volume and sound as if the drivers are about to liberate themselves if you try to give it a little kick.

As expected, the J&M's sounded a little boxy (to a large extent, I’d imagine much of this boxiness to be in relation to the shape and volume of the fairing - not simply the speaker itself), but nicely forward in the mids without being harsh in the top. With the tone controls at unity. However - I tried something I've not tried since it failed so miserably with the stock speakers -- I actually turned up the high end. A lot. And the low end. Quite a bit. And it actually worked.

The music (ZZ Top's "LaGrange" to be specific) started to jump out. The dynamics were much more intact than the "compressed and squishy" dynamics allowed by the HD speakers. The highs were still present and smooth (something I wasn't expecting - even from the J&M's) and the lows, while not "LOW" (what do you really expect...) were far more respectable without bottoming out the woofers.

I always thought this "squishy dynamics" thing was inherent to the head unit. I was very pleasantly wrong, as I discovered something I'd never thought I'd say in the same paragraph as "HD Stock Stereo" -- Headroom. Real, honest, contrast. Punch, clarity, volume -- even at higher volume. Which is something the J&M's do considerably (CONSIDERABLY) well over the stock HD speakers. The HK/HD head unit is actually a respectable unit with these speakers and I have no intention of modifying it or adding an amplifier at this point.

All in all -- These speakers aren't exactly on the cheap side (I've seen prices ranging from around $235-$275). But if you're looking for some serious (and I don't say "serious" lightly) improvement to your HD audio system, these are the ticket.

Downsides? Helmet. Look again at that stock HD graph again and guess what frequencies are attenuated very well by the shell and padding of a helmet. By design? Perhaps. The HD stereo always sounded pretty decent with a full-face helmet on. But if you're a non or 1/2 helmet wearer, or you want to pick up a serious amount of usable volume, you can crank the system happily with headroom to spare.

I give it a four out of five just for the slightly excessive boxiness (probably inherent to the design). But considering that I'd give the HD speakers a 2 out of five on a good day, that's something. I won't suggest or pretend that these make as pleasurable of a listening experience as a pair of Bowers and Wilkins 802's or Tyler Decade D1’s... But just as I wasn't embarrassed by my mufflers anymore when I added my Superflows, I'm no longer embarrassed by my speakers. And that little bit of boxiness (which most people probably wouldn't even really take note of) becomes a distant afterthought when the right song comes on...

Go order these things. Once they arrive, you're only an hour away from getting truly decent sound from your stock head unit.

ADDENDUM (10/22/2009): Okay, I've had a couple hundred miles to listen to these things. I have to admit that I'm not finding it easy to get past that 300-600Hz "boxiness" that's going on (which may be as much or more the fault of the fairing itself). HOWEVER: I'm also finding it VERY easy to get used to how much better they translate to the road... Voices are much more clear, rock guitars actually "growl" a bit (as they're supposed to), and that terribly fatiguing high end in the stock speakers is a distant memory.

"But what about the bass man?!?" It's much better. Of course, it's not "bumping" - But it's not going to - for several reasons. One of which is that a 50Hz wave is around 22 feet long. Low end needs space - Figure at least half a wavelength. On the bike, you have around 1/10th (walk back a car length and pay attention to how much more low end you can hear - Keep in mind that it will be quieter due to the distance - But the frequencies that are clear at that distance will change quite a bit). "But I hear the bass in my living room and that's not 22 feet long..." True to some extent - But you're also hearing reflected low end. Add to that the fact that your subwoofer also has (A) volume (space) and (B) is actually designed for that purpose. HD's bat-wing fairing is neither. Not by a long shot. That said - the low end that you're "allowed" to hear is much more clear, much more clean, much more dynamic and has there's much more available headroom.

As far as that boxy midrange, I think most people will get over it quickly once they hear the improvement. At risk of beating a dead horse, I spend a lot of hours every single day listening to a set of loudspeakers that are almost incomprehensibly accurate and consistent to the average listener - So every time I hear the J&M's, I have to admit that it's a little "alien" to my ears - Not that the HD speakers weren't also - But just in a different way. The J&M's are a much better way.