Streaming and Bluetooth Speaker Measurement Beginnings
The Urge to Measure
I haz it. I just can't give up on the idea. If I'm going to review stuff I've simply got to have some sort of measurement. Maybe it's a disease, but I've got it.
I've got some Bluetooth and network streaming speakers in the house, and while I've got no problem figuring out which ones sound good to me, I can't help having this urge to measure them. I don't think anything particularly complicated is required; a simple frequency response measurement should do. I gave Ben Faber, CEO of Faber Acoustical, a call, told him what I wanted to do, and asked if I could play around with his iOS acoustic measurement software a bit. He pointed me toward Signal Scope Pro. It's a cool measurement app featuring FFT and 1/3 octave spectral display, oscilloscope, sound power meter, and signal generator, with numerous controls to set up each function. I leave you to explore the web site for full info on the app as I'm only using it in a fairly simple mode.
For these tests I simply attach either my Galaxy S3 or Apple MacBook to the speaker via Bluetooth, AirPlay, or whatever network streaming protocol the speaker normally uses, and then play a pink noise track. I then position my iPhone with Thumb Tack mic at the edge of my diningroom table one meter away from the streaming speaker which is position at the edge of another table to reduce any reflections, and take a measurement.
There are ways to take higher resolution measurements if I used the generator in the Faber Acoustical apps, which is synchronized with the analyzer in such a way as to produce rapid measurements without a lot of time averaging, but unfortunately it can't do it over Bluetooth, which is the most common way to communicate with this type of speaker. So, for the moment, I've opted for this simple method. Another cool thing about it is that I can go to a big-box store and measure the streaming speakers there with little trouble using this method. A good way to dig through a bunch of these gadgets quickly.
I know it's not earth-shaking news, but I took some measurements on a big handful of streaming speakers today in preparation for an upcoming review of the Creative Soundblaster Roar SR20, and thought you just might like to have a look.
JBL Flip ($99)|
During a little break in the action when I was at Harman last year learning about their headphone target curve research, I asked Sean Olive which of their Bluetooth speakers he liked. He pointed out the Flip saying it was pretty good for a hundred bucks. It's a little honky sounding, but much better than most other BT speakers the size of a Coke can. Not much bass though...as you'd expect from something this size.
UE Boom ($199)|
I really like the Boom and have reviewed it here. It's definitely more coherent and neutral sounding than the Flip. The measurements show it as a bit smoother in response, but in listening it seems like the difference is greater. I also hear the Boom as having less bass than the Flip, though the measurements show them as somewhat similar.
Creative Soundblaster Roar SR20 ($199)|
I definitely hear more bottom end in the Roar than the previous two, and while it doesn't sound honky like the Flip, it does sound more uneven and less coherent than the Boom. The measurement looks like it's got more deviation from flat than the Boom, but less variance than the Flip, so I guess there seems to be a moderate correlation so far. The strength of this little gadget is all the features, which makes it well worth while for some people despite its so-so sound quality. Review soon.
Soundcast Melody ($449)|
I reviewed the Soundcast Melody earlier this year here. You can see some bass appearing with this somewhat larger boombox, and frequency response is fairly even relative to the previous units. I can also begin to see a trend with a slightly warm tilt on all the responses except the Flip so far. Not sure if this is from the speakers themselves or room reinforcement. I'll probably go out in the back yard and take a few measurements again just out of curiosity. If the room is adding some warmth, then measurements at stores might not translate directly. We'll see.
Cambridge Audio Minx Air 200 ($499)|
Getting up in cost now, and this baby's got much more bass umph than the previous units. Response is quite even and flat until about 10kHz. I mentioned this product in my Cambridge Audio CES 2014 spot here. It uses balanced mode radiator drivers. Very basically, a BMR driver acts just like a normal speaker at low frequencies, pistoning in and out, but higher frequencies excites modal vibrations annularly from the center of the driver. (For more info look here, then here.) The advantage of this type of driver is that it maintains a wider dispersion at high frequencies, and that, it seems to me, would be quite beneficial for a speaker that's intended to sit in one place a fill a room with sound. I did indeed hear better off-axis treble dispersion with this speaker and speech intelligibility was good any where in the room, but the treble as a whole both on and off axis was a little lifeless.
Bluesound Pulse ($699)|
In terms of straight-up fidelity the Bluesound Pulse is my favorite of the bunch. I was quite surprised to see the tipped up treble of these measurements. I guess I hadn't noticed it before, but after seeing these plots I do hear the upper-treble as fairly pronounced with this speaker. The thing is, it's sort of intended to produce high quality background music for your home and I think adding a bit of high treble lets it have some air and sparkle even when less than optimally positioned in the room. I also would have though these had more bass from my listening. I've got a number of Bluesound products in the house right now, and boy, is this a cool system. Review soon.
Philips Fidelio Sound Spheres ($799)|
Wow! The Philips Sound Spheres are cool! Wife acceptance factor is huge, and for an audiophile, these things really satisfy. Looks somewhat uneven in the plot, but to my ears they're pretty good. The amazing thing is the imaging: while the image isn't as pin-point specific as a really good system, the sense of space filling with these guys is amazing. The image is well behind the speakers and fills the space floor-to-ceiling, and spreads to just outside the speakers. Yes, they're expensive, but compared to the similarly priced B&W Zeppelin they do a MUCH better job of filling a room with music. A really cool speaker for the spaces in your home that don't have a big rig (AirPlay makes them useful primarily to those who are Mac/iTunes centric), these will get a review.
Please let me know if there are any other products in this category you have an interest in, I'll try to get ahold of them for a listen. And I'd entertain the idea of higher resolution measurements of these products if you think it would actually be more useful...the subjectivist in me thinks "they're boomboxes, it's no big deal, you know which ones sound good", the objectivist in me says, "better measurements are better, silly boy." What do you think?