Dayton Audio B652 loudspeaker Measurements

Sidebar 3: Measurements

The $39.80/pair B652 is by far the least expensive loudspeaker ever to be reviewed in Stereophile. I examined its performance with DRA Labs' MLSSA system, using a calibrated DPA 4006 microphone to measure the speaker's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield responses. The B652's voltage sensitivity is specified as 87dB; my estimate was a little higher, at 88.4dB(B)/2.83V/m. The Dayton's nominal impedance is 8 ohms, which my measurement confirmed. Fig.1 shows that the impedance remains between 4 and 8 ohms throughout almost all of the audioband, rising to 12 ohms at the woofer's sealed-box tuning frequency and to 9 ohms in the mid-treble.

Fig.1 Dayton Audio B652, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

There are small discontinuities in the impedance traces between 200 and 300Hz and between 600 and 1200Hz. These indicate the presence of some kind of resonances in these regions. The enclosure was very lively when tested with the traditional knuckle-rap test; examining the vibrational behavior of the panels revealed very strong resonances at 273, 344, and 488Hz (fig.2). I detected no resonance at higher frequencies, however.

Fig.2 Dayton Audio B652, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of top panel (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

The 6.5" polypropylene-cone "woofer" is tuned to just over 100Hz. Most of the response rise in this region in fig.3 will be due to the nearfield measurement technique, but the B652's low-frequency alignment does appear to be a little underdamped. The farfield response on the tweeter axis rises throughout the midrange, with then a somewhat peaky output throughout the treble. (I removed the grille for the measurements; leaving it in place had surprisingly little effect on the B652's behavior, other than filling in a little the response dip at 2kHz.) This peakiness leads to the higher-than-specified sensitivity, but whether or not it is heard as brightness will depend on the speaker's dispersion.

Fig.3 Dayton Audio B652, anechoic response on HF axis at 50", averaged across 30° horizontal window and corrected for microphone response, with nearfield response of woofer plotted below 300Hz.

Fig.4 shows the B652's lateral dispersion, referenced to the tweeter-axis response. The speaker is quite directional between 2 and 7kHz, which will work against the on-axis peakiness in the same region, though the use of a small-diameter (5/8") tweeter results in a wider-than-usual radiation pattern in the top octave. In the vertical plane (fig.5), a suckout at the crossover frequency develops immediately above the tweeter axis. Tall stands will work better than short stands with this speaker, especially as the mid-treble output drops a little just below the tweeter axis, which will work against the tendency to brightness.

Fig.4 Dayton Audio B652, lateral response family at 50", normalized to response on HF axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

Fig.5 Dayton Audio B652, vertical response family at 50", normalized to response on HF axis, from back to front: differences in response 45–5° above axis, reference response, differences in response 5–45° below axis.

Turning to the time domain, the B652's step response on the tweeter axis (fig.6) indicates that both drive-units are connected in positive acoustic polarity, the decay of the tweeter step blending smoothly with the start of the woofer step. This blending suggests optimal crossover design. The cumulative spectral-decay plot on the tweeter axis (fig.7) shows a surprisingly clean decay over much of the audioband, but with strong ridges of delayed energy at 1.4kHz (the frequency of one of the wrinkles in the impedance graph) and 4.8kHz. The former will add hardness to the B652's balance, the latter a somewhat steely character.

Fig.6 Dayton Audio B652, step response on HF axis at 50" (5ms time window, 30kHz bandwidth).

Fig.7 Dayton Audio B652, cumulative spectral-decay plot on HF axis at 50" (0.15ms risetime).

While the Dayton B652 has some severe measured problems, it actually performed much better on the test bench than I was expecting, given its price. When you consider that the build budget of a speaker selling for less than $40/pair will be no more than $8 for both speakers, assuming the usual 5:1 ratio of retail price to parts cost, the B652's measured performance is actually quite remarkable—and certainly better than the plastic squawkboxes sold for use with computers.—John Atkinson

COMPANY INFO
Dayton Audio/Parts Express
725 Pleasant Valley Drive
Springboro, OH 45066
(800) 338-0531
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COMMENTS
Skyrider's picture

I will tell this story often.  My roommate had a pair of Celestion Ditton 110 bookshelf speakers, probably $100 or so apiece.  They were hooked up with skinny wire to my JVC boombox and all was sitting on my living room carpet. I was listening to a classical FM station and was absolutely riveted to the music.

This is what matters most: "Does it make Music"? Does the music draw you in and keep you there.  Scintillating highs and earth-shaking lows don't mean beans unless your system makes MUSIC.

Don't ever forget that.

kevon27's picture

This industry has built itself on the notion that It's about the gear. You can spend $100000 on speakers alone so you can finally hear that cow bell in the far background being struck by the drummer no more than 10 times during the entire song. But it's all about the fine detail you say. REALLY, you need to get a life.

We need to get back to the music..

JIGF's picture
PeterHH's picture

I can't begin to afford 90% of the stuff reviewed in stereophile but reviewing a $40 pair of speakers is silly. If all you have to spend is $40 buy something on ebay or at a flea market. There are some decent speakers for around $100 from Cambridge Soundworks, whose late founder Henry Kloss made cheap but good a specialty. But really if all you have to spend is $40 you are a pretty unusual audiophile.

I have heard very enjoyable sound from unlikely systems, like the car radio in my father's 62 Cadillac - far superior to the one in his 67 Cadillac! But there is no science or system of finding such setups: they are just stumbled upon. There would be no point in reviewing them. You just have to hear them, and if you do hear them you may not share the owner's enthusiasm.

One of the great mysteries of audio is how mini-speakers can sound good enough to justify their price tags. These speakers are simply incapable of giving you the music on the record. Never mind the explosions or bass drum whacks; they can't even give you the bottom notes of the piano or cello. And yet we often prefer them to perfectly fine full range systems at the same price or a much lower price. Maybe we tell ourselves we're going to add a subwoofer (doubling the price before we're through!) But the little speakers sound good without a sub and sometimes adding a sub ruins it. Maybe the question is whether you listen to the equipment or to the music. If the latter you will probably want something that can produce bass notes from time to time. But if you just like to marvel at the clarity of your tweeters, the hell with the bass!

ashwinsrf's picture

You are shortsighted if you think anything can be too cheap to review.These speakers can give 300 usd speakers a run for their money. So to hell with your too cheap to review comment.

Get your facts right before posting. Your post just sounds like the rambling of a man who thinks money makes everything right.

ralphgonz's picture

I kind of agree that if you're broke you should be buying used audio gear on ebay. But you better have the DIY chops to repair a DOA purchase. Shipping can play havoc on 20 or 30 year old speakers, breaking crossover components loose from the cabinet and breaking soldered connections.

For everyone else, these Dayton speakers look like an amazing deal. It would cost twice this amount to build your own entry-level speakers.

tubeampking's picture

After some hemming and hawing I figured I'd drop the $40 and get a pair of these. They should be here in a day or two. I honestly am eager to hear them after all the press surrounding them.
First let me say that I'm a working class schmuck who can't afford speakers costing in the thousands, although I have heard some "high-end" gear and am considered by some to have a very good ear. That being said, I was surprised to see that the B652 has a sealed cab...anyone have any feelings or insight on this that they'd want to share.
I have yet to own a speaker that does all things well...my current set up has a pair of Optimus Pro LX10s, a pair of Infinity SL 20s, a pair of JBL 2500s, a pair of Optimus Pro LX4 with the crossovers tweaked a la Black Dahlia site. Low end is delivered by a pwered Polk Audio sub. I can say that each of these have strengths and weaknesses. The LX 10s have a mushy midrange ( I hope to improve that with some tweaking ), the 2500s have fizzy tweeters, the SL 20s are great for live recordings...very open and airy...and the tweaked LX4s have made more than a few people soil themselves. I'm thinking about building my own cabs for the SL 20 woofers and a pair of Linaeum tweeters...more on that later. Any input on any of this would be well appreciated...

yogacraig's picture

One of my first enlightening listening experiences, regarding audio equipment anyway, was when a roommate's friend counseled him to buy a used Dynaco stereo 70, the corresponding preamp (I forget the model of Dynaco),and a mostly plastic Lenco TT with a Linn Basic cartridge, the sum of which played through a pair of 1970's Lloyds speakers that the roommate already owned. No mods, no expensive cables. I would never have guessed those speakers had any music in them, but they sounded musical and enjoyable, despite still having limitations. Music and fun making things sound better.

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