Pioneer SP-BS22-LR loudspeaker Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Pioneer SP-BS22-LR's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield responses. For logistical reasons, the sample I measured, serial no. LFNV0082030C, was from a different pair from the ones auditioned by Bob Reina.

Pioneer specifies the 'BS22's voltage sensitivity as 85dB/2.83V/m. My B-weighted estimate was actually a little higher, at 86dB(B)/2.83V/m. Fig.1 shows how the Pioneer's impedance magnitude and electrical phase vary with frequency. The minimum impedance is 4.5 ohms at 250Hz, and there is a combination of 6 ohms and –33° at 160Hz, but neither of these affects the fact that the speaker is relatively easy to drive. The specified impedance of 6 ohms is a little on the conservative side, given that the SP-BS22-LR's impedance remains above 10 ohms for the entire treble region.

713Pionfig1.jpg

Fig.1 Pioneer SP-BS22-LR, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

There are small wrinkles in the impedance traces just above 200 and 300Hz, as well as one around 1600Hz, which would imply the presence of enclosure resonances of some kind at these frequencies. However, using a plastic-tape accelerometer to investigate the cabinet's vibrational behavior with the speaker supported on upturned cones, which allows resonances to develop to their fullest, the strongest mode I could find was on the sidewalls, at 297Hz (fig.2). This mode was also present on the top panel, as well as others at 357Hz and 1kHz (not shown). I would have expected this mode to add some midrange congestion, and it's fair to note that BJR did comment on there being "a subtle bit of chestiness in the speaker's lower midrange."

713Pionfig2.jpg

Fig.2 Pioneer SP-BS22-LR, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of side panel (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

In the impedance-magnitude trace (fig.1, solid), the valley centered on 71Hz between the twin peaks in the bass suggests that this is the tuning frequency of the rear-firing port. This was confirmed by the fact that the minimum-motion notch in the woofer's nearfield output (fig.3, blue trace) occurs at the same frequency, which is about 11Hz higher than that of the SP-BS41-LR but lower than the tuning frequency of its predecessor, the SP-BS21-LR. The sharp peak at the tuning frequency in the port's output (red trace, plotted in the ratio of its diameter to the woofer's diameter) suggests a high-Q woofer alignment. This is probably a good idea, given that the driver's radiating diameter is just 3.5". There are a couple of resonant modes in the port's midrange output, but these are well suppressed. The complex sum of the nearfield woofer and port responses (fig.3, black trace below 300Hz) peaks a little at the port tuning frequency before rolling off rapidly, though the ultimate rolloff slope is a little slower than the usual 24dB/octave. There is only a hint of the usual upper-bass boost that results from the nearfield measurement technique.

713Pionfig3.jpg

Fig.3 Pioneer SP-BS22-LR, anechoic response on HF axis at 50", averaged across 30° horizontal window and corrected for microphone response, with nearfield responses of woofer (blue) and port (red) respectively plotted below 300 and 900Hz, and complex sum of nearfield responses plotted below 300Hz (black).

Higher in frequency in fig.3, the Pioneer's farfield response, taken with its plastic-frame grille removed, slopes up a little from the lower midrange to the upper midrange, but with then a flat response through to the top octave where there is a slight excess of energy. This will tend to compensate to some extent for the speaker's dramatically restricted horizontal radiation pattern above 8.5kHz (fig.4), which is very similar to the older Pioneer's. Similarly, the slight flare in the off-axis behavior in fig.4 coincides with a slight lack of energy in the on-axis response, shown in fig.3. In the vertical plane (fig.5), a suckout in the crossover region develops more than 5° above and 10° below the tweeter axis. Using stands to bring the tweeters to the same height as the listener's ears will be critical with this speaker.

713Pionfig4.jpg

Fig.4 Pioneer SP-BS22-LR, 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.

713Pionfig5.jpg

Fig.5 Pioneer SP-BS22-LR, 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.

In the time domain (fig.6), the tweeter's output leads that of the woofer, but its decay blends smoothly with the arrival of the woofer's output, implying optimal crossover design. Both drivers are connected in positive acoustic polarity. The SP-BS22-LR's cumulative spectral-decay or waterfall plot (fig.7) is impressively clean throughout the treble, though there is a small ridge of delayed energy at 1776Hz, this corresponding to the ripples seen in the decay of the woofer's step response.

713Pionfig6.jpg

Fig.6 Pioneer SP-BS22-LR, step response on HF axis at 50" (5ms time window, 30kHz bandwidth).

713Pionfig7.jpg

Fig.7 Pioneer SP-BS22-LR, cumulative spectral-decay plot on HF axis at 50" (0.15ms risetime).

Considering it costs just a penny under $160/pair (and is often advertised for $130/pair), the Pioneer SP-BS22-LR shows little compromise in its measured performance, other than its necessarily limited low-frequency response and correspondingly underdamped woofer alignment. I was alarmed by that lively enclosure, but the radiating area of the affected panels is, of course, small, and this will also be influenced by the coupling material used on the stands' top plates. Measurements I did 20 years ago indicated that small pads of Blu-Tack were very good at damping cabinet resonances. (See "The Sound of Surprise.")—John Atkinson

COMPANY INFO
Pioneer Electronics (USA) Inc.
PO Box 1540
Long Beach, CA 90801-1540
(800) 421-1404
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COMMENTS
fvelasco's picture

Anyone listen to the floorstanding in this series, the SP-FS52's? I would like the floorstanding if it will sound as clean as the bookshelf. And at the same price, $129, I am torn on which way to go. I tried listening to them in the store but I couldn't get a good feel for them, and for some strange reason they wouldn't let me borrow them :)

Stephen Mejias's picture

The floorstanding Pioneers are sold individually; the standmounts are sold per pair. So, while the SP-FS52 costs $260/pair, the SP-BS22 costs $130/pair. Note that the price of the SP-BS22 has just officially been reduced to $130/pair from the original price of $160/pair.

I haven't heard the floorstanders, but I suspect they maintain the smaller speakers' tonal qualities, while offering greater frequency extension and being capable of playing at higher volumes. Michael Fremer wrote about them for AnalogPlanet.

fvelasco's picture

I did realize that after I posted, I got a little excited! Thanks for the direction, I'm kinda new to the whole audiophile community and really appriciate you taken time to reply.

SridharPoli's picture

I am on budget. Can you please suggest me the best stereo amplifier for Pioneer SP-BS22 under $200?

Walter Martin's picture

I don't know that there is a "best," but the Onkyo TX-8020 receiver has gotten good review and is available for $159 on Amazon. I think it would be an excellent match, even if you don't care about the tuner and just use it as a preamp and power amplifier. For even less money, you could also consider one of the inexpensive tripath (also called "Class T") amplifiers available from places like Amazon and Parts Express.

SridharPoli's picture

Heyyy Walter, Thanks for suggesting me with a better choice with the modest budget I have. I am ordering Topping TP30 (I think that's the Tripath Class T amp you are suggesting) and i am VERY EAGER to get it soon. Just cant wait having the Pioneer SP BS22 at home just sitting in the packaging box and don't have an amp to get it playing :-)

Walter Martin's picture

That is not the only one, but yeah, that is the type I was talking about. I have a friend running $500 speakers off of a similar one. Even though he and I have different ideas of what sounds good, he is very picky about sound and is quite happy with it. By all reports you should have a nice sounding system for very little money. Enjoy.

ccfk's picture

I've had these speakers for about four months now and the only thing I've heard them struggle with is Public Image Limited's "First Edition", which is a sonic monster.  For $130 a pair they're a no brainer.

Snowdog57's picture

These speakers are a perfect addition to my 27" iMac (with the ubiquitous Lepai 20-20 amp). Given the glowing reviews of other sites, I took the chance and picked up a pair at a small shop in Seattle that gave me ample time to audition them - sure they sounded good there, but what about when I got home? Hooked them up and couldn't believe the quality of the frequency range. Having purchased the Dayton B652s online about 6 months ago (purchased solely on glowing reviews), I was greatly disappointed. They sounded flat, as in no depth whatsoever, and narrow fq range. So, naturally, I was wary of the Pioneers at first, but after listening to them I know I'll be purchasing more in the future - without reservations!

Et Quelle's picture

Why take the time to talk about this plain, ordinary speaker? No one is dreming of this? You buy it just to have a speaker.
The enthusiast wants monitors they can collect, pass down and drool over. A non audiophile will snatch it up though?

Pioneers have bass. My mom has used them for years. They went further maybe with this and make it condusive to piano. Whar-
fedale has got to be better, cooler and worthy of drooling I like the middle ground monitors; slightly pricy but not 25,000$

Stephen Mejias's picture

With respect, these Pioneers, designed by Andrew Jones, are not your mom's (or your dad's) Pioneers. Their looks may be plain, but their sound is remarkable. They very easily hold their own against much more expensive speakers, the Wharfedales included.

Ben2talk's picture

A rhetorical question surely, or do you scorn those who are unwilling to fork out big bucks for 'real hifi'.
Hopefully there will always be a few paying attention, though I love my main stereo speakers I'm in no position to match up a 'good' 7.1 or even 5.1 system.

These pioneers sound very sweet, their warm character matching my front B&W pair at a cost (685's at 45,000 baht here...) of 5000 baht. I'd never even listen to Pioneers unless I'd read this article..... I still cannot quite believe 1. The quality for a Pioneer or 2. The way they blend in and extend the sound field.

gn77b's picture

speaking of Wharfedale, I watched (read? I forget) an interview with Andrew Jones where he mentioned that generally cheap speakers are actually just built to provide "some" sound, drivers thrown together in a decent-looking box. funnily enough, the first example that came to mind was Wharfedale, which have an incredible finish for the price but I'm not sure there's more to it :D

Stephen Mejias's picture

Read our complete review of Wharfedale's Diamond 10.1 here. I also spent some time with the speaker.

It kicks ass and is one of my favorite speakers.

JIGF's picture

Funny how Andrew's much more expensive design up a few posts from here gets 0 comments vs 8 comments here.

Utopianemo's picture

Okay, although I have been eyeing Mr. Jones's monitors since before the last model came out, I had decided that for my upgrade I was going to go with the Wharfedale Diamond 10.2, the larger sibling to the 10.1's. Now, the 10.1's were glowingly reviewed everywhere, including here. I know the Pioneers are really good, but what do you mean exactly by "they hold their own" against the Wharfedales?

My choice to go with the Wharfedales over the Pioneers was based on the fact that I tend to favor a warm midrange, as well as my assumption that were I to crank the volume(as I like to do from time to time in my somewhat large room), the Pioneers wouldn't be able to remain as composed and dynamic as the Wharfedales.  It's also why I was planning on going with the 10.2. Admittedly, I haven't been able to listen to the Wharfedales yet as the nearest dealer is 2-1/2 hours away and in another state.

So Steven and/or Robert, given the choice, price notwithstanding, would you pick the Pioneer SP-BS22-LR over the Wharfedale 10.1? And related to that, do the Pioneers respond well at loud volumes? 

Thanks so much,

Nathan Daniels

Stephen Mejias's picture

Hi Nathan. Thanks for reading and thanks for your questions.

I know the Pioneers are really good, but what do you mean exactly by "they hold their own" against the Wharfedales?

I'm working on a Follow-Up for our October issue, which will make direct comparisons between the Pioneer SP-BS22-LR and the Wharfedale Diamond 10.1, so please stay tuned for that. In Bob Reina's review of the Pioneer, he mentions a few differences between it and the Wharfedale, so check that out.

The Pioneers respond fine to high volumes, but this fact also depends on how high you mean, the size of your room, and your amplifier. That said, if you want more size, volume, and warmth, definitely go with the 10.2s. No question about it.

Given the choice, price notwithstanding, would you pick the Pioneer SP-BS22-LR over the Wharfedale 10.1?

Given the choice, price notwithstanding, I would pick both. I could live happily with the sound of either. If I had to pick just one, I would pick the Wharfedale because it's prettier.

Utopianemo's picture

Stephen,

thank you for the insight. I enjoyed Bob's review and I am looking forward to the October issue!

tcmalibu's picture

While I do not consider myself an 'audiophile', I've been buying and listening to pretty good gear since the early 70's. Over the past 40 years I found that my ears always turned to british speakers and have rarely swayed from B&W in the last 15 years. After reading the review I bought the Pioneers, thinking what the hell - at this price who cares - maybe they will surprise me a little. After a good solid listen, and with the realization that they are not close to being broken in, I now find myself fearful of compaing them to my B&W 805D's and giddy with the idea that I just found a ridiculously good speaker for this kind of money. It's like finding a Pinot Noir at $10 a bottle that rivals $100 bottles.

And Kudos to SM for a spot on review - ".... made it an excellent match for well-recorded voices." indeed - Lyle Lovett singing 'Baltimore' was mesmerizing. Audio is feeling like fun again!

Ben2talk's picture

Me too, shocked that these shoeboxes make good surrounds to a B&W front end!

deckeda's picture

Stephen, I was glad to see last year's SP-BS21-LR mentioned since I own a pair and since they completely flew under Stereophile's radar when all the hubbub about the SP-BS41-LR was being published. So the brief comparison with the newer pair is interestting.

Oh, and for another reason: The SP-BS21-LR's were generally more available than the SP-BS41-LR's were. But whatever. Who knew?

I also have the SP-C21 center channel speaker and together with the SP-BS21-LR's makes a seamless presentation for movies.

Thanks again and for the link to MF's review of the floorstanders. I was on the fence last year and almost bought them (the predecessor SP-FS51-LR actually) but not being able to hear them took the "lesser risk" and picked up the '21s instead, not knowing A. Jones had a potential winner there, too.)

SridharPoli's picture

Thanks for recommending the SP BS 22's.

Walter Martin's picture

Sorry, this was a reply to a comment above that somehow ended up down here, so I deleted the content.

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