Sony APM-690's in the house (pix)

OK, I did it, I bought those Sony APM-690 speakers because they were $20, in great shape and I want to hear what a flat square speaker sounds like. It has one 10” square woofer, one 4” square mid, and what looks like a 1.5” round paper cone HF. Really nice coated fabric surrounds. The cab is medium weight MDF, ported, and it looks like there is no dampening material in the cab. Now here is the kicker… they say “made in USA” on the back!!! The drivers must weight quite a bit as the cab looks fairly light but the speakers weigh about 35-40 pounds each. The lady I got it from said “they sound terrific” and came from a system they bought for over $1000 about 10 years ago. Now you know what I know about these. I will rip them open and take pics of the drivers when I get a chance. I’ll also let you know what I think of them sonically.

Square speakers… yeeehaaaa

Those are wild!! And here I thought Kicker was the first with square drivers.....

Yeah, check out the rear of the drivers...

hmm...seems to me like they wouldn't be as efficient as a cone, but the off axis response would be better.....

now im just blathering on.

I think the idea is the sound waves do not cross each other so it limits them canceling each other out. Of course speakers have been made in the cone shape forever so :scratch2:

I just had to have square speakers cuz I’m THAT guy. :screwy:

I remember those. It was SONY's idea to be different by selling square cones. APM (Acoustic Piston Motion). They made all these claims about how they were better than round cones. Well, it just goes to show you different isin't always better. Kicker, though, makes some really good square subwoofers for automobile use, not to be confused with these full range boxes from sony. The destroyer was the square mids and tweets. Just ruined the sound. Anyway, let's see what they sound like. Have you hooked them up yet?

yeah! hook em up man!! We'll be over in a few! lol

Now that's a cool lookin' speaker. Curious to hear your opinions on the sound.

JC

Don't remember exactly where but I saw a pair of those for sale in the last couple of weeks. Passed on them myself but would be interested to hear your opinion. Square drivers seemed too strange for me.

Alan

scolba said:

hmm...seems to me like they wouldn't be as efficient as a cone, but the off axis response would be better.....

now im just blathering on.

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Yep. And I bet they put out square waves rather than sine waves. :thmbsp:

LOL....hardy har har. :nutz:

JimmyNeutron said:

I remember those. It was SONY's idea to be different by selling square cones. APM (Acoustic Piston Motion).

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It's actually Accurate Pistonic Motion.

JimmyNeutron said:

They made all these claims about how they were better than round cones.

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The main advantage wasn't really anything to do with them being square, it was about the flat, rigid, honeycomb drivers that were supposed to have less resonances (=distortion) than typical paper or plastic cones. The square panels just gave them a little larger area and made them easily recognizable as different from the typical drivers.

JimmyNeutron said:

Well, it just goes to show you different isin't always better. The destroyer was the square mids and tweets. Just ruined the sound.

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Is that based on personal experience or factual evidence of some kind, or just wild speculation on your part?

Ok, got a chance to try them out a little last night. Funny thing is I was really full of anticipation because of the strange drivers and was very interested in the sound they put out. I have to tell you… these things sound really good. I mean great in some respects. Let me start with the good and work down.

First off the bass response and dynamics are wonderful. Some of the best sounding woofers I have ever heard. I was not prepared for this. When setting them up I looked at the medium to thin MDF cabs, the plastic square (and short) port, and looking through the port the lack of damping material and quit frankly I was assuming this might not be a good speaker especially where bass reproduction is concerned. I could not have been more wrong in my assumption. The bass is very full, clean, low and tight. I have a live Stanly Clark / Larry Carlton / Billy Cobin recording that simply jumps from the speakers because of the bass content and roundness. Typically I like a sealed enclosure (bass reflex) as apposed to a ported one because I always found ported enclosures to be a bit boomy and flabby (inaccurate?). Not these. Lots of really musical bass response. I also played some live Maxwell (black guy with a beautiful woman like voice) which sounded really rich and deep. Also sounded good with old Dire Straights. Basically the bass response was very impressive and rates near the top of what I have heard. Very musical, warm yet still accurate.

Now things get a little complicated. Did I like the critical mid range? At first I found it kind of flat and un dynamic / complex. Not unlike a good studio monitor, flat response and not overly musical. This can be good and bad. It seemed accurate and did have good mid content but not overly complex or striking in any way. In comparison to the amazing low end it seemed to lack character. The more I played with the EQ and different albums (CD’s) I found out something very interesting, this speaker is revealing. I have a few recordings I have always thought the drum sounded cheesy on or some part of the music was just not right, maybe recorded strange or drum machine sounding. This speaker amplifies these weaknesses in the recordings. Actually I think amplifies might not be the right word, maybe it is accurate to the point of its own demise. Seems to reveal my good recordings from the bad. If you’re looking for a good speaker to play background music from different sources and don’t want to touch the EQ this wound not be a good speaker for this. If you wanted to critically mix music (studio monitor) this might be a good speaker. Personally I like to tweak EQ’s and find many of my recordings require that as they are drastically different (I listen to a huge variety of styles). The yummy bass may make it hard to mix music with this speaker though as playback through other lesser speakers may not sound as full and rich as it did through these.

So now the HF. The tweeter is the weakest link in this picture for me. At first I thought I did not like the mid driver. The more I listened to different material and EQ’ed all over the place to see what is going on I found the HF driver to be mediocre and not a match for the other drivers. Leave it to the round driver to mess it up for the square ones. I have never been a big fan of paper cone tweeters. I love the sound of soft dome tweeters and this speaker would border on spectacular with a good soft dome tweeter installed. Nothing terribly wrong with the tweeter and it adds good clean top end just not very dynamic, or musical. I wish for more chime and crispness to the top end. I think a good tweeter in this speaker would really open it up and show that the mid driver is good and just not being complimented by the tweeter and adding dimension to the package. On a good note, the tweeter is smooth and not taxing or shrill.

I did not get them set up until late and the house had quite a bit going on so my evaluation is not complete. I want to test it at higher volumes and with different material. I also was auditioning it using my $5 Sansui 7070 and while that’s a good amp my Pioneer SX-1010 I think will bring even more out of the speakers. My wife commented on how good the sound was before noticing the “new” set of speakers. “What the heck is up with the square speakers”. They do seem to get good and loud and seem to stay consistent with more volume although they do gain some mid / HF in a good way when turned up and the bass seems to keep its tight and full sound without getting flabby. Imaging and soundstage seems above average.

I am very busy this week / weekend but will try to get some more time in front of these and update as I gain more info.

The mad man in me really wants to hear these with a soft dome tweeter, who makes a square one

Overall I am quite impressed with these. Best $20 speaker I have heard so far. :thmbsp:

ByrdWyngs said:

Is that based on personal experience or factual evidence of some kind, or just wild speculation on your part?

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It's actually based on the fact that when I sold audio gear many years ago I also sold these sony systems. The square speakers were always included on the rack systems and rarely any were ever sold by themselves. I've heard these speakers and once you hear them you too will know what i am talking about. Also, why is it that there are only a handful of square speakers still being produced? Maybe because round is better? You'd be better off asking a speaker designer the virtues of a round versus square design as I am not qualified in that area. Sony did make a few attempts at some serious high end square speakers, though. But their primary focus and design is still good ole round speakers, as is every other manufacturer out there.

What I said in my earlier post abouot these speakers is strictly my opinion, don't take it for granite. But what I have heard about these speakers really leaves one wanting more.

JimmyNeutron said:

Also, why is it that there are only a handful of square speakers still being produced? Maybe because round is better? You'd be better off asking a speaker designer the virtues of a round versus square design as I am not qualified in that area.

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Maybe the fact that there aren't a lot of square speakers being made has nothing to do with which is 'better' as far as the sound is concerned, and has a lot to do with which is easier and cheaper to manufacture? Or maybe it's just that square speakers are a little too strange for a lot of conservative buyers? Or maybe it's a result of Sony's typically crappy marketing and lousy reputation during the '80s and '90's when the APMs were being made? Just because something sells better doesn't necesarily mean it's technically superior, and just because something didn't sell well doesn't prove that it isn't actually the better solution.

I happen to work with a couple of speaker designers and I have asked them about this. They can't think of any good reason that a flat square driver shouldn't sound as good as (and might actually be better than) a round cone or dome, all other things being equal. But it would be more expensive to manufacture - possibly a lot more expensive. Which means that in order to sell at a given price point compromises would most likely need to be made elsewhere in the design of the cabinets and/or crossovers that could negate any benefits from the driver design. Another thing to keep in mind is that (with a very few exceptions) Sony's 'traditional' speakers aren't particularly well known for their great sound quality, and any deficiencies in the APM systems probably has a lot less to do with flat squares vs. round cones than it does with Sony's implementation for mass market speakers at a relatively low price point.

Hey Byrd, I meant no disrespect to 888 about his purchase. I just gave my opinion based on my experience with the speakers. Actually, my bro-in-law still uses the set that came with his system from the 80's.

..."in order to sell at a given price point compromises would most likely need to be made elsewhere in the design of the cabinets and/or crossovers that could negate any benefits from the driver design."
......Well, we've all seen and heard some of the best, if not the best that the speaker world has to offer - no holds-barred, non-compromising speaker designs, and they are all round, which means that for most all speaker manufactures, the reason to not use square drivers and use round ones instead is a matter of sound quality and less a matter of compromise with x-overs, cabinets, or anything else. Wilson Audio, B&W, Infinity, etc all have no compromise speakers where price is no object, and they all use round drivers. A round radiator radiates a sound pattern in a spherical pattern. I may be wrong, but I'd gamble that a square driver does not, due to edge diffraction of the square cone. But that's an argument better left for the real speaker makers.

But in the end 888 has said that he likes the way the speakers sound, and that's all that matters. Heck, for $20.00 for the pair it's not a bad buy at all. I'm glad he's enjoying his purchase. :thmbsp:

Very well put ByrdWyngs. kfa888 seems to have a favourable impression of his APMs.

Perhaps these speakers are also very sensitive to the amount of power and type of amp hooked up to drive them, just like he is saying they are very revealing of the quality of the recording.

Would be interesting to drive these with some tube amp power maybe ? :scratch2:

JimmyNeutron said:

......Well, we've all seen and heard some of the best, if not the best that the speaker world has to offer - no holds-barred, non-compromising speaker designs, and they are all round, which means that for most all speaker manufactures, the reason to not use square drivers and use round ones instead is a matter of sound quality and less a matter of compromise with x-overs, cabinets, or anything else. Wilson Audio, B&W, Infinity, etc all have no compromise speakers where price is no object, and they all use round drivers. A round radiator radiates a sound pattern in a spherical pattern. I may be wrong, but I'd gamble that a square driver does not, due to edge diffraction of the square cone. But that's an argument better left for the real speaker makers.

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Actually, on those "no holds-barred" speakers you talk about, most of the good ones stray from the conventional round drivers. Take the Infinities you mentioned. The real good ones use square planar drivers for the critical midrange and hf. The only place the real good ones use round drivers is for bass where, quite frankly, driver geometry doesn't matter so much due to the size of the wavelengths in concern.

Regarding other speaker manufacturers, as far as I can tell, most make their basis not so much on the drivers they use, but on how they implement them. You can buy the drivers used in a lot of these mega-buck systems for very small fractions of the final price separately. The main cost comes in with the esoteric cabinet construction and the various, complex implementations of the crossover art. In fact, a lot of the drivers used started out as "off-the-shelf" before the no holds-barred" speakers came about and a fair number of good speakers share the same drivers simply because how they act is well documented and so can be readily corrected for.

Maybe the reason why these square drivers didn't catch on is because as ByrdWyngs said, Sony hobbled their own creation. Just think of all the superior technologies they've come out with (Beta, Digital Tape, SACD, BluRay, Trinitron, etc) that they've killed through inane licensing fees and limitations. Let alone the poor marketing and decisions Sony tends to make as a company in regards to getting new technology to catch on.

In the end, round radiators are round radiators, they've been around since the beginning and so people and, more specifically, speaker designers would rather stick with something they know and thus know the faults of rather than something new that could possibly require new approaches for implementation. That in the end costs more for the requisite research and the need to relearn how to do things right.

Just my $0.02.

Now, no matter what, I concur, $20 was a great deal.
- JP

Kencat said:

Would be interesting to drive these with some tube amp power maybe ? :scratch2:

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Actually I was thinking that 50 WPC of V-FET power might be just about right

Charivari said:

Now, no matter what, I concur, $20 was a great deal.
- JP

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No argument here on that count!

Ok, round or square, after second audition I love these speakers. Last night I had an empty house for about 2 hours and believe me I opened those babies up and let them sing. I think this is a great sounding speaker. I was spooked by stuff I heard in recordings I have listened to many times that I did not know was there. I have two live CD’s that I really like and are recorded well and I heard things like feet moving around, people talking in the crowd, etc. At 10-25 watts these things are singing and singing well. The dynamics, complexity, imaging and sound stage come alive with a little volume. I also like the tweeter better at higher levels, seems to come alive and gain personality. Still not really high end sounding top end but much better with a little juice behind it. I am also in love with that goofy square woofer. I don’t know if it has anything to do with the design (although I think it might) but the low end reproduction is very musical and pleasing to my ear. Even at higher levels it seems like the driver has to move very little and is very efficient at making low end easily. Additionally I ran my ear around the various drivers and it seems the woofer is providing a good amount of mid range content as well. Tapping on the woofer surface yields and interesting tone I don’t think you would find on a cone shaped woofer and I think might be part of the equation. I have admittedly had little experience with high end speakers (unless you call Bose 901’s high end as I have spent 30 years with those :>) other than expensive studio monitors for mixing multi tracked recordings but these speakers really impress me. I realize they are a goofy design and that they are built cheaply but heck if they don’t throw out some very pleasing music reproduction. To my ears these are the best speakers I own right now. Weird.

PS – As for efficiency these speakers react a little differently than others I have owned or tried. They seem very efficient at low volumes and I think the woofer efficiency has a lot to do with this adding a lot of full content with little volume. But, as you turn it up it handles loud music very well yet seems less efficient the more you turn it up. I turned it up so my wattage VU meters were showing 25-30 watts and my Sansui SP-3000 speakers would have been getting very loud and towards their limit where these still seemed very tight and good for more yet not providing quite as much volume. The SP-3000’s are the most efficient speakers I have. Most speakers I have had need EQing when cranked, although these gain mid and high end content it just gets better not louder and these speakers require very little or no re EQing so sound great at drastically different volume levels.

I was so impressed with the sound last night I forgot to even try my Pioneer SX-1010 to drive them.