The Yamaha NS A63x series of speakers have gotten a lot of love and hate. There is a lot of misunderstanding about these speakers. For example, people seam to confuse them for bookshelf speakers. They aren’t bookshelf speakers. Bookshelf speakers are designed to be listened to at a close distance. This series of Yamaha speakers, although small enough to be placed on a table, were originally designed for home theater use back in 1996. They were mean’t to be spread out and be far from the listener. The rest of the hate is from misinterpreting the principles of an acoustic suspension design. You NEED power for this series of Yamahas for any type of bass response. No, these speakers do not need a sub. In fact, my NS-A637s have earned their fair share of complaints from neighbors. In this article, I’ll be explaining my experience with these speakers over the years. Sit back and read along as I explain how to get big sound out of a smaller set of speakers.
Give them what they need.
Well I hate being the bearer of bad news but this series of Yamaha speakers is like taking care of a toddler. Give them a place to play (no pun intended) in an open space. Feed them well and they will perform well. Help them grow up into a larger set of speakers. Then, just then, you’ll have yourself a great set up that doesn’t take up that much space but will give you that classic, big, warm, HiFi sound that you’ve come to crave.
They’re not bookshelf speakers…
I’m going to explain in depth why you shouldn’t be sitting so close to your Yamahas. First off, take a look at how the drivers are arranged. Yamaha has been using this classic arrangement for years. In fact, Yamaha still is using this design. Although I have no experience with the new set, I’ve heard good things about them. If you want to take the plunge, you can find them hereon Amazon. Anyways, back to the point: The ideal speaker system for up close imaging is a 1-way speaker. Since designing a 1-way system is complicated and expensive, common bookshelf speakers are for the most part 2-way designs using a tweeter and a woofer. For a good example, take a look at my Electrohome SC 490s. The Yamaha NS-A63x series incorporate a 3-way design in an odd layout that simply doesn’t image well up close. This can destroy the illusion that the sound is coming from a single source. This is why you should never expect these speakers to work well as bookshelf speakers. Instead, set them up on stands and spread them out. The ideal listen position should be far from them.
Feeding The Toddlers
If you haven’t figured this out yet, I’m going to break this down. You need the power! That’s right, smaller speakers aren’t as sensitive. The Yamaha NS-A63x series fall into this category. They need a big amp or receiver. Back when my Dad had them, he had a Yamaha R-V702 AV Receiver. This AV receiver, although a late 90s one still had an excellent 2 channel rating. It pumped out a conservative 80 watts RMS per channel with no more than 0.09 THD (Total harmonic Distortion). Pretty much all modern AV receivers rarely have such clean 2 channel power. For those not familiar, total harmonic distortion is the amount of distortion the amplifier section produces at it’s max power. This has a direct relation with the sound quality you should expect when pushing hard to drive speakers like my Yamaha NS-A637s. Due to the fact though that my Dad’s receiver is not functional at the time of writing this, I have mine wired up to an even more powerful 1989 Kenwood KR-V126R. This receiver has a ridiculous power rating of 125 watts RMS per channel with no more than 0.008 THD. It has enough power to blow up the Yamaha NS-A637s. Let only the Yamaha NS-A635 and NS-636 which both have a lower power rating.
Helping The Toddlers Grow Up
Just how do you do this you might ask? Well let’s talk about a component that everyone forgets. This is component is what is known as a graphical equalizer. A graphical equalizer helps tame the way sound transverses from the speaker to the listener. They help combat room harmonics, frequency peaks and dips, and the overall frequency response. By using a graphical equalizer, we’re going to help distribute the excessive power we have on tap where it is needed. Specifically the low end. This can be used in tandem with your receiver’s tone controls to achieve a well tuned sound. When tuned right, this series of Yamaha speakers specifically the best of them, the NS-A637s will sound so good that you’ll forget about their small size. You might even forget that you’re listen to speakers.
Start with decreasing the mid bass down while increasing the lower bass. Take a look at my photo above. I’m using my equalizer to increase the sub bass (50Hz). I also increased the bass on the Kenwood’s built in equalizer. You can do this using your receiver’s tone control as well. Your ears will tell you when you have the right balance. You should also see your receiver’s power indicator (if your’s has one) start to jump with the bass. Now you’re feeding the toddler of speakers. On your equalizer, decrease 1KHz and bump 400Hz and 2KHz up a smudge. This takes care of the peaky 1KHz sound that the NS-A637s have and add some warmth. Now with the treble, decrease the 6KHz way down, while increasing 16KHz. Then turn up your treble using your receiver’s tone control to get the perfect balance. At this point, you should be ready to critically listen. Just remember that both your ears and your equipment may differ from mine. Feel free to make adjustments based off what your ears are telling you.
The result: Speakers that sound like they’re much larger.
At this point, you should be hearing warm, thunderous, and punchy bass. You should also be hearing, crystal clear transient response. The treble should be perfectly balanced between the mid-range driver and the tweeters. It’s surprising what the Yamaha NS-A637s are capable at such a small size. They are literally a perfect addition to your living room. Not only are they good with music, they make absolutely killer speakers for watching TV and movies with. They handle action movies perfectly. You will feel the walls vibrate in an average sized living room. You might also get complained about from your neighbors. Just one thing to remember, trust your ears. If you hear any breaking up, the woofers are bottoming out (voice coil is smacking the magnet). By then however, you should be getting plenty of low end out of them. I rarely turn mine up that loud. The lady next door hates me enough. As always, I hope you enjoyed the article. For now, enjoy this recording of my set in action.