re: Two channel audio/cd 'hi-fi' on a budget

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Should be here Friday.

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That's quick. I hope you like them, it is easy to recommend amps/preamps/integrated amps because it really is a matter of quality/power for the money along with a dash of aesthetics but speakers are like food everyone has different taste. As a result I like to recommend very neutral speakers but also lean to my taste in that they must have great imaging and be brutally honest with the recordings which will reflect badly on some recording engineers. One thing I like about Focal is they design and build all their drivers in-house in France and the Chora line has some great trickle-down tech from their much higher cost lines.

Optimus Pro SW-12

I vaguely remember these. The normal way to wire them would be to take the speaker-level outputs from the Yammy to their inputs then the sub has an output to run to the speakers. I do not know if the sub has a crossover on the output to the speakers or not and if it does I do not know what the frequency would be. If it does have a Xover it is almost certainly made with cheap electrolytic caps, sand-cast resistors, and iron core inductors, it might also be a cheap digital active Xover but I honestly don't know, during that timeframe many of the super budget subs had passive crossovers. At their age the caps are probably beginning to degrade. You also will have a sensitivity mismatch so the sub will likely play at a lower volume and you can't adjust it to blend them.

The other option would be to connect the sub to the Yammy's outputs for the B speakers. This would be my preferred way. A to the Focals and B to the sub that way you could switch the sub off from the front panel and directly compare just A to A+B. Since the sub is 8 ohms the amp will run both BUT not super loud for a long time. Just make sure if you do that you move the speaker impedance switch on the back of the amp to the 4ohm/2 sets of 8 ohm side. It will come with the switch on the single set of 8 ohm side. Who knows it may work for you. That is assuming you didn't buy a sub yet.

On the sub side if you are willing to up the budget just a little when you order the Pro version of the SVS 1000 subs adds a lot of value with the app based parametric equalization. It makes the sub much easier to blend with your mains especially since you don't have room EQ or other bass management in the Yamaha like you would in an HT receiver or pre/pro though some of the higher level 2 channel pre-amps are starting to have more room EQ/bass management.

BTW I don't think I mentioned it before but my choice for sealed vs ported sub when used for just music is sealed. With sealed you have a better impulse response of the sub because a port is just an air spring and like all springs it takes time for it to load up. You will get less group delay and phase issues at least until you start piling on the EQ filters. Finally, you don't have to worry about port velocity or resonance. The dirty little secret about almost all commercial subs and everyone I have seen under about $3,000 is they all have potential chuffing and resonance problems at high volumes. When designing a box for a sub you generally want to get the most extension (lowest frequency) and highest volume you can. Certainly, you are worried to some degree about harmonic distortion but that is more a result of the driver and amp vs the box itself. The problem for a commercial sub manufacturer is they need to have a relatively small box both for shipping and spousal acceptance factor. Low tuned ported subs really need a big box so that is the first compromise. The second set of compromises comes with the port itself. To prevent chuffing you want to keep the air speed in the port at the max power you plan to send to at or below 34 meters per second if both ends of the port have a proper flare, half that if they do not. So you use a bigger diameter port or multiple ports. If you increase the port diameter (or increase the number of ports) the velocity drops but the length becomes longer for the same tune and the first resonant frequency of the port drops in frequency. You want to keep the first resonant frequency of the port at least a full octave (doubling of the Hz) above the crossover frequency. So port velocity and first resonant frequency work against each other and optimizing the port diameter usually results in a length that is too long for a budget sub because they simply won't fit in the box that you can sell and ship reasonably. Take a look at JTR home subs for an idea what a more or less optimized box is for a serious home theater sub. The boxes I build for my HT subs are even bigger... but bigger boxes have their issues too. Sound waves propagate inside a box. The longer a dimension of the box is the lower frequency that will propagate in it and cause audible issues if that frequency is in the passband. You want to keep the longest dimension of a box shorter than one wavelength of the frequency twice as high as your crossover frequency.

The reality is the small ported subs sold in the mass market are compromised significantly. The designers know this but they have to build a product that sells. So small box, relatively low tuned with a lot of power. So why do they build ported subs? You can get a lot more output, especially near the tuning frequency than with a sealed sub. You also need a lot more power to get the same output from a sealed sub, while power is cheap it still isn't free. You can make sealed or ported work for either HT or 2 channel music with the right design choices but for 2 channel and keeping with smaller subs built in the commercial space sealed makes more sense 99% of the time, but some people will disagree.

Let us know what you think when you have it set up initially. I am really curious about your thoughts.



Dammit I did it again... sorry TLDR but I am still gonna hit submit.