Acoustic Research AR9LS owners? Just for thought

So, why is it so important to have these up againtst the wall? Is this just simply by design? Are my other speakers suffering due to being out from the wall about 16inches.... I dont know much about the yamaha amp... I just cant find any info on it. A-1000 integrated amp... it wasnt super high dollar, but was no cheapie either... I can only assume its pushing more power at 4 ohms. Please give me advice as to placement. I could move them into a bedroom that is 17x13.5 feet ***can you please tell me how a pioneer elite vsx-54tx would fare against the yamaha? It is rated at 100w per channel but might be more in stereo mode and may be a cleaner 200watts at 4 ohms??? Just a thought for you guys to ponder.

FWIW, I believe when the AR's came out 'depth of imaging' was something hi-fi enthusiasts didn't have in their sights yet. That came a few years later with Harry Pearsons focus of 'sound staging' including things like depth of image and air, etc. Designing the speakers system's bass to sound best when the speaker wall was backed up to the wall was no more that designing it to work as most folks were positioning their speakers then. Consider Allisons, Snells, etc. So it follows that if you pull these speakers out into the room to a locus where the speaker is about 25% or more of the room's length from the wall behind it you may loose a lot of bass, but you might, just might, greatly improve the speakers sound stage, i.e. width, height, and depth. And in practice you could add a sub woofer to compensate. Could. Maybe. :-) FWIW.

Agarrison, you need to search the link to Classic Speakers and go to the AR section and find information on the design of the AR-9 series. It all relates to room loading, frequency range of woofers and mid-woofers, and crossover points. Then you may better understand about placement. They will certainly play music out from the wall but you will be sacrificing their intended performance.

Your other speakers may be fine. But they might also improve with greater distance from the front wall. Normally bass information loads up (increases) near room boundaries (wall/floor/ceiling intersections). Placing most speakers too close to walls, and especially corners, results in excess bass loading. Some folks may like this as it produces more apparent bass, but it will not be clean and accurate bass. The AR-9 series was specifically designed to overcome this rule of acoustics.

I'm not familiar with any Yamaha or Pioneer gear so can't help there. My comments on amp power are a general guideline. Many people believe you should get x 1.7 to 2.0 the 8 ohm rating into 4 ohms. Thus a 100 watt amp at 8 ohms should output 170 to 200 watts into 4 ohms. Some amps may not even be fully stable into 4 ohms but any competent design should be.

WOW, thanks for the response guys. Here is another bone to throw at you to chew on. My yamaha has an option on it to run "auto class A" whatever that means. I have done some research on class A power but its confusing to me to say the least. I have noticed no audible difference when i use the class A setting but it does seem to run a lot hotter. Can anyone explain?

What I suspect is occurring - is that most amps operate in class a/b which means that its initial gain is in class a but it switches to class b at a very low levels. This switching from class a to b gives your amp the ability to operate up to a high power output but the switching can cause sonic issues some folks are sensitive to. So enter class A where the amp operates only in class A up to its rated power. No switching distortion, lower power, runs hot(er), and costs a lot of loot. A lot!

What I ASSUME Yamaha has done (remember there is no free lunch - no one is giving pure Class A amps for nothing) is that in 'auto class a' the Yamaha's class a is running up to a higher level before you switch to class b, so if you have efficient speakers you will never encounter the problems switching might intoduce. Its still a Class A/B amp, just smoother at higher power levels.

This is very common in Class A/B amps except most don't usually have an option and the class a power levels vary. Some manufacturers have the level high enuf that they try to pass off the amp by implication as pure Class A.

Hope that helps a bit.