My AR92s and my new Yamaha reciever-

[Guest marcopa]

I've spent sometime reading in the forum and find myself in the presence of quite and impressive group. I picked up on the issues of amplifiers, speakers and fusing. I sense danger. I have moved out of the 1980s recently and got a Yamaha rx-v2400 reciever with 7 channels and 120w per channel output. Or so that is what I have gathered. I have a fantasy- developing a surround of vintage AR speakers. I have my 92s for the fronts and a pair of AR book shelves (the model escapes me right now) for the surrounds and imagined finding others to fill this out. Does this make sense? I got the impression from my friend (a Yamaha vendor that installs modern systems) that speakers are more efficient now. I am worried that I will be overtaxing the reciever and under powering the ARs. Throw me a line I fear I am in way over my head. Thanks for any help Chris

[Guest Bret]

Chris -

You're fine with a pair of 92s and your Yamaha receiver. You need a subwoofer for doing surround sound because of the way it is done (recorded) and the 92s aren't up to reproducing the subsonics of explosions, anyway.

As for using ARs as surround speakers - well, it's been done many times, although I would think you'd need a really acoustically dead room for it to work well.

Bret

[Guest OldRelayer]

Chris,

I have a surround system that I have been to lazy to advertise that I will sell cheap. It is suppose to be nice, Cambridge soundworks, with a center channel and two surround speakers that are designed to mount on the wall and have two side firing drivers, not out the front of the speaker. Personally I really hate home theater and it was used for maybe 2 weeks and been collecting dust ever since. Let me know if you may be interested.

On the amp thing, I am a minority of one, I think, I dislike modern amps, they are light and appear to be over rated. I was playing with a Sony at radio shack was suppose to be 100 w/c for all 6 channels, it was light, I don't think it weighed 5 pounds and just didn't seem right to me, even a 2 channel 100 w/c amp should be pretty heavy. Unless some physical law has changed when you drive speakers you create heat and it takes mass to dissipate it. I was actually playing with another one at Circuit City, don't know what brand but it was set up, and driving either 2 Polk or 2 Infinity speakers, you needed to crank them to about 3 O'clock to get them to even sound like speakers. I know they read good, but there is some smoke and mirrors here that I don't understand. With any of my older amps, with a passive sub and sats that are only 88 db I barely can get them to 10 O'clock and at 12 O'clock I would have the neighbors at my door and I don't live in an appartment. I don't know what the average impedance of an AR-92 is but I suspect it is lower than 8 ohms.

Your stuck in the 80's, I am stuck in the 70's and I am not budging, a good place to be, we all have an opinion, none of them objective, I suspect.

Thanks

Barry

[Guest Bret]

>On the amp thing, I am a minority of one, I think, I dislike modern amps, they are light and appear to be over rated<

You aren't alone, or even in the minority. Take a poll around here and I think you'll find Parasounds and Adcoms and Phases Linear and Haflers and I think I may be the lone Sunfire owner in these parts.

But we're talking about a pair of AR-92s, not a 3a, LST, 9 (LS(I)), 90, etc. The 92s aren't as hard to drive as these others.

Heck, I'm driving a pair of 14s with one of those wimpy Panasonic digital receivers at 100w/channel. It really isn't all that bad. You can hear a lack of "umph." I'd never even try to drive my 9s with any but the largest receivers ever made (and, in fact, did use receivers for several years).

Bret

[Guest marcopa]

If it helps me it all- the reciever weighs a ton- Well thanks to you all- I am a bit more brave now- I have been doing some more homework- it seems the (4 ohm) 92s need surrounds- I spoke with Mr. Miller (quite a gent) about doing the work and debating tryng my jewelers hands at it. I went to the wood shop and dug out my pops old ARs which turned out to be AR6s in the low 3000s. ( 8 olm) I pulled off the grills which seemed to have been undisturbed and discovered dust for surround on one. The pots, when turned, seem to a novice, to give meaning to that scratchy description I note being used here about. What really set me back, was the tarlike coating on one of the cones. see photos. Can this be as-built? What gives? recone and surrounds? Mr. Miller, I think, is about to be come my new best friend. see my photos. Thanks for the help. PS What about the 8vs 4 olm thing?

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[Guest OldRelayer]

Gawd, why would someone do that to a woofer. You might have Bill take a look at it, but boy it sure looks like trash to me. But there are people with a whole lot more experience with such things that may have a solution for getting that goop off the woofer. I have to ask, why??.... what did that driver ever do to anyone that it deserves such a horrid fate.

The Impedance or the OHM value if you will is based on the most basic of physical principals in electricity. Ohm’s law. Simply put the lower the value the more current needs to be supplied by the amp. But Impedance in a moving target it is different at different frequencies so when a speaker is rated at 4 ohms, it means in the opinion of the manufacturer from his testing that the average impedance is 4 ohms. Which I guess is a fair way to access it and it is a safe assumption that a 4 ohm speaker is going to draw twice the current and demand much more of your amp than an 8 ohm speaker.

Weight is not the only indicator of a good amp, but it sure is a good starting place. A nerf car would get great mileage but I wouldn't want to be in an accident in one.

Yamaha has a good name and I was talking about a Sony (which has come to mean commercial crap). I guess my point with the amps of today is don't just read the specs and think you have a good one. Pick it up, crank it up and let it run a while, put your hand on it, if you don't burn your self at high volumes for 15 minutes you may have a good amp.

Or if you must have a home theater don't confuse it with a stereo system for music, set up the stereo as if HT didn't exist and then add the bombs and chase scenes later, you don't need a lot of fidelity to replicate a bomb blowing up, just a ton of air being pushed.

Thanks

Barry

[Steve F]

Some general words of advice might be helpful, re-printed here from one of my posts almost a year ago:

A few additional things to keep in mind regarding Home Theater in general, whether using AR speakers or any other brand:

The LFE channel (Low Frequency Effects) does indeed contain different bass information than the regular front channels. Even if the L/R speakers are selected as “Large,” they will be sent full-range material, such as music, that is different than the material contained on the LFE (the “.1”) channel. The LFE channel usually contains the explosions, crashes, earthquakes, etc. effects that are different than the normal soundtrack.

Now, when you select “Subwoofer—Yes” from your set-up menu, most receivers/processors gather up ALL the bass below 80Hz (or whatever electronic crossover frequency you’ve selected, if yours is selectable) from the LCR, surround, AND the LFE channels and then routes it to the “.1” subwoofer output. Therefore, the bass coming from your sub output (assuming you’ve selected “L/R speakers—Small”) is a combination of the 45Hz music tones in the LCR channels and the 22Hz warp engine rumblings on the LFE track.

Two things happen when you select “Subwoofer—No” from your set-up menu. First, you lose the ability to control (via the receiver’s or processor’s remote control) the LFE/Sub level from the convenience of your listening chair. One of the best things about using a powered sub is that your receiver’s remote lets you raise or lower the sub level remotely from your seat, while the program is playing. Very handy.

The other thing that happens when you select “Subwoofer—No” is that on Dolby Digital DVD’s, the LFE channel is folded back into the L/R channel signal, at a –10dB level compared to what it would have been on the separate “.1” channel. Dolby’s rationale for this was that when using regular speakers (no subwoofer), the LFE level should be reduced so as not to damage non-subwoofer speakers, but still present nonetheless (at a –10dB level) so you don’t miss any content.

As far as HT requirements for low-frequency extension are concerned, THX’s manufacturer’s requirements originally called for a response of –3dB at 35Hz with a 12dB/oct rolloff below that. Coincidentally, this is exactly the response of the AR 12”-woofer bookshelf models. However, THX’s requirement is for 105dB at the listening position (which can easily be 10-15 feet away from the physical location of the sub—do your inverse-square law SPL calculations!) in a 3000 cu. ft. room (pretty darn large—25 x 15 x 8’) without objectionable audible distortion. That’s a VERY stringent requirement, and a tall order for a pair of 3a’s or 11’s. THX’s latest “Ultra 2” standard calls for –3dB at 25Hz in a 6000 cu. ft. room, under the same distance and distortion conditions. I’m presenting the THX standards as an objective reference of performance level, not to be construed as an endorsement of THX one way or the other. However, this is representative of how loud some people expect their HT system to play.

Bear in mind that the AR-3, 3a, 11, 10 Pi, and 9 woofers were designed to reproduce the lowest musical notes on commercially-available recordings of the day (vinyl LP’s), at SPLs that were logical to expect at the time (about 100dB max. in a normal-sized living room). While these products can be used in HT systems with very good results, they are ‘70’s-era musical reproducers first, and slam-bang special effects reproducers second. Unless you have some overwhelming desire to keep Bill Miller very busy while making UPS even richer, I’d exercise a sane amount of caution and common sense when using 40-year-old classic speakers to play exploding Death Stars at deafening levels."

Steve F.