AR4x Power requirements

[Guest postjob62]

Hello all,

I've just registered and have a question.

I'm looking for a set of bookshelf sized speakers for my office, a carpeted room appx. 13x11x8. I like blues and classic rock music, and occasionally like to play it fairly loud. My receiver is a Marantz 2230, i.e., 30 pretty strong wpc.

I have always loved the old AR acoustic suspension sound, and am still using a set of AR2ax's I bought new in college in another room. I'm currently using a set of Baby Advent II's in the office with the 2230, and while the combination is pretty good, I think I could do better. I'm considering trying a set of AR4x's, and just wondered if you folks think I have enough power to push these speakers given the other variables I've mentioned. I know they are pretty inefficient (though I've never seen a figure published anywhere- maybe around 84 db?) but still, aren't they from the tube era where average power wasn't so high?

In any event, opinions on this matchup would be appreciated.

Thanks,

Ed

[charger3834]

ED,

That combination should work fine with the AR-4x. I have powered the AR-4x with a number of things over the years including the Marantz 2245 and briefly the 2220B. Marantz recievers seem to be rated pretty conservative so it's my feeling that you should have adaquate power. I don't think you should overpower them given some of your signal content. Having said that, the AR-4x is pretty darn robust given its age.

The AR-4x is an fantastic design and a great example of the Wide dispersion design methodology. Given its original price tag of 51-57 dollars, the frequency response is unreal. I highly recommend this model for anyone.

[charger3834]

Ed,

Just in case you have not heard a set, they sound just like a second genneration AR-2ax with a little less top and bottom end. Crossover frequency is 1200 CPS. You still have usable bass at 40 HZ and it is very smooth through its entire range. It will fill even large rooms with sound.

[Guest postjob62]

Brad,

Thanks much for your kind enlightenment. I have a set of 4x's spotted locally and I believe I will give them a try. I thought briefly about a second set of 2ax's, but the 2230 seemed to struggle just a bit when I hooked it up to my pair. It was in a larger room than these will go into, but still I thought they somewhat overpowered the 2230. My 2ax's are powered by an old Pioneer SX-750, and at least to my tired (and somewhat jaded) Woodstock-era ears, it is a magical combination indeed.

It's funny how in my case anyhow, what I grew up with is what I still love 30+ years later when technology in the audio field has advanced so much.

Guess I'll never attain audiophile status!

Ed

[charger3834]

>

>Guess I'll never attain audiophile status!

>

>Ed

Perhaps you already have ! I am by no means an expert in the audio industry however, my broad sense of it is that loudspeakers have not advanced as much as the "audiophiles" think. Live music does not seem to be the universal reference standard anymore. My general feeling is that many of these "high end" ideas can not always be substantiated by scientific methods. Perhaps too many mega-motored hot rots have damaged my hearing, but I can't here any real difference between a $20.00 interconnection cable and a $500.00 one !

Get those AR-4x's and call it a day.

[Guest Americain]

Ed,

If it makes you feel better I'm powering my AR3a's with an old Pioneer 626 receiver that delivers a whopping 27 watts per side. LOL. Yeah, I know, I know. But this is a secondary system in my upstairs office, my main system has a Carver amp with 200 wpc but I'm using this rather low powered receiver for now. The point is, I can play those speakers LOUD even though it's only 27 wpc. It sounds fantastic so enjoy your AR4x's, I'm sure they'll sound great.

Thom

[RoyC]

I've used many power supplies from Adcom and Crown to 25-30 year old Sansui, Pioneer and Technics equipment with various AR restorations in recent months.

As I type this I'm listening to a pair of 1969 vintage 4x's (cleaned pots and new caps this past weekend) through a 25 year old 35 watt/channel Technics receiver in a small room. They are incredible little speakers...warm, rich, lacking only the tiresome modern "sizzle". They are huge sounding for their size with any amp in a small room...then again that is what we love about all vintage AR models.

Disclaimer: big rooms and "extreme" volume levels can change the equation.

I recently sold all my Adcom stuff...just not as pretty to look at.

Roy C.

[Guest postjob62]

Well, Roy, I just sold my Adcom stuff as well. A late mid-life remarriage and subsequent redecoration of the living area dictated that my listening be banished to a smaller room out of sight. But to be perfectly honest, between my SX-750/2ax setup in the basement and my 2230 and upcoming 4x's in my office, I think I'm having more fun. With my 4 ohm 100 lb. 15" woofer floorstanders and appx. 375 Adcom wpc, there really wasn't much of a challenge.

Thank goodness I saved those 2ax's all these years! It really got me rekindled in the hobby.

Best,

Ed

[RoyC]

Welcome home Ed!

I have found that carefully restored vintage AR's with their friendly "wood and linen" look have regained acceptance in living rooms as well.

Another plus is that those big old magnets won't screw up the new generation of TV's!

Back on the power issue...My mid 70's AR Loudspeaker Manual recommends 15 watts RMS/channel for the AR-4xa (successor to the 4x) and 25 watts RMS/channel for the AR-3a! Whoa, not sure where we can find amps that small!

Roy C.

[charger3834]

>Welcome home Ed!

>I have found that carefully restored vintage AR's with their

>friendly "wood and linen" look have regained acceptance in

>living rooms as well.

>

>Roy C.

This is a good observation. AR's are actually quite good looking in nice condition. Perhaps we should photograph various AR models in different living areas for the library. We could even photograph them with pretty girls like the old car magazines.

[Guest Bret]

>We could even photograph them with pretty girls like the old car magazines.<

Hotpants or miniskirt? Can you still buy patent-leather granny-boots? And I know this is awful, but being a leg man, myself, I can't remember what they were wearing for tops. Anyone remember?

I think I may have an old magazine stuffed in a trunk somewhere that I bought at a car show back when the Batmobile and Paul Revere and the Raiders Coach and the Paddy Wagon, etc, were making show-car circuits. Maybe there are some examples in there.

I just had a potentially unpleasant thought. . . getting the same models. I mean, anyone seen Yvonne DeCarlo lately?

Back to the subject.

The 2ax/3a era speakers really are pretty and in this day and time when most furniture is paper-thin veneer over cardboard or "spray-on" opaque finishes over bad wood (and I can't believe what I have to pay for this junk), the speakers may be some of the prettiest furniture in the room. The kids' 2ax's are much more acceptable in their rooms than a pair of AR-11s would be (even though I'd rather listen to the 11s).

As far as power goes, I think I've said this before, but I listened for years to 2ax speakers on a 45w/channel receiver and it sounded great. Can't ever have too much power though.

I was selling gear during the "receiver wars" and have owned both a KR-9600 and a Pioneer SX-1980. I kinda got spoiled that way.

Bret

[RoyC]

>I just had a potentially unpleasant thought. . . getting the

>same models. I mean, anyone seen Yvonne DeCarlo lately?

I had the same thought Bret, and somehow knew that you would be along to get the wording right :-)!

I guess no matter how much we polish the wood and clean the grills, the tweeters and woofers are still aging underneath. Now I'm depressed.

Roy C.

[Guest postjob62]

Brad, Roy and all who helped me with my questions in my original 4x post- thanks so very much! They are home and hooked up to my 2230 as I write, and oh my goodness- it is an equally magic combination to my SX-750/2ax matchup, at least in this smaller room.

I'll have many questions down the road, but for now, a couple regarding room placement.

With the "wide dispersion" tweeters, should these be toed in a little or not?

How far should they be from the back wall? Can't get close to the corners due to other furniture.

Finally, I am in the process of building some appx. 26" speaker stands designed to get bookshelf speaker tweeters up to ear level. Will stand placement cause me to lose bass with these little guys? Right now they're on about 6" of phone books (on top of a carpeted suspended wood floor) and they sound phenominal.

Thanks,

Ed

[charger3834]

>

>With the "wide dispersion" tweeters, should these be toed in a

>little or not?

There have been many discussions on this forum regarding the wide dispersion design methodology and near vs far field listening. These threads are good reads, as they are written by more knowledgable forum members than myself. Essentially the answer to your question is that it will make little difference if you "toe" them in or not. AR speakers were not designed to "image."

>

>How far should they be from the back wall? Can't get close to

>the corners due to other furniture.

AR recomended that the cabinets be placed close to the wall 6-10' apart and 3-4' off the floor. I just read that off the back of an AR-4x.

>

>Finally, I am in the process of building some appx. 26"

>speaker stands designed to get bookshelf speaker tweeters up

>to ear level. Will stand placement cause me to lose bass with

>these little guys? Right now they're on about 6" of phone

>books (on top of a carpeted suspended wood floor) and they

>sound phenominal.

I think they sound a little "boomy" at a 6" height. They will sound better further off the floor. Feel free to experiment with placement and the level controls; let your preferences be the guide.

>

>

[Guest postjob62]

Brad , Thanks-I'll continue with my stands and give it a try.

Tweeter pots have been by-passed on these, so adjustment there is not an option. At least from a mental standpoint, I like this option even though it isn't histiorically correct. By nature, I'm not a person of moderation- I like extremes in about everything- and the idea of the tweets being full- bore is appealing to me. In fact, I had been toying with the idea of doing this to my 2ax's. It would certainly eliminate fiddling with the pots.

Given my proclivity for "wide open", does this make sense?

Ed

[charger3834]

>

>

>Given my proclivity for "wide open", does this make sense?

>

>Ed

I wish that I could say yes because the bypass option is quick and easy, and cleaning the pots is a pain, however, the wide open position is not where the smoothest response will be. A bypassed pot is about 1 db higher than the wide open position. The spectral balance is a little wrong and the driver will really sound too bright relative to real music. The "normal" position or slightly increased will be your best bet for most rooms. Keep in mind this 2.5" cone unit is crossed over at 1200 HZ and it handles a big chunk of the vocal range. AR wanted the wider dispersion drivers doing more of the work.

The case is more or less the same for the 3.5" mid range unit of the 2ax. You could get away with bypassing the supertweeter of the 2ax which has a "normal" position that is pretty close to wide open. This is due to the relative ineffeciency of this driver. This driver only handles frequencies over 5000 or 7500 HZ, depending on which version of the 2ax you have.

[RoyC]

Ed,

In my experience the optimal height/placement (and for that matter pot settings) are dependent on how "live" the room is, especially as it pertains to flooring material.

As for "bypassing" the pots...have the pots been eliminated completely, or have you placed a jumper between pot terminals #1 and B? The latter is preferable to elimination as it maintains 15-16 ohms in parallel with the tweeter, and is equivalent to the pot being fully open. Eliminating the pots completely will throw the original crossover point and balance off.

I prefer the 4x tweeter setting between the "optimal" dot and the fully "increased" position. The tweeter can get a bit blaring or harsh at higher volumes with the pots fully open.

If your pots are beyond fixing, conventional, inexpensive 8 ohm l-pads would work OK as both the AR-2ax and 4x are rated 8 ohms. It would give you more flexibility.

Roy C.

[Guest postjob62]

You know Roy, I don't know. The guy who did it is an experienced audio tech and just said he had "bypassed" the pots because they were too far gone. I can try to email him and see what technique he used, but if this helps any, the plastic turning knobs are still on the back of the cabs and they still feel the same- just don't make any difference when they are turned.

Does this shed any light on what he did?

I realize that just because they sound great to me it doesn't necessarily mean they sound optimum or even correct.

Ed

[RoyC]

The fact that the pots are still in the cabinet is hopeful. Its easier to "bypass" by keeping them in the circuit and simply connecting a wire around the variable resistance portion. Even when the pots are shot the parallel, fixed resistance portion is always OK and still usable for that purpose. Its likely that is what he did.

If they sound good Ed, thats all that matters...

With the 2ax's you could probably get away with bypassing the tweeter, but I would leave some kind of control on the mid.

Roy C.