One owner AR-7 find

[ReggaeBen]

Hello everybody,

Found myself an original pair of AR7's in almost mint condition. First thing that struck me was there miniature like size!  They still have the original surrounds and even came with the box, this will be nice and simple to have them up and running again.  

I've tested the tweeters with 1.5v battety, removed the woffers and inspected inside the cabs. They contain fibreglass fill with Sprague compulytic 6uf, this is the crossover without coil and just a two way switch.  Noticed a slight sag in both spiders, one slightly more so, have not come across this yet and would be interested to hear some thoughts on this. 

I've previously used surrounds from Simply Speakers and an ebay guy going by the name of Looneytunes2001, both with great results.  However with postage to Aussie being a consideration, I always look to source from fewer places as possible. So, I need to order some parts from Parts Express, and they have the 8" that's needed.  Has anyone experience with using theirs? 

Next time I hope I come across one owner AR3a's!!!

Ben 

 

[lARrybody]

Great looking examples of some AR 7's. I have two pairs with Vinyl covering and one with wood veneer. I use the filled fillet surrounds (boston type) surrounds nowadays on my 8 in woofers, but the JBL/Bose type work just fine. I would say the Parts Express surrounds should be OK. Maybe double check the inside and outside diameters plus the roll width.  

[ra.ra]

Hi Ben - - - that pair appears to be in very good condition. I have a couple pairs of AR-7's, and the pair shown here (s/n 005817 and 8) have wood veneer and date codes (7250) seven weeks earlier than yours. These now have the Bose/JBL foams with the more traditional roll profile which are very easy to install, and you can see the re-foamed woofers have been installed 180° from original position to try to counteract any effects of gravity that may have created spider sag. I have no experience with the Parts Express foams, and cannot recall where this batch was purchased for a number of 8-inch AR woofers a few years back. In this pair, the original Sprague Compulytic caps measured about 6.1 ohms, so I left them as-is and they sound terrific.  

[frankmarsi]

""and you can see the re-foamed woofers have been installed 180° from original position to try to counteract any effects of gravity that may have created spider sag.""

ra.ra,  I always did the same with the 26+ 3a woofers I did re-foam since 1989.

Did it make a difference?  Well, I suppose it did, naturally.

 

[ReggaeBen]

Think I'll go with the standard type roll and not the filled fillet type, mostly to retain the original character of them and partly because the Boston's are a PITA to fit! I'll investigate some more into the Parts Express type, but its likely they'll do fine as mentioned.  Glad too that I've got the Sprague's in there, I've planned just to test and leave them be like you suggested, ra.ra.  The woofers will get flipped 180° and left to see if they give any issues after another 45 years

Thanks ya'll 

Ben

[ra.ra]

5 hours ago, frankmarsi said:

I always did the same with the 26+ 3a woofers I did re-foam since 1989.

Like most of what I've absorbed, that bit of advice (rotate 180) was gleaned from the wise men that have preceded me. At an age where I now curse certain consequences of gravity over time, the concept of woofer rotation sounds very sensible to me, too, and it just might help alleviate Ben's concern about his spiders (could this be considered a mild form of arachnophobia?). But why-o-why, pray tell, would anyone be re-foaming 26+ woofers within thirty years? If not a lucrative side business,  does this offer a glimpse into the habits of a serial driver abuser?  Was this a typo?.....twenty-six, really?  

3 hours ago, ReggaeBen said:

....the Spragues.....I've planned just to test and leave them be...

My experience keeping the original caps was positive, if not a bit surprising, so it's good to know you'll be measuring first for confirmation. 

[frankmarsi]

To answer this :

""But why-o-why, pray tell, would anyone be re-foaming 26+ woofers within thirty years? If not a lucrative side business,  does this offer a glimpse into the habits of a serial driver abuser?  Was this a typo?.....twenty-six, really?  ""

 

I own four AR-LST's since '87, in '89 when I did their first refoam, there weren't any surrounds available to me or anywhere that I knew of in  NYC but from one guy in the back of stereopile magazine. Those were some of the first available with cut to fit seams. There wasn't pages full of possible options like there is today 30 years later on the auction site or anywhere else. Oh, 'fillet' surrounds, not in the early years.

Four LST's X four refoams because the early surrounds available were not of good quality and gave into wear in a short time so, I had to do over four in just a few years time.

Then I've purchased spares and refoamed them to have on reserve only after installing them, they were found to be rubbing or the VC was bent by the previous owner's use or, they didn't have full-travel. Then in 2014, there came two AR-9's and they needed six more to be done.

So, with over 18 spares in reserve, I've learned to be ready for almost any situation.

I've owned AR 12 inch woofers since 1972 and always felt that they are the best for home use.

I'm lucky that I purchased mostly all of my used 12 inch AR woofers on the auction site when they were going for $50. a piece.