John McPeak/Foam

[owlsplace]

19 hours ago, stupidhead said:

Hi David, try this link http://stores.ebay.com/looneytune2001/ . I have hard time finding him sometime too!

Yes, thanks ... put him on my follow list.

[DavidR]

I finally got around to measuring the foam and driver cones for 10" AR90 woofer and some 8" LMR.

The Springfield Speakers dimensions were suitable for the 8" but the 10" didn't match up well at all. I then took Owlsplace advice and looked at Audiodogs AR foams and also the JBL. The JBL actually matched up a bit better. I sent Audiodogs an email and asked about the compliance, the darker vs the lighter stiffer foam and if he'll ship in a box. I'm waiting for his response.

[DavidR]

Here's the response I got from Audiodogs:

Hi! There is certainly a lot of misinformation and unrealistic thinking going on out there in the speaker world these days. Firstly speaker manufacturers do not produce the parts or at least in the majority of cases. What they do is go to the experts who can supply parts to the speaker designers specifications. It just so happens the surround that is specified for the JBL 125A is also specified for the AR 10" speakers, while the Boston Acoustic style filleted edge 10" surround is most certainly not specified for either. Speakers are a sum of their parts change one part and you change it all. Nothing is done by accident or by someone saying hey that looks real kool. It is not uncommon for a designers to select parts off a shelf. This particular cone with this Voice coil and that suspension and this particular surround will produce a particular sound because each parts specifications have been well documented. Those parts may be selected based on other factors such as the size of the cabinet and configuration of the speakers and the type of Crossover being used. Its all like a big puzzle that fits together to produce what the designer was wanting to achieve.
The US manufacturer that makes these surrounds recommends this surround for the JBL 125A and others and the AR 2 and other AR 10" speakers based on its dimensions, profile design, texture, thickness and roll size etc;
These are the foams that I sell and they are grey in color not black and compliant (thinner) that most surrounds. They will function like the originals and to me that's the name of the game. Hope this was helpful."

[wilson]

Interesting.  I did end up getting the Boston foams.  They appear to be the same as what I last received from John McPeak.  They are certainly much more compliant than the light grey ones that I received from Looney Tunes (same as in DavidRs photo).   I'm going to use them.  One of the reasons that I decided on the Bostons is that they are an acoustic suspension speaker whereas the JBLs are ported. Had I emailed Audiodogs and received the above reply I probably would have gone with the JBL.

I would be interested to know more about Roy's opinion of the Boston foams. 

 

[DavidR]

What's odd about Audiodog's response about the JBL and AR foam being the same is that he lists the dimensions and the info he provides gives diff dimensions for each and diff part numbers.

The Boston foams may be the way to go. Who is selling them as of now?

[RoyC]

First of all, John McPeak Is no longer in business, and he will be missed. He had much speaker building experience, and we shared a great deal of information and measurements over the years...and it was through this relationship that we discovered that Boston Acoustic replacement foam worked very well with AR 10 inch woofers. The implication that Audiodogs or any other foam retailer knows what is "specified" for 40 year old AR woofers through some sort technical insight is unlikely. That retailer as well as most others are purchasing most, or all, of their foam from one wholesaler in Arizona (MWA). In fact, the only foam actually "specified" for AR woofers is the uniquely sized 12 inch replacement foam. MWA will sometimes make recommendations based on feedback from the field, which is how the JBL replacement was found to work well in the first place.

John and I found that MWA was becoming inconsistent in what was being sent out as JBL 125A and JBL 118/Bose 301 replacement foam (recommended for AR 8 inch woofers). Increasingly, the foam was becoming thicker and less compliant....more like generic foam. Compounding the issue, given that generic foam fits AR 10 inch (and 8 inch) woofers and looks the same as the JBL foam, is that it is very easy for a wholesaler or retailer to get away with sending a cheap, less compliant replacement.

Consequently, we experimented with acoustic suspension design-specific 10" BA foam, given its high compliance and high quality. It was a perfect fit, and we found it was easily the equal or better than the high compliance version of JBL replacement foam. We also knew that BA foam could not be confused with any other due to its unique appearance. John began sending out BA foam for AR 10 inch woofers instead of the inconsistent (and easy to substitute) JBL replacement foam. The good news is the latest batch of 125A foam I saw in Larry/Vintage AR's shop was the proper high compliance version, so both types still work well for the AR 10 inch woofer (though only the JBL replacement can be used when gluing to the back side of the cone). Btw, Boston Acoustic foam is sold by most decent retailers. Just ask for it by name.

A year or so ago, MWA began sending out a different version of the AR 12 inch foam. It was thicker, had a smaller irregular roll, and did not fit as well as the preferred version. MWA admitted it was less expensive...and it would have become the "specified" replacement if there was no alternative. Fortunately, I got Larry to convince MWA to resume stocking the better foam, albeit at increased cost. In the same vein, the spider being sent out for the AR 12 inch woofer is now a lower compliance version...because MWA says demand is not sufficient to stock the preferred high compliance spider. (I have since found one in their catalog which works as well as the old one, but was not, um, "specified".)

If you are a CSP forum member don't assume a seller of replacement foam knows any more than you do about AR speakers.

Roy

[DavidR]

Roy,

Is there a Boston Acoustics foam for the AR 8" woofers, as well ?

Do you have any suggestions who to turn to for these foam surrounds?

[RoyC]

On 5/3/2016 at 2:51 PM, DavidR said:

Roy,

Is there a Boston Acoustics foam for the AR 8" woofers, as well ?

Do you have any suggestions who to turn to for these foam surrounds?

David,

The 8 inch Boston foam is very compliant, and will work with most AR 8 inch woofers, but it does not fit as well as the somewhat less compliant Bose 301 replacement foam. Many retailers are sending the least compliant generic foam for AR 8 inch woofers because it fits well.

The most reliable retail seller I have used in the past couple of years is Speakerworks.com http://www.speakerworks.com/default.asp They carry more than the usual MWA fare, and is the only retailer (or wholesaler) I am aware of selling very small midrange replacement foam.

Roy

[DavidR]

Thanks Roy

[ra.ra]

Thanks, Roy, for the update on John McPeak's status - - many of us remain thankful for his helpfulness and enjoyed doing business with him. Also, thanks to you for sharing some of the background that went into these recommendations for replacement foams, and for the nod to Speakerworks. Your efforts at conducting this research are methodical and thorough, and along with many others, I very much appreciate being one of the beneficiaries of your generous benevolence.

[RoyC]

You're welcome, ra.ra and David. It is gratifying to see the high quality of restorations and repairs being accomplished through the information and experiences being shared by you and other "driven" members in this forum. Lately, I've found discussions about cabinet repair and refinishing particularly interesting and informative.

I forgot to add that I've personally been using only the easy-fit Bose 301 surround for 8 inch AR woofers. It is also the one Larry/"Vintage AR" sends out in his 8 inch kits.

Roy