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Some Mods to the AR-9


wsill

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Hello everyone,

I wanted to report on two mods I have made to my new to me AR9's ( I have had them 2 weeks now).

1) I added 1/2 closed cell foam around the upper midrange.

I definitely hear a difference; with the foam there is more spaciousness and sounds now not coming directly from the speaker cabinets.

I have less inclination now to set the upper midrange switch to -3db. The foam I inserted was from Home Depot used for insulating air conditioner wings.

I'm not sure that this material the best to use but it works.

It's reversible smooth of corrugated. See picture.

2) I removed the "chromed" edges around the woofer grills. I think the speakers just look better now.

I am also experimenting with tip toes. Tighter bass  and midrange with tip toes. Though can't move and you loose some of that "fat" bass.

Has anyone else here made mods as I have and what's your experience with these and others.

The AR9's are just fantastic speakers.

Bill

 

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Congratulations on your new AR-9 speakers, Bill - very nice!

Years ago, my son and I had a lot of fun restoring and modifying the AR-9 when a pair could be had for less than $200, and there seemed to be an unending supply.

As has been mentioned, absent foam inserts for the dome drivers was not uncommon, and it was debated as to how useful they and the Acoustic Blanket actually were.

My favorite looking/sounding restored AR-9 systems were without the Blanket, foam inserts, "chrome" trim, and the vinyl stickers under the three level control switches. Spiked feet and  new metal binding posts (very nice ones are available from Parts Express) are also beneficial mods. There's been a lot written on restoring the AR-9, especially regarding crossover repair, cabinet refinishing, and wiring options. The very best I've heard were the stripped AR-9 systems in a vertical bi-amp orientation using a pair of Adcom GFA-555II power amplifiers, driven by an Adcom passive preamp, with active EQ for the woofer section using an Audio Control low frequency equalizer. The result was ridiculously good, with excellent imaging & detail, and clean & tight bass response.

Here's a link to a couple of old AR-9 posts, but there are many more on this site by several past/present AR-9 owners:

http://www.classicspeakerpages.net/IP.Board/index.php?/topic/1280-nude-ar-9-pics/

http://www.classicspeakerpages.net/IP.Board/index.php?/topic/1433-new-ar-9-project/

 

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First and foremost, a big Congratulations Bill...!  I'm so glad that your speaker search landed in the past, with the AR-9's.  Some of the best ever.  Enjoy, and keep us updated on how they work out.

Also, ar_pro, I absolutely love those Naked-9's!  Absolutely gorgeous.  If I ever find a pair, I'm definitely going to do the same thing.  I wish my 90's had a veneered front, and I'd strip them down.  

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20 hours ago, wsill said:

I am also experimenting with tip toes. Tighter bass  and midrange with tip toes. Though can't move and you loose some of that "fat" bass.

I've always wondered about the need for these spikes.   My AR9's stand on a carpet with thick foam base on a concrete floor.   With my installation, I wonder how these spikes could possibly help because they aren't "coupled" to a wooden floor as they would if in the living room.   Right?  (That's one of the few advantages to having one's system banished to the basement.)

Also, regarding the foam around the tweeter, I installed some aftermarket felt from vintage-ar:

https://www.ebay.com/itm/ACOUSTIC-RESEARCH-SPEAKER-AR-9-AR90-AR91-AR92-AR11-AR-10PI-TWEETER-RINGS/192715894526?hash=item2cdec32efe:g:vnEAAOxyhodRzaLC:sc:USPSFirstClass!07869!US!-1

Did it make a difference?  Perhaps, but if so it was subtle.

I never tried installing anything around the UMR.   As I noted in another post, I'm extremely happy with my AR9's right now and hesitant to fool with them any further.

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  • 1 year later...

g`morning pals , this is my first post here , regarding the tweeter and mid range felt / foam , what are these made of ?? i am about to purchase a set of AR9 ,those parts were removed and since i have never seen another AR9 set before , i don`t know anything about what materials these inserts would be made of ..... i can still see the velcro round pieces on the speakers tho .....any help ? 

thank you !!!

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41 minutes ago, Rickyboy said:

i don`t know anything about what materials these inserts would be made of ..... i can still see the velcro round pieces on the speakers tho .....any help ? 

The acoustic blanket is made from industrial felt, almost identical to this: Difficult to buy in speaker size quantities.  Min purchase 3yds at $82/yd. 

 

 

https://www.thefeltcompany.com/f-15n-wool-felt-1-2-thick-x-72-wide/

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4 hours ago, Rickyboy said:

g`morning pals , this is my first post here , regarding the tweeter and mid range felt / foam , what are these made of ?? i am about to purchase a set of AR9 ,those parts were removed and since i have never seen another AR9 set before , i don`t know anything about what materials these inserts would be made of ..... i can still see the velcro round pieces on the speakers tho .....any help ? 

thank you !!!

 

The tweeter and midrange inserts were a fairly stiff open cell foam.  It was very different in feel to the felt acoustic blanket.  Harder and more plastic in nature, compared to the blanket.  Some use A/C filter foam, to cut inserts from, but the AR inserts were thicker and stiffer.  Still, you use what you can.

Acoustically, I doubt the inserts do much.  They are more for cosmetics.  The acoustic blanket alone, most likely has the biggest audio impact.

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More from the stitching and quilting world; first we got grill cloth and batting now we have wool ironing mats/acoustic blanket.  Except for the color this is the same material used as acoustic blanket on the AR9 series.   The 24 x 17 size is enough for one AR9.  The link is to Amazon but fabric shops carry them as well.

https://www.amazon.com/dp/B08RHSNB8C/ref=sspa_dk_detail_0?pd_rd_i=B08CC3MQWK&pd_rd_w=Zd6Fp&pf_rd_p=b34bfa80-68f6-4e86-a996-32f7afe08deb&pd_rd_wg=1XLvK&pf_rd_r=10NHSV0BKS5B2Z5K83K5&pd_rd_r=2fd737f6-9f05-4fe7-8065-c7423415413c&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExMTg4NFgxWUs4SzlKJmVuY3J5cHRlZElkPUEwNjgyOTQ5MVZIN0g3NDUyQThGOCZlbmNyeXB0ZWRBZElkPUEwMDkwNzM0MkdFMDI0OUNYSUNLMSZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

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On 1/30/2021 at 3:30 PM, Rickyboy said:

g`morning pals , this is my first post here , regarding the tweeter and mid range felt / foam , what are these made of ?? i am about to purchase a set of AR9 ,those parts were removed and since i have never seen another AR9 set before , i don`t know anything about what materials these inserts would be made of ..... i can still see the velcro round pieces on the speakers tho .....any help ? 

thank you !!!

On 1/30/2021 at 8:19 PM, Stimpy said:

 

The tweeter and midrange inserts were a fairly stiff open cell foam.  It was very different in feel to the felt acoustic blanket.  Harder and more plastic in nature, compared to the blanket.  Some use A/C filter foam, to cut inserts from, but the AR inserts were thicker and stiffer.

 

I still have the original foam inserts around UMRs and tweeters in my AR-90s.

The foam that is very close to the original is the sponge filter material that is used in external canister filters for fish tanks.

You can buy it in sheets in some pet stores.

The sponge material that was installed in my fishtank filter looked exactly the same in texture as my original AR foam inserts.

There are different densities and cell sizes, you should go for the finest/smallest:

Reticulated-filter-foam-cell-structure10

http://www.spongesupplier.com/product/10ppi-to-60ppi-saltwater-fish-tank-aquarium-filter-sponge-bio-filter-sponge/

10ppi-to-60ppi-saltwater-fish-tank-aquar

 

l

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  • 1 year later...
4 hours ago, John S. Holmes said:

I have a pair and they have been re foamed but what do you do with the dry rotted foam in the very bottom near the woofer?

Mine are turning to dust, if I take it out wht kind of material do I replace it with?

Thanks

Are you referring to a 9 or 9ls?

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5 hours ago, John S. Holmes said:

I have a pair and they have been re foamed but what do you do with the dry rotted foam in the very bottom near the woofer?

Mine are turning to dust, if I take it out wht kind of material do I replace it with?

Thanks

If you are referring to AR9LS speakers, with their down-firing woofers, many use Sonic Barrier as a replacement.  Parts Express sells several types, depending on the thickness required?  You'll have to measure and cut it to fit.

Sonic Barrier

 

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  • 3 months later...
On 9/20/2019 at 3:15 PM, wsill said:

 

I added 1/2 closed cell foam around the upper midrange.

Has anyone else here made mods as I have and what's your experience with these and others?

The AR9's are just fantastic speakers.

Bill

 

20190917_162645.jpg

 

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I know this is an old post, but I wanted to add my results in response.

When restoring my 9s, I also wanted to fill the empty surrounds for the UMRs. Since I had ones around the tweeters, I matched the foam density and ordered a freakishly large piece on Amazon.

The foam was grey, but I had a plan. First, I trimmed its outer rectangle and trial fit. Then I searched around the house for a disc to use as a template for the driver’s outer surround. I ended up using the lid for the bean hopper on an espresso grinder. Then I shot it black with SEM dye.

I think they look great.

Since I have so much extra material, PM me if you’re interested in this.

 

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