AR91 rebuild project

[Pete427]

As a new member to this site and a proud AR90 owner which i have had since new i just bought a pair AR91 speakers cabinets and grills from a eBay seller which are like new to install the components i have had for some time.

The question I have is there a good reason why AR originally used hot melt glue and staples to mount the crossover boards to the cabinets backs. If repairs are required to the crossover board they are hard to take out and can be damage.

Is there a better method to reinstall the crossover boards to my AR91 cabinets so they can be remove easily if any work is required to be done in the future.

I was thinking to reinstall the crossover boards with wood screws and soft putty like material to seal them.

Any better suggestion?

Pete

[Joel]

When I did my AR90's, I did it in the box through the woofer holes. It was pretty tight, but manageable.

The AR9 was a lot easier to work with inside, and the bottom crossover is screwed in so It can be removed.

-Joel

[HarryM]

I did my 91's through the woofer hole. It wasn't that bad

[ar_pro]

The crossover construction was sort of indicative of the era, where very few manufacturers were concerned with appearance, or ease of service - especially 35 years down the road.

The hot glue & staples are a pain to remove without damaging the board, but it is possible if done carefully.

Have you considered constructing a replacement board, and attaching it as you've suggested?

[Pete427]

Thanks everyone for your response!

The AR91 speaker cabinets i bought have no crossover boards or speakers i will be using a nice pair of crossover boards i had bought with speakers over a year ago see images.

The question i am asking is it important to reinstall the crossover boards to the manufacturer specifications using hot melt glue and staples or is there a better method so they can be remove easily if future repairs are required.

Will wood screws and soft putty sealant or gasket do the job without disturbing any of the cabinets performance.

Pete

[ar_pro]

Since they're already out, I'd remove any remaining glue that's still inside the cabinets, and replace the cheap masonite boards with 1/2" plywood.

You could then do a clean, airtight, and permanent install using glue & screws that would be better than the original.

Is there a reason why you'd be interested in removing the crossover at some future date?

[Pete427]

Thank ar-pro for your input it is very much appreciated!

The reason i would like to be able to removing the crossover if required in the future is due to a bad experience i had with my AR90 when they were taken to so called reputable speaker repair company to have new foam surrounds replaced on 8" and 10" speakers which they did a good job but they also decided to put new caps on all crossover boards as to one of the speaker boxes lacking in the midrange. When the job was done they had made a mess of the crossover boards because of the confined working space they pulled the board out and made a mess putting them back. After the job was compete the technician then told me that the crossover boards wasn't the problem the speaker box had a upper midrange nearly gone which need repairing.

After that experience I have bought a nice pair of crossover boards to replace the damage boards. That is why i want the crossover boards to be removable on the AR90, but with the AR91 there seems to be a good deal of room to do any type of repairs if required so i will install nice set of original board have using melt glue and wood screws as you have suggested.

I will keep you informed as to how i go bringing the AR91 back to life

Kind Regards Pete

[michiganpat]

I'd probably clean off the hot glue, use some 1/16" or 1/8" foam tape like this

http://meniscusaudio.com/gasket-tape-100ft-p-844.html

and some 1/2"-5/8" long #8 or #10 pan head sheet metal screws, 14 per board (4 in the corners, 2 in between top and bottom, 3 in between on each side.

something like this

http://meniscusaudio.com/8x-12-ss-pb-screw-p-380.html

http://www.fastenal.com/web/products/detail.ex?sku=11135700

[Pete427]

Thank michiganpat for the information and site, your suggestion should be good way to go in resolving this issue of reinstall the crossover boards to the cabinets.

Kind Regards Pete

[JKent]

I'd probably clean off the hot glue, use some 1/16" or 1/8" foam tape like this http://meniscusaudio...00ft-p-844.html

and some 1/2"-5/8" long #8 or #10 pan head sheet metal screws, 14 per board (4 in the corners, 2 in between top and bottom, 3 in between on each side.

something like this

http://meniscusaudio...crew-p-380.html

http://www.fastenal....ex?sku=11135700

FWIW I'm with Pat. You could also use self-stick foam weatherstripping or double-sided foam tape. The idea is to get an air-tight and rattle-free seal. I would not fabricate new boards--after all, you went to the trouble of purchasing original AR 91 boards, with all the appropriate lettering on them. Why change? I'd keep them as original as possible.

Do those boards have capacitors on them? I would suggest testing them (at least). And if there are any of those black PVC caps with red ends (as mine had) definitely replace those.

Kent

[Glenn E]

I'd go with Pat's idea but maybe use some appropriately sized wooden strips along the edges and screw down through these. You will save on some screws this way and still get a nice seal.

Glenn