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4x power handling and sealer Q's


Guest tdeutsch

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Guest tdeutsch

The literature for the AR-4x says to power it with 15 watts minimum. At the moment, I have mine hooked to a Yamaha with 85 per. Should I avoid going more than halfway? How loud is too loud with these small but well-built speakers? (Mine are the earlier Ar-4x with no ribs on the woofer) Will I hear some muddiness or mild distortion before I damage the speaker? What are others using to push AR-4x's?

On a side note, I probably should re-seal the cloth surrounds. Layne's website says that he sells a superior ("stays flexible") butyl latex sealer while everyone else sells Elmers glue as sealer. Fine. Sold. Problem is (and this has been discussed here) nobody can get in touch with Layne. So, does anyone have any non-Elmer sealer to sell me or know where I should buy some? Also, should I seal the speaker cones themselves? Just the front, or front and back?

Thanks yet again!

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BEWARE RE-COATING CLOTH SURROUNDS!

Re-coating cloth surrounds is a process, which if done correctly, can produce the correct result. However, if an improper coating is applied, the driver will be rendered useless.

Recently, I measured the free resonance frequency (f sub s) of six AR-4x woofers; their values were: 32-, 32-, 37-, 37-, 58-, and 68-Hz, respectively. I believe the correct f sub s range is 32-to-37 Hz; Tom can correct if my memory is poor.

Close inspection of the last two drivers showed that the light yellow/tan cloth surround (from an AR-4 measuring 58-Hz) had simply hardened with age, whereas the other (a ribbed AR-4x measuring 68-Hz) had been re-coated with a layer of butyl rubber. The person who did the recoating applied a thick coat (likely) of undiluted butyl rubber. This increased f sub s from its design value of ~32 Hz to 68 Hz! Obviously this driver, if installed in a -4x would not have hte AR-specified f sub c!

At some point, I will experiment with suitable solvents to see if the offending material can be removed and re-applied properly. If it cannot be removed, the woofers are unsuitable for use.

IMO one should first test the woofer in-cabinet for air leaks. If there are no air leaks, then there is no reason to even *think* about applying anything! (unless the unit has an unacceptably high f sub s).

If the unit has a high f sub s, or has an air leak, then one must apply the correct sealer with great care.

Tom Tyson posted this information some time ago--in that post he described, I believe, a water-soluble coating along with instructions on its proper dilution. I have used Loctite Black Rubber Sealant diluted with a solvent such as hexane or lacquer thinner, but I cannot describe how thin--I just cut it until it appeared to have a viscosity similar to that of water. It worked, but Tom's material is likely superior.

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>The literature for the AR-4x says to power it with 15 watts

>minimum. At the moment, I have mine hooked to a Yamaha with 85

>per. Should I avoid going more than halfway? How loud is too

>loud with these small but well-built speakers? (Mine are the

>earlier Ar-4x with no ribs on the woofer) Will I hear some

>muddiness or mild distortion before I damage the speaker? What

>are others using to push AR-4x's?

>

>On a side note, I probably should re-seal the cloth surrounds.

>Layne's website says that he sells a superior ("stays

>flexible") butyl latex sealer while everyone else sells

>Elmers glue as sealer. Fine. Sold. Problem is (and this has

>been discussed here) nobody can get in touch with Layne. So,

>does anyone have any non-Elmer sealer to sell me or know where

>I should buy some? Also, should I seal the speaker cones

>themselves? Just the front, or front and back?

>

>Thanks yet again!

Hi Tom;

In and about the 1/2 way mark will usualy be sufficient with your set.

If you go to the AR library, download and printout the AR factory fusing sheets, and also the AR/Teledyne speaker manual.

Look at the fusing information for the AR-4x.

I believe it is a FNM 6/10 amp slow blow fuse.

Further on, it tells you the various times verus power, that can be anticipated back then, when new.

There is a probablity that you may just still burn out your tweeter and not blow the fuse.

This statement is with even 15 watts per channel amps.

In fact the lower the wattage of the amp, the more likely, with high volume, a driver un-fused will blow or burn out.

Do checkout crownaudio.com and read that information.

I had the opportiunity of servicing AR speakers many moons ago, and saw more that one charcoal voice coil.

The fuse will ever so slightly add an increased amp load, affect damping factor, probably even add a smidgen of distortion.

Well worth while adding a fuse, than worrying about these other miniscule issues.

It is like wearing an uncomfortable seatbelt.

At the present time the 6/10 amp fuse, is the lesser of the evil.

See the "other forum" regarding fast blow fuses from Nov/05.

This will give you more insight, knowledge and options as well.

I already wrote regarding the Armorall treatment.

Good luck, good questions.

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