Help: New ADS L620's are Muddy

Received these via Pony Express off of Craigslist and after reading all the glowing reviews about ADS speakers, was really looking forward to giving these a spin.

What a disappointment.

What I've got on my hands are none of the shimmering highs and punchy bass that I've read about. Instead, I'm mired in mud, mud and more mud. No note separation and a very flat sonic experience. At first I chalked it up to "this must be what ADS speakers sound like" but there's no way ANYONE would think these sound good.

Now, as a bit of background, these speakers sat unused in a closet in a climate controlled for 15 years. Do vintage speakers need to "open up" after sitting unused for any length of time? I've read that some people think they've experienced this, but is there really anything to it?

I did a search and read that it may be cone sag (guess that happens to the best of us once we reach a certain age, eh?) so I tried listening to them upside down and had the same, flat boring experience.

The drivers seem to be tight to the cabinets, the cabinets are solid though one has a slight side seam separation on the bottom. That said, both of the speakers are exhibiting the same characteristics.

I may try to shoot some video switching between my JBL's, Wharfedales and these to see if I can provide some context for what I'm describing, until then, any and all help is appreciated.

Are the tweeters working? I ask because many of the classic ADS speakers had fuse-protected tweeters. The tweeter fuses are in a small compartment in the back of the speakers. Some models even included extra fuses in that same compartment. Check and see if those fuses are blown. If it's not that, I don't know what it is.... I have a pair of L620's and they are excellent speakers. Mine also have that same tweeter/fuse arrangement.

sounds like they are not.
bad fuses, Tweeters, or (least likely but still formally possible) crossover capacitors (or maybe even a wire off one or both speakers' tweeters inside?).

They'd never be described as "muddy" in good working order.

never, ever...

John

Those are fantastic speakers, so like others have said, something is amiss. Check the fuses and make sure the tweeters aren't blown.

Before my original post I knocked the bass and mids all the way down and the treble all the way up to test the tweeters and thought I heard sound coming from them, along with the woofers.

After the response questioning the tweeters was posted, I tried again, this time the speakers were upside down as part of my "cone sag" test and there didn't seem to be anything coming from the tweeter, only the woofer.

I checked both fuses and they seem okay but I'll get some replacements today to see if that helps.

Here's to hoping that's all it is....

Anytime I get some older speakers, I open 'em up and take a look inside just to see how things are. You never really know what's been done to the speaker before you got them. This is where a DMM or even a LCR meter come in handy.

If yours are the newer model with metal grills, each speaker came from the factory with two fuses. One in series with the tweeter and one spare in a dummy slot. If yours only have one then someone must have already been in there.

Make sure the fuses are in the correct slots. While you're at it, make sure it's the correct size. I believe they should be 1.25A or 1.5A.

Mine are the cloth grills with only the one fuse as far as I can see.

So, I pulled the fuses, they looked okay but I grabbed a couple replacements just as part of the process of elimination; alas still nothing from the tweets.

Then I noticed the fuses I pulled originally (and found replacements for) were 10A 250V 312. The back of the speakers clearly states "1.6A Max AGC 3AG"...

Have to confess that I'm pretty ignorant about the compatibility of fuses at this point. Is this good news because I can replace them with the correct size and it should work or bad news that since the fuse was the wrong size it may not have blown if needed and fried the tweeter?

a 10 amp fuse could permit a fatal overload to the tweeter.
Here's what I'd do (but please use your own judgement and gauge your own comfort level before proceeding!)... I'd remove one tweeter from one speaker and carefully feed it a very low volume low-level signal (sans) crossover from a radio, discman, or amplifier/receiver (start at zero volume and slowly turn up just a tiny bit). If you hear the signal, the tweeter is at least functional; if not, it's probably toast. The other way to check the tweeters, if you have a DMM (digital multimeter), VOM (volt-ohm meter) or VTVM (vacuum tube voltmeter) is to check for continuity of the voice coil with the "ohms" or "resistance" setting on the meter. You should see a DC resistance of a few ohms; if the resistance reading is "infinite", the voice coil is open.

HTH.

You will find GLOWING reviews on just about any piece of gear you care to mention. Folks make a $5 garage score and they think they have struck gold. So, your disappointment is not surprising.

I've found most ADS to be exactly as you described. The woofer simply does not have the motor for an acoustic suspension and you need loads of power to overcome the internal pressure. Ask AR owners. The tweeter is treated cloth and if you are lucky, it is not coated in hair or other muffling fibers. I've seen them coated in animal hair so much so they look like tennis balls.

Did you try ye' olde toilet paper tube test for the tweeters? It's as simple as put one end of the tube up to your ear, and the other end in front of the tweeter playing at low volume. The tube makes the sound coming into your ear extremely directional, so what you point it at is what you hear.

Taylor Playe said:

Then I noticed the fuses I pulled originally (and found replacements for) were 10A 250V 312. The back of the speakers clearly states "1.6A Max AGC 3AG"...

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I think you may have discovered why the speakers sat in a closet for 15 years. At a guess, I'd say that a previous owner upped the amp rating on the fuses because the correct fuse kept blowing (because the amplifier was overloading them). Then the fuses held up just fine but the tweeters got cooked.

The correct amp rating for the fuses is set at a level where there is enough current for optimum performance but the fuses will blow at a level approaching the point at which damage is likely. What the person who replaced those fuses did was to increase the maximum current allowed to reach the speakers by a factor of six. Nuts! It's like the old homeowner's "trick" of using a penny to "fix" a blown fuse.

The L620s are very much worth fixing. If you find that you need to replace the tweeters you're sort of in luck because the L620 used perhaps the most commonly used tweeter in the ADS line, the #206-0100. There is a supercession to part #206-0116, a "ferro-fluid" cooled equivalent so finding them (you know where) won't be too difficult.

The first thing to do would be to pull the tweeters and check them with a digital multimeter. They're 4 ohm tweeters so your reading should be around that.

John

SoCal Sam said:

You will find GLOWING reviews on just about any piece of gear you care to mention. Folks make a $5 garage score and they think they have struck gold.

Click to expand...

You'll also find reviews or opinions on the interwebs trashing some of the very best gear ever made. Opinions........... Like another body part, everybody's got one.

I think the OP deserves to find out what he's got without too much concern for the opinions of others. Clearly, with 2 dead tweeters, the speakers aren't performing at their best so at the moment there's more "there" there. If, after repairing them, the OP doesn't like what he's hearing he can always sell them to some "idiot" who believes what he reads on the net.

John

All,

Thanks for the valuable input, it's all appreciated. I will definitely keep you posted...

While there are varying personal opinions on everything, the widespread positive reviews, and test results showing flat response, makes it very unlikely that the ADS speakers are completely missing treble. That doesn't mean everyone will like their sound, but it suggests that a complete lack of treble is due to a malfunction.

I use a pair of L500s in my living room. I've tried a number of different speakers, include Paradigm Studio 20's, and find the L500's clearer.

620's rock

I had a pair that I sold last year. Owned them 2 years, cabs a little beat but drivers in good shape and working properly. I never really heard of A/D/S speakers before reading about them here. Well I got the 620's for chicken feed, took em home, fed em some watts and I was like "Wow"! They sounded great, not muddy or lacking highs at all. Bass was deep enough and had good punch. I only sold them (at a profit) because I had too many bigger pairs of speakers sitting around and not enough room.

If yours sound muddy there's something wrong with them.

Hey Taylor, just a thought. Are the cabs sealed properly? Along with non-working tweeters, air leaks can really hamper the performance of woofers.

RickeyM said:

Hey Taylor, just a thought. Are the cabs sealed properly? Along with non-working tweeters, air leaks can really hamper the performance of woofers.

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Exactly. Always a good thing to check but leaky cabinets will diminish the bass, not kill the highs, I'm pretty sure the OP has dead tweeters or bad caps. "Muddy's" a pretty good description of a speaker with non-functioning tweeters.

John