Best tweeter Solution for AR3a

[dynaco_dan]

Hey, I just noticed that Madisound is closing out some "classic style" Vifa 3/4" domes.

http://www.madisound.com/catalog/product_i...roducts_id=1647.

These might be worth looking at as a replacement for the AR tweeters, especially since 3/4" domes are getting pretty rare. It's not going to be a drop fit, electrically or mechanically, but these guys have pretty good dispersion by contemporary standards, and would probably reward some crossover modification effort. The frequency region where their far-off-axis dispersion becomes a little rough is rather high, and so this is not likely to be a serious audible deficiency. Also, they are cheap!

Note: I used to be affiliated with Vifa, but haven't been for some time, and have no commercial interest at stake. Just happened to see the tweeters on sale. I do know that Vifa generally makes a well-engineered, consistent product.

-k

Hi Ken;

Thank you very much for the heads up, Ken.

Another alternative tweeter for the experimenter and those on a more limited budget as well, as long as they are available from them.

[dynaco_dan]

Hey Pete,

That one looks promising. Hi-Vi Research is producing excellent drivers for the price.

I've had some luck with another <$10 Hi Vi tweeter with a wide enough flange to fit without modification. It is 4 ohms with a relatively high fs as well, but has the larger, 1 inch dome. I used a parallel .06mh inductor, 1 ohm series resistor, and 3.3uf cap in place of the original 6uf cap.

Roy

Hi Roy;

Thank you for adding another reasonably priced alternative tweeter to the tweeter mod list

[RoyC]

Roy,

Was just looking at your picture and noticed the heavier gauge wire you used on both the mod and the tweeter. What gauge did you use? Was there a particular type/brand of wire? Most of all, how did you mate it with the original tiny wires?

As I get ready to rebuild mine, those wire are a real concern. They seem so fragile and they can't be very efficient.

oldguide,

The surface wire is 22 gauge stranded "hook-up" wire...nothing fancy. (I believe it was purchased from Radio Shack.) It just needs to be small and flexible enough to easily pass through the gap between the tweeter magnet and the cabinet hole. It connects the rear tweeter terminals and the internal wiring with the front cabinet tabs, to which it is soldered. The original tinsel wire from the old tweeter is not used at all.

If you need to extend the original (copper) tinsel wire of an old tweeter, a few strands of speaker wire twisted together can be soldered to it. The small gauge wire works just fine for the very short runs required to complete the connections. Efficiency is not an issue. (The hairlike wires going into the old tweeter domes are MUCH smaller than that!) It makes me smile to watch folks struggle with fancy mega-wire when restoring these old speakers. The original crossover wires were seldom larger than 20 ga. There is nothing to be gained with anything much thicker. When wiring AR crossovers, I use tinned wire (sold as "marine wire" today), just like the original stuff. It is very durable, resistant to corrosion, and very easy to work with.

Roy

[oldguide]

oldguide,

The surface wire is 22 gauge stranded "hook-up" wire...nothing fancy. (I believe it was purchased from Radio Shack.) It just needs to be small and flexible enough to easily pass through the gap between the tweeter magnet and the cabinet hole. It connects the rear tweeter terminals and the internal wiring with the front cabinet tabs, to which it is soldered. The original tinsel wire from the old tweeter is not used at all.

If you need to extend the original (copper) tinsel wire of an old tweeter, a few strands of speaker wire twisted together can be soldered to it. The small gauge wire works just fine for the very short runs required to complete the connections. Efficiency is not an issue. (The hairlike wires going into the old tweeter domes are MUCH smaller than that!) It makes me smile to watch folks struggle with fancy mega-wire when restoring these old speakers. The original crossover wires were seldom larger than 20 ga. There is nothing to be gained with anything much thicker. When wiring AR crossovers, I use tinned wire (sold as "marine wire" today), just like the original stuff. It is very durable, resistant to corrosion, and very easy to work with.

Roy

Thanks for the tips. That must be the AB Tech driver rather than the original. Those are great pictures showing how to set that up that should be in the restoration manual or at least with the chart. Nice job!

Since I just picked up some used tweeters, I guess I will end up soldering a larger wire to the "tinsel." Those things seem so fragile that if you breathe on them they'd break, but obviously they lasted this long and lasted my removing my old drivers. Has anyone ever contemplated redoing the old surface mount wiring hookup with something more robust such as a connector block or is this a restoration issue?

I decided early on with this job that I would try to stick with originals as much as possible, but where the originals could be replaced with something more robust I would do it. So I have cleaned the old pots (which weren't that bad) and kept them, but will upgrade the crossover with the restoration "book's" suggestions. I also will probably add some decent speaker jacks to replace the the posts and nuts on the back.

Along the same lines does it make sense to upgrade the wiring to the woofer while I am at it? The run is short enough I suppose it's not that big a deal and the wires look like 20 gauge.

[RoyC]

Thanks for the tips. That must be the AB Tech driver rather than the original. Those are great pictures showing how to set that up that should be in the restoration manual or at least with the chart. Nice job!

Since I just picked up some used tweeters, I guess I will end up soldering a larger wire to the "tinsel." Those things seem so fragile that if you breathe on them they'd break, but obviously they lasted this long and lasted my removing my old drivers. Has anyone ever contemplated redoing the old surface mount wiring hookup with something more robust such as a connector block or is this a restoration issue?

Along the same lines does it make sense to upgrade the wiring to the woofer while I am at it? The run is short enough I suppose it's not that big a deal and the wires look like 20 gauge.

Thanks oldguide...We're already considering some added photos and revisions to the restoration guide.

The tinsel lead is really not all that fragile. It connects to the tiny voice coil wire under the tape, and THAT is very fragile. It is also difficult to reconnect if it becomes separated from the tinsel wire.

I wouldn't replace the cabinet terminals (front or back) as they are seldom a problem, and it would diminish the speakers value if you intend to sell them someday. I would only replace the woofer wires if they become too short after removing the woofers, which is sometimes the case. Replacing the woofer wires, and terminals will not "improve" the sound unless there is a bad connection. The capacitors, and sometimes very corroded level controls, are typically the only internal components that will require replacement.

Roy

[oldguide]

Thanks oldguide...We're already considering some added photos and revisions to the restoration guide.

The tinsel lead is really not all that fragile. It connects to the tiny voice coil wire under the tape, and THAT is very fragile. It is also difficult to reconnect if it becomes separated from the tinsel wire.

I wouldn't replace the cabinet terminals (front or back) as they are seldom a problem, and it would diminish the speakers value if you intend to sell them someday. I would only replace the woofer wires if they become too short after removing the woofers, which is sometimes the case. Replacing the woofer wires, and terminals will not "improve" the sound unless there is a bad connection. The capacitors, and sometimes very corroded level controls, are typically the only internal components that will require replacement.

Roy

Thanks much!

Kind of thought that is what you would say.

Those tiny wires still worry me. When I unsoldered them I was able to actually unravel most of them from around the posts, but some broke before I could get them completely unwound, but not enough to not be able to make the connection again. The "book"--as I am starting to call it--has a nice illustration of how to repair a broken wire, but I still wonder if going up to just a little but heavier gauge using the same type of connector would be a better solution. The one thing that worries me about that is once you decide to cut and connect there is no going back, plus you would probably have to remove the black tape the holds it to the driver which would risk just what you warn against. Maybe the best thing is to follow the old advice, "if it ain't broke, don't fix it," which it sounds like you are advising. If the tiny wire breaks, then think about replacing it.

Take care and appreciate your help immensely. I am beginning to see how you folks really get into this.

One side comment to the old AR hands, As I started refinishing the cabinets I noticed the joints and the corners--not too shabby. The corners are not just mated but actual finger joints. Not only does that make the cabinet more solid but also more air tight. Makes me admire the people who built these even more. I doubt you would find any contemporary speaker, regardless of cost, with wood joints like that.

[oldguide]

Probably time to end this thread as it has become quite long. I will try to monitor the site and add to the chart as new ideas come up and post them in a new thread.

Thanks again to everyone who contributed to this. It helped me A LOT!

[Pete B]

I've searched but cannot find Ken's tweeter study, has it been removed or can

someone post the link?

[Carlspeak]

I've searched but cannot find Ken's tweeter study, has it been removed or can

someone post the link?

The link is here, but it doesn't seem to work any more. Guess you'll have to PM KK for his report. It's post #86.

http://www.classicspeakerpages.net/IP.Boar...=1649&st=80

[Pete B]

FWIW, I placed and order within the last few days at Madisound and spoke to

them about the Vifa DX19TD in Oldguide's chart. It is not going out of production

according to them, no problem getting more stock. I believe that it is now

part of the Peerless V-line product offering but still the same part. This tweeter

is not a 10 or 20 year old product, closer to 5.

http://www.madisound.com/catalog/product_i...roducts_id=1647

[Carlspeak]

FWIW, I placed and order within the last few days at Madisound and spoke to

them about the Vifa DX19TD in Oldguide's chart. It is not going out of production

according to them, no problem getting more stock. I believe that it is now

part of the Peerless V-line product offering but still the same part. This tweeter

is not a 10 or 20 year old product, closer to 5.

http://www.madisound.com/catalog/product_i...roducts_id=1647

It looks like it should play okay as a substitue with respect to its Fs and Re specs. However, a close look at it's power response plots shows it has pretty poor dispersion characteristics similar to 1 inch domes.

[Guest special rider]

Will the same tweeters fit and work in my AR11s?

[Pete B]

It looks like it should play okay as a substitue with respect to its Fs and Re specs. However, a close look at it's power response plots shows it has pretty poor dispersion characteristics similar to 1 inch domes.

Fs is way too low to be used without a crossover mod. This is probably an

excellent tweeter but it is not drop in IMO. Not sure how you come to that

conclusion about the off axis response, I would not agree.

[Carlspeak]

Pete. The AR-LST brochure shows off-axis response (OAR) curves for the 3/4 inch dome tweeter. They look better than the Madisound tweeter.

KK's ABT tweeter study also shows 30 and 60 deg. off axis curves based on his testing. He concluded the 'new' 3a tweeter has superior OAR. The ABT 3/4 inch tweeter was about the same as the 3a at 30 deg. off-axis and somewhat inferior at 60 deg (about 10 dB down). The Madisound tweeter is -7 dB at 30 deg and -10 to -15 dB down at 60 deg. The AR303 tweeter was significantly more directional.

Believe other off-axis curves can be found elsewhere here but got tired of looking. Maybe Tom Tyson could post some fresh ones from the AR archives???.....

The numbers clearly show a difference. However, will the average listener notice a problem with the Madisound tweeter? I suspect NOT.

[genek]

The numbers clearly show a difference. However, will the average listener notice a problem with the Madisound tweeter? I suspect NOT.

Well, they certainly won't notice if they don't have originals to compare them to. But there are other little "AR experiences" they may miss out on.

I remember the first time someone who had never heard a classic AR speaker heard mine. It was a 20-something coworker (it was the early 80's and I was just 30 myself at the time) who had just bought his first "good" stereo. He walked around my living room for a while with his eyes wide open and his mouth agape, then turned to me and said, "You have a stereo image *everywhere in the room.* That's not fair!"

I'd hate to have to give up those little triumphs.

[Pete B]

Pete. The AR-LST brochure shows off-axis response (OAR) curves for the 3/4 inch dome tweeter. They look better than the Madisound tweeter.

KK's ABT tweeter study also shows 30 and 60 deg. off axis curves based on his testing. He concluded the 'new' 3a tweeter has superior OAR. The ABT 3/4 inch tweeter was about the same as the 3a at 30 deg. off-axis and somewhat inferior at 60 deg (about 10 dB down). The Madisound tweeter is -7 dB at 30 deg and -10 to -15 dB down at 60 deg. The AR303 tweeter was significantly more directional.

Believe other off-axis curves can be found elsewhere here but got tired of looking. Maybe Tom Tyson could post some fresh ones from the AR archives???.....

The numbers clearly show a difference. However, will the average listener notice a problem with the Madisound tweeter? I suspect NOT.

Yes Carl, I'm aware of the wonderful off axis response of the AR-3a/LST tweeter,

but your statement compared the Vifa and 1" domes which I disagree with.

It is difficult to generalize so I'll bow out of this one.

[dynaco_dan]

FWIW, I placed and order within the last few days at Madisound and spoke to

them about the Vifa DX19TD in Oldguide's chart. It is not going out of production

according to them, no problem getting more stock. I believe that it is now

part of the Peerless V-line product offering but still the same part. This tweeter

is not a 10 or 20 year old product, closer to 5.

http://www.madisound.com/catalog/product_i...roducts_id=1647

Hi Pete;

I just wanted to make a comment on this particular tweeter only.

If I was faced, today, with the same decision of about 10 or so years ago, in deciding on a replacement set of 8 tweeters for my LST's.

I believe that today, I would now have bought these instead of the AB Tech replacement tweeters.

I did not have many options at all back then, with the 4 ohm rating in particular.

At 1/3 the price and with my hearing loss, I am certain that I would not know the difference, considering there was no functional tweeters to compare to at that time.

***Even in the case of the AB Tech replacements that I did end up with, at least that version, I do not know what the sound difference is compared with the old original 3/4" OEM tweeters.***

Now that I wrote that, I do have another top pair with the original drivers but at this point I do not want to be critical of them as they are, old and used with degrading foam.

Besides, the tweeter version made today may sound different again for a complete and true analysis.

In the case of AR-3A's, there may be a difference that might cause me to not accept them, I do not know.

At least there is an affordable replacement for the time being, thank you for the data link.

In the case of AR-3A's I would also replace both tweeters to match their output, without question.

Please continue to add to this topic, Pete, you offer us all a lot of insight, thank you very much.

I might get upset at one pair or the other, if I did not find them to my liking.

Comparisons lead me to updating for many years and lotsa dollars later.

[kkantor]

For what it is worth, here's an opinion:

As the field of suitable replacement tweeters gets thinner and thinner, it is becomes increasingly important to prioritize the aspects of datasheet performance which are going to have the most impact on sonics. Far-off-axis response, above 15 KHz, is not going to have as nearly as much effect on the sound of the system as other factors. Of course, if specs like sensitivity, impedance, frequency response and resonance characteristics are equivalent, there will be benefit to the widest possible dispersion over the top octave. (At least in terms of re-creating the original 3a flavor.) However, the results will be all the more satisfactory if one avoids sacrificing these important things in order to get the best 45-degree response at 20 KHz. Yes, 1" domes sound a little different than 3/4" domes. But remember, two tweeters with two different Fs's are also going to sound quite different when dropped into a given design.

-k

www.kenkantor.com

www.ztamplifiers.com

BTW- I just finished several hours of listening/measuring helping an engineer friend works bugs out of a DIY speaker design. His complaint was that the system was too "harsh, bright." His approach was to work on the tilt of the tweeter response, but that wasn't working, and he was stumped. What was it? A small rise in the region between 1.8 KHz and 4 KHz. IE- the "top octave" of sound is really quite sonically minor in the scheme of things. (My friend is <30, and has intact hearing, too....)

[soundminded]

For what it is worth, here's an opinion:

As the field of suitable replacement tweeters gets thinner and thinner, it is becomes increasingly important to prioritize the aspects of datasheet performance which are going to have the most impact on sonics. Far-off-axis response, above 15 KHz, is not going to have as nearly as much effect on the sound of the system as other factors. Of course, if specs like sensitivity, impedance, frequency response and resonance characteristics are equivalent, there will be benefit to the widest possible dispersion over the top octave. (At least in terms of re-creating the original 3a flavor.) However, the results will be all the more satisfactory if one avoids sacrificing these important things in order to get the best 45-degree response at 20 KHz. Yes, 1" domes sound a little different than 3/4" domes. But remember, two tweeters with two different Fs's are also going to sound quite different when dropped into a given design.

-k

www.kenkantor.com

www.ztamplifiers.com

BTW- I just finished several hours of listening/measuring helping an engineer friend works bugs out of a DIY speaker design. His complaint was that the system was too "harsh, bright." His approach was to work on the tilt of the tweeter response, but that wasn't working, and he was stumped. What was it? A small rise in the region between 1.8 KHz and 4 KHz. IE- the "top octave" of sound is really quite sonically minor in the scheme of things. (My friend is <30, and has intact hearing, too....)

It is also my experience that a rise of even one or two db in the region between 2 and 4 khz, especially at 4 khz compared to 2 khz will result in an unnaturally hard bright brittle sound which will eventually become very irritating. It is especially noticable on recordings of pianos and particularly violins. Solo violins will lose all of their sweet musical character and mass violins will sound unbearably hard and shrill. This may be a ear catcher to tyros shopping for speakers in a store but it is death valley to someone who wants an accurate reproducer of acoustic instruments. You can play with wires, phonograph cartridges, and tube amplifiers with hit and miss (usually miss) results but short of redesigning the speaker, an equalizer gives a quick and effective fix. That's a taboo in most audiophile's way of thinking. BTW, in my experience, a dip of a couple of db in this region creates a remote and indistinct sound lacking presence, almost as unacceptable as a rise. This is a very critical region of the audible frequency range and it may be the range in which human hearing is most sensitive.

FR in the top octave remains very important to me. My most recent hearing tests confirm that I have no loss of sensitivity out to the limit of the test I took, 10 khz. Even though the contribution of content of most music above 10 khz is a small percentage of the total sound, my experiments have convinced me that it still matters a great deal and there are a myriad of details about the way this sound arrives which alters the way the rest of the sound is perceived. For those who cannot hear above 10 khz for whatever reason, whether or not this content is present and in what form will not matter. BTW, tests done several decades ago on aboriginies in remote regions of Africa proved that men in their 70s who were not exposed to loud noises in their lives had sensitivity to the highest frequencies equal to that of teenagers. While some loss of hearing is due to injury, disease, genetics, it is not necessarily due to ageing and most of the time, I think it is the result of self inflicted injury or at the very least, indifference and failure to wear hearing protection when exposed to loud sounds in our noisy society. Exposure to very loud electronically amplified music is a particularly common cause. You can always buy more audio equipment but you have only one set of ears and so far, in almost all cases nobody knows how to restore them to their original condition once they are damaged.

[genek]

As the field of suitable replacement tweeters gets thinner and thinner

I was wondering if anyone has tried using the 3/4" dome tweeter from the AR-5/2ax in 3a's. I know the nominal impedance is different, but what else is? If the response and dispersion are comparable and the impedance is the primary difference, couldn't that be compensated for? These tweeters appear to be quite a bit more available used than 3a/LST tweeters, if my auction browsing is any indication.

[RoyC]

I was wondering if anyone has tried using the 3/4" dome tweeter from the AR-5/2ax in 3a's. I know the nominal impedance is different, but what else is? If the response and dispersion are comparable and the impedance is the primary difference, couldn't that be compensated for? These tweeters appear to be quite a bit more available used than 3a/LST tweeters, if my auction browsing is any indication.

Rated at 8 ohms (dcr at around 6 ohms), the 2ax/5/LST-2 version of the 3/4" dome tweeter is twice that of the 3a/LST tweeter. This of course requires a capacitor change to maintain the same crossover point, but a more significant issue is that it is not as sensitive. It therefore produces even less output in the 3a, where the more sensitive original tweeter is already pretty much maxed.

On the other hand, I have used 3a tweeters (with a slight increase in cap value) in AR-5 and 2ax systems with excellent results.

Roy

[onplane]

This of course requires a capacitor change to maintain the same crossover point, but a more significant issue is that it is not as sensitive. It therefore produces even less output in the 3a, where the more sensitive original tweeter is already pretty much maxed.

Roy

I agree with Roy here. I doubt there is any way to make the 8 ohm tweeter work in 3a, unless you bi-amp. Problem is the less sensitive tweeter would never be in balance with the woofer. With a bi-amp you could:

1. cut back on the mid-driver via the pot (in short balance the tweeter to the mid-driver)

2. ratchet up the volume control on the amp driving the mid/tweeter to bring both drivers in balance with the woofer.

Roy, I'm still thinking about doing this with the original 3a tweeter. That is, cutting back on the mid driver and increasing the volume on the mid/tweeter amp. My only fear is will the old tweeter:

1. put out more volume

2. handle the additional power

Roy, any thoughts?

Regards,

Jerry

[RoyC]

My only fear is will the old tweeter:

1. put out more volume

2. handle the additional power

Roy, any thoughts?

Regards,

Jerry

Hi Jerry...you biamping madman !

Your fear is probably justified based on my observations of the current condition of the old tweeters. The altered crossover point (due to the impedance difference between the 3a and 5 tweeters) would still be an issue as well.

Roy

[genek]

Bump

Anybody have any experience with this one?

http://www.tymphany.com/datasheet/printview.php?id=112

It's the first dome I've seen in ages where the dome isn't recessed all the way down into the flange. Wonder what it sounds like.

[Carlspeak]

Well, it's 4 ohm and that's about the only thing it's got going for it. The off axis response isn't much different that a conventional spherical dome tweeter and the flange OD is too small to fit the 3a tweeter flange hole. That Cadillac bumper phase plug could also be a source of problems.The price is a bit steep considering you can get a closeout 4 ohm AR dome weeter from Parts Express for about $12 http://www.partsexpress.com/pe/showdetl.cf...tnumber=279-280. Yes, the PE tweeter also has a smaller flange OD. The the cost savings should be an incentive to fabricate an adapter plate.

http://www.classicspeakerpages.net/IP.Boar...acement+tweeter