Carlspeak Posted February 27, 2007 Report Share Posted February 27, 2007 At the suggestion of a post reader, I've created this brand new post to satisfy a curiosity I have regarding what settings AR3a owners typically have their speakers at.I got a couple of responses at the end (pg. 5) of the topic "AR3a potentiometers - factory setting vs bypassing". But then it got buried in obscurity and thus, this more dedicated post is intended to try and get more responses.Let's hear it from more readers! Where are your pots at?1) full increase?2) something different from full incr. (describe as best you can)?It's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
onplane Posted February 27, 2007 Report Share Posted February 27, 2007 >>Let's hear it from more readers! Where are your pots at?>1) full increase?>2) something different from full incr. (describe as best you>can)?>>>It's all about the music>>Carl>Carl's Custom LoudspeakersHi, Carl!! Your survey is a really good idea!! I'd also like to know where people have those old pots set.On my 3a's the tweeter is totally by-passed (which yields almost 1db MORE than the pot at FULL).On the mid-pot I have the driver lead soldered to the top of the pot. This is exactly the same as MAX increase 40 years ago. That is, back when there was zero corrosion on the pot contacts.Regards,JerryPS: At one time I tried by-passing the mid-pot. Subsequently, I realized that by-passing the mid-pot effectively "gave back" that 1db on the tweeter, and I really like that little tweeter boost! Further, with my hearing any boost in the high end is most appreciated. Link to comment Share on other sites More sharing options...
Steve F Posted February 27, 2007 Report Share Posted February 27, 2007 Tweeter--'Max'Midrange--halfway between 'Norm' and 'Max'To my ears, this presents a very listenable and enjoyable tonal balance, and minimizes the slightly "woody" midrange coloration that characterizes the 3a.Steve F. Link to comment Share on other sites More sharing options...
joelongwood Posted February 27, 2007 Report Share Posted February 27, 2007 The pots on my 3a's are set as follows: Tweeter on full, and mid almost at full. My 2a's and 5's are also set with the tweeter at full increase but with the midrange set between the dot and full. The High Fidelity magazine review of the AR5's in 1969 found the flattest response in their listening room was achieved by setting both the tweeter and midrange pots at full. They found that the full midrange setting eliminated an audible depression at 2000 hz. My listening room is a bit live.At Jerry's suggestion, I passively bi-amped my AR3s.....completely bypassing the tweeter pot, and soldering the midrange to the top of the pot. I really like the result, but I'm happy with my functional AR's the way they are.I also have a pre-1970 pair of 2ax's whose pots are shot. I jumped the wires across the pot and find the midrange is too forward for my taste. The tweeter level, however, is just fine. I may bi-amp or clean the pots on those. Link to comment Share on other sites More sharing options...
RoyC Posted February 28, 2007 Report Share Posted February 28, 2007 Carl,Tweeters a hair less than full "increase", and mids on the "increase" side the of the dot.Things change considerably when using the AB Tech "replacement" tweeter.Roy Link to comment Share on other sites More sharing options...
onplane Posted February 28, 2007 Report Share Posted February 28, 2007 >Carl,>>Things change considerably when using the AB Tech>"replacement" tweeter.>>Roy>Hi, Roy!!You mentioned this before. Do you have the same tweeters that Frank complained about? As I recall, Frank was upset over the excessive mid-frequencies put out by that tweeter.(Naturally, this is compounded in the Frank's LST's by the fact that there are 4 tweeters per box!)Roy, are you still using the 6 mfd cap?Regards,Jerry Link to comment Share on other sites More sharing options...
Guest matty g Posted February 28, 2007 Report Share Posted February 28, 2007 >Let's hear it from more readers! Where are your pots at?>1) full increase?>2) something different from full incr. (describe as best you>can)?>>>It's all about the music>>Carl>Carl's Custom LoudspeakersCarl - Tweeter at maximum, midrange just above normal. Same for my 2a's and 5's.Matt Link to comment Share on other sites More sharing options...
dynaco_dan Posted February 28, 2007 Report Share Posted February 28, 2007 >>>Let's hear it from more readers! Where are your pots at?>>1) full increase?>>2) something different from full incr. (describe as best>you>>can)?>>It's all about the music>>Carl>>Carl's Custom Loudspeakers>>Carl -Tweeter at maximum, midrange just a hair below maximum for my AR-3A's.Same setting since they were new in '69 - '70, except for a few turns to clear up the volume level. Link to comment Share on other sites More sharing options...
RoyC Posted February 28, 2007 Report Share Posted February 28, 2007 >Do you have the same tweeters that>Frank complained about? As I recall, Frank was upset over the>excessive mid-frequencies put out by that tweeter.Hi Jerry, These are the same tweeters. The only similarity between the AB Tech tweeter and the old tweeter are the physical dimensions.>Roy, are you still using the 6 mfd cap?No, it was no longer an AR-3a with that arrangement. I am now trying it with the AR-3a Limited tweeter crossover which is a 4uf cap and a .16mh parallel coil. John O'Hanlon and I are also experimenting with further crossover modifications related to the level controls, which, incidentally, are very much needed with this tweeter. We are awaiting Ken Kantor's assessment of this as well as the other tweeters I sent him before proceeding much further. We are on opposite coasts, so they are not due in CA until this weekend.We will post results in the future.Roy Link to comment Share on other sites More sharing options...
Guest groved Posted February 28, 2007 Report Share Posted February 28, 2007 Great idea!All four of my AR-3a's are set as follows:Tweeters- set to max.Mids- half way between "normal" and max.Three of four AR-5's are set at:Tweeters- set to max.Mids- half way between "normal" and max.The fourth AR-5:Tweeter- set to max.Mid- set to max.(this mid needs the boost, as it's a little "dim"!)All units have stock drivers.Also, there is some variation in all of the above tweeter/midrange outputs (when bench tested out of the speaker with no crossover, using a signal generator).I've mixed and matched all of them to create the "best pairs" (of course I did not mix 3a and 5 units!) Regards, Doug Link to comment Share on other sites More sharing options...
Carlspeak Posted March 1, 2007 Author Report Share Posted March 1, 2007 >>Carl - >Tweeter at maximum, midrange just above normal. Same for my>2a's and 5's.>>MattThanks to all who have responded so far. There appears to be a trend developing (i.e. tweeter pots are generally set to max and the mid is somewhere between the dot and max).I made an interesting discovery today that may quantitatively support those settings. I was doing a 1/3 octave warble tone test curve on my "control" AR3a speaker as part of a project to develop a 3a upgrade using new mid, tweeter and crossovers. Note that the control speaker has all original components.With both pots set at full increase, I found a hump in the midrange response. I backed off on the midrange setting a bit and the hump flattened out. It would appear that what I did to flatten my response curve is akin to what most of you have been doing intuitively to get the sound to your satisfaction. Attached is a graph of my results.It's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
onplane Posted March 1, 2007 Report Share Posted March 1, 2007 Carl, this is very interesting!! What you see as a "humb", I see an an opportunity! Any chance we could get you to run one more plot with:mid pot at: MAXtweeter pot: Totally by-passedI'm curious as to whether the tweeter can catch up with the mid-driver. Even with your mid-pot at 45 degrees, it looks at though the tweeter could use a few more db.One last question, Carl, what is the condition of your pots? I mean, are they in decent shape from a corrosion standpoint?Regards,Jerry Link to comment Share on other sites More sharing options...
Carlspeak Posted March 1, 2007 Author Report Share Posted March 1, 2007 >Carl, this is very interesting!! >>What you see as a "humb", I see an an opportunity! >Any chance we could get you to run one more plot with:>>mid pot at: MAX>tweeter pot: Totally by-passed>>>I'm curious as to whether the tweeter can catch up with the>mid-driver. Even with your mid-pot at 45 degrees, it looks at>though the tweeter could use a few more db.>>One last question, Carl, what is the condition of your pots? >I mean, are they in decent shape from a corrosion standpoint?>>Regards,>JerryI'd like to follow up on your suggestion Jerry because I'm curious myself. However, my 3a upgrade project is long overdue. It will take some time to open up the control speaker and do the bypass, etc. Besides, now that I've started comparison testing, I don't want to disturb anything with the control speaker mid-way thru data gathering.I will tell you this though. I calculated the average dB value over the 'humped' range and got 84.7 dB for the midrange max pot position and got 80.4 for the backed off position that flattened the response. I doubt bypassing the pot will make up that 4.3 dB difference since max increase is very close to 0 ohms resistance across the pot contact to mid-post.The pots are in reasonably good shape. I made sure of that when I reassembled the control speaker so I would be confident it was in good working order for comparison testing with my upgraded unit. BTW, that 45 deg. value is what I estimated I backed off the knob pointer to.It's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
Carlspeak Posted March 1, 2007 Author Report Share Posted March 1, 2007 >Carl, this is very interesting!! >>What you see as a "humb", I see an an opportunity! >Any chance we could get you to run one more plot with:>>mid pot at: MAX>tweeter pot: Totally by-passed>>>I'm curious as to whether the tweeter can catch up with the>mid-driver. Even with your mid-pot at 45 degrees, it looks at>though the tweeter could use a few more db.>>One last question, Carl, what is the condition of your pots? >I mean, are they in decent shape from a corrosion standpoint?>>Regards,>JerryAlso forgot to add in post #12:If you are even able to raise the tweeter's output to match the midrange, you'll then have both drivers at a significantly higher output level than the woofer. Probably not a good idea considering the outstanding bass AR3a woofer's have.It's all about the musicCarlCarl's Custom Loudspeakers;( Link to comment Share on other sites More sharing options...
RoyC Posted March 1, 2007 Report Share Posted March 1, 2007 >If you are even able to raise the tweeter's output to match>the midrange, you'll then have both drivers at a significantly>higher output level than the woofer. Probably not a good idea>considering the outstanding bass AR3a woofer's have.That is an excellent point, Carl. It could compromise, at the very least, the original "warm" character of these speakers. Roy Link to comment Share on other sites More sharing options...
onplane Posted March 1, 2007 Report Share Posted March 1, 2007 >>Also forgot to add in post #12:>>If you are even able to raise the tweeter's output to match>the midrange, you'll then have both drivers at a significantly>higher output level than the woofer. Probably not a good idea>considering the outstanding bass AR3a woofer's have.>>It's all about the music>>Carl>Carl's Custom Loudspeakers;( Carl, I totally agree with your observation, but NOT your conclusion. Look, regardless of what we do, your plot shows we are down 10db at 100Hz. There is simply NO way we should "pad" the mid and tweeter to compensate for this 10db. After all, the AR-3a's are already one of the most inefficient speakers.IMHO, the solution is to bi-amp and "prop-up" the low end with amplifier power. I mean, amps are soooo cheap, especially mid-power amps. All we need for the mid/tweeter amp is 20 to 35 watts per channel and we let our main amp "Wrestle With the Woofers". (alliteration intended! )Regards,Jerry Link to comment Share on other sites More sharing options...
Guest Bret Posted March 1, 2007 Report Share Posted March 1, 2007 >Look, regardless of what we do, your plot shows we are down 10db at 100Hz. There is simply NO way we should "pad" the mid and tweeter to compensate for this 10db. After all, the AR-3a's are already one of the most inefficient speakers.<The plot is suspect. Down 10db at 100Hz simply does not agree with anything I've either experienced, or ever read, or ever seen, about an AR 12" woofer and it flies in the face of common-sense and experience. This looks closer to the graph I'd expect from a Tonegen replacement driver installed in a 3a.In order for Carl's plot to look like this I can only GUESS that either the 3a was re-surrounded with a non-compliance foam edge, was re-surrounded out of "0" height-wise, has a replacement driver in it, or is in some other way badly impaired.The resonance of a properly functioning 3a is somewhere around 40Hz. BUT, as we discovered years ago goofing around with Tonegens, if you change the Fs of the driver by 5-10Hz upward (later drivers, poor rebuilding, etc) you increase the Fc of the system dramatically. The two things (cabinet volume and woofer Fs) combine to make the problem really bad and easily audible.So the whole idea that we're going to adjust anything to match this obviously problematic speaker-system is probably a very, very bad idea.IF the plot itself is accurate, adding another amplifier won't fix this speaker.Bret Link to comment Share on other sites More sharing options...
RoyC Posted March 1, 2007 Report Share Posted March 1, 2007 >Look, regardless of what we do, your plot shows we are down>10db at 100Hz. There is simply NO way we should>"pad" the mid and tweeter to compensate for this>10db. Jerry,Huh? If that really was the case, it would be all the more reason to pad the other drivers. >IMHO, the solution is to bi-amp and "prop-up" the>low end with amplifier power. I mean, amps are soooo cheap,>especially mid-power amps. Please do not turn this into another "bi-amping solves all problems thread". Let us discuss just the speakers for a change!Roy Link to comment Share on other sites More sharing options...
ar_pro Posted March 1, 2007 Report Share Posted March 1, 2007 Hear, hear!After countless posts on the subject, most of us should, by now, have a pretty good understanding of what Jerry's so-called bi-amp configuration is all about. Enough, already.Bret is correct - something's not right with that woofer. Link to comment Share on other sites More sharing options...
Guest crawlspace Posted March 1, 2007 Report Share Posted March 1, 2007 I have been visiting this site only since December when I bought a used pair of 3a's and had no clue what I had. Although I read many posts and enjoy them, my technical knowledge is about 1/100th of what is generally discussed here. So, my pots are where they are just to work. I had to turn them back and forth for a long time when I brought the speakers home to get them working. The mids appear to be about 3/4 and the highs near full. However, I have a question. One of the tweeters recently stopped alltogether and I can't get it working. Since I now know that caps should be replaced, mid pots cleaned out, and maybe have tweeter pots bypassed, does anyone know of anyone in southern New Jersey area who would know what I was talking about if I mentioned these changes? I see a gentleman named Carl has a business up north but I don't like the idea of sending them through the mail system. Lastly, I can really notice that one of the tweeters is out when I stand in front of the speaker. From a distance, though, it is not too evident.Thanks Mike Link to comment Share on other sites More sharing options...
RoyC Posted March 2, 2007 Report Share Posted March 2, 2007 Mike,It is likely that the corrosion finally got the best of that tweeter pot.I have restored many 3a's and would be glad to walk you through the troubleshooting and repair process. I also have a variety of 3a parts, including refurbished pots.You can send an email through the forum if you think I can be of assistance.Roy Link to comment Share on other sites More sharing options...
dynaco_dan Posted March 2, 2007 Report Share Posted March 2, 2007 Hi Mike;The AR-3A is a wonderful speaker even without the tweeter working. Link to comment Share on other sites More sharing options...
Carlspeak Posted March 2, 2007 Author Report Share Posted March 2, 2007 >>Look, regardless of what we do, your plot shows we are>down 10db at 100Hz. There is simply NO way we should>"pad" the mid and tweeter to compensate for this>10db. After all, the AR-3a's are already one of the most>inefficient speakers.>>The plot is suspect. Down 10db at 100Hz simply does not agree>with anything I've either experienced, or ever read, or ever>seen, about an AR 12" woofer and it flies in the face of>common-sense and experience. This looks closer to the graph>I'd expect from a Tonegen replacement driver installed in a>3a.>>In order for Carl's plot to look like this I can only GUESS>that either the 3a was re-surrounded with a non-compliance>foam edge, was re-surrounded out of "0" height-wise,>has a replacement driver in it, or is in some other way badly>impaired.>>The resonance of a properly functioning 3a is somewhere around>40Hz. BUT, as we discovered years ago goofing around with>Tonegens, if you change the Fs of the driver by 5-10Hz upward>(later drivers, poor rebuilding, etc) you increase the Fc of>the system dramatically. The two things (cabinet volume and>woofer Fs) combine to make the problem really bad and easily>audible.>>So the whole idea that we're going to adjust anything to match>this obviously problematic speaker-system is probably a very,>very bad idea.>>IF the plot itself is accurate, adding another amplifier won't>fix this speaker.>>BretYour suspicion regarding refoaming is indeed true. However, post refoam tests confirm it is basically the same as original.Fs = 16 hzSens = 88 dBRe = 3.34 ohmsBox Fc = 40 hz.Everything seems normal. Remember, however, the pot settings are HIGHER than normal which may explain the 10 dB difference with the woofer.It's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
onplane Posted March 2, 2007 Report Share Posted March 2, 2007 >>However, I have a question. One of the tweeters recently>stopped alltogether and I can't get it working. >>Lastly, I can really notice that one of the tweeters is out>when I stand in front of the speaker. From a distance,>though, it is not too evident.>>Thanks Mike> Mike, there is a very good chance your tweeter is working just fine. There is a thread called toilet paper tweeter test. Read that thread, get a mono source and some music with lots of high frequencies (like a jazz trio where the drummer is using his cymbals a lot).Then do the toilet paper test on both speakers. If you hear sound in both, then the tweeters are working. If one is much louder than the other, your problem is:1. corrosion in the tweeter pot (highly likely)2. cap that has drifted in value and needs to be replacedRegards,Jerry Link to comment Share on other sites More sharing options...
onplane Posted March 2, 2007 Report Share Posted March 2, 2007 >Everything seems normal. Remember, however, the pot settings>are HIGHER than normal which may explain the 10 dB difference>with the woofer.>>>It's all about the music>>Carl>Carl's Custom LoudspeakersHi, Carl!Just a quick question. When you measured the frequency response was this at 1 meter with a 1 watt (2.83 volts rms) input to the speaker?Regards,Jerry Link to comment Share on other sites More sharing options...
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