Aadams

Tom Tyson Thanks. I can work with this too. I actually thought there must be blending. I don't have time tonight but I will make a new chart showing a 3db and 6db down tracing. It seems logical turning the pot down any degree from max has to proportionally diminish output of all frequencies handled by driver so the graph line should be pretty much the same slope and linearity. Should it not? It seems almost impossible that I could be totally incorrect on this. Aadams

The thread is still creeping but that is ok because it is near the end. SteveF, my eyes were damp after reading your closing remarks. Speaking of the 3a as you did, reminded me of the great warrior Achilles who, with his classic look, could do extraordinary things but was terrible at picking the right shoes. I spent this afternoon listening only to my 3as. In my experience, there is still no speaker better at presenting a large-scale string recording. My 9s have more bass and the sound chiseled but they don’t ever provide a “you are there” experience as the 3s sometimes do. Maybe that is why Roy Allison was so interested in the sound of Chicago Symphony Hall. That takes care of the 70s and 80s. Adams

Thread creep alert This thread IS NOT about how good or bad the AR12” woofer is at producing voice or mid-range frequencies, though apparently it is quite good in comparison to other similar woofers. This thread IS about how evidence shows, with each new generation of speakers, AR sought to increasingly diminish the role of the 12” woofer in the critical range between 80hz and 1000hz when used in their premier products. Some of the reasons for crossover choices are known but one thing verifiable today, beginning in 1979 the “AR Sound” that is today still seen as a measurement standard, is the sound of the 4 ways, in which the woofer was used for its best purpose and the critical mid- range was left to smaller drivers. AR3 - 1000hz AR3a - 575hz AR10Pi, 11 - 525hz AR98 - 200hz AR9, ls, lsi, - 200hz Adams

3 posts prior. LST is cited as not having this problem but the LST also had a completely different approach to achieving "spectral balance". I have never heard an 11 or a 10pi and not seen a graph for either and don't know if that same notch at 575hz is present. I also stated in the previous post that the problem could be solved with a 1/3 octave equalizer. IMO neither the world's most powerful tweeter nor a simple treble control adjustment around 5khz will restore the missing harmonics and overtones, between 600 and 1600hz, so you can clearly hear what Ellen Foley is singing, which is the origin of this thread. Good to see you back. Adams Addendum: I found this in archives: A letter from Allison to Hoffman, 1970. Items D and E give insight into the thinking of the creator about the objective of the 3a design-----------Clearly, not drum demos in club sized rooms. There are no response curves for the ADD designs to be found.

Agree . Voice is the only sound most untrained ears can blindly discern with good discrimination IMO. IMO, the tweeter issue is unrelated to the woofer output at 500hz and was just an easy target. Also, probably the the only way to make a 2ax outperform a 3a is by focusing on a specific type of human voice and ignoring all of the other superior aspects of the 3a that are happening simultaneously. Ultimately, with the emergence of high power amps and fascination with loudness, even a perfected 3a would not be competitive. Today, if I felt it were important enough, I would use a $300 31 band equalizer to eliminate the issue it but in the 1970s an Altec Acoustavoicette was around $700. And, who sells a pair of speakers one moment and in the next asks "what about that equalizer?" Adams

The modified chart below is what I see based on the clarification above and the tendency of owners to keep the 3a mid output at around the attenuator mid point. Maybe the 10Pi addressed this. I know the LST did.

Thanks. There is a thread here asking 3a owners where they set their mid and tweeter controls. I think the vast majority said tweeter max and mid at the mid point. I was the same. This tells me the relative lower sensitivity of the mid is not a problem so much as the inability to contour the specific output in the voice band which leads to equalizers or complexities that many don't want to deal with. Its also ironic that, at the time in their lives when they worry most about about tweeter roll off, most geezers can't hear above 10khz, frequently less. The topic is still AR woofers and crossovers but borders on mods and tweaks. BTW all of my 12" 3 way ARs are 12" off the floor and about 1 ft from rear walls. Regarding your statement above Does this imply that if I were to place AR58s or 11s ( for instance) back to back, in AR9 fashion, on the floor and limit their output to 200hz, I could achieve AR 9 level bass to 32hz that could also be easily managed? Assume the tweeters and mids have been cannibalized. Adams

Tysontom In retrospect, the above comment sounds perhaps terse and dismissive. It was not meant that way. That equalizer influences the sound of all my systems and it is simply not worth the effort to live with the ripple it will create for me to attempt resolving this tiny bit of difference. I am fortunate that someone with your deep knowledge of AR, and speakers in general, is around and willing to talk about this. There are many that hole up and don't bother. Apology offered. The topic is still AR woofers and crossovers. Re the 3a. I spent a lot of time listening to a wide variety vocals yesterday. Without a reference, it is difficult to find fault in how the 3a presents voice but in relation to more recent vintage speakers that have smaller drivers covering the voice range, my 3a seems to add a slight warmth or heaviness in the tenor and low alto voices. The difference is most noticeable with female voice. The arcane 20 seconds of which I spoke earlier is a low alto female voice. I am still surprised at the superior presentation by the 3a of string ensembles and live recordings. I no longer shop for new speakers but I would be surprised to hear anything new that can top an AR3a in those areas. I don’t think this is true with voice, now that I am beginning be more attentive to musical lyrics. Most people today, who listen to music, listen to music with lyrics and that is why I suspect AR changed the sound of their systems in such a telling way, beginning with the AR9. Edit: I think the difference could probably be equalized out,with a 1/3 octave equalizer, to be practically imperceptible but back then that wasn't a cost effective idea. Adams

I should give credit to a recent discussion in the AR forum for providing impetus to achieve this version of the system. Had I not looked more deeply into the capabilities of DSP regulated amps as a result of that discussion, I believe this system would still have its previous klugey, less resolving, form. So, hats off to the CSP! Adams

The point in question is not important to me and I did say it was arcane. I have absolutely zero dispute with anything you have said and have complete confidence it is accurate. Have you listened to the piece of music in question? The final 20 seconds is all this is about? Regarding mid-range fidelity: I can verify you are correct. The mid range driver can be heard to reproduce the lyrics with unquestionable clarity if your ear is very close to the driver. Same for the woofer, as I said before. And you appear to agree with me the apparent improved vocal clarity of the AR9 is because the voice range is contained almost entirely in the 8” driver. My point was merely that the AR3a ultimately is not as good at presenting vocals in my living room at 12-15ft as my AR9s and by extension any of the other 4 way ARs which are very similar. Whether the cause is diffraction or splitting the instrument in the crossover and creating difference in timing or phase, related to driver location, I do not know but somebody at AR decided the difference was sufficiently great that in 1979 all top of the line systems became 4ways for at least a decade and the 12” 3 way became second tier. The two speakers in question are on a 10 band software equalizer seen below The room is 3000cft and rectangular, moderately live. The full wall opposite the speakers in the long dimension is a bookcase full of irregular shapes. Speaker attenuators or pots are set to max output. I think you are going to say the equalizer settings put the 3a midrange at a disadvantage due to its slightly reduced output in relation to the woofer. You very well could be correct, but I am not changing anything because this is not a genuine problem. The only thing you have said that I take issue with is people are better at hearing differences in strings than voice. The only reason I caught this is because I understand spoken English. If this had been German, Italian or Stradivari or Guarneri It would have been heard as fadeout music and completely unnoticed. If you hear a familiar voice you can put a face with it. When you a hear a middle C can you, or most people, distinguish between a viola and violin? Much less which luthier did the build. Cheers Adams

From the beginning this has been an experiment. One big concern was becoming so invested emotionally or financially that I could not admit failure or remain objective. I avoided the financial problem by refusing to spend money on anything that could not be employed in another system or given away without regret. The subjective, emotional investment was avoided by knowing that I always had 9s and 3as as reference and backup when I needed to calibrate my ears and if the experiment failed I would still have good sound. Because I have not moved this system into a big room to assess it directly against my 9s and 3as, I will not say that it is an unequivocal success but, in this small 1000cft room I find myself frequently smiling at what I hear and am astonished at how little effort and time it would have taken had I known the direct path at the time I started. The cost. If you have read the opening post to this thread you know the original cost included a new pair of powered sub-woofers for which I was willing to spend up to $1000 and was 80% of the budget. Except where noted below everything else was purchased used or already in my possession. After the sub-woofers were returned and this became a “Frankenstein” experiment the incremental cash outlay stood at around $200. In its current and final form, the total expenditure is very close to $750 as follows: Pre amp – Pioneer 850 that once drove AR58s system Equalizer- Realistic 10 band already in use with AR58s BA CR65 speakers x 6 Approx $30 each New Crown amp for 2 ohm load- $299 New Crown amp to isolate and drive AR58 woofer $250 New XLR cables $15 AR 58s – Previously used as separate system and AR9 standby parts bin. Total incremental cost was $744 If the project had failed the Crowns would be used on my 9s and 3s so there never was real fear of failure. Aadams

I started this thread almost three years ago, at the time a little more ignorant than my current state. I am now confident there is no practical, cost effective, way to make four pairs of AR3as perform like 2 pairs of LSTs. This thread should be terminated and ignored. correction: 1 Pair of LSTs Adams

Thanks. Check your feed. Also your message box is full again. Adams

Keeping in mind the thread topic of woofer crossover points: For me imaging is a fortuitous by-product. I normally listen to these speakers at 12-15ft and just park my brain listening but sometimes one is drawn to the lyrics of a song. When there is a solo voice I begin to focus on intelligible lyrics within the balanced overall sound, which is how I came to discover this threshold difference between the 9 and the 3a. The speakers are sitting side by side, inches apart, on different amps, same source, same equalizer and attenuators at zero. The referenced passage is not absolutely clear on any speaker of mine at normal listening distant but is less so on the 3a. To hear it clearly on the 3a your ear needs to be almost in the driver, maybe 3" away at low volume. I know the woofer is doing its part but it does not reproduce frequencies much above the crossover point. If a performer sings a 440hz A, then the first natural harmonic is 880hz. With a 575hz crossover design, the fundamental and some overtones will be placed in the woofer and all prominent harmonics and remaining overtones are in the mid and that is what I hear. This is not true with the 9 or the 3 but it is for all other 3 way 12" ARs. It is not a problem I was just pointing out some arcana that can be demonstrated at my house with my limited resources and what I have observed when instruments are split by crossovers. This same effect can be observed by crossing a powered woofer in the low mid range and spatially separating it from the upper drivers. A vocal recording will seem to bounce from speaker to speaker And, I am not criticizing the 3a because I have never heard anything superior for presentation of orchestral recordings but, human voice can reveal its weakness perhaps because we are most sensitive to those frequencies and timbres in which we naturally communicate. Perhaps keenness for speech is why I have not read of Live vs Recorded tests being done with vocalists. Aadams

Lots of options for speaker arrangement. The pictures show what seems optimal and very pleasant in this room. First one shows the 30 degree offset of the satellites. The second image is the view from the center line. I get a sweet spot up close and spaciousness when I move back. This is far better than the first generation of this hybrid.

This brings attention back the point of greatest distortion at normal listening levels, the area around 300hz, which is only two semi-tones away from 262hz (Middle C) and the area around which most popular music vocals are performed. Here is an arcane bit of trivia. If you listen at the end of “Paradise by the Dashboard Lights” which is sung well below 500hz, you can clearly hear in one channel Mr. Loaf singing “It was long ago and far away ……………… while in the opposite channel Ellen Foley is singing a different lyric in counterpoint. The Ellen Foley lyric is not completely intelligible on a 3a but can be heard on a 9 or another speaker where the voice is carried in single driver. The arcane part is she can be heard clearly in the 3a up close in the mid-range driver alone as harmonics and overtones or in the woofer alone as fundamentals but back off and let the two sounds merge and it gets garbled. With a crossover above 300hz voices are split from their harmonics and overtones between the mid and the woofer. A crossover at 200hz puts almost all voice in a single driver as with a crossover at 1000hz. I don’t know if driver arrangement, distortion or woofer crossover point is the answer, but voices are clearer when the they are carried in a single driver IN MY EXPERIENCE. Hence the 4 way and maybe the inevitable de-emphasis of dispersion and power response. Adams

Thanks, both of you. This post was pointing out that AR apparently saw a way to improvement in their full range TOTL by lowering the 12" woofer crossovers. It never got lower than 525hz until they incorporated cone mids. For me, the matrix shows, at normal listening levels, the distortion of the woofer at 80hz is equal to the rated distortion of some amplifiers, which is good for a speaker. To bad they didn't test all the way to the 700hz crossover point of the 12" three way verticals. IN MY OPINION the AR 12" speakers with the lowest woofer crossovers sound better, in the music packed human voice octaves, than those with higher crossovers. Adams

Also a great use for thousands of old Advents.

Onplane After this post I will shut up and just watch. There are several paths to achieving your goal. The summation of all that has been posted in this thread is whatever pleases your ears is the solution and whatever you choose will stand a better chance of pleasing your ears if you use an equalizer IMO. Adams

That phrase does appear once in the body of the post. The other phrase is featured more prominently at the beginning and the end. The OP can clarify.

I am not going to hijack this thread, but I want to reiterate a point that has been made at least twice earlier. The topic is “how would you achieve the “AR sound” with modern components?”--- not current production. Pete B has pointed out that it can be done with an equalizer and used BA T 1030s. I have said it can be done with an equalizer and any AR12” woofer and used satellites. I feel sure both approaches rival the sound of an AR 4way. I know it is true in one case. The OP suggested powered subs and satellites so, in deference, we are exploring that path but, he has not said which of his ARs is the target. The AR3a sound will be near impossible so, are we aiming for a 910 sound? Onplane, if you actually pull the trigger on this project, after getting everything set up, are you going to trust your ear and say close enough is OK or AB against one of your ARs? Are you awaiting assurance that the NHT roll off will blend with the sub-woofer? No one here seems to know. Would you consider using a high cut filter in case it doesn’t blend? Will you be using an equalizer? Or, are you expecting the sub and sat combo to meet expectations out of box once they are wired up and balanced? Am I being too forward? Adams

Not saying you intentionally implied a budget but the OP set a bar of "not mortgage the house". Two SVS subs and 2 NHT 2.1s are approx $1250. 2 non-collector AR12" $300, 1 DSP amp $250 2 NHTs $250 equals total $700. I set of of AR3 $1500 +/- ? AR 90, AR9, LS, LSi, working and delivered $1250 -$2000. I could be off but not much.

RE: your statement about recreating an AR 4 way was an oblique reference to a budget. The total current price to set a pair of correctly working AR 4 ways in your listening space, depending on your location, is between $900 and $2000. ALTYamaha: If I were getting a new ported 3way with zero WAF concern, I would look at these instead but they still need a sub woofer. This isn't happening ---------just talk. https://www.jbl.com/studio-monitors/LSR6332R.html?mrkgcl=741&mrkgadid=3277020484&rkg_id=h-34eb7610d9fe4ac3e9257a267087e337_t-1523885412&product_id=LSR6332R&adpos=1o3&creative=252671587334&device=c&matchtype=&network=g&gclid=EAIaIQobChMI6Ne7wPO-2gIVwyOBCh39HAMlEAQYAyABEgLvZfD_BwE Note: If a person prefers the pre-ADD sheer silk sound of the 3 series, LST or LST2, he or she might want to purchase a properly working set of those and not try this approach because IMO it will not be successful. Adams