Andre_Db66

Old oak dining table, 2.5 inch thick, hollow and filled with bird cage sand. 100 pounds per speaker approximately. Alnico JBL and Philips drivers As you can see i am into reusable materials and technology. That also sparked my love for AR and Advent... Potential critical load and deadly phase rotations, very severe descriptions for an open baffle system speaker that is used as nfm. I understand what you are saying and under normal circumstances where the speakers would be asked to deliver maximum power like in a computed box which is made with t&s parameters accordingly, this would certainly be an issue. As my open baffles are only used near field at 7ft, and the usage of drivers that are suitable but not specifically meant for this purpose i am mainly dependant on visual and auditorial inspection of the system. Read.... correction of the filters. When i play too loud the xmax limit becomes a problem for the K145 anyway, also for the AD1255. The latter being only 30 watt and highly sensitive will only allow moderate input from any given amp, tube or SS. The bass is turned up only so far to keep the balance right and carefully monitoring the xmax. The amplifier used for this is a professional amp which delivers a low impedance load without problems and also has clipping warning lights and overlaod protection. So i do not feel there is much to fear, i am safely playing music. A bump in the frequency range can be heard as it is unnatural and therefore eliminated simply by careful listening. The room is very small actually and the speakers are comparable to headphones this way, so anything that is not right will pretty soon give listening fatigue. I am on the right track, only need to tweak the lot a bit more... As the philips is playing full range, the tweeter and 15" bass is only there to add the missing frequency ranges.

Noted... thank you.

I used a calculator from DIY, not the tables. Perhaps i should experiment more with the inductor value. I cranked that one up so much because i was still hearing so much high pass which obviously ceased when i implemented a capacitor. All materials used were laying around so i did not spend any money as it is not the definitive solution. Lack of time prevented more tweaking. I will do more listening and fiddling soon. According to the chart the 17mH may well be enough as long as i include a cap...

So a smaller value cap and start with say .05 mH inductor? Next week i will buy a second set of AR5 EU version 2000 range serial # with hopefully alnico woofers. I shall try ro implement this to the ali tweeter through a/b comparison and post my results. First i will objectively describe the difference without tweaking.

Please do not read an angry intonation, rather encouragement... I guess i am more pragmatic than the average Joe, with no degrees and not having finished high school, yet doing revision of CD players, amplifiers, speakers, computers and even building tube amplifiers and tube pre amplifiers. I know curiosity killed the cat, but it also has 9 lives... I think in general it is great to revive quality products rather than contributing to our consumption society. Nowadays stuff is even designed to break down after x amount of service life. Crazy...

For the love of.... Frank, Just spend the 16 bucks on 6 and spend an afternoon reviving a set of busted tweeters and find out if you like it or not. How can somebody else ever be the judge of that other than your own ears... 😁 YES! This solution is the answer to all those collecting dust. HiVi was a nice advice were it not that those drivers do not fit in the cabinet and on average the speakers do not sell anymore because anybody can see it has been replaced which makes it a cheap solution. Do my AR5 speakers or AR2ax look that way at first and second glance? I dont think so. They have the original fit and sound fabulous when giving a demonstration. (I am someone who never ever wants china products. These VC has been the first product EVER that i bought from alixpress, beside PSvane tubes... but that is not ali, however they are chinese unfortunately) My friend is the living proof. His AR11 sat in his sons garage for 10 years and i convinced him to refoam and he informed me of the VC deal. He is now a happy man of 76 on a budget listening to his all time favorites again. He bought a set or AR7 for surround speakers to accompany them...

Nice work! I tried multiple times to extract the original voice coil to achieve a similar result as you, but only ended up destroying the dome. I stopped trying after the 3rd attempt. Now i rip the old one out and find the result with the soft dome something i can live with. There are more aspects that define an AR speaker than just the dome material or VC. If the HiVi can achieve a similar acceptable satisfying result, yet fails to fit properly in the cavity of the cabinet, i find your or my solution a much better compromise. I understand very well what you mean with your output explanation, and i suppose you alter the suspension because the old suspension has aged too much, therefore reducing output and showing less potential even with pots open... I have the same now, there is no absolute need to open up the pot completely, there is more than enough dynamics available.

In the past months while being a member and frequent visitor here i learned a lot, and thanks to the rudimentary explanation from Roy about XO's in general have been able to save a lot of AR speakers... Not only AR has been salvaged but also very cherished Beovox K series with NOS Peerless drivers which i bought all over the world, ie tweeters from Italy, mids from Canada and woofers from Switzerland. The original drivers and XO being 3.2R i had a serious problem as all the NOS drivers were 8R. I had already found NOS Philips XO's in kit form but the frequencies were off... Also i have Philips 12 inch broadband open baffle speakers i designed combined with JBL 15 bass drivers and Peerless tweeters. I was using 3 amps and electronic XO. With my newly acquired knowledge and DIY XO calculator i wound inductors for the JBL, and the Philips XO, found the correct capacitors with some trial and error and now have the sweetest sound, judged not by apparatus but simply by ear and playing music. I tend to say, if it is tiring something is off. I can listen to these sets for hours. Same rule of thumb is apllied to the AR tweeters. I have not measured anything so cannot elaborate on that. However, the original tired tweeters i tend to have tge pot wide open and the mid tamed around the middle or even less depending on tweeter performance. Now after installing these cheap(3$) VC's i can assure you that the balance in the sound is back. Upon taste you can now exagerate the amount of mid and high to your taste and it is not harsh or anything, it is spot on to me. The boomy bass of the 12 inch or even the 10 in AR5 is accompanied by the exactly the correct amount of treble. On the paper on the back it reads that opening the pots up gives most natural sound... this is true again. Installation i was actually only being pragmatic. I did not think it was a good idea to have the lead wires on the metal faceplate so i first covered the entire faceplate with black adhesive plastic from automotive. Friend if my wirked in a factory similiar to 3M adhesive plastics. I the cut out th gap right to the edge with a hobby knife. Applied some glue, same i used for the refoam job to VC and edge of the gap. Waited a bit and stuck it on, figuring it would be a 3$ loss if i did not get it centered right. Before mentioned shop charges 80$ for this experiment btw. Go figure the cost for the LST2. Sold btw... but that is how i ran into the idea that if professionals are doing this, why cant i? A friend of mine had salvaged his AR11 tweeter, speakers which i have encouraged him to fix, refoam etc. He bought them new back then and is enjoying them again now everyday. He is 76 and has a small pension so these absurd costs were out of the question. I am happy for him and very greatful that he applied this method. I otoh unfortunately have 6 HiVi tweeters new in their boxes which never will be used for 180$... 🤔 so you live and learn, my motto, always!

Unless you are very young, autistic and have a hearing abnormality of perhaps 30k or more, (there are people like that), i doubt you will actually perceive it as sounding bad. I have been advised this china soft dome by total speaker repair here in Holland, claiming that is what he always uses to keep originality and lifting the quality of high frequencies in AR speakers. I fully agree with this, as i find paying 80$ p tweeter ex shipping completely absurd for speakers costing 400$ a pair when i could not point out the contrary blindfolded... The suspension in AR tweeters is old and stuck diminishing the perfomance severely. It is the best one can do and this forum is all about repairing or refurbishing... In the event of 4R or 8R not being appropriate, one can always use resistors or inductors like the HiVi tweak. Rest my case and will enjoy the music again... 😁

.....and yes, they are better than the old tired AR tweeters, but, disputed by purists. As i am writing this, i am enjoying wonderful highs on my AR5's It almost takes getting used to the dull sound again of the AR3a afterwards, although having 6 tweeters, 6 mids and 3 woofers does balance things out pretty well. 😁

0 replies.... TY

Yes i read that, also that it became the industry standard and basis for modern day hearing aid. My deceased father had that problem. Not so much hearing loss in the high frequencies, but a specific band created a gap. It drove him crazy to be in a loud restaurant because the background noise would impede him from the ability to converse and the noise was intolerable. Now i think he should have done more tests probably, but i can imagine all this works very frustrating while trying to lead a normal everyday life... My wife had hearing loss her whole life and is now carrying aides costing a small fortune of 4500$. Goes to show how advanced that tech must be by now...

WDRC... i just read up on him on wikipedia. Nice to be able read about his achievements and he seems kind of like an einstein of acoustic tech. It is always wonderful to learn more about certain meaningful pioneers. I cannot pinpoint any specific people but here in Holland, Philips had a lot of meaningful inventions. Motion feedback for one. Almost no chamber for the woofer yet amazing bass. I have those speakers also and it is truely wonderful, the speaker barely fits the cabinet as it has been divided into 2 separate housings. The amplifier, accesible from the backside occupies more space than the woofer. In terms of distorion i would say that there is very little and it is precise. Also the pinnacle Philips AD1255 broadband speaker is magic. Very sought after these days and worth a bunch. CD players, disputably the best with their 1540 dual DAC chips and i could go on. True pioneers... wonderful!

The magnum K brochure clearly states what you describe here. "The bass reproducer is a new 12" unit with a unique moving assembly. Air cushion is employed(first used by Goodmans in the 1930's) The result is minimal distortion right down to 20hz." They have a special kind of surround, which after all those years is still good, at least in my cabinets. Most speakers were made with folded cone material and hard to move, which is why for example old jbl/altec or philips can be used for open baffle perfectly. Perhaps i am stirring in a pot of q's which have no straight a's. I do understand the legal complications Vilchur ran into and the money being made off the product lines (and Kloss later on) giving good enough reason not to pursue, but i also have a feeling it seems somehow shady that the competition basically already had invented this theory, but failed to document and patent this alltogether... leaving it for grabs, just my 2 cents. British and Americans always had a competitive standoff on all sorts of things when it came to inventing stuff... I find in a A/B comparison between ar3a and magnum k that i cannot decide the winner. Perhaps the Magnum because in the end i find them more revealing, but it is a slight margin. Though if forced to choose and leave behind all i have with only one winner, it would be th K...ing 😁 If only there was someone in this forum who could objectively discuss this pov, having both pairs as well. I know the forum is primarily for restauration, and if it were not for you loyal folks, many, many AR and the likes would have ended up in the dumpster. I really appreciate that. However, i am trying to find out more about the roots of the product. In the end, its nice to study acoustics, invent speakers, but you have to make a living, so noone does that for a hobby. Being commercial about it is not abnormal and that brings forth greed for more. AR produced many speakers to stay competitive, so i am only saying this was there all along from the start. Anyway i am starting to rant... Cheers

And Goodmans used the foam blocks too before H Kloss. So there seems to be copying involved... sadly i cannot find any documentation, so that was my point of this topic. I guess the knowledge on AR here is abundant but lacking the judgment on competition from other manufacturers. Wikipedia also doesnt mention Goodmans though it is evidential to me that suspensiion technique was used simultaneously.

Now i have an even funnier picture of the situation... 😁

🤣

Going to read about this... thnx. Unfortunately i can find very little about Goodmans in general and nothing about their air cushion suspension. So is also hard to determine if this knowledge was studied by E Vilchur and then perfected. What i do notice is that there is consequently fibreglass used in AR enclosures but H Kloss used foam exactly the same type and method as in the Goodmans. My Magnum K are from 65, H Kloss was not producing Advent yet i believe. Ideas were perhaps spread, studied or reused and improved in those days... a very common thing in asia still.

Hearing only up to 8k... i thought my hearing had diminished a lot with 12k.

It might be my english but i cannot follow what you are saying... What i meant is that some people are primarily drawn to vintage speakers which are not made of composite, plastic or otherwise modern materials. AR belongs to the finer sounding lot among these wooden boxes. That can be a nostalgic issue or simply preference of sound character. Personally i love the looks combined with the sound quality. I tend to stay away from modern speakers. Furthermore i was only referring to closing your eyes that there is nothing old about AR speakers as they can directly compete with for example KEF LS50 meta that i have. State of the art modern technology vs old in terms of age yes, but acoustically up for the task of strong competition regardless of age and looks and materials used. Both have to be setup properly in accordance with room acoustics but then i find them a close match regardless of 50 years of age difference. Yet, how subjective is speaker comparison anyway?

Within the realm of different system approaches there are also advantages and disadvantages. I concurr with above opinion of the result not beong better yet often only different. A broadband speaker in backloaded horn, one point source approach, electrostatic, open baffle, bass reflex, acoustic suspension/air cushion suspension closed box, transmission line etc have all got their appeal. I find it hard to choose one as a winner because the enchantment is primarily the material. The nostalgia of old and bulky wood vineer speakers is not for everyone taste, closing your eyes and listening to the magic is universal though. In that respect AR or Advent can directly compete with any modern speaker thrown in the comparison chart.

Foam inside like advent, very similiar sound like ar3a only as though a veil has been lifted. Deep bass, deep stage, high stage, characteristic laid back sound but very revealing and detailed. 3D almost like wearing headphones. I am afraid this is the strongest competition in my view to AR and Advent that i have in posession. LST, NLA, 3A come close but this is much more what speakers should sound like, as it makes all the above have to acknowledge their superiority. It can be debated this is my subjective opinion but look closely at the picture, i own LST, ar3a, also improved and NLA which are setup elsewhere. All of them wonderful speakers, but lacking the finesse and micro detail and being bass heavy doesnt make up for the lack of all that in mid/high range. Dont shoot me for applauding my latest acquisition on CSP, yes i know they dont belong here as they are british, but wasnt Cambridge UK before Cambridge USA? 😉 Anyway, still no one answered or enlightened me on the question of patenting or inventing the closed box concept naming it as in topic title or as AR refers to it... i remain curious about this infringement. No flame war intended btw. I am an enthusiast without prejudice and can enjoy any good sounding speaker. Brand is not important in this case and my main living room setup is and will remain 2 sets of ar3a accompanied by a set of LST all driven by 400 watt/channel yamaha amps. Do the math that is 1.2kW per side, in the middle an 18inch RCF sub @60hz driven bij a 1.6kW Crown K2. Believe me, regardless of the origin and age of the speakers, that rocks hard with disregard to material played, electronic, jazz, heavy metal or dub step. It is unfortunate that the Goodmans are not that powerful and i do not dare to crank them up that much. Yet they are marvellous at normal to louder level... not crazy loud.

I have 3 different era small bookshelf speakers that do not belong in a bookshelf... paradox i know. They directly compete or outclass the mid/high combination of AR3a or LST. Rogers LS3/5A Monitor Audio Studio 2 KEF LS50 Meta I also have comparable speakers with oval racetrack 12 inch bass directly comparable to AR3a or LST and find them very detailed in the bass and much more open. They are however not modern speakers. The KEF kit 3(concertos). They are from 71 btw.

Which is not British anymore but in some weird way German... the war was fought for nothing!