Guest S.C Posted April 1, 2004 Report Share Posted April 1, 2004 I recently found out the AR9k which were sitting on the living room not being use were my dad's speaker. I am living in my aunt place. Her ex husband brought 4 12" JBL woofer to replace the broken 12" woofer. However, it won't fit cuz the speaker mounting place ain't round. One more problem, the front woofers are also broken. How cna I fix it, or any replacement were suggested in this forum? Plz help. Link to comment Share on other sites More sharing options...
Guest Brian_D Posted April 1, 2004 Report Share Posted April 1, 2004 >I recently found out the AR9k which were sitting on the>living room not being use were my dad's speaker. I am living>in my aunt place. Her ex husband brought 4 12" JBL woofer to>replace the broken 12" woofer. However, it won't fit cuz the>speaker mounting place ain't round. One more problem, the>front woofers are also broken. How cna I fix it, or any>replacement were suggested in this forum? Plz help.Not sure what an AR-9K is, but it sounds like you have AR 9's. (4 woofers with flat sides)If the woofers just need refoaming, this can be done cheaply by a professional, or you can do it yourself. As an alternative, there is a replacement speaker available that will fit the hole, and perform similarly to your original. (The same goes for the 8" woofer on the front)As a side note, if you are not interested in keeping these speakers original, and only want them repaired so they're functional it would be worth looking into selling them. These are precicely engineered quality speakers that would suffer greatly from some random replacement driver. The value of these speakers, even in their current state, is significant, and I'm sure several people on this forum would be interested in acquiring them. The money gained from their sale could afford you some very nice, new speakers. Link to comment Share on other sites More sharing options...
soundminded Posted April 1, 2004 Report Share Posted April 1, 2004 This is a well intentioned but naive approach to repairing your AR speakers. It is fatally flawed for several reasons IMO. Loudspeakers, especially woofers work as an integral system with their enclosure. The AR design and the JBL design may seem superficially similar to the untrained eye are actually radically different in concept and in practice. The AR driver is made to be installed in a sealed enclosure of a specific internal volume. The JBL driver is made to be installed in a "horn" loaded or "ported" enclosure. The mechanical porperties of each are optimized for their particular enclosure type. They are electrically very different. Most AR 12 inch woofers are relatively inefficient and have a 4 ohm impedence. Most JBL 12 inch woofers have an 8 ohm impedence and are relatively efficient. They have other electrical differences as well which means a crossover network designed and built for one will not work properly with the other. If you insist on trying to install one or more of the JBL drivers, you can work around the mounting problem. You could mount the JBL driver to the front (with the basket proturding through the back) of a separate baffle board of 1/2 or 3/4 inch plywood with a suitable opening for the driver and large enough to be attached to the AR cabinet from the outside. You may have to stack two or more baffleboards to allow the back of the JBL driver to clear the opening in the AR cabinet. You will also have to devise different grill cloths. You can attach this combination to the AR cabinet with screws but be cautions because when you decide that this doesn't work and that the proper way is to either have the original drivers repaired or purchase exact replacements after you hunt them down, any holes you make in the AR cabinet will have to be filled and sealed air tight.Good Luck Link to comment Share on other sites More sharing options...
Guest S.C Posted April 1, 2004 Report Share Posted April 1, 2004 The AR 9K is the same as this one http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...&category=14993I'm not sure is the driver completely disfuntional or not, but the the plastic which surround the outside rim are gone. How can I test to see the driver condition? Do I just plug in the sources and play? I want to repair it.... but I'm a student..... It will be good If and only if the plastic thing have to replace. Oh thx for your advise. Link to comment Share on other sites More sharing options...
soundminded Posted April 1, 2004 Report Share Posted April 1, 2004 You have one of the finest loudspeakers made by AR or anyone else. You would do well to research this site and other sources to find qualified people to help you restore this speaker to its original performance. It can give someone many more years of listening pleasure. It would be a real shame to butcher it by trying to jury rig a fast or cheap fix which will compromise its performance terribly. There is much advice on this site already which will point you in the right direction and I am sure many other people posting here will give you additional contacts should you need them. Link to comment Share on other sites More sharing options...
Guest Bret Posted April 1, 2004 Report Share Posted April 1, 2004 Your speakers need to be "re-surrounded" or "refoamed." Call it that and almost anyone will know what you mean.About checking for driver function -> Usually the same company that can resurround them professionally can repair them if they do not work. Repairing the old drivers is less expensive than buying replacements.Yes, you could just hook them up and see if they play, but I would not do that since you can do permanent damage.To make a suggestion about repair services, it would help if you told us where you are.As you've already been told, you have a pair of speakers that cost on the order of $1,800.00/pair in 1979. If you will repair them correctly they will sound as good or better than anything you could purchase today for thousands of dollars.One other thing you should know: These speakers *require* a large amplifier to sound their best.In this forum's library you will find an owner's manual. I think you would enjoy reading it if you haven't read it already. Bret Link to comment Share on other sites More sharing options...
Guest S.C Posted April 1, 2004 Report Share Posted April 1, 2004 Ya, I had already done some reasearch on the web, and I ended up to this up-to-date website. b4 I was posting in here, I had downloaded the info + manul that I needed . Btw, I am living in Milpitas, CA, (Santa Clara County) What will be availiable in here, and the cost? I saw a post said someone will charge $35/speaker ..... (may be in pound). To tell u the truth, I just knew that these speakers were belong to my father on yesterday. I will begin this story when thiefs broke into my dad's house and stole all his stereo equirment except the speakers. After that my parents decided to move to HK and started a life there. They eventually left these speakers to my aunt since they didn't want to ship them oversea and he didn't have any stereo equirment left. Fast forward like 18-20 years later, I once again steped on this land to reclaim my recidency and study aboard (not really aboard, I was born here....wierd) I ended up living with the same aunt that had my dad's speakers. I got into Chip Amp building (GainClone) recently, and I am build one recently. Yesterday, my aunt saw me doing my design in the living room and asked me to help her repair these AR9. Then she told me about the story behind these speakers. I'm more than greatful that they didn't throw it away... ! As I metioned above, will a GainClone beable to drive this speaker?It is basically putting resitor + cap around a chip which I am using LM3875TF. Since the chip is just a mini solid state circuit board, why not make it simple to just use a chip with shorter path..... That's what ppl think in this forum www.diyaudio.com Link to comment Share on other sites More sharing options...
soundminded Posted April 1, 2004 Report Share Posted April 1, 2004 These speakers work best with amplifiers that can deliver at least 60 watts per channel over a bandwidth of 20 hz to 20 khz with less than 1/2% distortion. Many users find that more power will make them sound even better. No "chip" amplifiers that I am aware of fall into this category. Chip amplifiers are usually small low power fractional wattage to a few watts at most. Even a 10 or 20 watt per channel amplifier will not begin to indicate what performance these loudspeakers are capable of. A PA amplifier or an amplifier intended for use with electrically amplified musical instruments is also usually a poor choice. If money is a problem look for a used low cost receiver on places like e-bay or in local second hand electronics stores manufactured by a high quality manufacturer like Marantz. Many high quality units of this type made in the 1970s and 1980s are available for under $100. You can often judge an amplifier by its weight. The power supply for this type of amplifier or receiver has a very heavy power transformer, large electrolytic capacitors, and if it is solid state, large heat sinks. If it is a tube amplifier, it will have large output tubes and large heavy output transformers. Try to find one in good working condition and this combination will give outstanding performance from compact discs, phonograph records, and tapes once the speakers are restored. Link to comment Share on other sites More sharing options...
Guest Bret Posted April 1, 2004 Report Share Posted April 1, 2004 >I saw a post said someone will charge $35/speaker ..... <That's about right for a re-surround job, in US $. Not expensive at all, really, except there are 6 drivers.I don't know of a service in your area, but others here might.And, no, I'm sorry, but the amplifiers you have in mind probably won't do. Instead of spending huge dollars buying replacement drivers, I would encourage you to repair the drivers you have and spend some money on a *big* amplifier.You can buy working Hafler amplifiers and preamplifiers pretty cheaply on eBay. They may not be optimum, but they are adequate. The biggest of the late 70s receivers from Kenwood (KR-9600), Pioneer (SX-1980), or Marantz (4300) would be a reasonable match. Unfortunately, these receivers tend to sell for a premium, so it might be less expensive to buy Hafler seperates, or Carver. Carver made a few big receivers, too.Bret Link to comment Share on other sites More sharing options...
Guest dogmeninreno Posted April 2, 2004 Report Share Posted April 2, 2004 >Ya, I had already done some reasearch on the web, and I ended>up to this up-to-date website. b4 I was posting in here, I had>downloaded the info + manul that I needed . >>Btw, I am living in Milpitas, CA, (Santa Clara County) What>will be availiable in here, and the cost? I saw a post said>someone will charge $35/speaker ..... (may be in pound). >>To tell u the truth, I just knew that these speakers were>belong to my father on yesterday. I will begin this story when>thiefs broke into my dad's house and stole all his stereo>equirment except the speakers. After that my parents decided>to move to HK and started a life there. They eventually left>these speakers to my aunt since they didn't want to ship them>oversea and he didn't have any stereo equirment left. Fast>forward like 18-20 years later, I once again steped on this>land to reclaim my recidency and study aboard (not really>aboard, I was born here....wierd) I ended up living with the>same aunt that had my dad's speakers. I got into Chip Amp>building (GainClone) recently, and I am build one recently.>Yesterday, my aunt saw me doing my design in the living room>and asked me to help her repair these AR9. Then she told me>about the story behind these speakers. I'm more than greatful>that they didn't throw it away... ! >>As I metioned above, will a GainClone beable to drive this>speaker?>It is basically putting resitor + cap around a chip which I am>using LM3875TF. Since the chip is just a mini solid state>circuit board, why not make it simple to just use a chip with>shorter path..... That's what ppl think in this forum>www.diyaudio.comhere is a link to Neals Speaker Service in Sacramento. Ron does excellent work and is reasonable. Dale in Reno....http://www.nealspeakerrepair.com/instructions.html Link to comment Share on other sites More sharing options...
Guest Damon Hill Posted May 1, 2004 Report Share Posted May 1, 2004 >These speakers work best with amplifiers that can deliver at>least 60 watts per channel over a bandwidth of 20 hz to 20 khz>with less than 1/2% distortion. Many users find that more>power will make them sound even better. No "chip" amplifiers>that I am aware of fall into this category. Chip amplifiers>are usually small low power fractional wattage to a few watts>at most. Even a 10 or 20 watt per channel amplifier will not>begin to indicate what performance these loudspeakers are>capable of.I'm driving my AR-11s with a couple LM3886 amplifier chips, whichare capable of 60 watts with low distortion. The newer LM4780can be paralleled to 120 watts. The popular "GainClone" uses aLM3875 which is good for up to 50 watts or so. All of these aretrue monolithic 'chip' amplifiers, not hybrids. They will drivelow efficiency speakers to reasonable levels, perhaps lacking onlyin the deep bass where the most power is needed. See:http://www.national.com/pf/LM/LM3886.htmlOf course, a bigger amplifier will be best where a large room and/ora lot of deep bass reproduction is required. My Leach DIY amplifieris good for as much as 200 watts/channel into four ohms, and soundsbest with my AR-11s (rescued from Goodwill for $18).Lots of good electronic and speaker projects and help are availableat: http://www.diyaudio.com Link to comment Share on other sites More sharing options...
Guest S.C Posted May 9, 2004 Report Share Posted May 9, 2004 Thx all of you guys ! Man, I refoamed my speakers yesterday by using foams from simplyspeakers.com. It was great, and I watched "Saving Private Ryan" with great joy. Now, I am a happ man after all hehe. Link to comment Share on other sites More sharing options...
Guest Brian_D Posted June 27, 2004 Report Share Posted June 27, 2004 Great!We're glad to see another pair back in "original" condition, and in service!I was inspecting my speakers yesterday after moving them and noticed that on the serial number badge, the first letter after the model designation is a "K"It makes sense now that you would call them AR9K's since the K is printed next to the AR9 and the rest of the number is stamped into the badge!Enjoy!-Brian Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.