Re: phaseplugged a bolton 12dw22
And where did you get the phase plug from? It appears to be solid aluminium.
Isn't this sort of surgery very difficult? How do you get precision? Do you do any tests afterwards (other than the mandatory listening tests) to figure out whether there are any distortions/mechanical vibrations, etc or not?somakmaitra said:
And where did you get the phase plug from? It appears to be solid aluminium.
Hi Soma
You have a nice workshop and your speaker surgery pictures made me go back 20 years when i used to do these kinda surgeries with speakers and use to bang the magnet to my wrist to hear that the noice from the banging was good. If there was a rub of the voice coil or sound of the spider or some other problem one could place his ear near the wrist at the time of the magnet hiting the wrist and can make out if the speaker will be ok ( of course a light hit of a magnet on the wrist not a big bang) i think this might be poplular with the speaker manufaturers in India who do repair work on speakers. In those days i used to wonder what quality of wire in the voice coil will make them sound good, what kind of purity was there in the copper wire in the voice coil, cus the speakers that i used to open up and were from abroad they had a nice bright evenly winded voice coil, and one can then see the local made voice coils and were not of that good quality. With all those years passing by and getting married and now with two kids, times have changed a lot, but the day i saw Asawaris seems i have gone back 20 years of my life. Thanks to you guys now i have good online friends like you who share their experiences and that guides me not to make mistakes in buildng my speakers.
BTW somak where did u get these phase plugs?
God Bless you guys
Regards
You have a nice workshop and your speaker surgery pictures made me go back 20 years when i used to do these kinda surgeries with speakers and use to bang the magnet to my wrist to hear that the noice from the banging was good. If there was a rub of the voice coil or sound of the spider or some other problem one could place his ear near the wrist at the time of the magnet hiting the wrist and can make out if the speaker will be ok ( of course a light hit of a magnet on the wrist not a big bang) i think this might be poplular with the speaker manufaturers in India who do repair work on speakers. In those days i used to wonder what quality of wire in the voice coil will make them sound good, what kind of purity was there in the copper wire in the voice coil, cus the speakers that i used to open up and were from abroad they had a nice bright evenly winded voice coil, and one can then see the local made voice coils and were not of that good quality. With all those years passing by and getting married and now with two kids, times have changed a lot, but the day i saw Asawaris seems i have gone back 20 years of my life. Thanks to you guys now i have good online friends like you who share their experiences and that guides me not to make mistakes in buildng my speakers.
BTW somak where did u get these phase plugs?
God Bless you guys
Regards
Hi Digital
I hope this helps you with the driver findings
http://www.dhandanought.org/tcpip/site/?q=node/24
Hello Tarunda
Just finished reading ur story on ur web page. Thats an excellent write up, brilliantly presented, took me back in my childhood days, rememberd all the electronic equipment i had and made and experienced just like you did. I still am in process of getting myself a decent music system for last some years, unfortunately my income is not on a higher level but steadily it is growing and i am sure as my business grows i will be able to get some good equipment for me. I am a movie love so i decided to go in for a 5.1 channel amp and then speakers, after that i will venture into 2 channel and and seperate speaker set for them. Your cambridge amp experience now lures me go to the cambridge dealer (fortunae to have one in Ludhiana) and listen to the amp.
Regards
Just finished reading ur story on ur web page. Thats an excellent write up, brilliantly presented, took me back in my childhood days, rememberd all the electronic equipment i had and made and experienced just like you did. I still am in process of getting myself a decent music system for last some years, unfortunately my income is not on a higher level but steadily it is growing and i am sure as my business grows i will be able to get some good equipment for me. I am a movie love so i decided to go in for a 5.1 channel amp and then speakers, after that i will venture into 2 channel and and seperate speaker set for them. Your cambridge amp experience now lures me go to the cambridge dealer (fortunae to have one in Ludhiana) and listen to the amp.
Regards
Hi Somak
After digging into my old stuff i finally found the driver i purchased 8 years back I Delhi It was a die cast 8 inch driver the masket is of hard aluminum and polycone with 1.25 inch voice coil. I purchased it from chandni chowk from a boltom dealer. At that time i was living in Agra and saw this driver in a speaker box asked that man where he purchased it and went the other day to buy one for me. i bouht just one to see how it sounded. The name is BOSCHMAN AXIOM. last year i went to Delhi to the same bolton dealer to buy a pair, but to my disappointment the manufacturer of the driver had gone from Delhi. i asked the dealer who was making them and he said two brothers from Calcutta and they have gone back to calcutta. i have some pictures taken today, tried my best to take good pic although my digi cam has some problem in macro focusing but i think they are good to see the see the details.
You are in Calcutta is you can inquire if they are available in Calcutta or not. It is a nice strong driver and I have taken out every part of it cus it was lying there in one of the cartons and was like some rotten mango. Will try to repair it and do a full blown surgery to it. I found out the voice coil is wound on aluminum sheet. The voice coil came off from its base (aluminum) and now I will be using a normal paper base. Hope it works. Can you send me ur email, its hard to post pic so large in size here.
Regards
After digging into my old stuff i finally found the driver i purchased 8 years back I Delhi It was a die cast 8 inch driver the masket is of hard aluminum and polycone with 1.25 inch voice coil. I purchased it from chandni chowk from a boltom dealer. At that time i was living in Agra and saw this driver in a speaker box asked that man where he purchased it and went the other day to buy one for me. i bouht just one to see how it sounded. The name is BOSCHMAN AXIOM. last year i went to Delhi to the same bolton dealer to buy a pair, but to my disappointment the manufacturer of the driver had gone from Delhi. i asked the dealer who was making them and he said two brothers from Calcutta and they have gone back to calcutta. i have some pictures taken today, tried my best to take good pic although my digi cam has some problem in macro focusing but i think they are good to see the see the details.
You are in Calcutta is you can inquire if they are available in Calcutta or not. It is a nice strong driver and I have taken out every part of it cus it was lying there in one of the cartons and was like some rotten mango. Will try to repair it and do a full blown surgery to it. I found out the voice coil is wound on aluminum sheet. The voice coil came off from its base (aluminum) and now I will be using a normal paper base. Hope it works. Can you send me ur email, its hard to post pic so large in size here.
Regards
Good drivers on this continent.
My two bits on this subject.
It's easy to make a loudspeaker if all it has to do is make some sound. Everyone on this continent can make his/her own 'custom' speakers as every single part is available across the counter in most large cities at very low prices.
While many on this forum keep asking about details on making drivers I see several 'screwdriver mechanic' type people buying plenty of cones, frames and magnets etc from the local market. So they must know how to assemble their own loudspeakers. There must be numerous unknown brands and/or repair people around.
However to make very good loudspeakers and design them so that a consistent product can be made on an assembly line is not easy at all and is a time and cash consuming business. Additionally to make them cost effective they must be sold in large quantities . The only two local companies that I am aware of that produce consistent products and have a reasonably 'large' production facility are Iwai and Peerless India. Both were set up explicitly for export . They didn't set themselves up and then go around lookijng for buyers. They had some buyers already and catered to their requirements. Now I guess they are established and so they sell to others also.
To make what we refer to as ' high end' drivers would need more investments and these companies could do it if they could get enough sales , which would mean mostly international of course. We can see that they haven't done this yet and so it would mean that maybe it isn't possible quite yet. I think most drivers that are exported are lower mid or low end types.
If anyone on this continent can design something really good , possibly a bit different from usual drivers (?) , they might be able to manufacture it and sell it globally. The moment that happens , economies of scale will pop right up and the manufacture might be more optimal in some other land. Additionally it might generate more revenue and be easier to implement if located in a more business friendly atmosphere . The bottom line is that money talks and it appears to talk louder in other environments at the moment !
My two bits on this subject.
It's easy to make a loudspeaker if all it has to do is make some sound. Everyone on this continent can make his/her own 'custom' speakers as every single part is available across the counter in most large cities at very low prices.
While many on this forum keep asking about details on making drivers I see several 'screwdriver mechanic' type people buying plenty of cones, frames and magnets etc from the local market. So they must know how to assemble their own loudspeakers. There must be numerous unknown brands and/or repair people around.
However to make very good loudspeakers and design them so that a consistent product can be made on an assembly line is not easy at all and is a time and cash consuming business. Additionally to make them cost effective they must be sold in large quantities . The only two local companies that I am aware of that produce consistent products and have a reasonably 'large' production facility are Iwai and Peerless India. Both were set up explicitly for export . They didn't set themselves up and then go around lookijng for buyers. They had some buyers already and catered to their requirements. Now I guess they are established and so they sell to others also.
To make what we refer to as ' high end' drivers would need more investments and these companies could do it if they could get enough sales , which would mean mostly international of course. We can see that they haven't done this yet and so it would mean that maybe it isn't possible quite yet. I think most drivers that are exported are lower mid or low end types.
If anyone on this continent can design something really good , possibly a bit different from usual drivers (?) , they might be able to manufacture it and sell it globally. The moment that happens , economies of scale will pop right up and the manufacture might be more optimal in some other land. Additionally it might generate more revenue and be easier to implement if located in a more business friendly atmosphere . The bottom line is that money talks and it appears to talk louder in other environments at the moment !
Re: Good drivers on this continent.
A lot of fairly high end drivers with some exceptions (but these exceptions are really small quantities of some really nutty priced drivers) are made in China. I dont know of a single major speaker manufacturer who does NOT have a presennce in China.
The 3 major components ( Ferrite/NdFeB magnets, cones with surrounds and baskets.) are produced in China are prices that are below the cost of the raw materials of these components in India. Under these conditions Peerless and Iwai are doing an admirable job.
ashok said:
A lot of fairly high end drivers with some exceptions (but these exceptions are really small quantities of some really nutty priced drivers) are made in China. I dont know of a single major speaker manufacturer who does NOT have a presennce in China.
The 3 major components ( Ferrite/NdFeB magnets, cones with surrounds and baskets.) are produced in China are prices that are below the cost of the raw materials of these components in India. Under these conditions Peerless and Iwai are doing an admirable job.
HI ASHOK & NAVIN
Some of the things you have writted are well said. realy apriciate that kind of thougts from you. Thats very right to survive in this competetive world is very hard and cheers to Peerless India and the other company for making a product that has a world standard and quality. Yes to set up a manunafuring line up and also to sell is a tough job and in this fiel of drivers its even tougher in India. when i first time saw asawaris and those kevlars i had goose bums all over my body. I have for so many years have seen B&W's kevlar cones drivers and its proud to know and see that they are made in india and in such a good finish. although i have not got hands on them but from what ever i have read it seems that they are the best buy in Indian circumstances. i have attached a photo of the driver if any of you want some more pics i can mail i have several pics taken of this driver and 8 years back i was so impressed with the driver.
You can see the drive has good wear and tear marks cus of the rough useage, but i can still remember the day i purchased it. i expected a clear high class sound from it cus of good finish and sturdy make. but when i attached it the the amp it sounded like it was made for the low frequency ( to used as a sub).
Thanks
Some of the things you have writted are well said. realy apriciate that kind of thougts from you. Thats very right to survive in this competetive world is very hard and cheers to Peerless India and the other company for making a product that has a world standard and quality. Yes to set up a manunafuring line up and also to sell is a tough job and in this fiel of drivers its even tougher in India. when i first time saw asawaris and those kevlars i had goose bums all over my body. I have for so many years have seen B&W's kevlar cones drivers and its proud to know and see that they are made in india and in such a good finish. although i have not got hands on them but from what ever i have read it seems that they are the best buy in Indian circumstances. i have attached a photo of the driver if any of you want some more pics i can mail i have several pics taken of this driver and 8 years back i was so impressed with the driver.
You can see the drive has good wear and tear marks cus of the rough useage, but i can still remember the day i purchased it. i expected a clear high class sound from it cus of good finish and sturdy make. but when i attached it the the amp it sounded like it was made for the low frequency ( to used as a sub).
Thanks
Attachments
have four of Vifa BG18WK03-04 and i dont have specs for these. Please. Help me find the specs for these drivers.
here is the pic of the driver
http://www.caraudio.com/forum/showthread.php?t=281713
here is the pic of the driver
http://www.caraudio.com/forum/showthread.php?t=281713
kamal6767 said:
Some of the older kevlar's were made in India. The latest incranation of B&W kevlar cone mid is not made in India (to the best of my knowledge).
BTW kevlar comes it's own problems. Not all Kevlar cones can be treated the same. I worked with some early (late 80s) Focal Kevlar cones and found that they had some really difficult break up nodes. The first (DIY) Kevlar cones that I used that were easy to work with (relative to other Kevlars) were the ScanSpeak (predecessors of the 18W8546).
The difference was not in the cone material but in the surround. SS worked on a surround that could damp the resonaces. I know that Ted Jordan had written a paper on this wrt to Aluminum cones (which he worked on for a long long time) but I assume the same would apply to Kevlars and other stiff materials.
Hi Bro Somak
I have this 8 inch driver which i mentioned in my above posting. For last 8 years it is with me and i have not used it for last 6 years. When a took it out from the carton i found out that some of the parts were like deteriorating and the glue was loosing its strength and everything was coming apart. In past (23 years back) i had done some reconing and changing the voice coil and cones of the drivers. Now back to this driver, i took the driver and dismantled it, separated each and every part and will put it together again ( i hop i dont end up like "all the kings horses and all the kings men could not put humpty dumpty together again".) My real problem is that the voice coil got off from its aluminum base. I have some options and i want to u to give me ur precious opinion. Options are:
1. To go to the speaker repair market and have it repaired done just the voice coil replacement as the cone is in good condition but I don’t know how the other voice coil would behave as the voice coils sold in the market have no ohms rating or watt rating confusing.
2. But a same size paper based voice coil of same size and unwind it, have my original glued to the paper base as the aluminum base of my original voice coil seems to be not useable anymore.
3. Have a complete makeover of the driver.
4. The other option I have in mind is to use the OHP sheet as the base and stick the voice coil on it and then see what the outcome would be
Please suggest what I should do
Regards
I have this 8 inch driver which i mentioned in my above posting. For last 8 years it is with me and i have not used it for last 6 years. When a took it out from the carton i found out that some of the parts were like deteriorating and the glue was loosing its strength and everything was coming apart. In past (23 years back) i had done some reconing and changing the voice coil and cones of the drivers. Now back to this driver, i took the driver and dismantled it, separated each and every part and will put it together again ( i hop i dont end up like "all the kings horses and all the kings men could not put humpty dumpty together again".) My real problem is that the voice coil got off from its aluminum base. I have some options and i want to u to give me ur precious opinion. Options are:
1. To go to the speaker repair market and have it repaired done just the voice coil replacement as the cone is in good condition but I don’t know how the other voice coil would behave as the voice coils sold in the market have no ohms rating or watt rating confusing.
2. But a same size paper based voice coil of same size and unwind it, have my original glued to the paper base as the aluminum base of my original voice coil seems to be not useable anymore.
3. Have a complete makeover of the driver.
4. The other option I have in mind is to use the OHP sheet as the base and stick the voice coil on it and then see what the outcome would be
Please suggest what I should do
Regards
Dear Kamal ,
You have to do a complete reconing to get good result .
I have seen very good quality imported voice coils of Chinese and Thai origin available in the market they are mostly 8 ohms made of aluminum or Kapton former .
Also change the spider .
the total cost will be probably :-
VC :- Rs 30 -50 each
cone : Rs 30
spider :Rs 10-20
Gasket Rubber :Rs 10
Use Araldrite Rapid as glue .
You should take the unit to a reconer as they will be able to center the coil better . If you do it on your own it might or might not be able to center the coil .
Regards ,
Somak
You have to do a complete reconing to get good result .
I have seen very good quality imported voice coils of Chinese and Thai origin available in the market they are mostly 8 ohms made of aluminum or Kapton former .
Also change the spider .
the total cost will be probably :-
VC :- Rs 30 -50 each
cone : Rs 30
spider :Rs 10-20
Gasket Rubber :Rs 10
Use Araldrite Rapid as glue .
You should take the unit to a reconer as they will be able to center the coil better . If you do it on your own it might or might not be able to center the coil .
Regards ,
Somak
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