TS parameters for Bolton
Thanks a lot Vivek for the information.
But it would have been of great help if you could post acrosss the TS parameters for the Woofers from Bolton.
And I would like to share with you a funny experience I had here in Cochin when I was searching for a pair of Bolton Woofers.
I had enquired in Bangalore and found that the Bolton 20W22( the exact model name evades me) costed 600+ rupees.
But when I enquired in Cochin, I found the same 20W22 for 320 bucks!!! And the dealer claimed it to be 'ORIGINAL'!!!
Then I asked of he had some thing that cost around 600 bucks and he said he had the AH series from Bolton. It read something like 20AH22 and the cost was 520 bucks. When I asked him the difference, he said that all that differred was the model name and no quality difference would ever be there!!! While in truth, one model had a foam surround, while the other was a fabric surround!!!I said a salaam to him and pushed off.🙂
Now I am really in a big confision as to from where I can get the original stuff.
And I when I asked for something with came with specs, I was shown a woofer from Jacob's. Anyone heard of this brand?
Build quality looked impressive, but the specs were still hard to find!! Suppossed to be manufactured by a company in Dubai.
So kindly post across the specs for Bolton Woofers if you have them with you.
Regards,
Linoj.
Thanks a lot Vivek for the information.
But it would have been of great help if you could post acrosss the TS parameters for the Woofers from Bolton.
And I would like to share with you a funny experience I had here in Cochin when I was searching for a pair of Bolton Woofers.
I had enquired in Bangalore and found that the Bolton 20W22( the exact model name evades me) costed 600+ rupees.
But when I enquired in Cochin, I found the same 20W22 for 320 bucks!!! And the dealer claimed it to be 'ORIGINAL'!!!
Then I asked of he had some thing that cost around 600 bucks and he said he had the AH series from Bolton. It read something like 20AH22 and the cost was 520 bucks. When I asked him the difference, he said that all that differred was the model name and no quality difference would ever be there!!! While in truth, one model had a foam surround, while the other was a fabric surround!!!I said a salaam to him and pushed off.🙂
Now I am really in a big confision as to from where I can get the original stuff.
And I when I asked for something with came with specs, I was shown a woofer from Jacob's. Anyone heard of this brand?
Build quality looked impressive, but the specs were still hard to find!! Suppossed to be manufactured by a company in Dubai.
So kindly post across the specs for Bolton Woofers if you have them with you.
Regards,
Linoj.
dumrun
hi
there may be 2 causes for the price discrepency
1) All of boltons lower priced models have been copied and are easily available
the lower priced models have been copied by numerous company in delhi (that where mostly all shops purchse spare in bulk as its the cheapest in india)
to avoid copy models purchase only the drivers which uses an imported cone - as these cones will not be available easily
2) bolton normally sells through a distributor and does not fix individual shop prices by printing a MRP on the speakers
therefore originals may be sold at the price the shop keeper has valued the product at irrespective of his cost price
this is the biggest problem with us driver manufacturers we need the shop keepers as they give the best volume sales - and if we launch a web site the prices will be open and a shop keeper may not stock the speaker at all unless he can make a good profit
by the way the most of the philips (other than the dome tweeters are copies too)
suranjan
hi
there may be 2 causes for the price discrepency
1) All of boltons lower priced models have been copied and are easily available
the lower priced models have been copied by numerous company in delhi (that where mostly all shops purchse spare in bulk as its the cheapest in india)
to avoid copy models purchase only the drivers which uses an imported cone - as these cones will not be available easily
2) bolton normally sells through a distributor and does not fix individual shop prices by printing a MRP on the speakers
therefore originals may be sold at the price the shop keeper has valued the product at irrespective of his cost price
this is the biggest problem with us driver manufacturers we need the shop keepers as they give the best volume sales - and if we launch a web site the prices will be open and a shop keeper may not stock the speaker at all unless he can make a good profit
by the way the most of the philips (other than the dome tweeters are copies too)
suranjan
hunter audio said:
Suranjan. pls dont equate salary/earning to knowledge.
gjo said:
Geroge, i would be happy to discuss the Astra off line. Holden although Australian makes as good as engine as Opel. I knew the engine was a Holden yet never fealt cheated. my car (Sept 1996) has not given me any serious trouble in the past 8 years.
Ashok took a peek into mine a few weeks back. Unfortunately his visit was sooooo short we did not get a chance to listen to it. Would have loved to know his opinion. BTW the door speakers are a real bother. I had to modify the door (fiberglass frame to fit drivrs with more depth). The drivers are a secret sauce. Built in Videbaek (DK).
Transnational brands
I remember walking down a place called North Point (I think) opposite Yishun Station in S'pore, and seeing a large kerbside sale of N*** sports shoes, at attractive prices. When I evinced interest, my friend said, "Oh, they must be made in ___" (he named a country.) I asked him what that means? Are they fakes? He said, no, they're made for N*** under N*** QC, but for poorer markets, where selling prices are lower. For such markets, N*** uses different quality standards, weaker material, etc. They thus remain competitive. That's why he always buys MNC products after checking the "made in" country's name, he explained. I was stunned. Later, another gentleman from Dubai confirmed exactly the same story. He said that a child's bicycle purchased in London is far more robust, long-lasting and well-made than the same bicycle (i.e. the same brand and model) purchased in Dubai. He went on to give me a few more examples.
As a backgrounder to this, I remember having one long and leisurely conversation in a train ride from Calcutta to Bombay, with a co-passenger, an elderly gentleman who owns a job-work bag manufacturing unit in Dharavi. His unit makes sports bags (the kinds which carry major MNC logos and are seen in fashionable gyms), laptop bags, etc, using nylon buckles, synthetic sheet material, etc. He told me that he can make a bag for me for Rs.1000 or Rs.4000, without cheating me in either case. He said that raw material (specially fittings like buckles, braces, etc) comes in all kinds of quality ratings, and their prices vary up to 1:10. The only difference will be breaking stress and construction... the differences will not be visible to the untrained naked eye. So he said that his unit makes bags of various qualities, depending on what the customer asks of him. And they often all look the same. I am still recovering from the shock of that revelation.
We fools believe that if we see one logo, one brand, we get one quality, wherever in the solar system we are. This is not true. And what these transnationals are doing is not illegal. It's we who are ignorant. Once I understood this, I've stopped believing blindly in transnational brands.... that brand means very little.
Tarun
This appears to be a very standard practice for transnationals. Friends who have lived in places like Dubai or S'pore (which gets goods from all over the world) tell me that they routinely check the "made in XYZ" label before they buy anything.gjo said:
I remember walking down a place called North Point (I think) opposite Yishun Station in S'pore, and seeing a large kerbside sale of N*** sports shoes, at attractive prices. When I evinced interest, my friend said, "Oh, they must be made in ___" (he named a country.) I asked him what that means? Are they fakes? He said, no, they're made for N*** under N*** QC, but for poorer markets, where selling prices are lower. For such markets, N*** uses different quality standards, weaker material, etc. They thus remain competitive. That's why he always buys MNC products after checking the "made in" country's name, he explained. I was stunned. Later, another gentleman from Dubai confirmed exactly the same story. He said that a child's bicycle purchased in London is far more robust, long-lasting and well-made than the same bicycle (i.e. the same brand and model) purchased in Dubai. He went on to give me a few more examples.
As a backgrounder to this, I remember having one long and leisurely conversation in a train ride from Calcutta to Bombay, with a co-passenger, an elderly gentleman who owns a job-work bag manufacturing unit in Dharavi. His unit makes sports bags (the kinds which carry major MNC logos and are seen in fashionable gyms), laptop bags, etc, using nylon buckles, synthetic sheet material, etc. He told me that he can make a bag for me for Rs.1000 or Rs.4000, without cheating me in either case. He said that raw material (specially fittings like buckles, braces, etc) comes in all kinds of quality ratings, and their prices vary up to 1:10. The only difference will be breaking stress and construction... the differences will not be visible to the untrained naked eye. So he said that his unit makes bags of various qualities, depending on what the customer asks of him. And they often all look the same. I am still recovering from the shock of that revelation.
We fools believe that if we see one logo, one brand, we get one quality, wherever in the solar system we are. This is not true. And what these transnationals are doing is not illegal. It's we who are ignorant. Once I understood this, I've stopped believing blindly in transnational brands.... that brand means very little.
Tarun
Re: TS parameters for Bolton
From Bolton directly. You can write a letter to their address in Faridabad, and ask them for specific model numbers and quantity. They'll send you (by ordinary post) a letter giving you their quote. You send them a DD payable in Delhi for that amount, and they'll ship you the drivers by road. I've ordered a few 6.5" midbass drivers this way; they're shipping them to me (I live in Bombay) by road. It's also much cheaper this way than buying from the local L.Road dealer, who also has misled me about availability of specific models.dumrum said:
Linoj, I do not have the parameters for the other Boltons. I bought a pair of Bolton 20SBW22 drivers for my HT sub project and measured the parameters myself.
Baazee auction deleted
Hey you know what. The Baazee controversial auction deal ended with all winning bidders deleted from the win. Whew! what a relief!!
Pats
Hey you know what. The Baazee controversial auction deal ended with all winning bidders deleted from the win. Whew! what a relief!!
Pats
Re: Re: TS parameters for Bolton
Thank you Tcpip for the advice. Could you please post across to me the address for Bolton. You could send it to my mail id at dumrum@hotmail.com if you prefer to keep it offline.
I had it with me for a long time, but somehow lost it. In fact I had even planned to visit the Factory in Faridabad when I was sent to Delhi on a project. But never got the opportunity.:-(
Am resending this as my previous post seems to have got jumbled up.. Sorry for that.
Regards,
Linoj.
tcpip said:
Thank you Tcpip for the advice. Could you please post across to me the address for Bolton. You could send it to my mail id at dumrum@hotmail.com if you prefer to keep it offline.
I had it with me for a long time, but somehow lost it. In fact I had even planned to visit the Factory in Faridabad when I was sent to Delhi on a project. But never got the opportunity.:-(
Am resending this as my previous post seems to have got jumbled up.. Sorry for that.
Regards,
Linoj.
I am Sorry and it was unethical of me to make a judgement of knowledge to salary earned , thanks for helping me improve - suranjan
Re: Transnational brands
hey you know even i feel the thing about trans nationals:
i have a sony hi fi home theater combo vcd player ... i had got it from dubai in one of my visits there. it is a made in usa. it gave me ultimate perfomance.
😎
then one of my pals after seeing my system bought one sony- the same model - but the india made one. and believe me ... we were both not very pleased ... on opening the set we came to realise the biggest differenct . the power supply section used a teeny weeny transformer in the india counter part. which in turn was effecting the bass out put of the set . well he managed to get the power supply tweaked up and the system was working fine but not as good as the us counterpart .....
seem s these things do happend.
Binil😎
tcpip said:
hey you know even i feel the thing about trans nationals:
i have a sony hi fi home theater combo vcd player ... i had got it from dubai in one of my visits there. it is a made in usa. it gave me ultimate perfomance.
😎
then one of my pals after seeing my system bought one sony- the same model - but the india made one. and believe me ... we were both not very pleased ... on opening the set we came to realise the biggest differenct . the power supply section used a teeny weeny transformer in the india counter part. which in turn was effecting the bass out put of the set . well he managed to get the power supply tweaked up and the system was working fine but not as good as the us counterpart .....
seem s these things do happend.
Binil😎
Re: Re: Re: TS parameters for Bolton
I have not yet received the drivers from Bolton. Once they arrive, I'll let you guys know. I guess you already know the T/S parameters of this one... Angshu supplied them to me. I intend to put them into tall floor-standers, each with four of these midbass units and one Peerless tweeter. And drive each driver with a separate gainclone (five gainclones per speaker box). 🙂 Honest. 😀
Wish me luck. 🙂
Nice to hear from you. 🙂 We've missed you in this thread and this one. Where have you been? Ashok (corbato) was so happy to make your acquaintance recently, and we haven't yet met. 😀navin said:
I have not yet received the drivers from Bolton. Once they arrive, I'll let you guys know. I guess you already know the T/S parameters of this one... Angshu supplied them to me. I intend to put them into tall floor-standers, each with four of these midbass units and one Peerless tweeter. And drive each driver with a separate gainclone (five gainclones per speaker box). 🙂 Honest. 😀
Wish me luck. 🙂
Re: Re: Transnational brands
This is very interesting, and probably has a very clear explanation. In the US, it's legally required by their FCC that any audio amplifier must publish power ratings in RMS continuous per channel, at 1KHz, and this should be verifiable. In India, there's no such legislation, hence manufacturers all advertise PMPO and give you rubbish when it comes to actual power rating. I can't even say I blame the manufacturer, if the Indian customer continues to flock to the showroom and pick up such junk. 😀 How many of your Yuppie friends have Bose Acoustimass, for instance? I have four such friends. And two of these four are qualified engineers. 🙂brokenbinil said:
Re: Re: Re: TS parameters for Bolton
Mr.J.S.Monga
Bolton Private Limited
14/3 Milestone, Delhi-Mathura Road
Faridabad, Haryana 121003
Please note that they don't use faxes, let alone the Internet, and hence can take time to respond and reply. They write replies on manual typewriters. Honest. 🙂
Here it is:dumrum said:
Mr.J.S.Monga
Bolton Private Limited
14/3 Milestone, Delhi-Mathura Road
Faridabad, Haryana 121003
Please note that they don't use faxes, let alone the Internet, and hence can take time to respond and reply. They write replies on manual typewriters. Honest. 🙂
Re: Re: Re: Re: TS parameters for Bolton
5 gain clones per channel! u are nuttier than me.
I did not know the other threads existed. I will be awfull busy for a while so i dont know how much i can contribute. however i will check them out asap.
ashok is a totally cool guy he has jump started my tube amp project.
tcpip said:
5 gain clones per channel! u are nuttier than me.
I did not know the other threads existed. I will be awfull busy for a while so i dont know how much i can contribute. however i will check them out asap.
ashok is a totally cool guy he has jump started my tube amp project.
Re: Re: Re: Re: Re: TS parameters for Bolton
Jokes apart, basically, there are sound reasons to use this architecture. Basically, the xo frequency I'm using is 2.5KHz, which means perhaps 75% of the actual energy in music will be below the xo frequency. This means that if I power the tweeter with X watts, I should probably power the midbass section with 3X to 4X watts. And my box has four midbass drivers, because otherwise I'll run out of excursion. (I'm building a sealed box, which always needs lots of Xmax from the driver. And these drivers have only modest Xmax. Hence the choice of multiple drivers.)
So, putting all this together, it seemed a very logical idea to build five small inexpensive high-quality amps, and use one for each driver. That way, I'll have about 40W on tap for the tweeter, and four times this for the midbass section. The gainclones are good amps in terms of sound quality; the only thing they lack is power rating. With this approach, I think I'll be able to get enough SPL even in a sealed box.
I resent this! I am not nutty. I am never nutty. All my decisions are based on sound engineering principles and fundaes picked up from Gooroo Angshoo.navin said:
Jokes apart, basically, there are sound reasons to use this architecture. Basically, the xo frequency I'm using is 2.5KHz, which means perhaps 75% of the actual energy in music will be below the xo frequency. This means that if I power the tweeter with X watts, I should probably power the midbass section with 3X to 4X watts. And my box has four midbass drivers, because otherwise I'll run out of excursion. (I'm building a sealed box, which always needs lots of Xmax from the driver. And these drivers have only modest Xmax. Hence the choice of multiple drivers.)
So, putting all this together, it seemed a very logical idea to build five small inexpensive high-quality amps, and use one for each driver. That way, I'll have about 40W on tap for the tweeter, and four times this for the midbass section. The gainclones are good amps in terms of sound quality; the only thing they lack is power rating. With this approach, I think I'll be able to get enough SPL even in a sealed box.
Yes, he's a gem, but be afraid of these bottleheads. Be very afraid. Before you know it, they'll shove a pentode down your ... throat. They do such things for fun, you know. Be very afraid. 😀
T/S parameter for Bolton
Please check post 180 in this thread where I had poasted some of the T/S parameters of some Bolton Drivers I have used.
http://www.diyaudio.com/forums/showthread.php?postid=180165#post180165
Please check post 180 in this thread where I had poasted some of the T/S parameters of some Bolton Drivers I have used.
http://www.diyaudio.com/forums/showthread.php?postid=180165#post180165
Re: Re: Re: Re: Re: Re: TS parameters for Bolton
hold on.....a minute....the 75% you are talkng about is the energy spectrum for western classical musicin pre CD days. rock ranges from 75/25 (The Who) to 70/30 (Tom Petty, Pink Floyd) elecotronic music is 65/35 (kraftwerk etc...). I actually did energy analysis 20+ years ago. However a 3:1 ratio for midbass:tweeter is good.
Few home audio tweeters need to or can handle 40W rms. The best in this respect are the Dynaudio D28 and the Morel MDT33 and even they would be hardpressed. tweeter protection against transients is usually a solution that creates a bigger problem that it solves. most manufactuers solve this by using higher order XOs instead. if you are going to be active on the tweeter you might be able to build some protection into the tweeter amp (or maybe Ashok could interest you in building a 5W SE amp for the tweeter).
As far as excursion is concerned. how big is your room? what is Sd and Xmax of the woofer? hat Max SPLS are you expecting? I suspect 3 8" woofers with a Sd of 200cm2+ and Xmax (linear one way) of 6mm should suffice for a room of say 250sq. ft x 10 ft ceiling.
also 3 x 8" woofers will mean that the center of the tweeter is about 33" from the floor. This is good listening height.
If you are interested in 4-5 8" woofers there is an alternate solution. push push 2.5 way. with 1 8" going to 2.5k and the other 3-4 being run to about 300-400Hz.
BTW ashok already has shoved not 1 or 2 bottles down my throat but a full complement of 10
😀 
😕
tcpip said:
hold on.....a minute....the 75% you are talkng about is the energy spectrum for western classical musicin pre CD days. rock ranges from 75/25 (The Who) to 70/30 (Tom Petty, Pink Floyd) elecotronic music is 65/35 (kraftwerk etc...). I actually did energy analysis 20+ years ago. However a 3:1 ratio for midbass:tweeter is good.
Few home audio tweeters need to or can handle 40W rms. The best in this respect are the Dynaudio D28 and the Morel MDT33 and even they would be hardpressed. tweeter protection against transients is usually a solution that creates a bigger problem that it solves. most manufactuers solve this by using higher order XOs instead. if you are going to be active on the tweeter you might be able to build some protection into the tweeter amp (or maybe Ashok could interest you in building a 5W SE amp for the tweeter).
As far as excursion is concerned. how big is your room? what is Sd and Xmax of the woofer? hat Max SPLS are you expecting? I suspect 3 8" woofers with a Sd of 200cm2+ and Xmax (linear one way) of 6mm should suffice for a room of say 250sq. ft x 10 ft ceiling.
also 3 x 8" woofers will mean that the center of the tweeter is about 33" from the floor. This is good listening height.
If you are interested in 4-5 8" woofers there is an alternate solution. push push 2.5 way. with 1 8" going to 2.5k and the other 3-4 being run to about 300-400Hz.
BTW ashok already has shoved not 1 or 2 bottles down my throat but a full complement of 10
😀 😕Re: Re: Re: Re: Re: Re: Re: TS parameters for Bolton
The Xmax of these 6.5" Bolton drivers (the 16SJW22) is aboiut 6mm peak-to-peak, I think. Check the post Angshu has cited above, for full details. Bolton calls them subwoofers, because their other 6.5" drivers have less Xmax. I'm expecting that I'll be able to get 100dB+ of SPL with four of these per channel even in a sealed box, without having to go to the Xmax limit. I intend to use Linkwitz Transforms to get the Qtc and fc right.
You're probably dead right, but I am not inclined to fine-tune the power distribution any further. My aim is primarily to ensure that both the midbass and the tweeter sections get enough power for "normal" listening, that's all. BTW, I wonder what was the xo freq for which you did your energy analysis?navin said:
I guess so. But you see, I no longer have the freedom to change drivers. I have decided to use these Bolton 6.5" midbass units based on extensive feedback from Angshu and the sound that I've heard from them. It's not just good enough to choose a driver based on its Xmax and diameter, in this case you also havel to entrust the entire midband to it. Therefore, its accuracy and low-distortion characteristics for the critical voice range is really the deciding factor. This means that if I get an 8" driver with high Xmax but unknown midrange abilities, versus a smaller driver with lower Xmax but with superb midrange, I will go for the smaller driver and compensate by adding more drivers, I think.
The Xmax of these 6.5" Bolton drivers (the 16SJW22) is aboiut 6mm peak-to-peak, I think. Check the post Angshu has cited above, for full details. Bolton calls them subwoofers, because their other 6.5" drivers have less Xmax. I'm expecting that I'll be able to get 100dB+ of SPL with four of these per channel even in a sealed box, without having to go to the Xmax limit. I intend to use Linkwitz Transforms to get the Qtc and fc right.
I don't think I've grown up enough yet to understand this sort of architecture. Maybe next time... 🙂
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