Here's an update on my MP's sub...
The cargo company - Gati- have misplaced the parcel.
Man......why do such things always happen to me??....WHY???
However I do certainly agree with Navin, Tarun & George on Paleshas good quality of service. Initially was wondering why the long delay, so called his office to enquire. He wasn't available but the person who attended the call noted my Tel#. Soon enough I receive Palesha's call (Narendra Palesha??) informing it was promptly dispatched on 8th and it was supposed to arrive latest by 13th. Gave me the docket details and asked to confirm once I receive.
The cargo tracking details on GATI's website indicated the parcel has arrived my town on the 12th. But on contacting them said they dont have it and by oversight must have accidently gone to some other destination. They assured the're in the process of tracing it and will definitely be available in the next 2-3 days.
Meanwhile thought I'd start designing the cabinet.
Palesha had emailed the T/S parameters:-
10" DEEP DRIVER
Cone Material : Poly/Mica
Edge Material : Rubber
Maximum Power : 250W
SPL 1W/1M : 86 dB
Fo : 32 Hz
Bl : 12.4 TM
Mms : 94.8 g
Vas : 33.7 L
Qms : 3.53
Qes : 0.40
Qts : 0.38
Magnet Size : 40 Oz
Voice Coil Dia : 2"
Voice Coil : KSV
Xmax : 7.5 mm
Once Gati traces it, pray it arrives in one piece.
The cargo company - Gati- have misplaced the parcel.
Man......why do such things always happen to me??....WHY???
However I do certainly agree with Navin, Tarun & George on Paleshas good quality of service. Initially was wondering why the long delay, so called his office to enquire. He wasn't available but the person who attended the call noted my Tel#. Soon enough I receive Palesha's call (Narendra Palesha??) informing it was promptly dispatched on 8th and it was supposed to arrive latest by 13th. Gave me the docket details and asked to confirm once I receive.
The cargo tracking details on GATI's website indicated the parcel has arrived my town on the 12th. But on contacting them said they dont have it and by oversight must have accidently gone to some other destination. They assured the're in the process of tracing it and will definitely be available in the next 2-3 days.
Meanwhile thought I'd start designing the cabinet.
Palesha had emailed the T/S parameters:-
10" DEEP DRIVER
Cone Material : Poly/Mica
Edge Material : Rubber
Maximum Power : 250W
SPL 1W/1M : 86 dB
Fo : 32 Hz
Bl : 12.4 TM
Mms : 94.8 g
Vas : 33.7 L
Qms : 3.53
Qes : 0.40
Qts : 0.38
Magnet Size : 40 Oz
Voice Coil Dia : 2"
Voice Coil : KSV
Xmax : 7.5 mm
Once Gati traces it, pray it arrives in one piece.
hi
i wouldnt want this to be taken other wise - Price ?
and how much did the packing & forwarding cost you
suranjan
i wouldnt want this to be taken other wise - Price ?
and how much did the packing & forwarding cost you
suranjan
to roshan
2.1 K is not a bad deal at all really .....
hey roshan but u did not tell me about the doubt i asked u man .... please helpyaar ......u said i need to use a mono amp . now where do i get a left n rite channel in a mono.
2.1 K is not a bad deal at all really .....
hey roshan but u did not tell me about the doubt i asked u man .... please helpyaar ......u said i need to use a mono amp . now where do i get a left n rite channel in a mono.
roshan101 said:
The Bl/mms ratio is low for a 10" the peerless CSX 85016 has a Bl of 10 and Mms of 50gms. It's fs is 22 Hz, and it Qts is .35 which is close. only it's vas is 4 times the palesha.
hi
if the mag size is >= 155 mm X 20 and the top plate > = 6mm
its not a bad deal ,
Navin it seems this 10 inch has a larger motor stucture therefore better figure in the Bl to Moiving mass ratios
plus moulding pp cones deep is expensive and difficult , reinforcement is required (which makes the cones heavier) there fore the difference in VAS - may be , only may be
suranjan
if the mag size is >= 155 mm X 20 and the top plate > = 6mm
its not a bad deal ,
Navin it seems this 10 inch has a larger motor stucture therefore better figure in the Bl to Moiving mass ratios
plus moulding pp cones deep is expensive and difficult , reinforcement is required (which makes the cones heavier) there fore the difference in VAS - may be , only may be
suranjan
correct me if i am wrong...!
If i have not mistaken...the lower VAS just indicates that it has a bit more stiffer suspension...
Stiffer because it has to keep a higher moving mass in control..but stiffer suspension and a heavier cone also means u need a bit more force to move the cone around...that plus the efficiency requirement explains the higher Bl factor...Is that not so...!!
In that case would just the comparison of VAS really suffice??...other than the fact that they provide an indication of box sizes required...?? If that is the case the MP woofer would require a much smaller box than the peerless...!!(am i correct..?)
second thing...!! Yes i do understand that the top plate thickness would be responsible for the figuritive X-Max Specs...
but how does the size of the magnet really matter except for the final physical dimensions and mounting constraints...all that we are interested in finally is the Bl...arent we...?
ajju
If i have not mistaken...the lower VAS just indicates that it has a bit more stiffer suspension...
Stiffer because it has to keep a higher moving mass in control..but stiffer suspension and a heavier cone also means u need a bit more force to move the cone around...that plus the efficiency requirement explains the higher Bl factor...Is that not so...!!
In that case would just the comparison of VAS really suffice??...other than the fact that they provide an indication of box sizes required...?? If that is the case the MP woofer would require a much smaller box than the peerless...!!(am i correct..?)
second thing...!! Yes i do understand that the top plate thickness would be responsible for the figuritive X-Max Specs...
but how does the size of the magnet really matter except for the final physical dimensions and mounting constraints...all that we are interested in finally is the Bl...arent we...?
ajju
Yes, the Vas is a bit low. NET vol is a little less than 1 cu.ft. A bit strange for a 10" driver. But that's supposed to be good, right? Guess car subs are always designed to save space........Trade off being Fs in the 30's
Port length seems to be on the longer side. Calculating using WinISD , within permissible vent mach...
One min port dia of 6.5cms will require a length of 10.1". This would require flexible tubing - considering the small size of cabinet.
Next option : 2 ports 3.3cms dia require min length 5.24" . This is more reasonable. Wonder if 3.3cm port dia is too small for sub.
Binil, Let me rephrase....use ur stereo to convert to mono.
Port length seems to be on the longer side. Calculating using WinISD , within permissible vent mach...
One min port dia of 6.5cms will require a length of 10.1". This would require flexible tubing - considering the small size of cabinet.
Next option : 2 ports 3.3cms dia require min length 5.24" . This is more reasonable. Wonder if 3.3cm port dia is too small for sub.
Binil, Let me rephrase....use ur stereo to convert to mono.
o roshan
now i got it .... i think it was jus that i was racking my brains too much on that ...... well about the MP woofer hope u get it soon ....
do keep us updated ...
Binil
now i got it .... i think it was jus that i was racking my brains too much on that ...... well about the MP woofer hope u get it soon ....
do keep us updated ...
Binil
Well..Car subs might have huge VAS specs...!! especially the Free air mount catagory...they are just supposed to be mounted on a plank or the real parcel tray...Works very well for vehichles with good boot..!! But what the car woofers suffer from is a very peaky Q...
the Q's associated with the drivers are of teh order of .5 to .7...!!
Depends...Look at the air velocity plot in the port..that should be of primary concern...!! The next in line, but less critical, will be the acoustic resistance presented by the port and all...!!
hi
ajju - i was replying to the cost factor when i mentioned the mag
size , it has nothing to do with specs
secondly all u have mentioned as far as my knowledge goes is correct
x- max is above 7 mm
could roshan do a s- max test for me
its pretty basic
push the woofer down - with your hand apply force increasing it linearly and make a rough estimation of the amount the cone has travelled from rest - try and measure it i mm or try and make an accurate guess
next place both your palms below the cone and push - upwards - similarly to above and measure
(you can do this with a new 9 volt battery too)
i dont want to get into any stone throwing here its a simple test which i would like to advise all to estimate suspension linearity
till i cannot provide any products i have no right to comment on MP s
suranjan
ajju - i was replying to the cost factor when i mentioned the mag
size , it has nothing to do with specs
secondly all u have mentioned as far as my knowledge goes is correct
x- max is above 7 mm
could roshan do a s- max test for me
its pretty basic
push the woofer down - with your hand apply force increasing it linearly and make a rough estimation of the amount the cone has travelled from rest - try and measure it i mm or try and make an accurate guess
next place both your palms below the cone and push - upwards - similarly to above and measure
(you can do this with a new 9 volt battery too)
i dont want to get into any stone throwing here its a simple test which i would like to advise all to estimate suspension linearity
till i cannot provide any products i have no right to comment on MP s
suranjan
roashan at 1 cu. ft. volume what F3 are you getting? seems perfect for a sealed /aperiodc box car sub
Gati has finally traced the parcel. It should arrive tomorrow.
Suranjan, I'll do the measurements & let you know soon.
Navin, At 0.978 cu ft. its 34.12Hz. WinISDN shows EBP = 80 which makes it suitable for vented. Indicator bar is not too far from midway between vented & closed.
Suranjan, I'll do the measurements & let you know soon.
Navin, At 0.978 cu ft. its 34.12Hz. WinISDN shows EBP = 80 which makes it suitable for vented. Indicator bar is not too far from midway between vented & closed.
Just recd the sub. Fortunately there's not a single scratch. Driver was bolted to a thick circular piece of MDF...so everything is perfectly fine.
The polymica finish is pretty cool..and its got a huge surround..😀
Suranjan; mag size is about 150x20mm . Dont know what a top plate is...forgive my dumbness.
testing for Xmax .. could depress the cone to about 7-8mm. Lifting up was a bit tough.- came to about 5-6mm.
Cabinet isn't ready yet & didnt have a spare 10" cabinet, so had to test performance using ....a plastic bucket. -dont laugh. Well, that was a stupid idea. Didnt sound good at all.
Tried Suranjan's test method of applying signal w/o XO. Fed test tones from 10hz to 1 Khz. Beyond 200Hz theres a large reduction in SPL but not completely dead. Well, that test must be applicable for truly hi-funda subs.
Seems like it will require a powereful amp. Had to turn the knob of 40W amp to almost 75% to get a decent volume.
Of course all this could be totally wrong....remember I'm using a bucket.
Think it'll be a good idea to change the XO in the amp as well. Currently its a simple R-C based speaker level low-pass filter. Might be better if its changed to line level & add some sort of a bass booster.
The polymica finish is pretty cool..and its got a huge surround..😀
Suranjan; mag size is about 150x20mm . Dont know what a top plate is...forgive my dumbness.
testing for Xmax .. could depress the cone to about 7-8mm. Lifting up was a bit tough.- came to about 5-6mm.
Cabinet isn't ready yet & didnt have a spare 10" cabinet, so had to test performance using ....a plastic bucket. -dont laugh. Well, that was a stupid idea. Didnt sound good at all.
Tried Suranjan's test method of applying signal w/o XO. Fed test tones from 10hz to 1 Khz. Beyond 200Hz theres a large reduction in SPL but not completely dead. Well, that test must be applicable for truly hi-funda subs.
Seems like it will require a powereful amp. Had to turn the knob of 40W amp to almost 75% to get a decent volume.
Of course all this could be totally wrong....remember I'm using a bucket.
Think it'll be a good idea to change the XO in the amp as well. Currently its a simple R-C based speaker level low-pass filter. Might be better if its changed to line level & add some sort of a bass booster.
hi
thanks for the info - from the mag size its evident that the pricing is good
from your suspension - test , i suggest you break in the woofer
this is very important - do not go for the t/s parameters of the woofer as it is now
just briefly measure it - most probably it will be a bit off from -
MP s
break in the woofer (for some time) and take measurements
here are few things you can enjoy doing now
sweep the signal - (without the driver in a box) at a low appropiate volume
check the frequency where you get the max spl
then break in the woofer - and perform the similar test you will find the fs - going down
now since its going to be a sub i assume you will be tring to get your port tuning according to this - fs you have measured
feed a low signal of around 40 to 60 HZ and at around 4 to 5 watts (low volume) for the break in - check the back plate of the driver it should not heat up (if it heats lower the volume)
another big advancement you could eaily make - is make sure the port and driver is in phase
for this if you build in a phase control network at the pre stage of the amp - elektor has quite a few projects as to how this is done , using an op - amp , you could make it in a verro board
ill see if i can provide you an url of such a circuit
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also mount the driver at the exact centre of the enclosure (& if you off center the driver ) for a port ets - place it in such a way that the cone back is evenly loaded with a column of air
what i mean is if you divide the cone in two halves - a plane going through the center of the cone - right angles to the plane of the magnet plane
then each half of this cone should be as evenly loaded by the back air volume as possible _ this is to ensure a long period of running and avoid rubbing at high power
another thing with an x- max of 7 mm you ll be needing a 100 w amp plus
suranjan
thanks for the info - from the mag size its evident that the pricing is good
from your suspension - test , i suggest you break in the woofer
this is very important - do not go for the t/s parameters of the woofer as it is now
just briefly measure it - most probably it will be a bit off from -
MP s
break in the woofer (for some time) and take measurements
here are few things you can enjoy doing now
sweep the signal - (without the driver in a box) at a low appropiate volume
check the frequency where you get the max spl
then break in the woofer - and perform the similar test you will find the fs - going down
now since its going to be a sub i assume you will be tring to get your port tuning according to this - fs you have measured
feed a low signal of around 40 to 60 HZ and at around 4 to 5 watts (low volume) for the break in - check the back plate of the driver it should not heat up (if it heats lower the volume)
another big advancement you could eaily make - is make sure the port and driver is in phase
for this if you build in a phase control network at the pre stage of the amp - elektor has quite a few projects as to how this is done , using an op - amp , you could make it in a verro board
ill see if i can provide you an url of such a circuit
--------------------------------------------------------------------------
also mount the driver at the exact centre of the enclosure (& if you off center the driver ) for a port ets - place it in such a way that the cone back is evenly loaded with a column of air
what i mean is if you divide the cone in two halves - a plane going through the center of the cone - right angles to the plane of the magnet plane
then each half of this cone should be as evenly loaded by the back air volume as possible _ this is to ensure a long period of running and avoid rubbing at high power
another thing with an x- max of 7 mm you ll be needing a 100 w amp plus
suranjan
hi Suranjan,
Thanks for those tips. I'm not really too keen on measuring t/s paras - mainly because Im ill equipped. Dont have a signal generator or freq counter. Am using a CD for test tones-burnt from a tone generating software. My DVM can measure ACV only to a single decimal place - and have no idea of its accuracy.
I'm sure MP would have taken those measurements with utmost care & with much better equipment. Even if his figures are slightly off, the's still scope for fine tuning by varying portlength & adding extra felt.
Was planning to eliminate phase contol altogether. But now am considering to add one since you feel it indispensible. Hope a simple phase switch will suffice. Dont like to fiddle with too many controls. Planning to incorporate a simple circuit available at ESP site.
Abt the cabinet have attached a pic of design I have in mind. Hope this will be OK.
BTW - recd a call from Palesha yet again to ensure the driver was safe. I must say such kind of customer service is truly hard to find.
Thanks for those tips. I'm not really too keen on measuring t/s paras - mainly because Im ill equipped. Dont have a signal generator or freq counter. Am using a CD for test tones-burnt from a tone generating software. My DVM can measure ACV only to a single decimal place - and have no idea of its accuracy.
I'm sure MP would have taken those measurements with utmost care & with much better equipment. Even if his figures are slightly off, the's still scope for fine tuning by varying portlength & adding extra felt.
Was planning to eliminate phase contol altogether. But now am considering to add one since you feel it indispensible. Hope a simple phase switch will suffice. Dont like to fiddle with too many controls. Planning to incorporate a simple circuit available at ESP site.
Abt the cabinet have attached a pic of design I have in mind. Hope this will be OK.
BTW - recd a call from Palesha yet again to ensure the driver was safe. I must say such kind of customer service is truly hard to find.
Attachments
do tell us how the sub perfroms. i just realised it might be just the ticket for those NHT 3.3 like systems. a box that is 36"x6"x12" (internal) can house this 10" and a 5/6" 2 way. Only thing is in 1 cu. ft. how tight is the bass?
Hi Roshan
I've been following this thread for a while..Having been down the powered sub route acouple of times, I can also share my experience with you. First of all Mahendra Palesha is a really good guy to interact with-I've met him asa friend and had dinner with him a couple of times. So his call to you to check things up is no surprise to me..
My subs are powered by plate amps, one is 175w and another is 250w rms at 8 ohms, for a sub it is advisable to have enough juice on tap. Both have phase switches. I used 12 inch high excursion drivers, one is from Audio Concepts and another from Lambda Acoustics-arguably among the best sub drivers that were made-sadly they went out of business. One enclosure is sealed , downfiring, and the other uses a passive radiator. These are combined with stand mounted 2 ways.
What are your enclosure dimensions?
George
I've been following this thread for a while..Having been down the powered sub route acouple of times, I can also share my experience with you. First of all Mahendra Palesha is a really good guy to interact with-I've met him asa friend and had dinner with him a couple of times. So his call to you to check things up is no surprise to me..
My subs are powered by plate amps, one is 175w and another is 250w rms at 8 ohms, for a sub it is advisable to have enough juice on tap. Both have phase switches. I used 12 inch high excursion drivers, one is from Audio Concepts and another from Lambda Acoustics-arguably among the best sub drivers that were made-sadly they went out of business. One enclosure is sealed , downfiring, and the other uses a passive radiator. These are combined with stand mounted 2 ways.
What are your enclosure dimensions?
George
Hope I havent given the impression that the attached pic is my sub. Its a pic I picked up from another site. Just gave the dimensions to the carpenter. - should be ready in a couple of days. Its about 17"x12"x10" -internal w/allowance to house amp.
Navin, i'm not an experienced audiophile so cannot comment much on how tight or loose a sub sounds. Will give you a rough idea when its ready.
Navin, i'm not an experienced audiophile so cannot comment much on how tight or loose a sub sounds. Will give you a rough idea when its ready.
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