Group DIY Sub Build: With Peerless Driver and Forte 200 Watts Amp

[anujmishra]

I am planning to build a Indian procured sub for myself. It will be based on t.anthony's design <*All credit goes to t.anthony*> and I am planning no modifications into it. However, if any new good plan comes for box, I am open to consider it.

Driver: Peerless 12" Driver. 4 Ohm and 250 Watts.
Plate Amp: Forte 200 Watts amp at 4 Ohm

It will be VFM sub with max characteristics with Indian products. I thought lets ask fellow FM if they are also interested having this Sub for themselves. It will cost less than 16K (estimate). If there are sufficient members available, we can have better value proposition in building box for the sub.

Driver will cost around: Rs. 2800 + Shipping.
Amp will cost around: Rs. 5500+ Shipping.

Amp and driver will be procured from Varsha Electronics (JeetuBhai), Mumbai.
Similar Amp and Driver some other FMs procured in past. Here are the images of Driver

All pictures courtsey t.anthony from his thread.

Here is TS parameters for Driver:

Fs : 24.94 Hz
Re : 3.68 ohms
Qms : 1.17
Qes : 0.45
Qts : 0.32
Le : 0.53 mH
Vas : 256.35 liters
Mms : 59.71 gms
Cms : 678
BL : 8.80
SPL : 94.7 dB
Sd : 518.75 cm2

Here is pics of Amp:

Here is pic of Sub box:

All pictures courtsey t.anthony from his thread.

Build plan is available in t.anthony's thread.

Idea is to have group buy of Driver, Amp and build all boxes at one place with one Carpenter with proper laminate finish.

I will coordinate this activity for interested members right from procuring items to building and finishing. I have few carpenters who worked for me. Even, today they are working at home and building my AVR rack and LED back etc.

Please let me know if any of you interested. Minimum 4 numbers required to execute group plan. Otherwise, I will build for myself. As per my estimate total cost per sub should not go beyond 16K. But this is estimate. Final cost can be lesser than 16K. Cost will be finalized once, I will speak with carpenter. All expenses will be as per cost basis with maximum bargain from all involved vendors.

I am newbie in building sub, so would like to execute only successful plan rather than modifying it. Design of box look good to me and it is as per driver specification.

Let me know, any of you interested in this. And yes, as of now it is open to Bangalore residents considering the shipping for this big sub. But, if anybody want it to shipped at their risk and cost we can consider. It will be fine collaboration effort.

 

[anm]

great decision Anuj. I am in NCR so building cab may not work out for me.

 

[Flash]

ah Anuj, so Jeethubhai did send you a quote .
I was spot on with the pricing, so it seems

 

[anm]

is the woofer 4ohm?

 

[Flash]

is the woofer 4ohm?

Yes it is .
Most Sub woofers have a 4 ohm impedence.


@anuj :::
WIth a sub, the Cabinet is where the magic happens. Several hurdles you may come by -------
Damping, - get it wrong and there could be some serious trouble with cabinet resonance.
Make sure the cabinet is airtight as well

 

[cmsajith]

Anuj, great effort. If you need any help in your build dont hesitate to contact me.

 

[anujmishra]

great decision Anuj. I am in NCR so building cab may not work out for me.

Thank you.

ah Anuj, so Jeethubhai did send you a quote .
I was spot on with the pricing, so it seems

Yes, you are absolutely correct with pricing. Experience counts. :thumbsup:

is the woofer 4ohm?

Yes it is. I confirmed from Jeetubhai.

Yes it is .
@anuj :::
WIth a sub, the Cabinet is where the magic happens. Several hurdles you may come by -------
Damping, - get it wrong and there could be some serious trouble with cabinet resonance.
Make sure the cabinet is airtight as well

Well this is area we need help from experts like you. I am just volunteering to execute gyan I got from all you guys. I will not hesitate to ask you all questions. Also, I have our in-house expert near me Sajith (cmsajith). He already built mega monster sub for himself.

Anuj, great effort. If you need any help in your build dont hesitate to contact me.

Thank you Sajith. I will absolutely need your help. I will keep you posted about developments.

 

[gcpraveen]

I am also looking for this, but have never tried DIY . Will my yamaha 667 will drive this?
One of the forum member quoted wharf SW150 for 19k. hope this will be very powerful than that.
Anuj, are you coming for workshop in bangalore this sunday? I am novice in this. We can talk about this.
Praveen.

 

[Spinekar]

Thank you.



Yes, you are absolutely correct with pricing. Experience counts. :thumbsup:



Yes it is. I confirmed from Jeetubhai.



Well this is area we need help from experts like you. I am just volunteering to execute gyan I got from all you guys. I will not hesitate to ask you all questions. Also, I have our in-house expert near me Sajith (cmsajith). He already built mega monster sub for himself.



Thank you Sajith. I will absolutely need your help. I will keep you posted about developments.

so nice
this is like a feel good movie, something nice being started and everyone contributing there bit to help the cause.. keep it going guys, will watch till the end hyeah:

 

[anujmishra]

I am also looking for this, but have never tried DIY . Will my yamaha 667 will drive this?
One of the forum member quoted wharf SW150 for 19k. hope this will be very powerful than that.
Anuj, are you coming for workshop in bangalore this sunday? I am novice in this. We can talk about this.
Praveen.

Since, this will be active sub so any AVR/Amplifier can drive this sub.

Yes, I am coming for workshop on Sunday. I will be present till lunch and then
I have to move as guests are coming.

so nice
this is like a feel good movie, something nice being started and everyone contributing there bit to help the cause.. keep it going guys, will watch till the end hyeah:

Thanks.

 

[GeorgeO]

Tomorrow's workshop is a good opportunity for Bangalore folks to jump on this garvy train!

 

[anujmishra]

Not many people seems to be interested so I have started work on my building. Yesterday box was ready and I'm waiting for Plate Amp and Driver. Back part was not cut as waiting for dimensions of plate amp.

It is made of 19mm MDF. Carpenter cut the driver rounds by hand with small hand saw and it is perfect as per measurement given in the t.anthony thread.

Once driver will arrive I will hook-up amp and driver and do the testing.

Following are the open questions for finishing and damping. Need you help.

1. Internal damping with Fiberglass or bitumen?

2. External finishing of box. Options available of painting and laminate. I would go for laminate and looking for matching laminate with my speaker exteriors.

3. Where to find grill or cloth for sub? There are certain grills are on sale in ebay. Grills can be sourced from some auto-shop who builds sub for cars.

4. Black color port pipe with some exterior molding? Would guys who makes sub box for cars can make it available? What are other options available other than using regular PVC pipe.

 

[t.antony]

Panel damping with fiberglass is more effective than bitumen damping. However, if you have not worked with fiberglass before, I would suggest bitumen instead. Please keep in mind that process of damping the panels is different than stuffing the enclosure with fiberglass(glass wool).

For this enclosure only damping the panels is needed and stuffing of any kind is not required. Easy way to damp the panels is lining the insides with bitumen roofing sheets. These sheets usually comes in about 1mm thickness. Stick multiple sheets to increase the bitumen layer to about 5mm.

Making a flared port with pvc pipe is easy. Heat the pipe and press it against a spherical object. If you are planning to paint the pipe, first sand it with 120 grit paper.

 

[anujmishra]

Panel damping with fiberglass is more effective than bitumen damping. However, if you have not worked with fiberglass before, I would suggest bitumen instead. Please keep in mind that process of damping the panels is different than stuffing the enclosure with fiberglass(glass wool).

I have one question regarding damping. In automobile they use Rubber Paint for rust protection below. It is kind of bitumen type only but in paint type. It is said that it also dampens vibration in automobile.

If we coat inside box with rubber paint of 2 - 3 coats, would it work?

http://www.amazon.com/BlueMagic-950-Pure-Rubber-Coating/dp/B000CCFY9S

15 ounce Pure Rubber, contains no asphalt
Works as a sealer, sound deadener and undercoat
Fast drying, paintable
Tough and flexible, will not bleed

There are many Indian varieties available in hardware shops. I think after 2-3 application it will become 1mm thick. Suggestions please.

 

[anujmishra]

Can anyone reply that Rubber Paint would be valid option for damping Sub box in place of bitumen?

 

[t.antony]

1mm thickness wouldn't suffice. I don't know how effective the rubber paint is but Bitumen will be more cost effective for the required thickness.

 

[cmsajith]

another simple option is the wall tile, but need to stick it with good glue

 

[Flash]

I have one question regarding damping. In automobile they use Rubber Paint for rust protection below. It is kind of bitumen type only but in paint type. It is said that it also dampens vibration in automobile.

If we coat inside box with rubber paint of 2 - 3 coats, would it work?

MDF is a tricky material to work with . and using the wrong paint or primer can eat into the MDF. So not too sure how it would work.

So Bitumen sheets would be my first option .
However Pyramid Acoustic Panels can also do wonders and probably the best option if budget permits. - a costlier proposition though - you would need to factor in the space taken by the acoustic panels as well . so design your cab internal volume accordingly

Felt wadding is also another alternative.

 

[quad]

Dynamat or similar damping pad is likely to be more effective than the
rubber paint. Google for it.
Antony's suggestion of Bitumen sheet is a good, cost effective option.

 

[anujmishra]

Dynamat or similar damping pad is likely to be more effective than the
rubber paint. Google for it.
Antony's suggestion of Bitumen sheet is a good, cost effective option.

Thanks. Yes, Dynamat is extensively used in Autos for damping purpose. Bitumen sheets which in this case is feasible and inexpensive solution. I will go with it.

Tomorrow I will procure these sheets and put in my box. I will post pictures tomorrow.