My first speaker building experience

[photoprashanth]

Hi,
While browsing through this forum I developed some interest in building an HT speaker system.
I searched for some designs with locally available items. I could not find one design with
complete details. So I had to look elsewhere to get a design which was affordable.
I came across this thread
Maurbacs NS6 MTM
I selected this because of the cost of the drivers used in the design.

Drivers used are: Aura NS6-255 ($9) and Vifa BC25SC06 ($15).
I imported these speakers using iccworld ppobox. Finally when my shipment reached me in Bangalore,
I felt they costed a bomb just because I did not know about Volumetric weight. (8K for stuff and 14K for shipment ).

Started with creating the crossover and realized that getting Inductors is the biggest problem.
So I had to build a Jig to wound coils myself.

Bought Atlas Copperwire 18 gauge. Found online calculators to find the turns and
used my Android phone as counter (proximity sensor counter) and finally could wound the coils and
measured the Inductance with LIMP software. Fortunately the coils were within 5% variations.

Polyester Capacitors and Resistors were sourced from various shops on SP Road in Bangalore.

and this is my Crossover


I connected the crossover to the drivers and placed them in a thermocol box. They sounded pretty nice and crisp.

Now the cabinet building. I decided to build the cabinet myself and bought a Router and MDF.
Built a Router table. MDF flat panels were cut and used home made Jig for circle cuts and the flat panels were ready.
This is when I realized, carpentry is not for everyone. Needs lot of DIY passion.

Once again I had to visit SP Road to get T-Nuts and chip screws (for MDF).

Assembled the flat panels and flush mounted the drivers and the speakers are ready. And port, port is a round plastic container bought from Reliance Mart and cut to measure very much close to what the designer has suggested (both dia and length).



This speakers sounded nice but boom boom..

Damping/Deadening material: The designer suggested 1" open cell foam on the walls of the box.
I had to go to Minarva circle and bought a foam and no one knows whether it is open cell or closed cell.
No body in RC road knows whether the foam they have is open cell or closed cell. As suggested by someone in the forum,
I did uffff.. uffff.. and I could feel some amount of hot air coming through the foam. I thought may be Open Cell..

This foam lining did reduce the boom to some extent but not completely.
Hence bought some pillows from Reliance mart and lined the walls as shown in the picture and the boom boom is gone.


Now I am listening to these speakers from last one month and for me, they sound great.
I also have a pair of Yamaha speakers, compared to Yamaha speakers,
these speakers sound much better and crispier. I am loving them.

If you have any queries on sourcing of materials or address of the shops where I bought the items or anything else related to build. I am happy to help.

It is just a speaker building experience from a DIY enthusiast and I am not an Audiophile. Components used are not exotic, they are just whatever is available in the market.

If you want to listen to these speakers and stay anywhere close to Hoodi circle in Bangalore can visit my house on weekends. I would be happy to show them.

Suggestions are very much welcome.

Thanks for reading..
Prashanth

 

[yemyes4u]

Hi me2 wanna build 7.2 channel speaker system for onkyo 809

 

[S.P.KRISHNA]

I felt they costed a bomb just because. I did not know about Volumetric weight. (8K for stuff and 14K for shipment ).

Suggestions are very much welcome.

Thanks for reading..
Prashanth

Finally how much did the entire project cost you. You did not mention the impedence and wattage of the speakers. you should have seperated the tweeter portion plus or minus with midrange driver with a flat pannel which would have been useful as internal bracing also. This would have incresed the SQ.

Regards

 

[photoprashanth]

Finally how much did the entire project cost you. You did not mention the impedence and wattage of the speakers. you should have seperated the tweeter portion plus or minus with midrange driver with a flat pannel which would have been useful as internal bracing also. This would have incresed the SQ.

Regards

Actually I have not calculated the cost for entire project yet.
Biggest portion is of-course Drivers and shipment
Approximate calculation.
Drivers+Shipping = 22K (for 8 woofers and 5 tweeters) Fronts and Center are MTM and Surrounds are TMs and No Sub-woofer.
MDF 2 sheets = 3.2K
Copper wire for coils = 1K
Capacitors and Resistors = .5K
Screws and Fevicol = .5K
Binding posts = .7K
Misc= 1K

Veneering is yet to be done. Cost depends on the material.

I have also bought Router (4.5K), clamps, saw etc.. which I have not included in the costs.

May be total cost can come to 34K for 5 channels.

I am planning to build sub-woofer from peerless driver available locally.

Regards,
Prashanth

 

[GeorgeO]

Great job Prashant! I too have MTM speakers for my HT system, I built the Audax HT speaker system.

 

[vktarun]

Excellent Job Done ! surprisingly you have done all the steps yourself without any frofessional help.

Started with creating the crossover and realized that getting Inductors is the biggest problem.
So I had to build a Jig to wound coils myself.

What is that Jig and how Impedance was calculated?

Now the cabinet building. I decided to build the cabinet myself and bought a Router and MDF.
Built a Router table.

What is this router table ?


Regards,

Vipin

 

[koushik]

S.P.Krishna - Did not understand your last point about separating the tweeter with midrange or..

 

[sudhishkv]

Great job! Where do you put up? Want to check it out on a weekend if you are ok with it.

 

[photoprashanth]

Excellent Job Done ! surprisingly you have done all the steps yourself without any frofessional help.

Started with creating the crossover and realized that getting Inductors is the biggest problem.
So I had to build a Jig to wound coils myself.

What is that Jig and how Impedance was calculated?

Now the cabinet building. I decided to build the cabinet myself and bought a Router and MDF.
Built a Router table.

What is this router table ?


Regards,

Vipin

It is just a frame made using mdf to hold a big and a small bobbin and a handle to the small bobbin to rotate to wound the coil. Number of turns required can be calculated using online tools like
Inductor Designer / Calculator or Coil32 - the coil inductance calculator

To count the number of turns, I used my mobile phone as counter. There is a proximity sensor in android mobile phones. There are some free applications available to count the number times this sensor is activated. This is what I used https://play.google.com/store/apps/details?id=com.nll.acounter



(Screwdriver and small bobbin is just for illustration. I have used a different bobbin with wood round plates and a handle instead of screw driver to turn the bobbin).

After completing the winding the coil, I measured the Inductance using Limp and the document explaining how to measure RLC. Laptop with sound card which has line-out and mic or line-in is required.
This too needs a small jig as explained here
This jig can also be used for measuring T/S parameters of a speaker.

I felt it is safe to work on a Router table rather than hand holding the Router.
I built a very simple Router table by fixing my Router on top of a MDF sheet.
Much simpler than this. But in the same lines.

All the help is available in net

 

[photoprashanth]

Great job! Where do you put up? Want to check it out on a weekend if you are ok with it.

No Issues. Currently I have built only Front two speakers. I stay near Hoodi Circle on ITPL main road (Road from KR Puram railway station to ITPL). You can call me, I will PM my number.

 

[babloo64]

Actually I have not calculated the cost for entire project yet.
Biggest portion is of-course Drivers and shipment
Approximate calculation.
Drivers+Shipping = 22K (for 8 woofers and 5 tweeters) Fronts and Center are MTM and Surrounds are TMs and No Sub-woofer.
MDF 2 sheets = 3.2K
Copper wire for coils = 1K
Capacitors and Resistors = .5K
Screws and Fevicol = .5K
Binding posts = .7K
Misc= 1K

Veneering is yet to be done. Cost depends on the material.

I have also bought Router (4.5K), clamps, saw etc.. which I have not included in the costs.

May be total cost can come to 34K for 5 channels.

I am planning to build sub-woofer from peerless driver available locally.

Regards,
Prashanth

Good Job for your 1st Experiance.But I feel that end of the Day when you calculate the cost it will cross 50k with Final finishing for 5 speakers.

 

[photoprashanth]

Good Job for your 1st Experiance.But I feel that end of the Day when you calculate the cost it will cross 50k with Final finishing for 5 speakers.

Well I did not calculate precisely.

But whatever price I have provided is for 5 speakers. Though I have built only 2 speakers for now,
but all the components including cross-overs and binding posts, foam and polyfill etc are already available with me.
I don't see any costly Items (except Veneer) is needed any more.

I will calculate once again precisely once I get some time.

But one thing is true, Importing drivers is a costly affair.
I have lost the price advantage already with shipping costs. But I have to do this as I could not find any design with locally available drivers.
And learning speaker design is not easy. Initially I thought just measuring T/S parameters will do, but
when I read through many forums, I realized it is not for ME. It requires lot of passion, time and effort, and not to mention the measuring equipment.

I wish someone someday provides a good and completely documented design using locally available drivers in this forum.

 

[navin advani]

Hi,
While browsing through this forum I developed some interest in building an HT speaker system

Bought Atlas Copperwire 18 gauge.

and this is my Crossover
View attachment 8786

Damping/Deadening material: The designer suggested 1" open cell foam on the walls of the box.

This foam lining did reduce the boom to some extent but not completely.
Hence bought some pillows from Reliance mart and lined the walls as shown in the picture and the boom boom is gone.
View attachment 8788

Prashanth

Prashanth,

I would use Vero board for the crossover. It is easier.

With all speakers more so with bass reflex be very careful with damping. Too much damping can rob your speaker of life.. About 1 kg for 60 litres is a good guide. Also try a material called dampmat. It is locally made and excellent to damp resonant boxes, it is more used to damp doors in car audio installs.

For inductors the DCR is critical. Try to keep that under 0.1 ohms. 14SWG works till about 2 mH.

I assume you designed the crossover yourself. What software did you use?

There are many well documented designs on the Internet. Try googling Troels, Zaphaudio, Tony Gee, and even Madisound and Parts Express have simple designs.

 

[S.P.KRISHNA]

S.P.Krishna - Did not understand your last point about separating the tweeter with midrange or..

The movement of speaker cones will displace the air around it and it will be more in case of a woofer as it is designed for low frequency. For efficiency woofer enclosure require more of volume in the cabinet than to mirange and tweeter drivers. It is good to keep the dimensions of the mid and tweeter chambers less than the length of a wave at the crossover point and speakers producing frequencies of a wavelength less than its effective diameter will be very directional at those frequencies.

Regards

 

[photoprashanth]

Prashanth,

I would use Vero board for the crossover. It is easier.

With all speakers more so with bass reflex be very careful with damping. Too much damping can rob your speaker of life.. About 1 kg for 60 litres is a good guide. Also try a material called dampmat. It is locally made and excellent to damp resonant boxes, it is more used to damp doors in car audio installs.

For inductors the DCR is critical. Try to keep that under 0.1 ohms. 14SWG works till about 2 mH.

I assume you designed the crossover yourself. What software did you use?

There are many well documented designs on the Internet. Try googling Troels, Zaphaudio, Tony Gee, and even Madisound and Parts Express have simple designs.

Actually I built this Maurbacs NS6 MTM. Only difference is cross over components are not sourced from parts-express. Everything else is same and in consultation with the author of the that thread.

I just replicated that design and I am nowhere closer to designing own cross overs

 

[navin advani]

Actually I built this Maurbacs NS6 MTM...I just replicated that design and I am nowhere closer to designing own cross overs

How did you decide on this system over the many others? Size? Price?

I ask because this system does not go very low (F3 is about 50Hz) nor is very resolving. The GR research N3 (Danny Richtie) group buy would have been better VFM. I was tempted to join in the group buy but I already had 2 speaker systems (7.2 and 4.1) in the works and my wife would have thrown me out if I got involved in any more speakers.

 

[spirovious]

Congrats,thanks for detailed project post.Now how can you define Bass?Is it punchy,fast or smooth?Does it reach deep?

 

[photoprashanth]

How did you decide on this system over the many others? Size? Price?

I ask because this system does not go very low (F3 is about 50Hz) nor is very resolving. The GR research N3 (Danny Richtie) group buy would have been better VFM. I was tempted to join in the group buy but I already had 2 speaker systems (7.2 and 4.1) in the works and my wife would have thrown me out if I got involved in any more speakers.

GR research group buy was already over when I decided to build these speakers.
Those are lucky people who bought kits in that group buy. It is undoubtedly VFM deal and effort put in by some people in the process of that group buy is simply amazing.

So I looked elsewhere for VFM options and I decided on this design where the drivers used were from parts-express buyout deals ($9 for woofer and $15 for tweeter) and decided to import only drivers and nothing else. One more reason is the same drivers are used by Curt for his Sten II. But his cross over design is different.

All my calculations went for a toss when I actually got the Items in my hand. Shipping was at least 6-7K more than what I expected it to be.

May be I might have done some mistakes in selecting the design. I could have researched some more.
But I enjoyed the whole process of building the speakers and the speakers are not sounding bad either .

Regards,
Prashanth

 

[josephjohnt]

Hi Prashanth,

Look like you are having a great time. Congrats :clapping:

Its good to know that there is someone near. I would like to meetup with you some time. I will ping you my number.

Joseph

 

[photoprashanth]

Congrats,thanks for detailed project post.Now how can you define Bass?Is it punchy,fast or smooth?Does it reach deep?

I think someone else has to help me to describe this bass thing.
I felt it does not go deep and not very tight.
I feel something is lacking but I cannot say what is it.

Hoping someone will give some inputs and corrections after listening to them someday.

For me they sound good, may be for others they might sound crap. But sure I want to have listening impressions from others.

I am ready to accept any kind of feedback .

Regards,
Prashanth