my DIY "easy to make" fostex 103e fullrange speaker

[square_wave]

Awesome job ! They look rather cute.

 

[swami69]

Swami, a lot of DIYers recommend just one strand of CAT5 per terminal...your take on this???

Hi soulforged, honestly, did not give much thought to it when i did that. I just braided 4 strands per terminal. But, your statement is an eye opener and probably i will try redoing that part when i find some time, if it can improve the sound anyway.

swami

 

[magma]

well executed
nice finish

i bet we will soon see a DIY multidriver set

 

[Hari Iyer]

Hello all,

I want to introduce my DIY full range speaker to the forum. I bought a pair of Fostex FE103e drivers and looking for a plan to make a descent speaker. After researching many over the web, i thought a Zigmahornett design would suit this driver better (just 4") and also will look good. But, that design would involve more materials, a carpenter and time which i was not willing to wait for, as i wanted to try something quickly to see some results of this driver.

Then somewhere i saw a Japanese making a speaker with fostex drivers using Sewage pipes (local water pipes we use in our construction) and that looked very doable on my own without any help. So started off and the timeframe was just 2 days over the weekend. (tiresome, for sure)

The speakers in action in my living room.
View attachment 1964

Bought the following PVC pipes :
4" dia - 2 feet length x 2
L bend x 2
4" to 5" enhancer x 2
5" dummy end to close and hold the Drivers x 2
a small length of 5" connecting pipes
Went to a local wood working place and cut 2 x padauk wood pieces for the base stand - 1 feet x 9" and cut an arch at one end
Bought some L angles for fitting the tubes to the stand
Some brass nut/bolt to be used as the spikes
Now, painting :
bought a can of ready to spray acrylic paint
bought a sample can of Indian copper colour enamel paint
Some sanding papers
Silicon glue to fix joints etc.,
Gold plated binding posts

Construction :

• Cut pieces to desired length
• Sand them well for the paint to stick
• Fix everything to-gether for a trial
• Cut a precision hole on the 5" dummy for placing the driver. Place the dirver
• Do whatever padding/damping you want - I used Yoga Mat as one layer inside the walls of the pipes and some polyfill taken out from a pillow
• Once you are happy with how it sounds - dismantle

• Prepare the wooden stand using sanding, sealing, varnishing several times to get the gloss you want
• Drill holes for adding screws to fix pipes and spikes
• Prepare the pipes by applying a primer
• Drill holes for the L joint to fix
• Spray paint them
• Allow it to dry
• Add binding posts
• Solder wire to the driver and the binding posts
• NOW, start fixing only the tall pipe to the stand
• Once stable, add the top bend and the Driver side

View attachment 1959View attachment 1960View attachment 1961
View attachment 1962
You have your wonderful speaker.

Cost to make :

Drivers - SGD 150 per pair (INR approx 5500)
Wood - INR 300 including cutting
Pipes and other accesories - INR 800
Paint, varnish - INR 600

Now, the observations from my minimal listening to this beauty

Overall the sound is very good
Nice body to the sound
It provides a very good imaging and a great soundstage (i benchmarked it against the same song "bricks in the wall" we played few times in the chennai HFV meet yesterday and exactly followed the expert comments during the session)
Very detailed (need some more run in)
Crisp and clear
I mostly listen to soft, easy listening, instrumental types of songs and it suits perfectly - it may not suit some other genres like heavy rock etc.,
For some people, you can add a sub to take care of some bass freq. I am happy even without it.

My own considerations to improve it further :

• I currently run it with a SS NAD 355 amp and it sounds good, may be a tube amp will sound even better as they make the best pair
• This is not made to any specific professional measurements, just my own logic - trial and error
• No professional damping materials used - just household stuff

As it has come out nicely, now, i am confident of spending more time in getting a PROPER WOODEN ENCLOSURE made for this like a Zigmahornett or a TL design available over the net (after sometime though !)

Hope you all like it and i would suggest people to just try it out for fun using some local full range drivers and these pipes - may not cost even this much as the Fostex drivers are the most expensive in this whole cost.

This BEATS my Mission M32i hands down in details and clarity and now my mission bookshelf is pushed to my other room to play with my AVR.

All above are just my opinion and thoughts and i invite our forum members to come home whenever they have time to have a listen.

Thanks for taking time to read this.

swami

Hi Swami,

This looks like a very good TL design where the driver is monted on the closed end of the pipe. I will suggest some modifications to improve the sound even further,

1. Have a driver off-set of say 8" between the closed end and the open end. This will help in reducing the odd harmonics better.

2. Try damping the line with Dacron with varying density for atleast half of the line. The dacron should be loosely packed and should be more on the closed end and less in the open end. The open end should only damp the mid-range (till say above 1st harmonics) and not damp the low frequency.

3. Try using a Baffle-step circuit if the set-up is too bright to listen. Try having a step of around -9db/octave to tame the response say above 800 Hz.

4. Try to mass-load the terminus ie. reduce the area of the terminus to say just 20% to 25% of the area of the pipe. Your design seems to be a straight line design hence you can mass load to increase the low frequency response.

Do let us know if you could improve on the performance.

Best of luck and kind regards,

Hari Iyer.

 

[swami69]

Hi Hari Iyer,

Thanks for your valuable inputs to improve the performance. Can you clarify your point # 4 further - What do you exactly mean by this and how can i mass load the pipe which is open at the bottom.

I can try varying the density of the fill inside the enclosure and test as you have pointed out.

Please let me know.

swami

 

[hemantwaghe]

Hi
Our Dr Jaudere is using super chaep philips fullrange 8 inch speaker . are these useful here.

any super cheap and no brainer project involving therese?

 

[suri]

any super cheap and no brainer project involving therese?

Hi hemantwaghe,

Therese is a very good looking goan woman without brains - but she will be super-expensive!!:lol:

regds

 

[Hari Iyer]

Hi Hari Iyer,

Thanks for your valuable inputs to improve the performance. Can you clarify your point # 4 further - What do you exactly mean by this and how can i mass load the pipe which is open at the bottom.

I can try varying the density of the fill inside the enclosure and test as you have pointed out.

Please let me know.

swami

You can mass load the enclousre by reducing the area of the opening at the bottom to say 20% of the area of the cylinder. By doing this the low frequency response of the drive improves by 6dB/octave. Also do not overdamp the line. Try by using minimum damping of the line and increase the damping only if the mid-range is harsh. You should not try and damp the low-frequency. Also the bottom 1/3 length of the line should not be damped. Also damping should be very loose and not tight to prevent damping of the low frequencies.

Can you let me know the resonating freq and the Qtc of the driver?

 

[sub]

Hi

Thanks for your valuable inputs to improve the performance. Can you clarify your point # 4 further - What do you exactly mean by this and how can i mass load the pipe which is open at the bottom.

I think you can close the bottom with a stopper and cut a hole in it say 2 inch in diameter for compressed release of LF.

Regards

Sub

Video: Panny 32 LCD, PS3, Sony DVP-NS78H, Samsung DVD-P365H, WDTV, Big TV.
Audio: Yamaha RX-V661, Sansui G-5000, Hand Made Towers for stereo, Pioneer Linear Power for HT with Onkyo SL-107 powered sub.

 

[Chandan]

I just found this thread and the very simple way of building this fantastic looking speakers.
If you do not mind I have few questions:

1. Did you simulate the design before building? If yes then what is the name of the
program.
2. What is the japanese site where you saw this design?
3. Is not the sound a bit boomy? Does not the closed narrow pipe
introduce some unnatural sound?
4. This is most important. Where did you find Fostex 103E in India. I am also on a
lookout for this speaker.

I was planing an Open Baffle as it is simple. But your design seems to be simpler and cheaper. That is why so many questions.

Thanks and regards
Roushon.

 

[The_Falcon]

Great work !
so your are enjoying the music of your labour !

Are you taking new orders for these ? lol

 

[asliarun]

Hi



I think you can close the bottom with a stopper and cut a hole in it say 2 inch in diameter for compressed release of LF.

Regards

Sub

Video: Panny 32 LCD, PS3, Sony DVP-NS78H, Samsung DVD-P365H, WDTV, Big TV.
Audio: Yamaha RX-V661, Sansui G-5000, Hand Made Towers for stereo, Pioneer Linear Power for HT with Onkyo SL-107 powered sub.

An alternate way, as practiced by some, is to stuff the opening with a bundle of plastic drinking straws (cut into half). People normally do this for a (smaller diameter) bass reflex port, but I guess you could do this for your pipe as well.. you will probably require more drinking straws but they are quite inexpensive

 

[Hari Iyer]

Hi Hari Iyer,

Thanks for your valuable inputs to improve the performance. Can you clarify your point # 4 further - What do you exactly mean by this and how can i mass load the pipe which is open at the bottom.

I can try varying the density of the fill inside the enclosure and test as you have pointed out.

Please let me know.

swami

Mass loading the pipe means opening the pipe only 25% of the area of the pipe in the open end. This will help to increae the low frequency of the speaker system by 3dB. Also you can add a baffle step compensation circuit to the speaker by adding a inductor (around 1.75mH) in parallel to a 4.7 ohms resistor (wirewound - 5watss) and keep in series to the cross-over. This will reduce diffraction by around 6dB/octave and make the sound smooth overall. Do let us know how it sounds with these modifications. Also use low density dacron for the damping of the TL line.