Fostex BK12m speakers....finally done!

Because they do not stay in Mumbai. It is a fact I realised once I left Mumbai for Gurgaon post my 12 years stay there. Life goes little bit more mechanical way in Mumbai, plus time that I used to spent in local trains.
speaking of mechanical life, Bangalore is catching up Mumbai fastly!:indifferent14:
 
speaking of mechanical life, Bangalore is catching up Mumbai fastly!:indifferent14:

still a long way to go though.
another reason could be the size of the apt/houses in mumbai. the apt sizes start from matchbox, shoebox, cabinet etc:lol:

the 4.5 driver goes only upto 12k, where will the 6.5" and 8" drivers end. i doubt if the larger ones qualify to be called a fullranger, a tweeter will be a must.

I always had a doubt about the classic TLs, how easy is it to glue/nail those panels from just one side and keep it stable. it will be tough to use clamps also. So how do you go about it.
Are you planning to permanently close the side panel or keep it removable.
 
still a long way to go though.
another reason could be the size of the apt/houses in mumbai. the apt sizes start from matchbox, shoebox, cabinet etc:lol:

the 4.5 driver goes only upto 12k, where will the 6.5" and 8" drivers end. i doubt if the larger ones qualify to be called a fullranger, a tweeter will be a must.

I always had a doubt about the classic TLs, how easy is it to glue/nail those panels from just one side and keep it stable. it will be tough to use clamps also. So how do you go about it.
Are you planning to permanently close the side panel or keep it removable.
6.5" and 8" drivers have whizzer cone so there high freq. response is extended well beyond 12khz. on axis its 20khz as per the specs. but to make it really fullrange a tweeter is must. adding a tweeter wont cost much. a cap and a L-pad network.
panels are nailed from both sides. after the testing side panel is permanently closed. no panel is removable except that drivers and banana socket plate can be removed. everything else is permanently closed after the finishing.
 
6.5" and 8" drivers have whizzer cone so there high freq. response is extended well beyond 12khz. on axis its 20khz as per the specs. but to make it really fullrange a tweeter is must. adding a tweeter wont cost much. a cap and a L-pad network.
panels are nailed from both sides. after the testing side panel is permanently closed. no panel is removable except that drivers and banana socket plate can be removed. everything else is permanently closed after the finishing.

Yeah but when its getting done initially, the internal panels are fixed, but side panel is not. how do they stay like that while the glue dries.

what polish etc was used for finishing. I checked here in the market, you get cat polish and some powder to color it. Does that good finish. I see small shop furniture wallahs furniture thats polished and it looks absolutely disgusting. Was wondering what polish and dye/stain diyers use for their speakers.

You havent mentioned stuffing/lining. What did you use for that.

Anyone knows where we can get good polish stuff or other exotic stuff for finishing in bangalore. found a dealer for watco in delhi, but he doesnt ship. Only sells in gallons. per gallon is 3200/-.
 
Last edited:
Most furniturewalas have no clue how to surface or polish or simply don't want to.

Ideally the powder you're talking about is only used when there is a color mismatch and you want to match the color. But if the veneer is the colour you want (true color of the veneer only reveals itself when a little moist cloth is swiped across it to see what color appears) all you'll need is the surfacing and polish. The quality of a polish greatly depends on the surfacing done prior to it. And surfacing takes a lot of effort and these furniturewalas will put in only 10% effort into surfacing and charge you top ruppee.


As for polishes, three main routes are

ResizeofDSC04190a.jpg

- Polyurethane which is basically a polymer plastic based polish that gives a very high gloss only if the surfacing is done correctly it has shine but no glow.


jim%2B019.jpg

- French polishing is a wood finishing technique that results in a very high gloss surface, with a deep colour and chatoyancy. French polishing consists of applying many thin coats of shellac dissolved in alcohol using a rubbing pad lubricated with oil through repeated strokes.

441d1153805417-various-diy-speakers-projects-exodus3.jpg

- Jugar option is car polish which is usually urethane and not polyurethane, it can be as nice as polyurethane but it's durability properties are different.

In all three, the surfacing will determine the outcome of the polish. Bad surfacing (Majority of readymade handmade furniture in India) will lead to a bad polish. Furniture walas put too much powder and gala and end up making furniture look painted instead of polished and then they call that polish. Also these types of badly polished furniture will start to lose their shine in humidity because it's not really a polish nor a paint but more of a makeshift inbetween.

However I am not an expert on the topic, because my own jamo d830's have a finish I have no clue about or how was done. It does not seem like polyurethane or shellac.

The OP's polish seems like a variant of french polish but i cant say as the thumbnails are pretty small.
@ doors

Can you pm me the details about the dealer you found in delhi please, just in case i ever decide to do a diy in the future, thanks
 
Last edited:
Most furniturewalas have no clue how to surface or polish or simply don't want to.

Ideally the powder you're talking about is only used when there is a color mismatch and you want to match the color. But if the veneer is the colour you want (true color of the veneer only reveals itself when a little moist cloth is swiped across it to see what color appears) all you'll need is the surfacing and polish. The quality of a polish greatly depends on the surfacing done prior to it. And surfacing takes a lot of effort and these furniturewalas will put in only 10% effort into surfacing and charge you top ruppee.


As for polishes, three main routes are

ResizeofDSC04190a.jpg

- Polyurethane which is basically a polymer plastic based polish that gives a very high gloss only if the surfacing is done correctly it has shine but no glow.


jim%2B019.jpg

- French polishing is a wood finishing technique that results in a very high gloss surface, with a deep colour and chatoyancy. French polishing consists of applying many thin coats of shellac dissolved in alcohol using a rubbing pad lubricated with oil through repeated strokes.

441d1153805417-various-diy-speakers-projects-exodus3.jpg

- Jugar option is car polish which is usually urethane and not polyurethane, it can be as nice as polyurethane but it's durability properties are different.

In all three, the surfacing will determine the outcome of the polish. Bad surfacing (Majority of readymade handmade furniture in India) will lead to a bad polish. Furniture walas put too much powder and gala and end up making furniture look painted instead of polished and then they call that polish. Also these types of badly polished furniture will start to lose their shine in humidity because it's not really a polish nor a paint but more of a makeshift inbetween.

However I am not an expert on the topic, because my own jamo d830's have a finish I have no clue about or how was done. It does not seem like polyurethane or shellac.

The OP's polish seems like a variant of french polish but i cant say as the thumbnails are pretty small.
@ doors

Can you pm me the details about the dealer you found in delhi please, just in case i ever decide to do a diy in the future, thanks

I think its this one - Truworth Impex Private Limited. ph - 9312795676

Is polyurethane or shellac available in india. anyone knows where to get it in bangalore. dont remember seeing such stuff on sp road. is bamboo bazaar a better place for this.

by surfacing, you mean sanding and getting it smooth right. any other steps involved? wood is mdf, will be veneered.
 
Yeah but when its getting done initially, the internal panels are fixed, but side panel is not. how do they stay like that while the glue dries.

what polish etc was used for finishing. I checked here in the market, you get cat polish and some powder to color it. Does that good finish. I see small shop furniture wallahs furniture thats polished and it looks absolutely disgusting. Was wondering what polish and dye/stain diyers use for their speakers.

You havent mentioned stuffing/lining. What did you use for that.

Anyone knows where we can get good polish stuff or other exotic stuff for finishing in bangalore. found a dealer for watco in delhi, but he doesnt ship. Only sells in gallons. per gallon is 3200/-.
all panels except side panel are nailed so they stay stable. what is confusing you?
this speaker boxes were done in my hometown and not in blore. i dont know where good polishing materials available here. but i am sure there will be more choices available here than in my hometown. i think what polish we see in furniture shops and all, are mostly lamination and not veneer. as per my knowledge veneer comes in 4mm thinkness (2mm is also available i guess) with different shades/patterns. later it has to be polished with any color such as rosewood etc.

as in the plans i have done moderate stuffing (dacron) below the drivers and in the corners. without stuffing it was bit boomy. so i had to figure out proper amount of stuffing by trial and error.
 
Hi Prashanth,
Great work, which amp are you driving this? BTW the speakers at your place were also good, these speakers are sounding better than them?
your topping tp20 mark2 amp (25w) is driving them! :)
actually cant compare them. FS are truely full range covering from 40hz to 20khz and also are powerful. dual 6.5" drivers move more air, so bass is profound. compared to them fostex speakers dont do any such thing, but just sound nice in their own way.
after ur audition, i re-did the stuffing and some other tweaking. now the bass has become strong (not like before as it was sounding thin). please drop by sometime.
 
Last edited:
I think its this one - Truworth Impex Private Limited. ph - 9312795676

Is polyurethane or shellac available in india. anyone knows where to get it in bangalore. dont remember seeing such stuff on sp road. is bamboo bazaar a better place for this.

by surfacing, you mean sanding and getting it smooth right. any other steps involved? wood is mdf, will be veneered.

@OP sorry this is is semi offtopic but it may be useful for others so writing doors666 reply in detail here, please don't mind.


@Doors

Yes both are readily available and used by furniture polishing people.
And also yes, surfacing is the sanding down and removal of dust/particles on the veneer. Many people wash the veneer as well depending on which wood it is, as some expand too much from washing.

Steps you should take are these

1. Select a veneer with a color and texture which is according to your liking that will not need any kind of color modification. Just a coat of gloss. A good veneer is one with a lot of high contrast texture on it and not just a plain surface like this one below which is veyr boring.
Teak_fineline.jpg



The reason why wiping a moist cloth is important is because a veneer that looks like this at first sight
1008n.jpg


can reveal a colour like this once polished. Not to this degree but this is just to give you an idea.
WOOD_VENEER_WALLCOVERING_Andes_Rosewood_Flat_Cut.jpg


Look for a nicely textured veneer. The more the texture, the more beautiful it'll be. Take a look at this image to get an idea of truly beautiful breathtaking wood/veneer known as cocobola/bolo.
hero-cocobolo-taylor-guitars.jpg




2. Now cut a small section of the veneer and get a polisher guy, tell him to polish that piece of veneer. All you want is a coat of high gloss without any kind of added color.

3. Tell him to sand down the veneer along the direction of the texture and not against it. (on the final veneer if he sands it for 10 mins and says it's done, tell him to sand it again. A bad sanding = a bad polish.)

4. Wipe the dust and particles off, place your hand on the veneer surface to check if it's sanded / rough enough. Put on the fan and get rid of the dust in the polishing area.

5. Tell the polisher to proceed and do his mixture and apply it on the piece of veneer.

6. The first coat is usually not glossy, let it dry, sand it gently then apply again, check if gloss has come or not, if not, sand again gently then another coat. This has to be repeated till the desired glossiness if achieved. Each coat risks dust and particles getting stuck in that coat so watch out for that.

7. Approximate cost of polish material+labour should be around 3k.

8. Polish will take at-least 24 hours to dry and is susceptible to dust during that time.

Don't worry about if its polyurethane or shellac or car polish. Just get the polish guy to demo you what he can do on the small demo piece of the veneer first and then go ahead once you've reached a suitable position.
 
Last edited:
your topping tp20 mark2 amp (25w) is driving them! :)
actually cant compare them. FS are truely full range covering from 40hz to 20khz and also are powerful. dual 6.5" drivers move more air, so bass is profound. compared to them fostex speakers dont do any such thing, but just sound nice in their own way.
after ur audition, i re-did the stuffing and some other tweaking. now the bass has become strong (not like before as it was sounding thin). please drop by sometime.

Please find a tube amp to drive Fostex. They suck with SS. I know since I used them like this for about 2 years. I now use a sub to supplement the LF. The HF is still lacking though.

not me! my father! they were built for my father exclusively for hindustani classical music. and these speakers do really well for this kind of music...can go hours listening to them without a hint of listening fatigue
I too use Fostex 166e based speakers purely for listening to Carantic. Drop by for a listen with your Dad someday.

--G0bble
 
Last edited:
Please find a tube amp to drive Fostex. They suck with SS. I know since I used them like this for about 2 years. I now use a sub to supplement the LF. The HF is still lacking though.


I too use Fostex 166e based speakers purely for listening to Carantic. Drop by for a listen with your Dad someday.

--G0bble
tube amp is on the wishlist!
next best thing(or better option) is T-amp as per,
T-Amp - Class T integrated amplifier - [English]
and
6moons audio reviews: Sonic Impact Class-T amp
topping is also preferred by diy community.

i spoke to u sometime back. which sub ur using? is it matching well with fostex? any plans for adding a super tweeter?

surely will call and drop by sometime.
 
I too use Fostex 166e based speakers purely for listening to Carantic. Drop by for a listen with your Dad someday.

--G0bble

I am too planning a Linear TL with the Fostex 166en. How low does this go and are you using this in a TL configuration? How balanced is the mid-range and highs? Pls. enlighten me. Will this also be suitable for pop music / Disco types too?
 
tube amp is on the wishlist!
next best thing(or better option) is T-amp as per,
T-Amp - Class T integrated amplifier - [English]
and
6moons audio reviews: Sonic Impact Class-T amp
topping is also preferred by diy community.

i spoke to u sometime back. which sub ur using? is it matching well with fostex? any plans for adding a super tweeter?

surely will call and drop by sometime.

I use a REL T5. A low damping factor SS amp might work better with FR fostex drivers.

I am too planning a Linear TL with the Fostex 166en. How low does this go and are you using this in a TL configuration? How balanced is the mid-range and highs? Pls. enlighten me. Will this also be suitable for pop music / Disco types too?

See it goes low to 40hz if you measure, but the decibel levels of LF drops such that there is no punch or impact about it. Mine is a bass reflex BS. Midrange is bottom heavy i.e lower mids dominate and also a bit in the 2khz to 4khz putting it in danger of sounding fatiguing but not quiet. But we can attribute that to box design not taming it sufficiently. But all said and done it is transparent as hell to the effect that I cant seem to like any 2 way or 3 way that cost 3X more as they sound muffled in comparison, to my ears now well accustomed to Fostex with its magical mids.

Not recommended for disco music at all unless you add a sub. And too recessed in the upper HF although the tonality and timbre is right with chimes and tinkle bells, an extra bit of crispy splashy character here would have been a joy but alas.

Rather than add a super tweeter I decided to get Jordans jxr6-hd full range drivers that I expect will finish at the 120hz point with a bit of thin-nes in lower mids compared to fostex. Hope two drivers per side will add more body there with the REL T5 adding the missing LF below 100hz. Plan to start the speaker build as soon as the rains go away.

Edit: Adding the speaker measurements as measured by fellow member t.anthony
fostexspectrogram.jpg


peerlessfostex.jpg

See how it dips below 200hz? It still sounds a wee too thick in the lower mids and sometimes I wish it didn't, at other times I don't notice...

--G0bble
 
Last edited:
@OP sorry this is is semi offtopic but it may be useful for others so writing doors666 reply in detail here, please don't mind.


@Doors

Yes both are readily available and used by furniture polishing people.
And also yes, surfacing is the sanding down and removal of dust/particles on the veneer. Many people wash the veneer as well depending on which wood it is, as some expand too much from washing.

Steps you should take are these

1. Select a veneer with a color and texture which is according to your liking that will not need any kind of color modification. Just a coat of gloss. A good veneer is one with a lot of high contrast texture on it and not just a plain surface like this one below which is veyr boring.

2. Now cut a small section of the veneer and get a polisher guy, tell him to polish that piece of veneer. All you want is a coat of high gloss without any kind of added color.

3. Tell him to sand down the veneer along the direction of the texture and not against it. (on the final veneer if he sands it for 10 mins and says it's done, tell him to sand it again. A bad sanding = a bad polish.)

4. Wipe the dust and particles off, place your hand on the veneer surface to check if it's sanded / rough enough. Put on the fan and get rid of the dust in the polishing area.

5. Tell the polisher to proceed and do his mixture and apply it on the piece of veneer.

6. The first coat is usually not glossy, let it dry, sand it gently then apply again, check if gloss has come or not, if not, sand again gently then another coat. This has to be repeated till the desired glossiness if achieved. Each coat risks dust and particles getting stuck in that coat so watch out for that.

7. Approximate cost of polish material+labour should be around 3k.

8. Polish will take at-least 24 hours to dry and is susceptible to dust during that time.

Don't worry about if its polyurethane or shellac or car polish. Just get the polish guy to demo you what he can do on the small demo piece of the veneer first and then go ahead once you've reached a suitable position.

@cor, nice writeup there. @OP No intentions of hijacking the thread, but couldn't resit asking some questions.

For sanding the veneer, what size/number and type paper is required if we are doing by hand.
Can an orbital sander be used for this purpose or a finishing sander is required?

Thanks
 
@cor, nice writeup there. @OP No intentions of hijacking the thread, but couldn't resit asking some questions.

For sanding the veneer, what size/number and type paper is required if we are doing by hand.
Can an orbital sander be used for this purpose or a finishing sander is required?

Thanks

Use rougher gsm for initial sanding and softer gsm for subsequent sanding. Orbital sander is what everyone should use if they have one imo but in India most labour dont have one.
 
Order your Rega Turntables & Amplifiers from HiFiMART.com - India's reputed online dealer.
Back
Top