Indian equivalents of the following DIY items.

[Pixo]

Hello everybody

Sai,
Fevicol SH and SR998 are the most commonly used bonding adhesives for woodwork. Fevicol SH is synthetic water-based white glue and if i am not wrong, costs around Rs70 for a 500gm pack.Fevicol SR998 is synthetic rubber-based and this is the quick-dry yellow gum variety that was earlier mentioned in this post, which is normally used for bonding laminates to plywood. If you have any more doubts about them, check out Pidilite's Woodworking glues section. They have listed all the glues used in woodwork.

[ajju]

Sai,Tarun

Regarding the JBL's, i think they are out of production or something...i couldn't find any info on the net..the model is put as jbl40 and the two of them cost me around Rs1600.. The sonic character is good...the highs are melow and controlled..the overall sound is a little laid back...i presume it reaches only around 12-16 kHz which i felt was not that bad...all these typical desi records which are over-emhasized on the highs sound much better and dont induce the kind of fatigue..( i'm referring to the kind of ringing these records used to produce in my ears on some extended listening)...The overall sound is detailed and forms a good soundstage

like...
while playing the desparado soundtrack, which is pro-logic encoded, in normal stereo mode u can actually make out some gunshots panned far out from the speakers...basically the sound leaves the physical location of the speakers...the tabla and santoor sound quite natural...and one of the best examples to test the control on the mids and highs is Floyds Time...the ringing clocks..lots of timbre..i guess its kind of difficult material to reproduce....and there is a lot of intimacy in vocals of recordings like say nirvana unplugged, or coldplay...i am pretty much satisfied with this speaker considering what is available here locally...)

The flip side.
There is a wizzer cone attached to the cone which i find troublesome now, when i was experimenting with a bass reflex configuration for these speakers. They tend to produce a "Whizzzz" as they slice the air as the cone goes into uncontrolled motion below the tuned resonance frequency...either the whizzer has to be removed or, a piece of sponge is to be put under the whizzer to support it or smoothen out the edge of the whizzer by some cotton...yet to experiment on that...! In the TL this was not a big problem as the cone excursion was considerably less...i believe!
(BTW..Any quick suggestions/experiences on this problem...)

[ajju]

You were talking about the 5" drivers peerless. I had planned to have two 8" and a tweeter on each of the stereo speakers. What is your opinion.

I would prefer the 5" as opposed to 8" for the stereo fronts...i feel they will narrow down the face of the baffle thus improving imaging....

Actually the best person to comment on this would be Navin...

Over to Naveeen 'Bhaaaiii'...!

[ashok]

Using SR998 from Fevicol ( brand name) is not very easy on large surfaces. The SR998 glue has to be applied on BOTH surfaces and allowed to dry till tacky. Then you put the two surfaces together and hold them under pressure for several minutes.

This is Ok to glue shoe soles and other small items but not for large not very flexible material. If you get air pockets you had it though there are ways around it.
It is also OK to stick fabric or very flexible material like rexine or vinyl to wood.
Local carpenters use it because it sets very fast. It also comes off very fast if not done perfectly. Thats why you find wood work from these guys peeling off after several months!It also tends to form bubbles between the layers as it sets due to the evaporating solvent. The exact moment when you should put the sheets together is very critical. You need skill to get this just right!

For wood to wood the best locally available glue is Fevicol SH. There are lots of clones of this but I am not sure if they are as good when they dry. Fevicol also has a quick setting version of the usual white coloured SH. It is pale yellow in colour and is called Fevicol Rapid. It does not come in less than 1Kg packing. It is generally hard to find. You may have to call the Pidilite office to get details. I find that more useful as it starts to set in 15 to 20 minutes. Full strength takes several hours.

So if you plan to use SR998 do some experimentation with the cheap tube versions that you can get. ( fevibond etc).
Cheers.

[navin]

Originally posted by ajju
You were talking about the 5" drivers peerless. I had planned to have two 8" and a tweeter on each of the stereo speakers. What is your opinion.

I would prefer the 5" as opposed to 8" for the stereo fronts...i feel they will narrow down the face of the baffle thus improving imaging....

Actually the best person to comment on this would be Navin...

it all depends on what you are trying to do. if you want a bomm tizz spekaer with a midrnage suck out then 2 8" Xoed at say 1000Hz and a 1" XOed at 2000Hz would do that. it would still be lintenable for certain types of music.

few 8" operate well in the mid range and the few hat do are PA types and have high Fs which trnslates to limited bass. Also larger drivers beam a bit earlier and if oyu arre using larger drivers to higher midrange freq (read as 2000-4000Hz) then you might run into nodal effects.

in the end it all depends what drivers you are using. I onece built a very listenable system (atleast is beat all other $1000 per pair systems in a AVX test) using 2 8" and a 1" but in this case the 8" were very well behaved (Focal 8N515s- the neoflex cone was excellent) and the tweeter (Morel MDT33) had a very low Fs and could be XOed quite low. The MTM had a 6db electrical XO at about 1000hz and a 18db XO at about 2k I guess Baffel step must have filled in the gap.

JBL also built a very good 8" 2 way called the 82 in the late 70s. we used it as a stock speaker in college. it had a Ti dome and a plastic lens. anyone remember this?

all things remaing equal a 5" would have better midrange response but else bass (so what else is new) than a 8".

what drivers do you plan to use. what is you design goal? what music do you listen to?

[ssSai]

Thanks every body.

Ajju said a "over and out" to Navin "BHAI". I take over from there.

Well,

Navin bhai from the post I infer that using 8" is not a good option, execpt when you have a "Well Behaved" (could you define this please) one.

The most challenging was your last question.

I really have no idea whatsoever as to what cofiguration will make up my front streo system. May be you could advice me on that, I would be real thankful for that (I am serious, this is a request......................please do not charge me any consultation fees :-) )

The next question about my music taste.......

Actually Me and DaddyGreat listen to lot of music. Both of us view the money spent on this as an investment in entertainment.

I listen to Rock and ..........I really do not know what genre the others fall into....May be artists will do the work.......ACDC, AeroSmith, Black Sabbath, BonJovi, BryanAdams, DeepPurple, FireHouse, Metallica, Iron Maiden, Strtovarius, Guns N Roses.....


Dad listens to Abba, Carpenters, Boney.M, Classical, Lots and Lots of soothing INSTRUMENTAL (Saxophone, JalTarang, Sitar, Flute.........) He has got a better taste than me (He puts the whole house to sleep and I wake them up ).

My common sense tells me that these two are two extreme ends of music tastes and I cannot get the maximum of both from one set of speakers. I neither know what the optimum is.

So...........Please...................(without the consultation fees).



Also ajju talks about "Imaging" - More on this will be helpful AJJU. What is the relation between 5", 8" baffle narrowness and imaging?

Navin bhai (and everyone) what about "Amplifiers and India"??

[ssSai]

I feel this way because I could not get even info as to where is "Loud speaker design cookbook - Vance Dickanson" available.

And as far as I have seen every DIYer tells that this is a must have one. I mean sort of a Bible for DIYers.

[ajju]

Loud speaker design cookbook - Vance Dickanson

sorry for going OT....

try firstandsecond.com
i remember seeing it there..but at a price Rs2382...they'll get it for u...!!
but it was shown as out of stock last time i visited...
btw anybody interested in a group buy of the book..may be if some of us place the order together they will make attempts to procure it..!!

http://www.firstandsecond.com/store/...Search=1607771

What say...?


Does anyone have any info on "Acoustics" by Leo Beranek (hope i've spelled the author correctly) Provides good fundamentals on TS parameters etc...also Fundamentals of Acoustics by HF Olson
I've tried to read both of them but at that time i was too young to make out head or tail of what it was ..so just depended on some equations..but now i feel its worth a read..

ajju

[ashwin]

Hi,

to continue being OT , I got my copy of Dickason's book from fabmart.com, they do home delivery with cash on delivery in Bangalore. But that was more than a year back, I don't know if they still have the book in stock.

For general acoustics principles, I have "Fundamentals of Acoustics" by Kinsler, Frey, Koppens and Sanders, available quite cheaply from Gangarams. I have't gone through the whole thing yet, but it does have a chapter on transducers (but no info on TS parameters). I think a background in basic physics is essential to read this book.

Ajju, do you know where Olson's book is available?

- Ashwin

[navin]

Originally posted by ssSai
Navin from the post I infer that using 8" is not a good option, execpt when you have a "Well Behaved" (could you define this please) one.

I really have no idea whatsoever as to what cofiguration will make up my front streo system. I listen to Rock .....ACDC, AeroSmith, Black Sabbath, ...Dad listens to Abba, Carpenters, Boney.M, Classical,....He has got a better taste than me (He puts the whole house to sleep and I wake them up ).

My common sense tells me that these two are two extreme ends of music tastes

Also ajju talks about "Imaging" - More on this will be helpful AJJU. What is the relation between 5", 8" baffle narrowness and imaging?

Navin bhai (and everyone) what about "Amplifiers and India"??

yup today speakers are very often designed for particular listening tastes of the designer. case in point JBL 250Ti v/s Vandersteen 2C (and it variants). also in the old days there was a defined East Coast sound (meaning Boston, NY and Route 128) and West Coast sound (meaning LA). The are ofcourse cos that made speakers in Hope, Arkansas, Cambdridge, England, Videbaek, Denmark etc whose designs worked well from Antonio Vivaldi to Frank Zappa.

One time Horns for example had the reputation of only being suited for Rock but having heard Bach, Bizet, Beethoven...Tchaikovsky, Vivaldi on an all Klipsch system (2 x Kilpschorns and 2 x Belle Klipsch) powered by 4 Rowland Reseach 7 amps and a Mirco Seiki table etc...I conclude that a good design will suit all music.

in 1968-9 I was gifted a small system that used a Garrad table, Fisher TX100 (25W) amp and AR 2ax speakers. I played almost all music on it from Lawerence Welk to the Sound of Music to Iron Butterfly. It did almost of it equally well.

Ys if the drivers are well behaved (no ragged roll offs) atleast anoctave above the XO freq you can manage to build a good 8" 2 way. There are many fine exmples of this. You need to get a tweeter with a Fs of less than 900Hz. Usually such tweeters have limited HF dispersion (larger domes etc...) in the 10k+ / 30 deg off axis area. Look at a sens of about 88db+

Once you have a fine tweeter you need to find a 8" that has a smooth roll off never mind if the response does not go to 4k. even if teh response is flat to 1K if it rolls off gradually after that it is good. The reason I say this is that BSC can/will compensate for some/all loss in mid due to roll off. the woofer should have linear one way Xmax should be above 5mm. Sens of above 88db (since you are using 2 woofers and 2-4db of BSC) the resultant sens will match with a 88db tweeter.

this requires work...then using a simple XO one can build a nice 8" 2way (MTM or MMT etc.). XO the 8" at about 6db/1k and the tweeter at 12db/2k LR (if MMT) or 18db / 2k (if MTM) and you have a starting point.