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.
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.
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...
)
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...
)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'...!
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'...!
Sr998
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.
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.
ajju said:
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?
Challenging situation
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"??
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"??
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/books/info/BookInfo.asp?txtSearch=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
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/books/info/BookInfo.asp?txtSearch=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
books
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
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
Re: Challenging situation
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.
ssSai said:
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.
Hello everybody,
Both fabmart.com and firstsecond.com do not list the book in their catalog. Any ideas as to how I can get my hand on one.
Navin BHAI, I did understand what you meant but I really do not know what drivers to buy for the stereo system.
>>> Do I settle in for two 8" woofers and a tweeter in a MTM configuration.
>>> Do I decide upon two 5" or 7" mids and a tweeter.
>>> How about a 8" woofer, a 5" mid and a tweeter.
ANY SUGGESTIONS ON THE 5", 7", 8", AND THE TWEETER DRIVERS.
NOBODY is an expert in every thing right? Other wise there would be no MadiSound or AdireAudio........
If this is the case then all you DIYers are good at one and OK at the rest. So if you are good at the art of making a good cabinet, you look up to others for the crossover and amps.
I am a starter and I wonder how come every body are just avoiding the subject of Amplifiers. Do I assume that every one build their own amps (if that is the case "hats off to you"). I searched a LOT (I really mean LOT) and no one even has any idea of any amplifier of more than 60 watts RMS (forget the amps the car accessories people stock... half of them are crap and the rest should be costly crap).
Hence I once more request you guys........any idea on the drivers for the stereo setup and what about an amp for the sub and another for a stereo setup (head room for a home theater would be fine).
Both fabmart.com and firstsecond.com do not list the book in their catalog. Any ideas as to how I can get my hand on one.
Navin BHAI, I did understand what you meant but I really do not know what drivers to buy for the stereo system.
>>> Do I settle in for two 8" woofers and a tweeter in a MTM configuration.
>>> Do I decide upon two 5" or 7" mids and a tweeter.
>>> How about a 8" woofer, a 5" mid and a tweeter.
ANY SUGGESTIONS ON THE 5", 7", 8", AND THE TWEETER DRIVERS.
NOBODY is an expert in every thing right? Other wise there would be no MadiSound or AdireAudio........
If this is the case then all you DIYers are good at one and OK at the rest. So if you are good at the art of making a good cabinet, you look up to others for the crossover and amps.
I am a starter and I wonder how come every body are just avoiding the subject of Amplifiers. Do I assume that every one build their own amps (if that is the case "hats off to you"). I searched a LOT (I really mean LOT) and no one even has any idea of any amplifier of more than 60 watts RMS (forget the amps the car accessories people stock... half of them are crap and the rest should be costly crap).
Hence I once more request you guys........any idea on the drivers for the stereo setup and what about an amp for the sub and another for a stereo setup (head room for a home theater would be fine).
5" vs 8".
This is what i gather..Please feel free to correct me if i'm wrong..
1) As the size of the cone increases the chances of cone break up in frequency of interest are high. These have the effect of causing unecessary dips in the response. The no of modes of breakup within the frequency of interest also increase as the fundamentals go to the lower frequencies. Cone breakup in addition distorts the radiation pattern and causes huge lobbing effects at the specific frequencies.
2) Above manifests itself as huge irregularity in frequency response towards the higher frequencies. thus for a two way system u would require a 8" speaker with a well damped cone if a smooth response is to be obtained over the crossover points. Moreover the choice of crossover point becomes critical. also one might require a tweeter with a good midfrequency extension.
3) For a good point source representation it is best if the two units are concentric and time alligned. This is hard to achieve with off the shelf independent units. Conventionally we place the tweeter somewhere on the periphery of the larger woofer. At the crossover point, the woofer primarily radiates from the centre of the cone and hence the system can be treated as two point sources seperated by a distance equal to the distance between the centre of the speakers, the least here being the radius of larger speaker + radius of smaller speaker. This interaction also causes lobing effects on the final radiation pattern. And on either extremes of the usable range of a speaker the phase response is extremely unpredictable. Thus it becomes difficult to judge the interaction of seperation of the units and crossover frequency if we are using drivers which are crossed over at the boundaries of their usable range. If u select smaller dia woofers the high frequency extension will be better and hence mating it with a tweeter becomes a breeze. Also u can choose the crossover point such that there is still some overlap of the usable frequency range of the units which falls in their respective stopbands. Thus the speakers are never required to operate at the dirty extremes of their response curve.
4) Edge diffraction effects from the discontinuities on the front of the baffle. This can be tamed to an extent by shaping the edges of the baffle and using compensatory circuit. The idea behind having a narrower baffle board for the speaker mounts is to push the fundamental inteference frequency(which again causes lobing) to as high a range as possible so that the no: of harmonics falling in the audible frequency range are less and also the density of occurance is less.
All the above effects are extremely difficult to measure and control. But i feel the coloration due to these effects can be considerably less if woofers of smaller diameters are used and might have a positive effect in reducing them. The imaging(mainly attributed to the radiation pattern of a speaker) improves as the lobing effects in the response reduce.
ajju
This is what i gather..Please feel free to correct me if i'm wrong..
1) As the size of the cone increases the chances of cone break up in frequency of interest are high. These have the effect of causing unecessary dips in the response. The no of modes of breakup within the frequency of interest also increase as the fundamentals go to the lower frequencies. Cone breakup in addition distorts the radiation pattern and causes huge lobbing effects at the specific frequencies.
2) Above manifests itself as huge irregularity in frequency response towards the higher frequencies. thus for a two way system u would require a 8" speaker with a well damped cone if a smooth response is to be obtained over the crossover points. Moreover the choice of crossover point becomes critical. also one might require a tweeter with a good midfrequency extension.
3) For a good point source representation it is best if the two units are concentric and time alligned. This is hard to achieve with off the shelf independent units. Conventionally we place the tweeter somewhere on the periphery of the larger woofer. At the crossover point, the woofer primarily radiates from the centre of the cone and hence the system can be treated as two point sources seperated by a distance equal to the distance between the centre of the speakers, the least here being the radius of larger speaker + radius of smaller speaker. This interaction also causes lobing effects on the final radiation pattern. And on either extremes of the usable range of a speaker the phase response is extremely unpredictable. Thus it becomes difficult to judge the interaction of seperation of the units and crossover frequency if we are using drivers which are crossed over at the boundaries of their usable range. If u select smaller dia woofers the high frequency extension will be better and hence mating it with a tweeter becomes a breeze. Also u can choose the crossover point such that there is still some overlap of the usable frequency range of the units which falls in their respective stopbands. Thus the speakers are never required to operate at the dirty extremes of their response curve.
4) Edge diffraction effects from the discontinuities on the front of the baffle. This can be tamed to an extent by shaping the edges of the baffle and using compensatory circuit. The idea behind having a narrower baffle board for the speaker mounts is to push the fundamental inteference frequency(which again causes lobing) to as high a range as possible so that the no: of harmonics falling in the audible frequency range are less and also the density of occurance is less.
All the above effects are extremely difficult to measure and control. But i feel the coloration due to these effects can be considerably less if woofers of smaller diameters are used and might have a positive effect in reducing them. The imaging(mainly attributed to the radiation pattern of a speaker) improves as the lobing effects in the response reduce.
ajju
Hello everyone
Sai,
If you are thinking of making an amplifier yourself, here are some
Crescendo : I don't know much about this amplifier, but the schematics and the PCB pattern are already available. So you can save the time starting from scratch.
The Leach Amp : Professor Leach has a detailed description of this amplifier and the PCB pattern is availabe for this one too at his site.
Rod Elliot's P3A : check out the projects section of his site. It's titled Project 3A and hence the name. It should be capable of 100 Watts into 8 ohms.
I have a question for you guys :
I came across two Pioneer drivers - a 10" rated for 300W and a 12" rated for 650W (1000W peak!?) originally meant for car audio. I wondered if those would make a good choice for a subwoofer. What do you guys think?
Sai,
If you are thinking of making an amplifier yourself, here are some
Crescendo : I don't know much about this amplifier, but the schematics and the PCB pattern are already available. So you can save the time starting from scratch.
The Leach Amp : Professor Leach has a detailed description of this amplifier and the PCB pattern is availabe for this one too at his site.
Rod Elliot's P3A : check out the projects section of his site. It's titled Project 3A and hence the name. It should be capable of 100 Watts into 8 ohms.
I have a question for you guys :
I came across two Pioneer drivers - a 10" rated for 300W and a 12" rated for 650W (1000W peak!?) originally meant for car audio. I wondered if those would make a good choice for a subwoofer. What do you guys think?
ssSai said:
i built my own stereo pre and power amps but use a MArantz SR7000 for my AV setup. in fact my power amp is my own design based on teh B&K ST140 but using 3 pairs of output resistors instead of teh 2 they use. also using slightly different basing and a 1200VA tranny and 60,000uf of caps i get close to 200W at 8 ohms. the preamp uses relay switching and a OP275 for control.
ajju said:
materials are often as important as size as far as cone break up is concerned. sometime cone break up can start as low as 1000Hz. Edge diffraction is not the same as Baffe step. baffle step can be comepnsated more easily than edge.
almost all of the above is diffcult to control but more so for different listening rooms that is why i always say that the biggest advatage DIY has that they can compensate for the room.
Ampifiers amplifiers
Have you checked these forums?
You've already received excellent suggestions from Pixo. In addition, I'll add the books by Randy Slone and Douglas Self, which have PCB designs, in case you are willing to get them fabricated and start from there. (Randy also used to sell ready-made PCBs; you can send him email after you buy his books.) He starts with ultra-low distortion Class A 40W and Class AB 80W designs (0.0009% THD in Class B!), and goes up to 400W-RMS/ch designs using lovely L-MOSFET output devices. And his books are a total treat to read. I've seen umpteen circuit articles in Elektor and never understood any of them till I read Randy's books.
If you are open to investing, say, USD 500 for a monoblock amp kit, you can go for the AKSA amp kit. People claim it's absolutely top-class. There's one Singapore Website which seems to sell PCBs and full kits for high-quality amps; its designer is a member of diyaudio. And then there's the Pass forum on this Website which discusses Nelson Pass' amp designs. Those designs have a very loyal fan following and Nelson himself participates in "his" forum. If you want to build valve amps and can procure all the valves needed, I am sure the valve forum can point you to at least a dozen good sources of designs and kits. Check the Bottlehead site as one example.
Incidentally, the Crescendo, being an Elektor design, will have its PCB available for INR payment from the Indian publishers of Elektor. Contact them. You may have to hunt a bit for the devices it uses, though. And by all accounts, those who have built it say it's an excellent amp. If I had to build something that complex, I'd probably opt for the Leach amp or one of the Randy Slone designs. Just personal preference.
Tarun
Order from Amazon or Barnes and Noble, pay over the Net by int'l credit card, and either ship to a friend's address in the US and ask him to get it with him when he visits India, or get the book shipped direct by courier to your Indian address. No book is difficult to get sitting here in India if it's available with these outlets and you are willing to pay courier charges. In addition, almost all large bookstores in big Indian cities are willing to procure any book in print, if you can give them details (ISBN number, publisher name, etc). I know Strand in Bombay is willing to do this. They will typically charge list price plus 15% for shipping and overheads, and take 6-8 weeks of time. (Amazon often sells the books much cheaper, but if you add courier to India, it may turn out more expensive.)ssSai said:
I wouldn't exactly say this Website is avoiding discussing amplifiers, considering that there are forums for valve amps, solid state amps, and the highly specialised chip amps on diyaudio.com. We just don't like to mix up amps and speakers in the same forum.
I don't think DIY chaps on the amps forums here will agree that they're stuck with 60WRMS.
Have you checked these forums?You've already received excellent suggestions from Pixo. In addition, I'll add the books by Randy Slone and Douglas Self, which have PCB designs, in case you are willing to get them fabricated and start from there. (Randy also used to sell ready-made PCBs; you can send him email after you buy his books.) He starts with ultra-low distortion Class A 40W and Class AB 80W designs (0.0009% THD in Class B!), and goes up to 400W-RMS/ch designs using lovely L-MOSFET output devices. And his books are a total treat to read. I've seen umpteen circuit articles in Elektor and never understood any of them till I read Randy's books.
If you are open to investing, say, USD 500 for a monoblock amp kit, you can go for the AKSA amp kit. People claim it's absolutely top-class. There's one Singapore Website which seems to sell PCBs and full kits for high-quality amps; its designer is a member of diyaudio. And then there's the Pass forum on this Website which discusses Nelson Pass' amp designs. Those designs have a very loyal fan following and Nelson himself participates in "his" forum. If you want to build valve amps and can procure all the valves needed, I am sure the valve forum can point you to at least a dozen good sources of designs and kits. Check the Bottlehead site as one example.
Incidentally, the Crescendo, being an Elektor design, will have its PCB available for INR payment from the Indian publishers of Elektor. Contact them. You may have to hunt a bit for the devices it uses, though. And by all accounts, those who have built it say it's an excellent amp. If I had to build something that complex, I'd probably opt for the Leach amp or one of the Randy Slone designs. Just personal preference.
Tarun
Me Misinterpreted
Hello every body.
You people got me wrong, I did not mean what Tarun thinks. Let me explain.........
NOBODY is an expert in every thing right? Other wise there would be no MadiSound or AdireAudio........
If this is the case then all you DIYers are good at one and OK at the rest. So if you are good at the art of making a good cabinet, you look up to others for the crossover and amps.
The above is my case. I have not yet got the sealed enclosure stisfactorily into my system (brain) on the first hand and this is my first project. I therefore decided that building an amp is not my cup of tea. Hence I looked up to you people for some advice....
I am a starter and I wonder how come every body are just avoiding the subject of Amplifiers. Do I assume that every one build their own amps (if that is the case "hats off to you")
This goes to Navin BHAI and every one in the DIY amp club.
I searched a LOT (I really mean LOT) and no one even has any idea of any amplifier of more than 60 watts RMS (forget the amps the car accessories people stock... half of them are crap and the rest should be costly crap).
Given my take on the amp part of the DIY project, I went hunting for an "Off the shelf amp". I visited many places where I thought I could find an amp. My logic was, "If I can get a AVA250 amp for 178 USD, I should surely get a 250 watt amp here in Bangalore for atleast a 190 USD." But even after a LOT of hunting I found no one with an idea of a Home Theater amp of more than 30 watts per channel (forget a dedicated subwoofer amp). One thing I observed was that every one (at the shops) were showing me car ams when ever I ask a 250 watt amp.
The only place I got to see a 300 watt RMS (2 Channels) was at "ProFx" which is in Barton Center, M.G. Road, and the price was a whopping 28,000 (INR).
I hope I have not annoyed anyone.
Now since I have got my question right (Justified), any one want to guide this fellow??
Hello every body.
You people got me wrong, I did not mean what Tarun thinks. Let me explain.........
NOBODY is an expert in every thing right? Other wise there would be no MadiSound or AdireAudio........
If this is the case then all you DIYers are good at one and OK at the rest. So if you are good at the art of making a good cabinet, you look up to others for the crossover and amps.
The above is my case. I have not yet got the sealed enclosure stisfactorily into my system (brain) on the first hand and this is my first project. I therefore decided that building an amp is not my cup of tea. Hence I looked up to you people for some advice....
I am a starter and I wonder how come every body are just avoiding the subject of Amplifiers. Do I assume that every one build their own amps (if that is the case "hats off to you")
This goes to Navin BHAI and every one in the DIY amp club.
I searched a LOT (I really mean LOT) and no one even has any idea of any amplifier of more than 60 watts RMS (forget the amps the car accessories people stock... half of them are crap and the rest should be costly crap).
Given my take on the amp part of the DIY project, I went hunting for an "Off the shelf amp". I visited many places where I thought I could find an amp. My logic was, "If I can get a AVA250 amp for 178 USD, I should surely get a 250 watt amp here in Bangalore for atleast a 190 USD." But even after a LOT of hunting I found no one with an idea of a Home Theater amp of more than 30 watts per channel (forget a dedicated subwoofer amp). One thing I observed was that every one (at the shops) were showing me car ams when ever I ask a 250 watt amp.
The only place I got to see a 300 watt RMS (2 Channels) was at "ProFx" which is in Barton Center, M.G. Road, and the price was a whopping 28,000 (INR).
I hope I have not annoyed anyone.
Now since I have got my question right (Justified
), any one want to guide this fellow??Sai,
If u r looking for ready made amps ..y dont u consider local makers like Pulze or DNM pace etc..though i dont have any experiences with them... else if u want to try out urselves u get a large number of kits...basically buy the ready made PCB's (and u can redesign/tweak the basic circuit which is a rare case) or get better quality parts and assemble them. I'm sure they wont dissapoint u..! Otherwise u can use some IC's ...the STK series would be a good choice...they come in the same shape but various power ratings...may be u can bridge them...there are numerous options... Also i remember seeing a sub amp module(if we are talking about that) at the DNM stall at AV-expo bangalore...u can contact them for details. They sure will respond..may be a lil delayed though...BTW did u recieve ur shipment of woofers..?
If u r looking for ready made amps ..y dont u consider local makers like Pulze or DNM pace etc..though i dont have any experiences with them... else if u want to try out urselves u get a large number of kits...basically buy the ready made PCB's (and u can redesign/tweak the basic circuit which is a rare case) or get better quality parts and assemble them. I'm sure they wont dissapoint u..! Otherwise u can use some IC's ...the STK series would be a good choice...they come in the same shape but various power ratings...may be u can bridge them...there are numerous options... Also i remember seeing a sub amp module(if we are talking about that) at the DNM stall at AV-expo bangalore...u can contact them for details. They sure will respond..may be a lil delayed though...BTW did u recieve ur shipment of woofers..?
Ajju, do you know where Olson's book is available?
Ashwin...
There are a lot of them by Olson.
If its "Fundamentals of Acoustics by HF Olson" that ur referring to the copy i saw was a special reprint from a microfilm...and it was a pretty fat book with all kinds of data...very mathematical..covering all kinds of topics from normal baffles to various kinds of horns..noise control and all..but i remember seeing that it was out of print and only microfilm reprints are available ...i dont have that book now...i found it at the reference section of a research organisation's technical library...!
ajju
Ashwin...
There are a lot of them by Olson.
If its "Fundamentals of Acoustics by HF Olson" that ur referring to the copy i saw was a special reprint from a microfilm...and it was a pretty fat book with all kinds of data...very mathematical..covering all kinds of topics from normal baffles to various kinds of horns..noise control and all..but i remember seeing that it was out of print and only microfilm reprints are available ...i dont have that book now...i found it at the reference section of a research organisation's technical library...!
ajju
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