My OB speaker

[suri]

Beaming is not about bass, it's about uncontrolled dispersion. When you move around different parts of the room, you will hear gross issues in FR. Like I said, you may not even notice it that much...

What you were probably hearing was the typical Philips fullrange peaky sound signature, and once you cut the extra HF, you can hear it producing some bass. The bass was always there, just masked by the HF.

Actually, Fs is not a part of the T/S params, those are VAS, Qes, Qts, BL, mms etc. They help in designing a box for correct system compliance. The only thing needed for an OB is the Qts, so you know whether it will work in OB or not as low Q drivers do not work well there. Both Fs and xmax are quoted separately from T/S.

Most high-Q drivers, for OB use, have a very low xmax due to a stiff suspension required to set up the higher Q in the first place. Also, higher xmax drivers sound worse because of the length of the magnetic gap, with smaller xmax the designer can keep more of the coil in the gap so the driver is working in its linear range.

Mms has no correlation with reflections. It is a measure of the moving mass of a driver, including the air. It (in conjunction with BL) gives a measure of the total compliance of the driver. Or perhaps I'm not understanding where you're coming from?

Q is a measure of energy storage, very loosely speaking. It also is sometimes defined as the strength of resonance. A low Q driver or system will have a prominent and peaky resonance, lower Q drivers and systems will have gentler resonances. The principle is the same for all kinds of system Q - including those you may encounter in inductors, for example, not just speakers.

As a cat plays with a mouse, perchance?

 

[jaudere]

Hi jaudere
Sorry for joing in late. But you have done a good job. Finishing and workmanship is superb. I hope material you are using for cabinet is particle board or soft board, so sound waves inside the cabinet doesn't bounce back or you can use layers of cotton inside the cabinet. Old Philips stereo wood speakers used to have them. (Ignore this comments if you have already thought of that)
Keep up the good work and pl. put pics of finished product.
Regards
Hiten

Thanks for the complements.I will convey them to my carpenter. Actually what you are seeing in the pics is my test baffle when i was planning to use full range driver. when i read a lot after designing that thing, i decided to go to 3 way open baffle speaker. i am waiting for the final baffles.(supposed to arrive tomorrow.)
as the system is open baffle, there won't be any cabinet. of course the bass part will have folded wings . so the reflected waves are likely to create problem. will be using 18mm plywood. so i will need some damping.i have not yet finalized the material which is to be used for damping.

people have used a lot of things including bath towel.i may use foam.

Cranky, can you please suggest damping material? is foam alright? how thick it should be? or anything simple and non toxic? i have 2 kids at home. so I will need something non toxic.

 

[jaudere]

A baffle on the mid (I know you're using the Philips as the mid ) will help increase the efficiency a bit, there is a smidgen of a backwave even on a mid.

The whizzer can be removed by using a hobby knife to cut out the extended portion, followed by a scraper for fine trimming. Be careful not to remove any of the voice coil material, the whizzer is glued to the voice coil itself. Two runs are advised, and a practice run on a cheap driver will help you stay out of trouble. There are a lot of cheap (<100) speakers you can practice on.

hi cranky,

i am helpless till i get the baffles. at present i am listening to music on that half H frame-half no baffle design, that too on only one side. the other side is having a full ranger again without any baffle. i am supposed to get the baffles tomorrow. but even with the single channel, the music is better than my regular speakers.

today i listened to "Tere bin jeena nahi" by bali bramhabhatta(anupama verma and Bikram Saluja in the video) and Oh sanam by lucky ali. what an experience. i hope it will further improve after i get both channels on proper baffles.

about removing the whizzer cone, i think i should not fiddle with it,especially when i don't know the cut off between mid and the tweeter. if the point is around 5Khz, the whizzer cone should not interfere. to get a new driver needs a lot of efforts at my place. i will have to travel 250km to Pune to get a new philips driver in case i don't like sound after removal of the cone.anyway i am liking the sound with the cone on.

 

[jaudere]

hi friends. My baffles arrived today. I put all the drivers on the baffle and connected them to amp through cross over. As soon as i played a song , my wife reflexly told me that the speakers are much better. We listened to 'tu hi re' from bombay. What an experience. I had never before noticed that there is a sound of group violin in the background which follows the lead vocals. Just beautiful. Of course the drivers are yet to break in. Damping is to be done. Will upgrade the cables tomorrow but at present i am quite happy with the product. Will post pics soon.

 

[jaudere]

hi friends,

here are some snaps finally.still in testing phase. working great in 4 way. was lacking a bit in bass in 3 way design. thanks a lot to all those who helped me understand speakers and of course to my carpenter who helped me convert the theory into practical.

height: 4 ft, width 20", depth 1 ft max, wt, i don't knw. driven by yamaha rxv 361 and a locally made amp for sub. all the speakers including the subs are on open baffle.
cost: Rs 5000 in total for drivers and XO, wood work: rs 2500. transport, may be around rs 1000.

1) 4way design: philips tweeter, philips octagonal as mid, philips round as mid bass and 15" as bass, driven by separate amp.

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2) 4 way speaker
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3) tweeter and mid from back, with the XO
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4) the speaker is divided in 2 parts. upper for mid and tweet, lower for mid bass and bass. fixed with 2 large screws. the lower part has wider baffle: 40" including wings.did so as it will be helpful for transport in case i change my residence.
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5) this was a 3 way design. the lower 2 were connected in series to get 8 ohm load. was not using sub amp in this setting. the philips round full range was working as mid here.

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6)working on upper part
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7) the mid bass and bass baffle
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regards

 

[jaudere]

Hi friends,

here is the picture of final AV set up. of course it is yet to get polished.for that i will have to wait till the monsoon gets over.

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I will call it as PIY (plan it yourself) rather than DIY.i planned everything but the major work was done by carpenter. nevertheless i am quite happy with the result.

of course everyone thinks that his project is very good. someone else should appreciate it. i am going to get that chance on that week end.one of my friends who is a music buff and into DIY since long will be visiting my place. will let you know his opinion. of course all of you are welcome. the problem is that i stay in a typical konkan village(the ones which are run by Gram panchayat) about 300km from Mumbai. so one has to plan a picnic of 2 -3 days in case there is a plan to visit my place.

jaudere

 

[Hiten]

Hi jaudere
After polishing whole setup will look good. I hope sound quality is good as only you can be the judge. Anyway there is always a chance and fun to improve as a DIYr

Lucky you living in Konkan Village, Konkan and Goa are beautiful places.

my regards
Hiten

 

[grubyhalo]

Looks pretty neat and im sure sounds that way too. Don't forget to 'polish' the baffle, it would look nicer still. BTW, sounds like you're living in an idyllic place!

 

[jaudere]

thanks grubyhalo. What is an idyllic place? I am living my dream. My dream was to get best possible education in india , use it for people in rural india & at the same time enjoy my life without missing much of fun. God has been very gracious to offer me all of that.

 

[grubyhalo]

thanks grubyhalo. What is an idyllic place? I am living my dream. My dream was to get best possible education in india , use it for people in rural india & at the same time enjoy my life without missing much of fun. God has been very gracious to offer me all of that.

One definition of idyllic is simple and beautiful. Good to know you're living your dream, not a lot of people reach there.

 

[keith_correa]

hi friends. My baffles arrived today. I put all the drivers on the baffle and connected them to amp through cross over. As soon as i played a song , my wife reflexly told me that the speakers are much better. We listened to 'tu hi re' from bombay. What an experience. I had never before noticed that there is a sound of group violin in the background which follows the lead vocals. Just beautiful. Of course the drivers are yet to break in. Damping is to be done. Will upgrade the cables tomorrow but at present i am quite happy with the product. Will post pics soon.

Looks good - will look better after polishing. Good work.
And, Congratulations!!! :clapping:

 

[keith_correa]

thanks grubyhalo. What is an idyllic place? I am living my dream. My dream was to get best possible education in india , use it for people in rural india & at the same time enjoy my life without missing much of fun. God has been very gracious to offer me all of that.

I doff my hat to you for your ideals and more importantly - the way you live your dream. If only there were more people like you.

 

[Hiten]

Hey jaudere
wow serving in rural area, Just like in movie "Swadesh"
By the way I will also like to help, kindly mail me will try to help in any way as much as possible
my email : [email protected]
Regards
Hiten

 

[jaudere]

hi, friends,

i finally got a chance to put my system to some real test as my friend arrived yesterday (he uses his HTPC through his Denon 1908 and Jamo s406 at his home and has built many amps and speakers in his school and college days.)

i initially played some classicals(Sanjeev abhyankar), neil Diamond, Tu hi re etc. through DVD player. he said that the spekars are good but there is something lacking.he said that the sound was not reaching the centre of his brain. he loved the percussion part and some string instruments. one important thing he said was that the speakers are true to original.

then while talking, i told him that i have creative soundblaster live 5.1 in PC but could not install it as i have lost the CD. so we downloaded it from net, installed it and played through soundblaster.we also lowered crossover setting for sub out to 60 from 120Hz. with that sound through the soundblaster, he was mighty impressed. he said that now the music has started reaching his brain. then we played the famous "pipeline" on guitar,some more Neil Diamond, Enigma. he said the balance was perfect. the timing of instruments was precise.even i could notice some difference but could not describe it.(I am not an audiophile). he told me that midrange was lacking with DVD player digital out and Yamaha DAC(its yamaha RX V 361, the entry level model). with Soundblaster doing the DAC part, everything changed.so the Yamaha amplifier is good but not the DAC

so guys,
i am happy that i could impress an expert with the speakers with such a tiny budget. he said that the size of speakers is too big but that is the inherent problem with open baffles.

now i face some problem. i don't want to put my PC on just to listen to music. that is waste of energy. Yamaha DAC or DVD DAC are not great. then what are my options?
1) WD TV? 2) Oppo 980? . i am not going to go for dedicated CDP. will be too costly

 

[gobble]

Oppo 980 would be great I guess. Good all round buy for home ..

Congrats on the effort! Love the way you toiled! :clapping:

Cheers

 

[jaudere]

hi friends,

Some progress here. Nothing much aesthetically . so no photos. I tried some damping for the low frequency baffle. didn't have much choice. so i used 2 inch thick foam. i didn't think that it made an immediately noticable difference but i am noticing a significant change in the sound since last 10 days. it is as if the speakers are becoming alive. i am enjoying them much more. I don't know what made it so., breaking in after 1 month? better CDs? stuffing? whatever. i am very happy.hyeah:

decided to do some objective testing.i don't have any tools. so internet was my only hope. after searching on net, i found these.

http://www.dogstar.dantimax.dk/testwavs/3stepoct.zip

Audio Test Signals

with the help of these, i found that the lower end offrequency response range of my speakers is 40-50 Hz (32 Hz is barely audible, 40 is audible and 50 is loud, probably the resonating frequency of my woofer.)and upper is somewhere between 16KHz and 20KHz.
so i take my range as 45 Hz to 18000Hz. i think it is pretty decent for music.

please try this tool yourself and let me know your experiences with your speakers.

regards

 

[jaudere]

Hi friends,
yesterday i read miniwatt tube amplifier review by yesterday. I was really impressed. i was impressed by the last sentence the most
simplicity is the ultimate sophistication.

thanks a lot suprateep.

i don't know what clicked in my mind and i decided to run my speakers(except tweeter) full range without any intervening crossover.as it is i was using full range speakers as mid and low. so i removed the XO from the circuit.

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I liked the sound but it was lacking bass. this time i had taken 8"full ranger out and only 1 philips full range and 15" bass was playing. i was surprised. from what cranky had suggested, speakers with supple suspensions do not sound good on open baffle. this 15" is too supple. so i removed it from the circuit and put back 8" fullrange(whose suspension is very rigid) which is placed above this 15" woofer. the bass was back!! wow!

there was a great difference in how the songs started sounding. i listened to"How do I" from Con Air.

YouTube - How Do I Live

It was the first time i felt that the singer is standing in front of me.
then i watched the same song on youtube. and then i understood what is huge soundstage. My monitor is 22".
it could not match the environment created by my speakers. i think this is what is called as big sound stage.

then i used tweeters(through XO) to complement full rangers. that made the system complete. bass is good, tweeters are taking care of highs.

i made some conclusions

1)my 15" woofers are hopeless , at least on open baffle.

2) crossovers(at least the ones which i was using, philips 3 way)are not good. what they do is to divide signal and confuse speakers. the same instrument , say guitar, is played on bass when on thicker E string and played by mid when on the thinner E string on upper note

3) full rangers sound better when fed with full spectrum

4) large baffle(mine is almost 4ft, although in a folded fashion) gives you absolutely adequate bass if the driver choice is right.

5) if TS parameters are not available, the drivers with stiffer suspension are likely to give better bass on open baffle.

Cranky, please correct me here if i am wrong. this will be useful for selecting speakers for those who, like me, cannot afford imported speakers for experiments.

Luckily, the beaming , mentioned by cranky, is not noticeable to me. that makes me happy.

 

[jaudere]

If you get a crossover meant for one driver, and connect another driver to it, it will not work well. Period.

Really didn't get that.

I have connected only tweeter through crossover at present. all the other drivers are playing without crossover. the mid and bass of the crossover are not connected to anything. as you had told me, by keeping them open, i create infinite resistance and it does not matter. the remaining 2 drivers are connected in parallel to XO, so their performance is not related to XO .

if you are talking about my previous set up, the tweeter and mid were from philips and the XO also is from Philips. even the impedance was matched.so the mids should have been good. the woofers were of different company but even with those, the impedance was matched. so i didn't get it when you said"If you get a crossover meant for one driver, and connect another driver to it, it will not work well. Period."

on a different note, i am likely to go for an active XO with tweeter cut above 7000, woofer cut below 200 and 200-7000 played by a fullranger.

 

[jaudere]

hello friends,



finally my speakers are ready after a long wait. did many experiments on them(again as i said there were no objctive measurements but the sound tuned to my ears.)took out 15" woofers which i didn't like. I put 12" speakers in their place which are giving tighter bass.got the baffles polished. will post the pics soon.

so the final configuration is DVDP>>> coaxial to Yamaha RXV 361. sub out crossed at 120KHz fed to powered mixer(which works as sub amplifier250W RMS at 4ohms).). front speakers set as large and bass out through "BOTH". each speaker unit has 3 drivers.Philips tweeter playing through high pass 4Khz filter. the full ranger 8" driver getting full signal. the 3rd 12" speaker played by the sub amplifier, getting signals below 120KHz. all the speakers including the sub are on folded open baffle, a kind of U frame woofer. since the wings of the baffle are folded at 90 degrees(giving parallel surfaces), i needed some kind of damping. i have used 2" thick foam for it. i know it is not an ideal material, but i coudn't take risk of using glass wool on open baffle especially when i have two kids at home.
for movies, i keep front speakers as "small" on AVR speaker set up to protect full range drivers from low frequencies. i watched a few movies but they were not action movies, so the real test for movies not done yet but i am happy with the performance in music.

final cost of speakers: drivers with passive high pass filter: Rs. 3000. wood and carpenter, about Rs 4500.

 

[grubyhalo]

hello friends,



finally my speakers are ready after a long wait. did many experiments on them(again as i said there were no objctive measurements but the sound tuned to my ears.)took out 15" woofers which i didn't like. I put 12" speakers in their place which are giving tighter bass.got the baffles polished. will post the pics soon.

so the final configuration is DVDP>>> coaxial to Yamaha RXV 361. sub out crossed at 120KHz fed to powered mixer(which works as sub amplifier250W RMS at 4ohms).). front speakers set as large and bass out through "BOTH". each speaker unit has 3 drivers.Philips tweeter playing through high pass 4Khz filter. the full ranger 8" driver getting full signal. the 3rd 12" speaker played by the sub amplifier, getting signals below 120KHz. all the speakers including the sub are on folded open baffle, a kind of U frame woofer. since the wings of the baffle are folded at 90 degrees(giving parallel surfaces), i needed some kind of damping. i have used 2" thick foam for it. i know it is not an ideal material, but i coudn't take risk of using glass wool on open baffle especially when i have two kids at home.
for movies, i keep front speakers as "small" on AVR speaker set up to protect full range drivers from low frequencies. i watched a few movies but they were not action movies, so the real test for movies not done yet but i am happy with the performance in music.

final cost of speakers: drivers with passive high pass filter: Rs. 3000. wood and carpenter, about Rs 4500.

Nice to know! Congrats! :clapping: