My OB speaker

Hello friends,

after reading a lot about speakers, i finally decided to go the open baffle way. just experimenting a bit. I bought a locally made 12" speaker, no specifications available. the shopkeeper said that it was a woofer but it produces decent higher frqes and has a whizzer cone so i think it is a full range speaker. I built H frame with help of a carpenter.

size of H frame: height: 3 ', width 20" and depth 2'. built it arbitrarily.
after putting the driver in the frame, i found it lacking a bit in higher frequencies. surprisingly, i found that the bass is pretty decent, although i do not have any measures. everyone who has built a OB speaker says that it lacks in bass but whatever bass my speaker produces is more than enough for me.

the sound: i like it. my wife and my neighbour unanimously say that it is better than my regular speaker ( I use NX audio 2 way bookshelf , a pro speaker).even I do not feel that the sound of my original speaker is that great when i do A-B comparison.

delighted by the results and i have decided to go 1 step further. My philips 8" full rangers are arriving tomorrow(which say that the frequency range is 50Hz to 22Khz). so it will be a combination of philips full range without any cross over and a woofer from ahuja with one way subwoofer cross over by ahuja again.

Ahuja Sound Solutions

Ahuja Sound Solutions

i know that people dislike Ahuja and think that it is only meant for PA systems but no other Indian manufacturer gives so much technical detail including T-S parameters of drivers. it has a decent price and most importantly, it is readily available.

As a kid my house was filled with Ahuja, Philips and Murphy. Only Philips has survived into the modern age...

Post some pics.

hi,

my philips 8" full rangers have arrived. very good at mid and high frequencies. not good at low frequencies but that was expected. so anyway i am going to use woofer.

bit of a confusion.which woofer should i use?

i am thinking in terms of 15" woofer. either JBL 15" car woofer or ahuja 15" AS X200 woofer.
Ahuja has lower X max(only 4 mm) but better sensitivity(98dB) vs 92dB of JBL. JBL has better x max(14mm). JBL Qts is .6 , better than .54 of Ahuja(Qts towards .7 is better for OB)

now why sensitivity is important? Philips has sensitivity of 92dB/W/m. Open baffle has problem in bass. so if i use a bass driver with 6dB higher sensitivity, naturally SPL produced by bass driver will be higher and that will partially solve the low freq. problem.
another point : JBL frquency response is 28Hz to 450Hz so no need to use low pass filter. Ahuja response is upto 1500KHz so i may need to use a low pass filter at 250Hz.

so friends, please let me know if you have any experience with JBLs or any thoughts about the comparison that i have mentioned above.

hello,

the philips drivers are working well. the H frame is working well with single driver. To my surprise, unlike what others say, I am not missing bass at all(my room is small with 12'x14').I have not used it for movies but it does very well for music. 1 full range driver is in H frame and others are yet to get a baffle. the larger is 12" dolbycon driver(locally made) and smaller is Philips 8" full range. no crossover as all are full range drivers. yet to get the real feel of OBs as only one sided speaker is working. will build the complete pair after i shift to new house in another 2 weeks.

some how my Rs 2700 Taiwa amp is giving better results than Yamaha as far as bass goes.(both amps kept at neutral/tone defeat position).for mids and highs, both amps are same. probably the dolbycon 12" full range drivers which i am using now with philips are better suited for this amp.the results may differ when i use Ahuja 12"full range.using larger driver helps a lot in bass dept. about volume, i need to go upto only 9 o clock position on taiwa while on yamaha, it needs -25dB to get same results.

after listening to this crude OB design, i feel that my original bookshelves are too bright /sharp. even in bass dept, the bookshelves need a sub but OBs are doing well without sub. i don't feel like listening to them now. probably i am rediscovering my musical taste

i am attaching links to the photos. don't look at the designs and aesthetics. i sure once i put those bare drivers on open baffle, they will work better. i am just trying many variations

Photo Sharing by MyPhotoAlbum.com :: MyPhotoAlbum :: MY OB experience

Great Stuff!! Admire your DIY spirit!! Keep it going ...

Cheers

hello friends. Finally decided to go 3 way open baffle. I will be using speakers for music & movies. So philips full range may get damaged by sounds <50Hz heard in movies. So i have to introduce some protection for them. If i use 2 way crossover,most of the readily available ones cross at about 2khz. So i will lose part of the beautiful philips midrange. I am not an electronics man to build a crossover & to know the nuances of the components used. So decided to go 3 way. Here are the parts i am using. Bought them today in pune. 2 15" woofers by Greaton(made locally by order@rs 2600 a pair), 2 philips full range at rs600 a pair ,2 philips silk dome tweet at rs 500 a pair & philips 3 way crossover at rs 900 a pair. It doesnt mention the cut offs but someone who used them highly recommended. .

Can you post a pic of the silk dome?
Regards

hello gobble. Will post some pics as soon as my home net starts working. I am writing on my mobile at present. Had another question. If i just attach an 8 ohm resistor in place of the mid , will the crossover work? Idea of using 3 way is simple. A 2way xo has am odd cutoff point. 3 way will have one around 600hz &second around 12kHZ. Now i want to play the mid without any crossover circuit in between. So what i can do is attach the woof & tweet through the xo to the fronts & direct the bass through the fronts only. I can attach the philips full range to the surround terminal. My yam receiver should split the signal into 4 streams. Front 2 will get full signal with bass but wont play midrange. The full rangers should also get full signal minus the bass. This way i may protect my full range from low freq & at the same time get purer signal to get to the full range.

hello friends. Finally i have found a carpenter who is ready to work as per my direction. So i should get my baffles in another 4 days. Then i will experiment with xo or no xo. If i use xo , i will use tweeter. If i dont use xo, i will use 1 woofer & 2 full range speakers , one stressing on mids (locally made) the other on highs (philips). Somehow,based on the experience i got till now, i feel that i am going to chose the design without xo for the final version.Still have to access the net on mobile. So difficult to post pictures at present. I have pics on mobile but the size is huge . So cant post it.

we look forward to the pics jaudere.