I used these speakers first time in my college days, as the funds were limited, two clay pots were used as enclosures in an attempt to improve the sound of my ancient ITT tape recorder. The diy amps were built around TDA 2020 and austereo tone controls from Visha kits. The combination sounded nice and eventually ended up as ceiling speakers in our dining room. That was about 20 years ago. This humble speaker again caught my attention some time back when I started experimenting with open baffle speakers. They sounded nice in the open baffle with good midrange and a clean sound that you can relax for hours without fatigue. This is a good driver but not an excellent one, and its strength is in the lower midrange. IMO they sound more full bodied in that region compared to a 4 or 5 inch driver. The focus of this project is to get the best out of this driver and try to compensate its deficiencies with the help of other drivers. So the word reference needs to be taken with a pinch of salt. The total driver cost for this project (6 drivers) is about INR 2200. This is my frugal attempt at high end using inexpensive-locally available drivers 
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As Philips speaker division is acquired by Boston Acoustics, currently this driver is available from their vendors. More information is at this thread. - http://www.hifivision.com/diy/12792-ts-parameters-philips-8inch.html
The enclosure is a mass loaded transmission line (ML-TL) employing forward and backward firing drivers(bipole). Conventional bipoles use the same type of drivers, I tried to use a combination of drivers of different parameters such that they complement each other. This project started out of curiosity and in due process resulted in rewarding interactions with some very knowledgeable individuals. I would especially like to mention Martin J King of quarterwave.com for his valuable advice and encouragement for this project. The wealth of information available at his site and his MathCAD worksheets were instrumental in this design .
As the full ranger is compromised at the highs, Another tweeter was brought in for 4khz onwards, Since I had a pair of Philips IX9101A soft dome tweeter available with me, ended up using them. While full ranger fires forward, another inexpensive woofer Dainty PF0802B was used as the rear-firing driver. Here is a sketch of the enclosure
All the drivers I have chosen for this project are not known for their sonic abilities and its true that they do lack refinement. I am trying to use them in frequency bands where they produce least distortion, thus masking their deficiencies to a possible extent. The full ranger is an all paper driver and due to the extended range it can be crossed at a higher frequency this is advantageous as this single driver can cover the entire vocal band -200Hz to 3500Hz. A high crossover point will also reduce load and distortion on the tweeter. The woofers Fs is almost an octave below full ranger, so combined with the air column resonances of the enclosure it should be possible to attain better low frequency extension.
Since the enclosure is not a regular rectangular box, I chose to build a life size model in thermocol for the carpenter. Here is a picture.
The hollow stand will home the baffle step correction circuit and crossover components. Remaining area will be filled with sand, the cable will be drawn via this and terminate at the bottom.
I am thinking of attaching a phase plug for the full ranger to reduce on-axis beaming. Also there is a plan to fix the tweeter to this phase plug for a co-axial placement. Will update with pics.
.As Philips speaker division is acquired by Boston Acoustics, currently this driver is available from their vendors. More information is at this thread. - http://www.hifivision.com/diy/12792-ts-parameters-philips-8inch.html
The enclosure is a mass loaded transmission line (ML-TL) employing forward and backward firing drivers(bipole). Conventional bipoles use the same type of drivers, I tried to use a combination of drivers of different parameters such that they complement each other. This project started out of curiosity and in due process resulted in rewarding interactions with some very knowledgeable individuals. I would especially like to mention Martin J King of quarterwave.com for his valuable advice and encouragement for this project. The wealth of information available at his site and his MathCAD worksheets were instrumental in this design .
As the full ranger is compromised at the highs, Another tweeter was brought in for 4khz onwards, Since I had a pair of Philips IX9101A soft dome tweeter available with me, ended up using them. While full ranger fires forward, another inexpensive woofer Dainty PF0802B was used as the rear-firing driver. Here is a sketch of the enclosure
All the drivers I have chosen for this project are not known for their sonic abilities and its true that they do lack refinement. I am trying to use them in frequency bands where they produce least distortion, thus masking their deficiencies to a possible extent. The full ranger is an all paper driver and due to the extended range it can be crossed at a higher frequency this is advantageous as this single driver can cover the entire vocal band -200Hz to 3500Hz. A high crossover point will also reduce load and distortion on the tweeter. The woofers Fs is almost an octave below full ranger, so combined with the air column resonances of the enclosure it should be possible to attain better low frequency extension.
Since the enclosure is not a regular rectangular box, I chose to build a life size model in thermocol for the carpenter. Here is a picture.
The hollow stand will home the baffle step correction circuit and crossover components. Remaining area will be filled with sand, the cable will be drawn via this and terminate at the bottom.
I am thinking of attaching a phase plug for the full ranger to reduce on-axis beaming. Also there is a plan to fix the tweeter to this phase plug for a co-axial placement. Will update with pics.
