Hi Folks,
I am happy to share my journey from germination of the idea to build the Speakers to its fruition.
Background:
In the thread http://www.hifivision.com/diy/22729-bug-has-bitten.html, I outlined the circumstances that prompted me to consider a DIY build of Speakers.
Considerations:
1. No Cross overs between 200 & 4000 Hz - the most sensitive hearing range.
2. Lowest Order Cross Over to retain the efficiency
3. High efficiency to enable use with Tube Amplifier
4. Frequency ranging from 40 Hz to 20 Khz. The lower one for smooth
integration with Subwoofer.
Choice of Drivers:
This almost necessitated a choice of Full Range drivers. I considered Fostex, Mark Audio and AER Drivers. Mark Audio Drivers though nice were ruled out because of lower efficiency compared to others. AER Drivers were priced more than 10 times those of Fostex . Fostex appeared to be a logical choice and relatively easy to procure from Madisound USA.
To suit the desired Frequency Range, I opted for 8 FostexFF225WK full Range driver. This Driver though has good Low frequency range, has been known to be lacking in higher frequency. Hence I decided to enhance the upper end using moderately priced Fostex FT17H Horn Tweeter. Fostex recommend using their Horn Tweeter with a single Capacitor to protect it. Generally the Full Range Driver is not applied any Cross Over but rather allowed to naturally roll over.
Choice of Enclosure:
I was tending towards building Metronome ML TQQT - Speakers . However over next few days the location where the system would be placed was changed and at nearly 65 tall, the Metronome Speakers were considered to be too tall. Thus began a search for an alternate design albeit using the Drivers already with me. I narrowed down the design to that of Decware and Bob Brines.
Steve Deckert of Decware confirmed that the Drivers I had were suitable to be used in his Decware NFX as well as HDT design. HDT design is a bit unconventional and uses multi ports with a number of passive Drivers. On the other hand, Bob Brines designs are more conventional. I ordered Plans of both Decware HDT and Bob Brines designs. After some consideration, I opted for Bob Brines MLTL Mass Loaded Transmission Line design.
This design is of a straight tower with fairly large cross section. So the enclosure was decided to be built with rounded edges and soften the In Face feeling of the straight tower by reclining them. In consultation with Bob Brines, I decided to incline the towers by 7 degrees.
Subwoofer:
The MLTL Towers with chosen Drivers go down to a frequency response of 40 Hz. To further augment this, a Subwoofer was needed. I decided to build a Subwoofer using locally available 12 Peerless Driver. I also ordered a Dayton 240 Watts Plate Amp to power the Subwoofer from Parts Express, USA.
- To be continued -
Jayant
I am happy to share my journey from germination of the idea to build the Speakers to its fruition.
Background:
In the thread http://www.hifivision.com/diy/22729-bug-has-bitten.html, I outlined the circumstances that prompted me to consider a DIY build of Speakers.
Considerations:
1. No Cross overs between 200 & 4000 Hz - the most sensitive hearing range.
2. Lowest Order Cross Over to retain the efficiency
3. High efficiency to enable use with Tube Amplifier
4. Frequency ranging from 40 Hz to 20 Khz. The lower one for smooth
integration with Subwoofer.
Choice of Drivers:
This almost necessitated a choice of Full Range drivers. I considered Fostex, Mark Audio and AER Drivers. Mark Audio Drivers though nice were ruled out because of lower efficiency compared to others. AER Drivers were priced more than 10 times those of Fostex . Fostex appeared to be a logical choice and relatively easy to procure from Madisound USA.
To suit the desired Frequency Range, I opted for 8 FostexFF225WK full Range driver. This Driver though has good Low frequency range, has been known to be lacking in higher frequency. Hence I decided to enhance the upper end using moderately priced Fostex FT17H Horn Tweeter. Fostex recommend using their Horn Tweeter with a single Capacitor to protect it. Generally the Full Range Driver is not applied any Cross Over but rather allowed to naturally roll over.
Choice of Enclosure:
I was tending towards building Metronome ML TQQT - Speakers . However over next few days the location where the system would be placed was changed and at nearly 65 tall, the Metronome Speakers were considered to be too tall. Thus began a search for an alternate design albeit using the Drivers already with me. I narrowed down the design to that of Decware and Bob Brines.
Steve Deckert of Decware confirmed that the Drivers I had were suitable to be used in his Decware NFX as well as HDT design. HDT design is a bit unconventional and uses multi ports with a number of passive Drivers. On the other hand, Bob Brines designs are more conventional. I ordered Plans of both Decware HDT and Bob Brines designs. After some consideration, I opted for Bob Brines MLTL Mass Loaded Transmission Line design.
This design is of a straight tower with fairly large cross section. So the enclosure was decided to be built with rounded edges and soften the In Face feeling of the straight tower by reclining them. In consultation with Bob Brines, I decided to incline the towers by 7 degrees.
Subwoofer:
The MLTL Towers with chosen Drivers go down to a frequency response of 40 Hz. To further augment this, a Subwoofer was needed. I decided to build a Subwoofer using locally available 12 Peerless Driver. I also ordered a Dayton 240 Watts Plate Amp to power the Subwoofer from Parts Express, USA.
- To be continued -
Jayant