Started a new TL BS project last week using Dayton Reference woofers and tweeters.

Only one raw TL box is ready as of now for measurements and design of crossovers.

Some images -

Measured free air impedance and phase of the woofer

There is a variation of around 14% in resonance from the published values. Also other TS parameters are different by around 8% to 10%. So higher cost of drivers does not mean close tolerances - unless i am doing drastically something wrong in measuring the TS parameters using REW which i do not think so.

Measured unstuffed impedance and phase of the woofer

The tuning of the line is not ideal - this is due to the reduced cross-section of the line near the terminus causing the impednace peak to be less than equal. The tuning of the line is around 66Hz

Measured stuffed impedance and phase of the woofer

The impedance @ resonance is around 42% less than the free air impedance which indicates TL loading and removal of all odd harmonics standing waves. The line is tuned at exactly 66 Hz which is the gometric mean of the 2 peaks of the unstuffed line.

Combined impedance and phase of the woofer

Simulated cross-over for the TL speaker system

The cross-over frequency is at 1930Hz which is same as the Wave length of the centre to centre distance between the woofer and tweeter - 7 inches. Design goal was to have tight and punchy bass.

Tweeter reverse connected to check filter phase

The deep notch at the cross-over point with perfect phasing with tweeter reverse connected.

Will take another 2 weeks to build the crossover as per design and finish the box. Will keep updating as per progress. Thanks.

Only one raw TL box is ready as of now for measurements and design of crossovers.

Some images -

Measured free air impedance and phase of the woofer

There is a variation of around 14% in resonance from the published values. Also other TS parameters are different by around 8% to 10%. So higher cost of drivers does not mean close tolerances - unless i am doing drastically something wrong in measuring the TS parameters using REW which i do not think so.

Measured unstuffed impedance and phase of the woofer

The tuning of the line is not ideal - this is due to the reduced cross-section of the line near the terminus causing the impednace peak to be less than equal. The tuning of the line is around 66Hz

Measured stuffed impedance and phase of the woofer

The impedance @ resonance is around 42% less than the free air impedance which indicates TL loading and removal of all odd harmonics standing waves. The line is tuned at exactly 66 Hz which is the gometric mean of the 2 peaks of the unstuffed line.

Combined impedance and phase of the woofer

Simulated cross-over for the TL speaker system

The cross-over frequency is at 1930Hz which is same as the Wave length of the centre to centre distance between the woofer and tweeter - 7 inches. Design goal was to have tight and punchy bass.

Tweeter reverse connected to check filter phase

The deep notch at the cross-over point with perfect phasing with tweeter reverse connected.

Will take another 2 weeks to build the crossover as per design and finish the box. Will keep updating as per progress. Thanks.

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