3 way sealed speaker

[arunvenkats]

Hi folks,

Happy to present my first serious audio project. A DIY Speaker build. After a couple of months of design, and couple of weeks of sourcing and building the speaker is ready. The speaker itself was ready 3 weeks back, but was waiting for the Dayton calibrated mic to arrive to do an objective measurement. Got the results now, what do you think? Of course the SPL chart is not really the speaker performance alone, it is the speaker+room combination. Recorded at 75dB. Comments and suggestions are most welcome.

The design is a sealed unit. I do not have the time to tune a port so stuck with a sealed design. It started of as a 2 way system but eventually became a 3 way. The midrange is actually a midwoofer which I had already bought for the 2 way. But it worked out well. Peerless 1" tweeter + Peerless 6.5" mid woofer + 8" Peerless Woofer. The crossover was built with cutoffs at 300 Hz and 4000 Hz. The cabinet was built with 19mm MDF and finished with mica to suit my living room. I chose high sensitivity drivers for the tweeter and mid woofer (originally it was to be 2 way design) so that my small Fossi amp could drive them. Later on, I had to attenuate them in the crossover to match the woofer.

It ended up exceeding my expectations! Thoughts and comments most welcome.

Regards,
Arun

 

[mshifi]

View attachment 88874
View attachment 88875
Hi folks,

Happy to present my first serious audio project. A DIY Speaker build. After a couple of months of design, and couple of weeks of sourcing and building the speaker is ready. The speaker itself was ready 3 weeks back, but was waiting for the Dayton calibrated mic to arrive to do an objective measurement. Got the results now, what do you think? Of course the SPL chart is not really the speaker performance alone, it is the speaker+room combination. Recorded at 75dB. Comments and suggestions are most welcome.

The design is a sealed unit. I do not have the time to tune a port so stuck with a sealed design. It started of as a 2 way system but eventually became a 3 way. The midrange is actually a midwoofer which I had already bought for the 2 way. But it worked out well. Peerless 1" tweeter + Peerless 6.5" mid woofer + 8" Peerless Woofer. The crossover was built with cutoffs at 300 Hz and 4000 Hz. The cabinet was built with 19mm MDF and finished with mica to suit my living room. I chose high sensitivity drivers for the tweeter and mid woofer (originally it was to be 2 way design) so that my small Fossi amp could drive them. Later on, I had to attenuate them in the crossover to match the woofer.

It ended up exceeding my expectations! Thoughts and comments most welcome.

Regards,
Arun

Nicely done. Do they have grills

 

[Vineethkumar01]

@arunvenkats: Nice project.
If you want to understand more about the speaker performance, start by restricting the y axis of the freq response graph to lie between 40dB & 90dB (50dB range).

If you want, you can also mention model numbers of the drivers, centre to centre distance between each driver, and the crossover topology you used.

 

[arunvenkats]

Nicely done. Do they have grills

Thanks!
No grills at the moment.

 

[arunvenkats]

@arunvenkats: Nice project.
If you want to understand more about the speaker performance, start by restricting the y axis of the freq response graph to lie between 40dB & 90dB (50dB range).

If you want, you can also mention model numbers of the drivers, centre to centre distance between each driver, and the crossover topology you used.

Thanks!
Attaching the 40-90 dB chart here:

The drivers, all of them Peerless:

Tweeter : BC25TG15-08
Midrange: FSL-0615R02-08
Woofer: HDS-P830869

Attached the data sheets too.

The crossover is APC (All Pass Crossover) with crossovers at 300Hz and 4000Hz:
The circuit I used:


I had changed the attenuation resistance to suit the mid range and the tweeter (they are high sensitivity compared to the woofer). The circuit is used in this commercial product https://www.visaton.de/en/products/accessories/crossovers/hw-3130-ng-8-ohm Mainly decided to use a commercial design to save time mapping calculated theoretical values for capacitors and inductors to what will be available in the market as standard components.

Regarding the centre distance, I honestly did not put in any audio engineering decision on it. It was made to suit the overall dimensions, limited by a standard 8'x4' MDF sheet. I do not have a standard 2D drawing for the box. I made the drawing itself easy for the carpenter to understand. In fact I have him a tiny 3D printed version for him to understand easily




The 3D model for reference


The crossovers before wiring and soldering. Time was running out and I did have enough time to make a PCB. So created a 3D printed chassis to hold the components.



And the speaker before installing the drivers:


This is my first proper build. Happy to receive feedback.

Regards,
Arun