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

 

[Harsh007]

Sir approximate cost to build this ?

 

[arunvenkats]

Sir approximate cost to build this ?

Drivers ₹21,000
Crossover components ₹11,000
MDF sheet (1 Full 8'x4'), laminate, carpenter and driver cut out in CNC router ₹10,000
Misc. ₹1,500

Total around ₹43,500 (for a set of two)

 

[rwnano]

Well done sir

 

[Prijith]

Awesome. 3 way at a good configuration..

 

[int86]

Drivers ₹21,000
Crossover components ₹11,000
MDF sheet (1 Full 8'x4'), laminate, carpenter and driver cut out in CNC router ₹10,000
Misc. ₹1,500

Total around ₹43,500 (for a set of two)

I am new to hi-fi world. Want to know why crossover components cost this much.

 

[yogibear]

I am new to hi-fi world. Want to know why crossover components cost this much.

Because you want resistors to do their job accurately and literally = non inductive, high tolerance.

And there is no limit to inductors…. They can cost more than your drivers.

And you tend to use high voltage / high quality caps, again there is no limit to that too.

So you chose your poison.

 

[arunvenkats]

I am new to hi-fi world. Want to know why crossover components cost this much.

When I started the project, I did not think of this cost myself! It was a way over budget.

"Audio grade" capacitors are expensive. I chose to go for high(er) quality ones for the caps which are in series with the signal. For example the 33uF capacitors alone are around ₹1,000 each. You can get 33uF capacitors at ₹50 too. BTW many purists might consider the 1K caps I bought as just "ok". Finally it is your budget, your choice. For me this was a one off project and I don't know when I will build the next one. After spending so many weeks researching and designing, I did not want to compromise quality and introduce a weak link which might make all other choices/effort irrelevant. The next highest cost is the inductors. The big ones are around ₹1,000 again. The cost of the inductors are unescapable. The only way you can reduce the price is compromising on your design of frequency cut-off positions. For example, if you increase the low cut-off from 300Hz (my req) to 600Hz, the price will practically half. You can hand wind your own inductors as a true DIY project, but it is an involved process and I did not have time.

After investing on a high-res DAC and a low distortion power amp I wanted to do justice to the entire signal path. Again, your budget you choice! The range is quite high.

Mass produced crossovers will be cheaper and possibly high quality too. I cannot comment on that. When I was doing research, I saw the market flooded with some Chinese ones which looked like OEM components of some big speaker manufacturer. It is quite likely they are good quality but there are absolutely zero specs. I did not want to add a black box to my signal path. I knew my mid and tweeter were higher sensitivity compared to the woofer. So I had to attenuate those to match the woofer. No off-the-shelf crossover can do that. Also the Chinese ones I was talking about has attenuation build in and there was no info on how much it was. This was a no-no for me.

Regards,
Arun

 

[hemanth.hg]

Nice work and good-looking speakers, from where did you source the drivers?

 

[arunvenkats]

Nice work and good-looking speakers, from where did you source the drivers?

Thanks!

ElectroCarts Peerless by Tymphany

ElectroCARTS is a Domestic leader in the development and distribution of audio components. We offer various high-demand and hard-to-find products for the Home Audio, Commercial Audio, Prosumer/Professional Audio markets.

electrocarts.in

They referred me to their local dealer in Chennai. Picked it up from him. Very knowledgeable speaker builder himself with tons of experience.

Regards,
Arun

 

[hemanth.hg]

Thanks!

ElectroCarts Peerless by Tymphany

ElectroCARTS is a Domestic leader in the development and distribution of audio components. We offer various high-demand and hard-to-find products for the Home Audio, Commercial Audio, Prosumer/Professional Audio markets.

electrocarts.in

They referred me to their local dealer in Chennai. Picked it up from him. Very knowledgeable speaker builder himself with tons of experience.

Regards,
Arun

Good to know, thanks for the info.

 

[Nishank26]

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

Good project, is there anyway you provide audio samples too.

 

[arunvenkats]

Good project, is there anyway you provide audio samples too

I can try, but not sure if it would be the same as listening in person. I had shared the response charts earlier...

 

[Vineethkumar01]

@arunvenkats : Sorry for not replying here earlier. But based on this graph, it looks like you have 10dB cancellations in the 400Hz region and 4kHz region.
On top of that your tweeter level seems to be lower by about 5ish dB than the mid.

Given that the advertised crossover frequencies are around 300Hz and 3kHz, it is higly likely that those dips are caused by your drivers being out of phase.

This is a problem that typically occurs if you dont do crossover design based on individual measurements of drivers on the baffle and instead use a commercially available crossover with generic crossover frequencies.

If you are interested in improving this speaker performance, i would recommend starting with taking gated measurements of each driver on the baffle and revisiting the crossover after that. This means taking measurements of each driver from 1m away without current crossover with the speaker placed in the middle of a room up from the floor by atleast 1m

But first thing you can probably donis to invert the polarity of your mid and check if there is a difference in the measurements.

 

[Shafiqak]

Thanks!
Attaching the 40-90 dB chart here:
View attachment 88895
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:
View attachment 88899

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

View attachment 88900


The 3D model for reference
View attachment 88901

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.

View attachment 88902

And the speaker before installing the drivers:
View attachment 88903

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

Regards,
Arun

well built !!very elegant look

 

[arunvenkats]

@arunvenkats : Sorry for not replying here earlier. But based on this graph, it looks like you have 10dB cancellations in the 400Hz region and 4kHz region.
On top of that your tweeter level seems to be lower by about 5ish dB than the mid.
View attachment 89737
Given that the advertised crossover frequencies are around 300Hz and 3kHz, it is higly likely that those dips are caused by your drivers being out of phase.

This is a problem that typically occurs if you dont do crossover design based on individual measurements of drivers on the baffle and instead use a commercially available crossover with generic crossover frequencies.

If you are interested in improving this speaker performance, i would recommend starting with taking gated measurements of each driver on the baffle and revisiting the crossover after that. This means taking measurements of each driver from 1m away without current crossover with the speaker placed in the middle of a room up from the floor by atleast 1m

But first thing you can probably donis to invert the polarity of your mid and check if there is a difference in the measurements.

Thanks for the detailed reply. Very informative.

Will try reversing the polarity and check first. Already the mid and tweeter are reversed with respect to woofer though.