Diy speaker project - 2 way bookshelf

[biyer]

Hi Everyone,

Firstly I would like to thank a lot of people on this forum.

I just completed my first diy 2-way bookshelf speaker project. Please could you share your opinion and what I can do better next time.

Have been looking for a project to build for some time. I got an idea after I came across the post

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'Disassembly of psb Alpha B1 bookshelf speakers'

Dec 15, 2019

It's cold and windy outside, I'm bored, my hands are itching to do something, so here I am.

The psb Alpha B1 are my first "decent" speakers, purchased at a retail price of $299 CAD/pr. Needless to say that I have long outgrown them in the ten years since, and I'm fed up with trying to offload them through my local classifieds, so here I am ripping them apart.

I am not a speaker reviewer by any means.

Overview

Yes I took this picture after having removed the screws. There was also a metal mesh grille on this speaker that couldn't be removed normally: I pried...

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• Forum: Room Acoustics and General Speaker Discussions

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The above driver is still being manufactured in India (by Peerless Audio which is currently not related to Peerless Fabrikkerne but bought over assets of peerless's Indian subsidiary)

Peerless SM13-PCT-8 5.25" Hi-Fi Woofer Titanium Coated PP

Peerless SM13-PCT-8 5.25" Hi-Fi Woofer Titanium Coated PP Overview: This 5.25 inch 8 ohm driver is a member of the high performance HDA (High Definiti

diyaudiocart.com

Then came found another tweeter from peerless which was apparently used by the Energy Connoisseur series.

https://electrocarts.in/product/25mm-silk-dome-tweeter-low-fs-neo-system/

That's how project code name Alpha/Energy was conceived.


1. I started by measuring the TS parameters myself by using test jig (https://audiojudgement.com/measure-thiele-small-parameters-using-free-software/)

2. Then designed enclosure in WinIsd . The volume is approx. 9.14 liters with port diameter 2.25 inches, port length 6.2 inches tuned to 65hz

Enclosure was built using 18mm HDF wood which was scraps found at local CNC shop.

Dimensions are 7.5W x 10D x 13H inches.

3. Measured the Drivers in box and captured FRD and ZMA. I also captured the woofer in different axis's to find cone breakup. Used Dayton imm-6 mic.
4. Used xsim to design crossover.

5. Put everything together and measured the response

On axis 30.40.60 and 90 degree response

Near Field port (RED) , Woofer (BLUE) and Tweeter (GREEN)

the cabinet/ port resonance around 800hz needs to be addressed.

Pics

I will post proper pictures once I am done painting.

 

[biyer]

Finished Painting using Granotone Speaker Paint.

The Total Cost of project was under 190 $ (17000 INR)

Overall I am very happy with the project. They sound better than my Wharfedale Diamond 9.2. I am caught up with some family responsibilities will add additional measurements once I find time.

I am currently powering these using a TDA1521 board based audio amplifier which I built for testing.

 

[biyer]

Is it enough to just measure horizontal directivity for nearfield use? sub 3 meters

 

[biyer]

Also tried stuffing the port, like them sealed. planning to add a diy sub

 

[biyer]

have made few modifications. I have sealed the port and rounded the vertical edges of the baffle.

The orange response is without rounding
the blue response is with.

Both responses have 1/48 smoothing applied. Have deliberately

The peak at 4khz has almost vanished and the trough near 7khz has reduced. Slight more wrinkly response overall.
Next project I will be estimating baffle diffraction and rounding effect in Vituixcad.

Step Response

ETC

Still trying to understand how to interpret impulse and step response in terms what's a good response, Is this really that important?


Distortion :

CSD

Still need to take nearfield measurements, aliso will retake measurements with vertical and horizontal off axis measurements as well