2.1 Speaker System - DIY - Need Help

[MiteshR]

Hello FM,

Let me start by saying I am a complete noob, & I don't have knowledge or past experience of Electronics, crossover designing etc. but I am going to build this speaker system as this is my wish from past many years, and finally I am putting together a plan and investing my time and money in it.

Before posting this I've gone through the forum as much as I can for past 5 days, and watching YouTube videos for almost over two weeks I've come up with plan below.

I want to build a budget (under 25k) DIY 2.1 system for my desk, which is in the living room size (10x15x11h), These are for close listening as I spend most of my time in front of the desk, whether I am working or watching movies etc.
I have the basic tools needed for making enclosure, Circular saw, drill machine, etc. and a soldering iron, multimeter etc. I keep with me as I find this tools useful for fixing and making small diy projects.

The Amplifier I am going to use - https://www.amazon.in/AOSHIKE-DC12V-24V-Subwoofer-Amplifier-Bluetooth/dp/B07BKYL3GC/ref=sr_1_11?crid=1IK0IPOOTMUN6&dchild=1&keywords=2.1+amplifier+board&qid=1617604391&refinements=p_72:1318476031&rnid=1318475031&sprefix=2.1+ap,aps,258&sr=8-11

I am ordering all the components from online stores, mostly from diyaudiocart.com, and I've finalized the drivers below also I've designed a crossover for L&R speakers using Xsim software and for subwoofer I am not sure if I need a crossover or any electrical components.
Please have a look at screenshot below and please let me know if I can go ahead with this, though I am sure that's a crap design.
Please note I tweaked a design as per available crossover components.

The drivers I've finalized are

for Twitters 2 x https://diyaudiocart.com/Raw-Driver...TD20F-4-3-4-Soft-Dome-Neodymium-Tweeter-4-Ohm

for Midrange 2 x https://diyaudiocart.com/Dayton-Audio-DC130A-8-5-1-4-Classic-Woofer-Speaker

& for subwoofer https://diyaudiocart.com/Raw-Drivers/Subwoofer/Tang Band-W6-1139SIF-6-1-2"-Paper-Cone-Subwoofer-Speaker



Please give me directions here, if you think I need to change drivers, change the crossover components, If you have any ready plans for which parts are available online or in Mumbai if you can give me those, or if you think I wont pull this off with my limited knowledge or budget please let me know, I am open to all advises and comments.

Thanks.

and sorry for bad English.

 

[sashijoseph]

Hi Mitesh,
For a first time project building a proven design is often advised.
The Overnight Sensations by Paul Carmody is one such (budget) option.
The low bass it puts out for such a small speaker is amazing.
All the required parts are also available with diyaudiocart.

On the other hand,doing a scratch build can also be very rewarding and with some beginner's luck you may come up with a great sounding design.

The xover you've simmed shows a peak at ~1.8k probably caused by the tweeter's Fs.
Try using a higher order xover on the tweeter...a 3rd order electrical,say,and see if the peak is reduced.

 

[kapvin]

Hello FM,

Let me start by saying I am a complete noob, & I don't have knowledge or past experience of Electronics, crossover designing etc. but I am going to build this speaker system as this is my wish from past many years, and finally I am putting together a plan and investing my time and money in it.

Before posting this I've gone through the forum as much as I can for past 5 days, and watching YouTube videos for almost over two weeks I've come up with plan below.

I want to build a budget (under 25k) DIY 2.1 system for my desk, which is in the living room size (10x15x11h), These are for close listening as I spend most of my time in front of the desk, whether I am working or watching movies etc.
I have the basic tools needed for making enclosure, Circular saw, drill machine, etc. and a soldering iron, multimeter etc. I keep with me as I find this tools useful for fixing and making small diy projects.

The Amplifier I am going to use - https://www.amazon.in/AOSHIKE-DC12V-24V-Subwoofer-Amplifier-Bluetooth/dp/B07BKYL3GC/ref=sr_1_11?crid=1IK0IPOOTMUN6&dchild=1&keywords=2.1+amplifier+board&qid=1617604391&refinements=p_72:1318476031&rnid=1318475031&sprefix=2.1+ap,aps,258&sr=8-11

I am ordering all the components from online stores, mostly from diyaudiocart.com, and I've finalized the drivers below also I've designed a crossover for L&R speakers using Xsim software and for subwoofer I am not sure if I need a crossover or any electrical components.
Please have a look at screenshot below and please let me know if I can go ahead with this, though I am sure that's a crap design.
Please note I tweaked a design as per available crossover components.

The drivers I've finalized are

for Twitters 2 x https://diyaudiocart.com/Raw-Driver...TD20F-4-3-4-Soft-Dome-Neodymium-Tweeter-4-Ohm

for Midrange 2 x https://diyaudiocart.com/Dayton-Audio-DC130A-8-5-1-4-Classic-Woofer-Speaker

& for subwoofer https://diyaudiocart.com/Raw-Drivers/Subwoofer/Tang Band-W6-1139SIF-6-1-2"-Paper-Cone-Subwoofer-Speaker

View attachment 55985

Please give me directions here, if you think I need to change drivers, change the crossover components, If you have any ready plans for which parts are available online or in Mumbai if you can give me those, or if you think I wont pull this off with my limited knowledge or budget please let me know, I am open to all advises and comments.

Thanks.

and sorry for bad English.

hi Mitesh. Congratulations on taking the plunge. You will find the journey very rewarding.

some very first cut observations

1. the tb woofer is very inefficient. you will need lots of power to drive it. budget approx 5x - 7x the power you are feeding the satellites for comparable sound pressure

2. you are crossing over this tweeter too low. never mind the graphs, anything below 2.5k is likely to cause distortion in tweeter above low volumes

3. specific to the graph shown, dropping the XO frequency of the woofer a bit would even our your graph and remove that audible hump. (of course it is academic because you will need to crossover the tweeter about an octave higher)

4. Please do write in the z-offset (relative depth of the woofer versus the tweeter - you can use the speaker ED to figure out the depth.) otherwise your sims will not be accurate. one way of reducing z offset it to not countersink the woofer.

all the best!!

 

[MiteshR]

Hi Mitesh,
For a first time project building a proven design is often advised.
The Overnight Sensations by Paul Carmody is one such (budget) option.
The low bass it puts out for such a small speaker is amazing.
All the required parts are also available with diyaudiocart.

On the other hand,doing a scratch build can also be very rewarding and with some beginner's luck you may come up with a great sounding design.

The xover you've simmed shows a peak at ~1.8k probably caused by the tweeter's Fs.
Try using a higher order xover on the tweeter...a 3rd order electrical,say,and see if the peak is reduced.

Hey, Thanks for the reply, actually after posting this thread I went back to crossover design and changed the crossover to 2nd order and reduced the bump. but then again those parts were not available on web site, till now I've come up with 4 different combinations of speakers with cross over designs and ill be finalizing one of them if I get all the parts in cart.
and regarding the proven design I thought taking that route, even the Overnight Sensations kit is readily available on the website, but I am not finding it challenging enough and by the end of this project I want some learning about this subject, also I am by no mean audiophile or purist, at the end of this even if I make an fun/OK speakers Ill be much happier with the end results. right now I have 2.1 speakers from F&D and I am confident enough that this 2.1 will sound better than them.

 

[MiteshR]

hi Mitesh. Congratulations on taking the plunge. You will find the journey very rewarding.

some very first cut observations

1. the tb woofer is very inefficient. you will need lots of power to drive it. budget approx 5x - 7x the power you are feeding the satellites for comparable sound pressure

2. you are crossing over this tweeter too low. never mind the graphs, anything below 2.5k is likely to cause distortion in tweeter above low volumes

3. specific to the graph shown, dropping the XO frequency of the woofer a bit would even our your graph and remove that audible hump. (of course it is academic because you will need to crossover the tweeter about an octave higher)

4. Please do write in the z-offset (relative depth of the woofer versus the tweeter - you can use the speaker ED to figure out the depth.) otherwise your sims will not be accurate. one way of reducing z offset it to not countersink the woofer.

all the best!!

Hey thanks for the reply, this is exactly what I was expecting, a reply from a knowledgeable FM which will right fly by above my head, but Ill search & learn all the terms you mentioned here like 'z-offset' or 'countersinking the woofer' and try to incorporate it in the sims.
also do you suggest any other subwoofer? I need a subwoofer, I am not completely but kind of a bass head.
also what will be the ideal range of tweeter crossover.
Thanks.

 

[kapvin]

Hey thanks for the reply, this is exactly what I was expecting, a reply from a knowledgeable FM which will right fly by above my head, but Ill search & learn all the terms you mentioned here like 'z-offset' or 'countersinking the woofer' and try to incorporate it in the sims.
also do you suggest any other subwoofer? I need a subwoofer, I am not completely but kind of a bass head.
also what will be the ideal range of tweeter crossover.
Thanks.

z-offset is a fairly important variable when doing crossover design.

first term to understand is the design axis - an imaginary line from the baffle to the intended listening position. all sims optimise on the design axis. for simplicity sake it is taken as the centreline of the tweeter and perpendicular to the baffle, but of course, you can slope the baffle and then the design axis is not perpendicular. but for your first design work with a design axis perpendicular to the baffle and at the tweeter centre.

now x-offset and y-offset is the height and width difference of placement of the various drivers on the baffle. in a multiway design each driver will have its own offset (from the design axis- if you've taken tweeter centre as the design axis then the x and y offset will be zero).

so intiutively z -offset of the driver depth the acoustic centre of speaker (obviously more for a woofer than a tweeter) a lazy way to do this is to eyeball the Engineering diagram of the driver and estimate the voice coil depth. not precise but ball park. not doing this creates sim which is not that well connected with real world results.

i assumed since you are using x-sim that there was understanding there already. since its a 2 way, you may want to look at jbagby's PCD. not as flexible as x-sim but will be easier for a beginner (i think)

finally, please model the baffle step compensation, without which you are sure to find the bass very anemic.

on the Sub - the TB is an excellent woofer with amazing bass for its size. it just needs a lot of watts to sound loud since it is so inefficient. to explore the 11+ mm xmax you need an amp capable of 100+w of continous power.
dayton DC-160, even though its 8ohm is far more efficient and can be useful with 50w or less even

 

[MiteshR]

Hey Kapvin thanx once again, so I took the lazy way to calculate the Z-offset, I worked on the diagram which is there is spec sheet of the drivers I am using, it came roughly around 15mm, Just attaching a screen shot of how I calculated it


also made a new crossover sim with new set of drivers, please if you can take a look at it, & I think the baffle is pretty much compensated if I am not wrong. all the items are in cart. very excited.



Thanx.

 

[kapvin]

Hey Kapvin thanx once again, so I took the lazy way to calculate the Z-offset, I worked on the diagram which is there is spec sheet of the drivers I am using, it came roughly around 15mm, Just attaching a screen shot of how I calculated it

View attachment 56065
also made a new crossover sim with new set of drivers, please if you can take a look at it, & I think the baffle is pretty much compensated if I am not wrong. all the items are in cart. very excited.

View attachment 56068

Thanx.

hello,

that’s nicely done for z-axis. However, you should countersink the tweeter.Otherwise there will be response anomalies. countersink- make an additional groove for the tweeter faceplate so it sits flush with the baffle surface. Once the tweeter is countersunk, z axis offset will reduce (unless, of course you countersunk the woofer too)

i assume that you got the response files from somewhere. You will need to run them through jeff bagby’s baffle simulator to get the “corrected files”

why?
for woofer-the measurements you have will probably be done on a standard baffle and then blended with nearfield measurements for the woofer to get a simulation of an infinite baffle response. when the woofer is put in a box, the bass waves wrap around the box leading to cancellation. This is determined by the baffle dimensions. It leads to a 6db loss of response below the baffle frequency and therefore needs to be compensated in the crossover. How much compensation depends on the designer and the planned placement, —small room, corner placement can all mean that you can get away with less than 6db Compensation. Typically compensation is done by reducing output above step frequency.
For the tweeter, the baffle tends to play with the response so it is useful to understand the variations and see if any things needs to be addressed at crossover.

finally, if the box is going to be ported, it is useful the replace the impedance graph with the simulated one, since impedance peak changes can also impact crossover.

I think with that you will come along nicely. All the best.

 

[Nikhil Suryawanshi]

Hi Mitesh,
For a first time project building a proven design is often advised.
The Overnight Sensations by Paul Carmody is one such (budget) option.
The low bass it puts out for such a small speaker is amazing.
All the required parts are also available with diyaudiocart.

On the other hand,doing a scratch build can also be very rewarding and with some beginner's luck you may come up with a great sounding design.

The xover you've simmed shows a peak at ~1.8k probably caused by the tweeter's Fs.
Try using a higher order xover on the tweeter...a 3rd order electrical,say,and see if the peak is reduced.

Yess is best design .... Is in mid cost build ...... 50 watt / ch sufficient