Help me in simulating my first bookshelf speaker

[Dr.Lakshay]

Hello dear members,
After seeing so many people here trying diy, I myself have been wanting to try and build my own pair of bookshelf speakers.
Being impressed by the reviews of full range driver by sb acoustics sb65wbac25-4 I have decided to use it, but I knew it wont give good bass, so decide on FAST/WAF type of a bookshelf speaker. After searching around narrowed down on Dayton rs 180-4 as it has great reviews and I am getting a used pair for decent money to keep the budget low.
links to both the drivers:
http://www.sbacoustics.com/index.php/products/wideband/2-sb65wbac25-4/
https://www.parts-express.com/dayton-audio-rs180-4-7-reference-woofer-4-ohm--295-374
I am not sure how well these two will blend together but I guess we will see.
Now my biggest dilemma is should I go with ported or a sealed box. I want to go sealed as it would be relatively easier but I am realizing that I will be missing out on all the potential of the Dayton woofer in a sealed box.
Can someone help me to get started on some simulation software. I have downloaded winisd pro alpha and bassbox 6 pro. tried both but I am not able to understand how to add 2 drivers and get the resultant curve for the bookshelf speaker as a whole. I could draw the graphs for the woofer alone in a sealed and ported box will post the simulations soon and ask for your feedback.
I will be using a car amp lying unused with built in crossovers to avoid any crossover designing. would be crossing around 300-500hz whatever I like after fiddling with the crossover.
This project will be 2.0 stereo to be upgraded to 2.1 later for my bedroom.
I have placed the order for the drivers but am yet to receive them. so thought meanwhile will try my hands on simulation.
Thanks for your help in advance.

 

[Naveenbnc]

For your bass driver .... check this

EBP = fs / Qes

As a general rule:

EBP < 50 - use only for a sealed box
EBP 50 - 100 - can be used in either
EBP > 100 - vented box only

 

[Dr.Lakshay]

For your bass driver .... check this

EBP = fs / Qes

As a general rule:

EBP < 50 - use only for a sealed box
EBP 50 - 100 - can be used in either
EBP > 100 - vented box only

Thanks. According to this Dayton rs180-4 has EBP of 64 so can be used both ways. But what I see from simulation is that it can go quite low in a ported design. But if I add sub I don't need a ported bookshelf and can make them compact.

 

[diyaudio]

Contrary to popular belief, box tuning is not that critical. Tune as low as the driver XMax and box volume will allow.

 

[Dr.Lakshay]

Contrary to popular belief, box tuning is not that critical. Tune as low as the driver XMax and box volume will allow.

For ported, sealed or both?

 

[diyaudio]

Both

 

[Kannan]

Put the SbAcoustics in a well sealed and damped 250 cubic inch enclosure within the main enclosure.
It will completely isolate the wideband, which will be very good for SQ.

Go with a around 900 cubic inch sealed enclosure for RS180.

For ported, go with with a 33 liter box with a single port in the front.
The tuning frequency will be around 34hz.
2 inch dual flanged port of total 5 inch length or 2.5 inch dual flanged port of total 8 inch length.

Set the crossover point somewhere between 300 hz to 600 hz wherein the vocals are the most open, clean and weightly as well.

 

[soundnovice]

https://www.diyaudio.com/forums/full-range/273524-10f-8424-rs225-8-fast-ref-monitor.html
check this out
better than rs180 iin bass dept
with this u wont need subwoofer. put that money in buying rs225.
its good with both sealed and ported. in ported it can go close to 30hz. in sealed 50hz and a gentle rolloff.
its build thread is at
https://www.hifivision.com/threads/diy-fast-ref-monitor-designed-by-xrk-audio-only-enclosure.72702/

 

[Dr.Lakshay]

Both

OK. Will try simulations.

Put the SbAcoustics in a well sealed and damped 250 cubic inch enclosure within the main enclosure.
It will completely isolate the wideband, which will be very good for SQ.

Go with a around 900 cubic inch sealed enclosure for RS180.

For ported, go with with a 33 liter box with a single port in the front.
The tuning frequency will be around 34hz.
2 inch dual flanged port of total 5 inch length or 2.5 inch dual flanged port of total 8 inch length.

Set the crossover point somewhere between 300 hz to 600 hz wherein the vocals are the most open, clean and weightly as well.

Thanks for the valuable feedback sir. I tried simulating Sb25 in 2L box and it showed the highs were rolling off, I think I am doing something wrong there. Will try with your suggested 4L. Also I was thinking the same of using around 15L for rs180-4. 33L will make it too big I think. Will go with sealed most probably.

https://www.diyaudio.com/forums/full-range/273524-10f-8424-rs225-8-fast-ref-monitor.html
check this out
better than rs180 iin bass dept
with this u wont need subwoofer. put that money in buying rs225.
its good with both sealed and ported. in ported it can go close to 30hz. in sealed 50hz and a gentle rolloff.
its build thread is at
https://www.hifivision.com/threads/diy-fast-ref-monitor-designed-by-xrk-audio-only-enclosure.72702/

Hi thanks for the links but, the full range I have already ordered is different and the cone design is difficult for a first timer.

 

[keith_correa]

Read this - good information inside:
https://www.audioxpress.com/article/Test-Bench-SB-Acoustics-SB65WBAC25-4-2-5-full-range-driver

Also, manufacturer's XMAX numbers are conservative. A good ROT is to use 15% more than published numbers.

 

[Dr.Lakshay]

Read this - good information inside:
https://www.audioxpress.com/article/Test-Bench-SB-Acoustics-SB65WBAC25-4-2-5-full-range-driver

Also, manufacturer's XMAX numbers are conservative. A good ROT is to use 15% more than published numbers.

Hi. Thanks for the link. Had already gone through it before buying the drivers. But all I got from it is that it is a good driver for the money but didn't catch any of those technicalities or how to apply them to my project.
Thanks for pointing out the XMax thing.

 

[keith_correa]

Does your amp have a separate volume control for each channel?
The Dayton is around 5 dB more sensitive than the FR.

 

[Dr.Lakshay]

Does your amp have a separate volume control for each channel?
The Dayton is around 5 dB more sensitive than the FR.

Yea I'll be using car amp which has gain control. So I can set gain for both full range and woofer separately. Also the crossover will be set on the amp itself. Its a 5 channel amp so I can add subwoofer later.

 

[soundnovice]

any full range u use, put a pvc pipe behind it as much lengthy as much possible, even upto to the rear panel if possible.

 

[keith_correa]

I have downloaded winisd pro alpha and bassbox 6 pro. tried both but I am not able to understand how to add 2 drivers and get the resultant curve for the bookshelf speaker as a whole.

You're not going to be able to do what you need in these applications - both being box modeling software.
Try this:
http://www.audiodevelopers.com/Software/PSD_Lite.zip
It will let you do what you need and more - it's a toolbox.

 

[Dr.Lakshay]

any full range u use, put a pvc pipe behind it as much lengthy as much possible, even upto to the rear panel if possible.

Could you please explain the benefit of this arrangement?
Means even if the full range has its own sealed compartment, I should add a pvc pice behind it?

You're not going to be able to do what you need in these applications - both being box modeling software.
Try this:
http://www.audiodevelopers.com/Software/PSD_Lite.zip
It will let you do what you need and more - it's a toolbox.

Thanks. Will give it a try.