Print Page | Close Window

Portable stereo speaker

Printed From:
Category: Plans
Forum Name: New Projects Forum
Forum Description: Forum for new speakerplans projects, in memory of Tony Wilkes, 1953 - 2014
Printed Date: 07 December 2023 at 7:03am
Software Version: Web Wiz Forums 12.06 -

Topic: Portable stereo speaker
Posted By: Jack1991
Subject: Portable stereo speaker
Date Posted: 01 February 2023 at 1:38pm
Last year i built a portable bluetooth 2 way mono speaker which runs off a Makita 18v battery. Had a lot of fun doing it so now looking to build another one, but a different style, slightly bigger and bassier!

I am looking to use 2x full range speakers, stereo left/right. I am thinking of using:

Faital Pro 4FE32 Neo - 4" 30W 8 Ohm 91dB

And for the bass either:

1x Beyma 10BR60V2 - 10" 100W 8 Ohm 92dB
1x Beyma 12BR70 - 12" 125W 8 Ohm 93dB

My questions:

1. Would the 2x 4" be able to keep up with the 10" or 12" sub?

2. If yes, where would you reccomend crossing them over at?

3. Is there a formula to work out what size, mid/top to bass ratio at all?

I understand to look at the driver sensitivity dB itself. But the physical size of the driver has an impact too on sheer volume, which is where im unsure how to match it. As its going to be portable, i dont want to overkill the bass and have to turn the gain down loads when i could of just used a smaller driver. Whereas on the flip side i dont want to under do it as it will be used for bassy music.

My previous portable speaker was just a mono 2way so i knew what i was using would cope fine together and the crossover points were roughly dictacted by the tweeter anyway. But struggling a bit to find the answers and dont want to waste money on them to find out they arent suitable.

Amplifier ill be using the amp out my previous build which is a Sure Wondom 4 channel Jab5 DSP amplifier. 1 channel for left, 1 channel for right. Then the remaining 2 channels bridged for the Bass. 

Cheers 👍🏼

Posted By: DMorison
Date Posted: 01 February 2023 at 1:47pm
Best way is to throw the TS parameters of the drivers into WinISD or similar and model how loud they'll get while staying within Xmax in sensible box sizes.
That can also show how suitable a given bass driver is for any other design goals - eg many bass drivers aimed a going nice and low do not like being stuffed into compact boxes.


Posted By: Jack1991
Date Posted: 01 February 2023 at 1:51pm
Ah yes i have put the ts parameters and been looking at both drivers in there for a while now. But i didnt think winisd took into consideration the actual driver size aswell?

When i get home ill post the winisd results on here too

Posted By: DMorison
Date Posted: 01 February 2023 at 1:56pm
It actually does account for it, in that one of the TS parameters is SD - or Surface area of the Diaphragm, so bigger drivers have higher SD measurements. This plus Xmax effectively determine how loud a driver can get.

Posted By: Jack1991
Date Posted: 01 February 2023 at 2:02pm
Ahh ok perfect,i didnt realise that, thats great cheers!

On my previous speaker the bass is ~6db higher but could be more really. So ill use that as the benchmark i guess.

For the 12" driver i modeled it in a 40L box, tuned to 44hz and it looked pretty good to me, but im still learning. Anyway ill post results when home. Interested in your opinion. 

Posted By: Jack1991
Date Posted: 01 February 2023 at 8:50pm
Heres the winisd screenshot on the spl tab. 

This is the 12" Beyma woofer with the input power set at 100w. In a 40L box, tuning freq is 44hz. That makes the port the biggest i could possibly go. Also 40L is the biggest id be willing to go for portable size. I thought this sim looked pretty good. I have tried alot of different drivers now too and to me this seemed the better of the lot.

The blue line is the Faital Pro 4FE32 Neo. In a sealed box 4.5L. power set at 30w which is the rms of the driver. I guess as i will have 2x of these drivers it will roughly be 3db higher than the current line is at?

What do you lot rekon?

Posted By: Jack1991
Date Posted: 10 March 2023 at 1:45pm
I ended up building this and have finished making it now, real happy with how its turnt out. Here is some build pictures.

The back looks like a Canadian off South Park

With the build side of it finished I started taking measurments using a umik1 and rew, outside, on concrete floor, taken within roughly 1m, mic tip on the ground, then aimed the box so the centre of the drivers are aimed directly at the mic. Im still learning with this side of things but this is what i done and the outcome. Id be very interested in your opinions and if i done it correctly.

- first i took a measurement of the 2x 4"midtops, smoothed the curve. then measured again after e.q.  Repositioned the box to suit the sub driver, then took measurment, smoothed the response with e.q then measured again. 

- next i looked at the responses and set the crossover.

- with all drivers response smoothed and xover set, i repositioned the whole box so the centre point of all the drivers together aimed at the mic, and took a measurment of it altogether.

- e.qd that to what i have read or been told is a good nice sound. Which did sound loads better after.

Here is the rew response curve as it stands now. 

I havent had a chance to take it to the field just yet, to play it full volume and to make some more adjustments. It will only ever be used with a mobile phone bluetooth on spotify to play music i expect. So want to see if it distorts at full volume and to make some adjustments if so. 
Hopefully it sounds bassy enough too, sounds good in the garden or home but cant blast it loud obviously here. Also I have always been led to believe its best to only ever 'take away' when e.qing and not to boost, (not boost more than the original response anyway). But anyway if anyone has any advice to get the most out of it, or things to change let me know.

Cheers 👍🏼

Posted By: Lucasdude
Date Posted: 10 March 2023 at 4:21pm
Don't kick the baby!

Posted By: Jack1991
Date Posted: 30 March 2023 at 8:27pm
After alot of tinkering and listening i have finally e.qd it to my liking. Sounds loads better than the previous response graph i posted.

Went through my old posts from other topics to find someone posted a link about equal loudness contour graph and tried it like that and what a difference it has made! Its also been really interesting reading about equal loudness and how its percieved throughout the frequency range. Anyway  real happy with how it sounds now! Heres the response:

Posted By: infrasound
Date Posted: 31 March 2023 at 4:46pm
Nice work Clap

Posted By: Jack1991
Date Posted: 31 March 2023 at 5:36pm
Cheers infrasound, im looking forward to taking it out now, when we finally get a bit of sun! 

Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.06 -
Copyright ©2001-2023 Web Wiz Ltd. -