Makita builders radio

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   My brother has asked me to modify his makita  radio. I’ve also got one of these. They sound great apart from they have too much bass, and start to bottom out when you crank them up. As there are no tone controls on the unit I’m looking to add some passive crossover components to roll off some of the bass. 
Has anyone else ever done anything with one of these radio?

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GAZ. Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 January 2007 Location: Hertfordshire Status: Offline Points: 2433	Post Options Post Reply Quote GAZ. Report Post Thanks(0) Quote Reply Topic: Makita builders radio Posted: 23 April 2020 at 10:27am
	My brother has asked me to modify his makita radio. I’ve also got one of these. They sound great apart from they have too much bass, and start to bottom out when you crank them up. As there are no tone controls on the unit I’m looking to add some passive crossover components to roll off some of the bass. Has anyone else ever done anything with one of these radio?
	100% Earth Moving Bass

studio45 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3864	Post Options Post Reply Quote studio45 Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 2:56pm
	You'd be looking at inconveniently large capacitors and inductors to make a speaker level highpass filter. You'd probably want at least a 3rd order so as not to lose too much upper bass/low mids, meaning you need two large value non-polarised capacitors and a large value inductor. For example, if the woofer is 4 ohms and you want to cut the bass below 80Hz, you would need a 330uf capacitor in series, then a 6mH inductor to ground, then a 1000uF capacitor in series. Good luck finding a non polar 1000uF! If you want to cut lower, you need bigger component values still! Have you tried sealing up the bass reflex port in the radio? That should help with excursion problems at high levels. Further to that, you could also try putting wood blocks in the enclosure to reduce the volume.
	Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA

djeddie Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 April 2004 Location: Bristol Status: Offline Points: 4125	Post Options Post Reply Quote djeddie Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 4:10pm
	As Studio put... I looked at this too, but trying to find components and get them in theretoo proved a bit of a nightmare. There's been loads of posts on various forums about the bass level in these and it really surprises me Makita haven't issued a software fix for it... or someone hasn't managed to work out a proper fix/hack.
	Chas n Dave : it's like Drum and Bass but with beards. E=mc² ±3dB

SamV Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 21 October 2008 Location: London Status: Offline Points: 8711	Post Options Post Reply Quote SamV Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 4:41pm
	Why not take out the internals and put them in a new box, maybe with more efficient drivers.

Earplug Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 03 January 2012 Location: Europe Status: Offline Points: 7216	Post Options Post Reply Quote Earplug Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 5:04pm
	Or just add a sub box? You could roll off the internal speaker at around 150-200Hz with a single capacitor - which will be a simple find, then build something to do the bottom end.
	Earplugs Are For Wimps!

APW Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 13 November 2012 Location: Kent, UK Status: Offline Points: 1174	Post Options Post Reply Quote APW Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 7:44pm
	Just make a simple 1^st order high pass filter, for 80hz with a 4ohm speaker you need about 500uf in series with the driver. You will end up about 6dB down at 50hz. To make a 500uF non-polarized cap from two polarized, simple connect two polarizes caps of twice the value (1000uF) in "back to Back"series with either the negatives or two positives connected together. a typical 1000uf 35V cap is about 16mm (dia) x 25mm 35v caps will be fine as the supply for the radio is 18V Edited by APW - 23 April 2020 at 7:57pm

GAZ. Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 January 2007 Location: Hertfordshire Status: Offline Points: 2433	Post Options Post Reply Quote GAZ. Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 9:36pm
	The speakers inside are 8 ohm so presumably I’ll need a different value of capacitor?
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APW Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 13 November 2012 Location: Kent, UK Status: Offline Points: 1174	Post Options Post Reply Quote APW Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 10:10pm
	yes, you need about 250uF so you would need two 500uF in series..... 470uF is the nearest standard value. Edited by APW - 23 April 2020 at 10:11pm

GAZ. Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 January 2007 Location: Hertfordshire Status: Offline Points: 2433	Post Options Post Reply Quote GAZ. Report Post Thanks(0) Quote Reply Posted: 23 April 2020 at 10:13pm
	Perfect, I’ll give that a try and report the results. Many thanks
	100% Earth Moving Bass