Boominator MINI (development thread)

If production boomboxes are better or very close in sound to the mini the question then arises if the build is worth it. If we are going to spend 300 or so euro plus quite a few weekends of our free time then the objective as in most diy is that either we are going to save a lot of money or build something hi end. Or a combination of the two. But I feel with the mini that the cost is not worth it in the emd. I cannot say for example that it sounds much better than the harman go play which also has a better bass for sure and cost me the same.

Well I do not see a lot of driver options. Only two driver sets have been proposed and they seem to have  general support in this community. The monacor speaker and filter set plus shipping on it's own is around 200 euro as a starting point.
I think perhaps the bipole design is a nice concept for  use outdoor and no other production box seems to have it. For indoor use  or small garden use it is not cost effective at all. The increase in cost due to the "back " drivers does not enhance the sound much when using it near a wall. So I think perhaps the micro design is more cost effective.
In my view it would be a better project to go with a micro base and tweak the design with passive drivers or even add cheaper powered driver for the bass (using a separate mono amp or available 3 channel modules)  for better bass. The next step would be to increase the power supply voltage in order to squeeze out some extra db. A battery pack around 20V would do it or a dc dc converter on  12v battery pack which I have already tried (in order to simplify charging). Then I would look at DSP modules to increase efficiency and get the ideal response ( however these are a bit expensive).  Then you could look at 200-250 euro cost which would rival 400-500 euro speakers.


Edited by protos - 27 November 2017 at 10:41am

You might want to try using a preamp for the amp your using or possibly changing the amp to a maxamp, the difference is quite considerable. I initially used a Sure amp (2x15watts) on my Mini V2 before receiving the maxamp and when switching it, the mini was noticeably louder than with the Sure amp on a 12v battery. I will have to agree with Aterren the Mini with the NS6's has a much more robust sound and much more bass than the mini V2. Although the Mini V2 is not better sounding than the NS6 Mini it does beat most of the commercially produced speakers of its size with its efficiency. Most of them can play for about 8 hours on full volume before they run out of battery. The mini on the other hand can last more than double with the same battery capacity. I think it will be worthwhile changing the amp or adding a preamp to get the most out of your mini.

I would look to adjust the amp gain, or add a pre-amp as a first step, at least for testing.   Increasing the amplifier gain and decreasing the iPod volume improved sound quality and allowed me to play louder overall without distortion.   My Apple products seem to distort or at least degrade in sound quality at around 80% of max volume.   Is it possible you are experiencing something similar?

Output impedance of phone or ipod does not affect bluetooth levels. In a wired connection they are designed to drive low impedance earphones at max levels without distortion. I have used both android and ipod with bluetooth and wired connections and there is no problem with setting the volume at max. The iphone ipod do have higher volume output than samsung. The samsung I have used wired with a bedroom stereo at max volume with no distortion. With some music apps volume controls - not the phones- you could sometimes get distortion depending on the app. I think the output of the players is not the problem. As I said the mini does get quite loud and I appreciate your suggestions but we can only have a constructive conversation on loudness levels if we have some measurements. If for example you measure yours at 109 db with a 1khz sine wave at 1m and mine is only 103db then I know my set up is the problem. If yours is also 103 db then it is a design problem. Then we kow what to discuss.

ovaldezkep2 wrote: It would probably be easier to get some stats if you try what people are suggesting and measure the differences with what you used to test the mini. Not sure if anyone has accurate loudness stats for the mini using a calibrated mic.

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