The Boominator - another stab at the ultimate party machine

Ever looked at a voice coil? specifically the size of the wire? it'll be in the region of 0.05mm². Any hookup wire that you use will be thicker than that, and 0.75mm² is overkill. the problem with thick wires is that they are heavy and any movement when you carry the speaker will be translated as stress to the joint.


I would not wish to become involved in a Holy War but this is a bit like comparing apples to pears, voice coil wire to hook up wire.

Sorry to mix units but 8 inches of thick wire being heavy compared to a bunch of batteries. Like whut?

As to terminations. If you are soldering directly to speaker terminals pick some wire with a conductor diameter half the width of the terminal and get it on with a meaty soldering iron.

Don't forget to sleeve and support the joint with heatshrink, the type with internal glue, over terminal and extended an inch up the insulation. Then tie-wrap the cables as they exit to the speaker cage. Isolate and dress them for lack of buzz.
 
I've been lurking on this thread off and on now for the last several years, I finally find my self in a position to attempt to build myself one of these Boominators yet I am finding it extremely difficult to locate the Drivers needed for the build in the US . I have found a useful bit of info in the Boominator Digest unfortunately sourcing the drivers is proving to be quite difficult. Have there been any updates to the driver selection in the last 2 years or so? Or is this simply a matter of being too late to the party?
 
Minidsp settings??

This is a long shot but does anyone out there have Minidsp settings for a Boominator?
I've just accidentally wiped the Minidsp and I can't find the original file that Saturnus sent me years ago.
I trying to get it ready for the XR demos in Dublin and I don't have time to start from scratch again.
 
If you have a measuring mic, you should be able to do a better file in 2 hours, using Arta, REW or else.
If you match the box to the kind of room you are going to show it in, you might have a winner.
The basic file will only be what it is, basic.

Thanks man... yeah I could do that I just don't have the time.
Saturnus emailed me the settings for my setup years ago and I was just hoping someone else had them also.
 
From my notes:

Tweeter:
Gain: -5.2dB
HP 2302.21hz BW 18dB/oct (must be butterworth or bessel. Cannot be 12 or 24dB/oct)
LP 21120.0hz peaking LR 12dB/oct +4dB peak gain (if it does not have peaking LR filter then make it by having EQ +3dB@20khz)

Woofer:
Gain: 0dB
HP: 63.2132hz LR 48dB/oct
LP: 2171.62hz LR 24dB/oct
 
From my notes:

Tweeter:
Gain: -5.2dB
HP 2302.21hz BW 18dB/oct (must be butterworth or bessel. Cannot be 12 or 24dB/oct)
LP 21120.0hz peaking LR 12dB/oct +4dB peak gain (if it does not have peaking LR filter then make it by having EQ +3dB@20khz)

Woofer:
Gain: 0dB
HP: 63.2132hz LR 48dB/oct
LP: 2171.62hz LR 24dB/oct

That's a great help...thanks a mill!
 
Any Interest in CNC Flatpack and Drivers (USA)?

I plan to have a few CNC flatpacks made and I have a stock of the required drivers.

Ideally I would like to keep a few and sell a few. Is there any interest? I am located in Connecticut and can ship. Attached are a few photos from the last batch I did.

My signature also has links to the 'Boominator digest' and a couple of videos from the Boominator build.
 

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In the process of buying pieces to build a halfinator and have a question regarding the battery.

I will make a 12,000 mah 6s2p LifePo4 battery pack delivering 19.2v to a mono TPA3116d2.

Question one: Is this battery overkill either in voltage or capacity?

Question two: The battery will not be removable. I want the possibility to run speaker off mains. I know I can't charge and play at the same time as it will mess with the BMS. If I place a switch between the battery positive and the charger input positive, will this be sufficient to isolate the battery when running off mains or do I need a switch on each of positive and negative? (Equally a second switch between charger positive and amp in order to isolate that circuit while charging).

Thanks!
 
Note that the total response = electrical response + acoustical response.

This electrical cut off frequency is higher than you would normally expect. The resulting upward slope at most of the tweeters frequency range (3 - 13 kHz) is used to equalize the acoustic response of the PHT-407N tweeters, which by itself will slope downwards (especially off axis).
 
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Depending on the amp draw, the battery seems very large. I run mine on 6S 2.6AH and 5AH batteries. It seems to run forever but I use it in the garden and it is usually a few hours at a time.

Thanks!

Separately, do I need to flip polarity on my PHT407N tweeters (i.e. negative tweeter to positive amp) - diagram on digest suggests no, but Saturnus note is confusing:

Please note mistake: The plus on the tweeters should be connected to minus on the amp, not the plus on the amp as I have drawn here
 
This is the set up I am using in my halfinator. I've order all the bits. I am still confused by the comment in the guide "Please note mistake: The plus on the tweeters should be connected to minus on the amp, not the plus on the amp as I have drawn here" - is the diagram wrong, do I need to reverse polarity to the tweeters? A bit out of my depth but I understand the use of the crossover might require the tweeters to have polarity inverted?

Screenshot-2020-04-18-at-15-26-32.png


Also, I got used a sketchup template that was wrong and have an 18mm gap behind each driver. As this has been CNC cut and wasn't cheap, I am not keen to get a new one cut. If I pack behind each with 18mm ply (so there is 48mm of ply total between each driver, and backs of drivers glued on) will this affect sound quality? I am guessing the additional mass of the wood will reduce the db slightly as the drivers won't able to work together as efficiently.

Thanks!
 
This is the set up I am using in my halfinator. I've order all the bits. I am still confused by the comment in the guide "Please note mistake: The plus on the tweeters should be connected to minus on the amp, not the plus on the amp as I have drawn here" - is the diagram wrong, do I need to reverse polarity to the tweeters? A bit out of my depth but I understand the use of the crossover might require the tweeters to have polarity inverted?

Screenshot-2020-04-18-at-15-26-32.png


Also, I got used a sketchup template that was wrong and have an 18mm gap behind each driver. As this has been CNC cut and wasn't cheap, I am not keen to get a new one cut. If I pack behind each with 18mm ply (so there is 48mm of ply total between each driver, and backs of drivers glued on) will this affect sound quality? I am guessing the additional mass of the wood will reduce the db slightly as the drivers won't able to work together as efficiently.

Thanks!
First order crossovers are usually wired with same polarity, but there may be a funny bump or dip in response, run a sine sweep to see which seems better, listening to music you will not likely hear any problems, which, yes, implies that it doesnt actually much matter, so dont over think it. Same with the driver spacing, Saturnus said that putting the magnets together like that increases efficiency, i don't think he ever measured this, it could be true, but it could also be true that it makes them worse, in the cold hard reality of everyday listening you will probably be struggling to hear any difference.
 
First order crossovers are usually wired with same polarity, but there may be a funny bump or dip in response, run a sine sweep to see which seems better, listening to music you will not likely hear any problems, which, yes, implies that it doesnt actually much matter, so dont over think it. Same with the driver spacing, Saturnus said that putting the magnets together like that increases efficiency, i don't think he ever measured this, it could be true, but it could also be true that it makes them worse, in the cold hard reality of everyday listening you will probably be struggling to hear any difference.

Awesome, thanks, this definitely puts my mind to rest. I've learnt so much in the months spent researching this, but still know so little!

I understand the logic behind the speakers working together by being back to back, but as you say that doesn't mean it actually makes much (or any) difference in real life. I notice no back to back speakers in the soundboks, so maybe the difference isn't that big after all.

Based on the project spend so far, a soundbok is actually starting to look like a rather attractive proposition! :D Great work he's done there!