Fairly sure I mentioned that I have a different input cap on the amp6b that cuts at 60 Hz. You really can't go higher than that before it's noticable, unless you make a more complex filter than just changing the input cap.
Most mp3 don't have much info under around 40 Hz anyways, so it's not a major deal in my mind.
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Do you mean that the compression schemes used dump off the bottom of the band? Because I didn't think that was the case. Sure you need to have the dynamic headroom in the DAC, but in terms of compression I don't think high resolution at low frequencies takes up much space, so it's probably preserved pretty well. I could be wrong.
Far as the MP3 player, I Think that they are designed with the exact same considerations in mind far as amplifier loading and power consumption, only at the headphone level. If you only load the output with a few hundred to a couple thousand ohms you are likely to experience fair flatness down to 20. What actually comes out, of course, still depends on the recording. But you're definitely right, nothing much below 60 is gonna make it out of your speakers except as heat. Below 40 you're bound to increase overall distortion by eating up linear excursion as well.
Far as the MP3 player, I Think that they are designed with the exact same considerations in mind far as amplifier loading and power consumption, only at the headphone level. If you only load the output with a few hundred to a couple thousand ohms you are likely to experience fair flatness down to 20. What actually comes out, of course, still depends on the recording. But you're definitely right, nothing much below 60 is gonna make it out of your speakers except as heat. Below 40 you're bound to increase overall distortion by eating up linear excursion as well.
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In fact I got stuff coming down a 96kbs stream on the psychill station at di.fm right now that Looks to be about 10 Hz and loud. I can't hear it, it's just driving the woofers crazy in my dipole PC speaker setup... and I'm actually using an Ancient SB16. There's not supposed to be anything down there, but I got about 12mm P-P on a ten inch, doing nothing.
Yes, but still 400watts into your design...
By experience you are often amazed of how long these digital amps actually run on a 7aH SLA. In real life you rarely listen to max volume on all channels and with your design 4x100 watts is going to be loud!
The mileage of your battery will of course also depend on your music taste as pumpin out heavy bass of course demands more power than a tweeter.
As I mentioned previously the amp 4, amp1b or sure 2x100 watt might be a middle way if the 2x15 watts are too little and the 4x100watts too much.
I usually tick the sub-cut when I compress mp3s. That's a 24 dB/octave digital filter cutting at 40 Hz just like most professional amps are equipped with as standard.
Yeah, the Boominator is NOT designed to be fed more than about 50W per side which is about the maximum an amp9b can provide with real music signal.
It's pretty much designed to run on an amp6b or amp9b at both 12V and 24V.
That works.
Exactly. It's not like I'd ever use mp3s and certainly not an iPod for any kind of serious listening, so I usually use slight dynamic compression and sub-cut on my mp3s since they'd be mostly used for playing on an iPod, either on head phones or the Bomminator.
Question for Saturnus.
I myself do not have any soldering skills.So I was hoping to ordering an already built one from the "41Hz builders". I want the same one, as used in the new boominator. Could you then tell me what i should order after?
What i know the job contains:
amp9 BASIC
sealed aluminum boks.
I myself do not have any soldering skills.So I was hoping to ordering an already built one from the "41Hz builders". I want the same one, as used in the new boominator. Could you then tell me what i should order after?
What i know the job contains:
amp9 BASIC
sealed aluminum boks.
Hi ya'll
I'm planning to build a portable partymachine too, but i need some advice:
I've already ordered a TA2020 based amplifier from ebay.
My plan is to use a car battery as powersupply - it's no problem that it's heavy.
It should last long on a recharge, >4 days (10-14hours/day) if possible. I don't really know if the TA2020 is able to drive the speakers i'm planning to use:
-2x 10" HP-10W speakers
- 2x piezo's (dont know which kind, any good idea besides the one in the Boominator?)
Is this possible for the TA2020?
And what about battery power? Would it last (ex. 12 V 70Ah)?
And are car batteries bad in that purpose of bringing conteniously power? Any better ideas?
At last (newbie question):
How do you assemble the plywood? with glue?
Thanks
//Jens
I'm planning to build a portable partymachine too, but i need some advice:
I've already ordered a TA2020 based amplifier from ebay.
My plan is to use a car battery as powersupply - it's no problem that it's heavy.
It should last long on a recharge, >4 days (10-14hours/day) if possible. I don't really know if the TA2020 is able to drive the speakers i'm planning to use:
-2x 10" HP-10W speakers
- 2x piezo's (dont know which kind, any good idea besides the one in the Boominator?)
Is this possible for the TA2020?
And what about battery power? Would it last (ex. 12 V 70Ah)?
And are car batteries bad in that purpose of bringing conteniously power? Any better ideas?
At last (newbie question):
How do you assemble the plywood? with glue?
Thanks
//Jens
Car batteries aren't designed to be discharged to low levels, and so they will wear out quickly in this situation. A marine, or deep-discharge type is what you want. It might make sense to use smaller gel-cell (SLA) batteries such as the ones used in uninterruptable computer power supplies, etc. If you have an easy means of swapping, like an access door, you don't have to drag the huge car battery everywhere you go, just for extended events. In that case carry a charged spare battery or three.
--Buckapound
Hi Everyone! Now its my time for me to enter this awesome thread that´s got me hooked for a few days och straight reading page after page. Im impressed saturnus! Yor have done an awesome work in the Boominator design. I guess this is where it leads after a few revisions when you put toghether all the good idéas and experiences.
I have now made the decison in building my own Boominator because it´s dumb to invent the weel again! This build will be my second festival blaster with the first one beeing build on no calculations what so ever. ( i learned a few things, haha)
Now to the point! I have this evening put togheter a CADmodell and struggle to get the dimensions AND the Volume right for your original specs.
-When i mount the HP-10W magnet to magnet the total depth with 12mm plywood gets only 285mm. Wasn´t yours 300?? How? I have pressed the foam 3mm in on each woofer also.
-With a total length of 951mm (111mm goes to battery/middle department) d=285mm, H=300mm i get a volume of ~30L/ cabinet (centerbrace volume is in the calculations). Is this enough to end up with 23.45 as wanted? How much volume is taken by a HP-10W??
-How about the port, should it´s volume be subtracted from the cabinvolume also?
I have now made the decison in building my own Boominator because it´s dumb to invent the weel again! This build will be my second festival blaster with the first one beeing build on no calculations what so ever. ( i learned a few things, haha)
Now to the point! I have this evening put togheter a CADmodell and struggle to get the dimensions AND the Volume right for your original specs.
-When i mount the HP-10W magnet to magnet the total depth with 12mm plywood gets only 285mm. Wasn´t yours 300?? How? I have pressed the foam 3mm in on each woofer also.
-With a total length of 951mm (111mm goes to battery/middle department) d=285mm, H=300mm i get a volume of ~30L/ cabinet (centerbrace volume is in the calculations). Is this enough to end up with 23.45 as wanted? How much volume is taken by a HP-10W??
-How about the port, should it´s volume be subtracted from the cabinvolume also?
Hi there! Thanks for 10hours of intens reading through this ridiculously long thread
Any how, I think all my questions toward creating a portable system, has been more or less answered. Only one thing still remains uncertain.
The boominator is made for standing on the ground, with the speakers covered in grass. I am going to make a setup where the drivers are placed somewhat 40-50cm over the ground.
It has been said that the best outdoor settings to go for, is a Qbox at 1.1, with a tuning freq. at 80Hz, for a boominator clone per say. Since I am going to use the same drivers as the boominator, the specifications remain the same, but am I going to head for another Qbox, since my drivers are located 40-50cm over the ground? That is not something I have been able to figure out!
Could someone with that knowledge please help me out here?
And another thing, Saturnus wrote in post #438, that a "3dB peak at twice the tuning frequency" was perfect. Is that in general. Should I head for that too, when trying to figure out my tuning freq, with my drivers located that different than the boominator?
And just to make sure, all this about Qbox and tuning freq, is all just to find out the volume and measurements of the box you are placing the driver in, right?
Thanks in advance.. and btw. its really an amazing job everyone who have contributed to this thread have done, especially saturnus
Any how, I think all my questions toward creating a portable system, has been more or less answered. Only one thing still remains uncertain.
The boominator is made for standing on the ground, with the speakers covered in grass. I am going to make a setup where the drivers are placed somewhat 40-50cm over the ground.
It has been said that the best outdoor settings to go for, is a Qbox at 1.1, with a tuning freq. at 80Hz, for a boominator clone per say. Since I am going to use the same drivers as the boominator, the specifications remain the same, but am I going to head for another Qbox, since my drivers are located 40-50cm over the ground? That is not something I have been able to figure out!
Could someone with that knowledge please help me out here?
And another thing, Saturnus wrote in post #438, that a "3dB peak at twice the tuning frequency" was perfect. Is that in general. Should I head for that too, when trying to figure out my tuning freq, with my drivers located that different than the boominator?
And just to make sure, all this about Qbox and tuning freq, is all just to find out the volume and measurements of the box you are placing the driver in, right?
Thanks in advance.. and btw. its really an amazing job everyone who have contributed to this thread have done, especially saturnus
Last thing first. Yes, the port volume must be deducted from the total volume.
The woofer take up 2.10 liters each. And add the 0.15 liters each tweeter takes up as well.
Is that with the actual speakers? I know the official pdf lists 131.2mm total depth but unless they changed they design again since I last bought some HP10Ws last year, they're actually 136.1mm. Remember the grill and the sealing rubber gasket goes between the speaker and cabinet as well.
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Hi there! Thanks for 10hours of intens reading through this ridiculously long thread
Any how, I think all my questions toward creating a portable system, has been more or less answered. Only one thing still remains uncertain.
The boominator is made for standing on the ground, with the speakers covered in grass. I am going to make a setup where the drivers are placed somewhat 40-50cm over the ground.
It has been said that the best outdoor settings to go for, is a Qbox at 1.1, with a tuning freq. at 80Hz, for a boominator clone per say. Since I am going to use the same drivers as the boominator, the specifications remain the same, but am I going to head for another Qbox, since my drivers are located 40-50cm over the ground? That is not something I have been able to figure out!
Could someone with that knowledge please help me out here?
And another thing, Saturnus wrote in post #438, that a "3dB peak at twice the tuning frequency" was perfect. Is that in general. Should I head for that too, when trying to figure out my tuning freq, with my drivers located that different than the boominator?
And just to make sure, all this about Qbox and tuning freq, is all just to find out the volume and measurements of the box you are placing the driver in, right?
Thanks in advance.. and btw. its really an amazing job everyone who have contributed to this thread have done, especially saturnus
Yes, a Q of about 1.1 works very well outside. And the peak comes automatically when that Q is used for the tuning.
You can expect another design to measure the same as dBoominatør even with the same speakers.
The speaker placement on the ground and the bipolar construction is crucial to have it measure and sound correct.
If you use it inside however you must lift it about 1m of the ground and at least 50cm from the nearest wall or it'll have too much bass. Placed like that it sounds excellent though.
It should last about 120-130 hours (24/7 at max volume) on that battery.
Glue, clamps and screws is used to keep it together.
I don't know of any better piezos than those I use and I've tested 12-14 different models. They're better than the highly acclaimed Motorola orginals. Just remember to stuff the backside with putty to eliminate ringing.
A TA2020 amp is more than adequate.
V-bro on the 41hz forum makes assembled amp9basics for sale with why little overhead. They're completely ready-built.