I'm guessing that it's the DDX output drivers that are responsible for the majority of the idle consumption. So actually it's unrelated to the internal voltage regulators as long as supply voltage is relatively low, ie. under ~30V.
First post 
Hi guys, first poster here
I'm currently in the process of creating a boombox for Roskilde Festival '11, and the Boominator seems perfect in every way. I plan on making 2 boomboxes in total.
However, this also made me think about placing these to boomboxes in an upright position on a pedestal mounted on a wheeled carriage and then having a compartment between these boomboxes for adding bling-bling. I had the idea that it could be possible to lock the boomboxes to the pedestal and then be able to remove them if you wanted to just have a single boombox for carrying around.
Here is a drawing from Google Sketchup (keep in the mind that this is purely a concept drawing made in 5 minutes):
Now, I read that the Boominator is designed to staying on the ground, and that Saturnus wrote placing them above ground will result in "baffle stepping".
Would it be possible to eliminate baffle stepping by incorporating a 0.5 bass, as in setting up a low pass filter?
This makes me ask 2(3) questions in total:
Will placing the speakers around 80-100 CM's above ground in outdoor cause "baffle stepping?" And can this baffle stepping be fixed with adding a 0.5 bass?
- Will the speakers' new placement require a re-design of cabinets to accomondate a new optimal Q? I saw that Saturnus mentioned that 0.7-0.9 would be best, but isn't 1.1 the optimal Q for outdoor use?
Sorry for asking silly questions, but I am just learning about all this and I would like to produce good results
Hi guys, first poster here
I'm currently in the process of creating a boombox for Roskilde Festival '11, and the Boominator seems perfect in every way. I plan on making 2 boomboxes in total.
However, this also made me think about placing these to boomboxes in an upright position on a pedestal mounted on a wheeled carriage and then having a compartment between these boomboxes for adding bling-bling. I had the idea that it could be possible to lock the boomboxes to the pedestal and then be able to remove them if you wanted to just have a single boombox for carrying around.
Here is a drawing from Google Sketchup (keep in the mind that this is purely a concept drawing made in 5 minutes):
An externally hosted image should be here but it was not working when we last tested it.
Now, I read that the Boominator is designed to staying on the ground, and that Saturnus wrote placing them above ground will result in "baffle stepping".
Would it be possible to eliminate baffle stepping by incorporating a 0.5 bass, as in setting up a low pass filter?
This makes me ask 2(3) questions in total:
Will placing the speakers around 80-100 CM's above ground in outdoor cause "baffle stepping?" And can this baffle stepping be fixed with adding a 0.5 bass?
- Will the speakers' new placement require a re-design of cabinets to accomondate a new optimal Q? I saw that Saturnus mentioned that 0.7-0.9 would be best, but isn't 1.1 the optimal Q for outdoor use?
Sorry for asking silly questions, but I am just learning about all this and I would like to produce good results
I think you'd be better of using only half a Boominator (each end of the cabinet) as sats for this use and then have a dedicated sub solution, unless you have a specific reason for wanting 2 Boominators, eg. you want to be able bring one or both to a beach party or the like without having to lug along the whole set-up.
If using each end as a sat you should use a closed box instead, ie. don't make the reflex port/handle. Just replace it with a standard pole mount cup.
You could still use 2 Boominators as you describe but in that case I'd suggest having a helper woofer in the cart. For example 2 15" drivers on their own separate amp, otherwise it'll sound a little "thin" in the bass when lifted that far off the ground. That's actually the effect of the changed Q because you lose the only boundary it has (the ground) so you'll see a drop in both output level in the bass and a lower Q.
Please note that I'm talking enviromental Q here, not system Q. That won't change but the enviromental Q changes with the room it's placed in, and the placement in the room.
If using each end as a sat you should use a closed box instead, ie. don't make the reflex port/handle. Just replace it with a standard pole mount cup.
You could still use 2 Boominators as you describe but in that case I'd suggest having a helper woofer in the cart. For example 2 15" drivers on their own separate amp, otherwise it'll sound a little "thin" in the bass when lifted that far off the ground. That's actually the effect of the changed Q because you lose the only boundary it has (the ground) so you'll see a drop in both output level in the bass and a lower Q.
Please note that I'm talking enviromental Q here, not system Q. That won't change but the enviromental Q changes with the room it's placed in, and the placement in the room.
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It won't affect a Tripath or other class-D amp because they have low-pass output filters. It's more a problem with class-B amps as some can go into self oscillation which can fry the output transistors. Failure from self oscillation is almost instant, so if you see a big cloud of smoke and have to dive to avoid flying debris. That's what happened.
It's just a safety measure really. And besides piezos sounds better with the resistor than without (at least in my opinion).
I am wondering if we should calculate a different Q when our Boominator will be placed like this most of the time:
Is the wagon functioning as a real ground to stand on(so keeping the same Q), or should Q be something else? Because then I need to read up on some Q-theories soon.
An externally hosted image should be here but it was not working when we last tested it.
Is the wagon functioning as a real ground to stand on(so keeping the same Q), or should Q be something else? Because then I need to read up on some Q-theories soon.
It has less bass (lower Q) when on raised platform like yours. You can make the internal volume smaller (and change the port tuning accordingly) which will raise the Q to get an even higher peak to counteract the loss but that also means it will not go as low.
Quid pro quo. You get nothing for free especially with a design like this that is on the very edge of what is physically possible, and use every trick in the book, and some new ones, to inch out every possible ounce of performance.
Quid pro quo. You get nothing for free especially with a design like this that is on the very edge of what is physically possible, and use every trick in the book, and some new ones, to inch out every possible ounce of performance.
Saturnus, thank you very much for your feedback!
I think I will stick around with the idea of having a half boominator at each "tower" and then using the middle compartment for amps + batteries.
For a sub solution I thought of putting 2 HP15W's in bipolar between the two towers and then giving them their own amp. Will bipolaring these speakers be fine? And are the HP15W's good for this use?
Designing a cabinet for the HP15W's is a tad confusing. So far I have only been able to conclude that a sealed cabinet would be the best. How do I calculate the optimal dimensions? I cannot understand the calculators lying around the internet.
Sorry for all the questions once again!
I think I will stick around with the idea of having a half boominator at each "tower" and then using the middle compartment for amps + batteries.
For a sub solution I thought of putting 2 HP15W's in bipolar between the two towers and then giving them their own amp. Will bipolaring these speakers be fine? And are the HP15W's good for this use?
Designing a cabinet for the HP15W's is a tad confusing. So far I have only been able to conclude that a sealed cabinet would be the best. How do I calculate the optimal dimensions? I cannot understand the calculators lying around the internet.
Sorry for all the questions once again!
I don't think the HP15W is a very good woofer actually, the HP12W is better.
I use 2 of these for my sub (see earlier in this thread):
Basenhed 15 8 ohm Kenford ZYD385B-8-14 | BN203627 - Elektronik Lavpris
Pretty cheap, sounds pretty decent for the price.
You'll need a closed cab of about 100 liters per driver, and possibly add a linkwitz transform (a filter that extends frequency range a bit).
Bipolar isn't needed for that low frequencies really. It'll be pretty equally loud no matter if it's in front of or behind.
I use 2 of these for my sub (see earlier in this thread):
Basenhed 15 8 ohm Kenford ZYD385B-8-14 | BN203627 - Elektronik Lavpris
Pretty cheap, sounds pretty decent for the price.
You'll need a closed cab of about 100 liters per driver, and possibly add a linkwitz transform (a filter that extends frequency range a bit).
Bipolar isn't needed for that low frequencies really. It'll be pretty equally loud no matter if it's in front of or behind.
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Hello everyone!
I'm starting a boominator project, I will put up pictures as I go along.
every pic will end up in this message wich makes it easier for all of us to overlook.
Thank you Saturnus for sharing such a refined and awesome design, I may have some questions but I hope I won't be too mush of a bother!
Heres a first pic.
I went ahead with chipboard as material for the box, don't know if it was wrong of me but if it doesn't work out ill have to do it again I guess.
Thank you, ill be back!
I'm starting a boominator project, I will put up pictures as I go along.
every pic will end up in this message wich makes it easier for all of us to overlook.
Thank you Saturnus for sharing such a refined and awesome design, I may have some questions but I hope I won't be too mush of a bother!
Heres a first pic.
I went ahead with chipboard as material for the box, don't know if it was wrong of me but if it doesn't work out ill have to do it again I guess.
An externally hosted image should be here but it was not working when we last tested it.
Thank you, ill be back!
@Saturnus
Wouldn't adding a linkwitz transformer mean slightly more output = more power consumption? Or will it just make a better frequency response? I assume that the purpose of the linkwitz transformer in this case is to increase the frequency range
If it means more power consumption, I think I will leave it out for this time
@Darkwithin
Looking forward to following your project!
Wouldn't adding a linkwitz transformer mean slightly more output = more power consumption? Or will it just make a better frequency response? I assume that the purpose of the linkwitz transformer in this case is to increase the frequency range
If it means more power consumption, I think I will leave it out for this time
@Darkwithin
Looking forward to following your project!
It seams like I'm unable to edit my post so I guess I'll be posting pictures in new posts, but that'll work out as well
Ordered
-20W Solarpanel(775 SEK) and a regulator(375 SEK). site: 24volt.eu
-Resistance 5W 150 OHM (~7 SEK) site: conrad.se
Not yet ordered
-2x 12v acid-led
-AMP6-BASIC
-4x p.audio HP-10W
-4x Piezo QLM-1005
I don't think i forgot something but if you people notice something out of place, please do not hesitate on putting me on the right track!
thanks // Marcus
Ordered
-20W Solarpanel(775 SEK) and a regulator(375 SEK). site: 24volt.eu
-Resistance 5W 150 OHM (~7 SEK) site: conrad.se
Not yet ordered
-2x 12v acid-led
-AMP6-BASIC
-4x p.audio HP-10W
-4x Piezo QLM-1005
I don't think i forgot something but if you people notice something out of place, please do not hesitate on putting me on the right track!
thanks // Marcus
Hi there.
I finally made it through the entire thread...
I'm currently designing our new boombox, with the following components:
-Amp6B (all soldered and working)
-4 Eminence Delta 10A (98.8dB)
-4 Eminence APT 150 (105dB)
I'll won't be able to use the battery from our old boombox, because it died last summer. At 120Ah and weighing ~40kg, it was too big anyway.
So a new one it is, but what to get?
At first I was pretty hooked on a couple of 7-14Ah SLA's. They should supply me with enough power, and they could be wired in series for 24V later on.
They have a few disadvantages, though:
-I've used them as backup for alarm systems at school (I'm an electrician), and they died pretty fast if allowed to run flat (I killed two sets in 8 weeks).
-For the price of two, I can almost get a 75Ah marine battery instead, allowing us to power some LED lights, and charge cellphones and Ipods.
I've been reading a bit about LiFePo batteries. They looked ideal, until I noticed something. In the spec sheet, it says that running them lower than 10V will damage them. In the specs for the TA2020 chip, it says minimum supply voltage is 8,5V. That sounds like a good way to kill an expensive battery pretty fast?
I finally made it through the entire thread...
I'm currently designing our new boombox, with the following components:
-Amp6B (all soldered and working)
-4 Eminence Delta 10A (98.8dB)
-4 Eminence APT 150 (105dB)
I'll won't be able to use the battery from our old boombox, because it died last summer. At 120Ah and weighing ~40kg, it was too big anyway.
So a new one it is, but what to get?
At first I was pretty hooked on a couple of 7-14Ah SLA's. They should supply me with enough power, and they could be wired in series for 24V later on.
They have a few disadvantages, though:
-I've used them as backup for alarm systems at school (I'm an electrician), and they died pretty fast if allowed to run flat (I killed two sets in 8 weeks).
-For the price of two, I can almost get a 75Ah marine battery instead, allowing us to power some LED lights, and charge cellphones and Ipods.
I've been reading a bit about LiFePo batteries. They looked ideal, until I noticed something. In the spec sheet, it says that running them lower than 10V will damage them. In the specs for the TA2020 chip, it says minimum supply voltage is 8,5V. That sounds like a good way to kill an expensive battery pretty fast?
Nikolaj, it's highly recommended that you buy a battery protection PCB when you buy your LFC cells. These ensures correct balancing, over- and under-voltage, temperature, and etc protection. It doesn't matter what kind of battery it is. All batteries are irreversably damaged when allowed to run completely flat, it's just a question of how much damage is suffered. LFP cells, especially the newest type with yittrium that has up to 5000 cycles before deteriation (up from 2000 with standard LFP cells), seems to be the most resilient battery type also in this respect.
Wubbaz, yes, it'll mean more power consumption to add a linkwitz transform (a lot more in fact).
Darkwithin, Thanks and good luck on your project. I wouldn't have used chipboard (not even MDF) but plywood which is also what I recommend. Make very sure you seal every single surface also internally, so that the chipboard doesn't pick up too much moisture. Otherwise it'll become very heavy and fall apart very fast. The internal forces put on the wood is quite extreme.
Wubbaz, yes, it'll mean more power consumption to add a linkwitz transform (a lot more in fact).
Darkwithin, Thanks and good luck on your project. I wouldn't have used chipboard (not even MDF) but plywood which is also what I recommend. Make very sure you seal every single surface also internally, so that the chipboard doesn't pick up too much moisture. Otherwise it'll become very heavy and fall apart very fast. The internal forces put on the wood is quite extreme.
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Saturnus, maybe you can help me out here? I've tried to calculate a new boxvolume with different Q's at this site:
Speaker Box Calculations
but no matter what I choose as a Qtc (which I presume is the Q you are talking about?), the calculated boxvolume doesn't change. It is always ~2 cubic feet. What am I missing?
And do you have an estimate of what our Q and target frequency should be in our case?
I haven't been able to find any info on 'outdoor Q' or 'outdoor speaker enclosure volume' etc. anywhere :s
Speaker Box Calculations
but no matter what I choose as a Qtc (which I presume is the Q you are talking about?), the calculated boxvolume doesn't change. It is always ~2 cubic feet. What am I missing?
And do you have an estimate of what our Q and target frequency should be in our case?
I haven't been able to find any info on 'outdoor Q' or 'outdoor speaker enclosure volume' etc. anywhere :s
I'll leave the transformer out for now then ;-)
I was wondering if this amp:
MKll Version Tripath TA2020 PCB 25w CLass-T amplifier on eBay (end time 11-Mar-11 02:09:19 GMT)
Would play alot different than a Amp6B? I am asking due to limited funds, and since this amp is based on the Tripath 2020 PCB and is cheaper than the Amp6B, I am thinking it would prove for a decent alternative. What are your thoughts on this?
I was wondering if this amp:
MKll Version Tripath TA2020 PCB 25w CLass-T amplifier on eBay (end time 11-Mar-11 02:09:19 GMT)
Would play alot different than a Amp6B? I am asking due to limited funds, and since this amp is based on the Tripath 2020 PCB and is cheaper than the Amp6B, I am thinking it would prove for a decent alternative. What are your thoughts on this?
Since it uses the same chip If there is any difference at all, you certainly wouldn't be able to notice on a boombox, no matter how good quality it might be.
The main reason I recommend the amp6b is that I know it uses high quality components and have an almost unlimited lifetime. At least my first one is still playing nicely. I've had several of those cheapo e-bay T-amp suddenly die on me and other people. Probably because they're not built to endure the extreme temperature and moisture conditions that a boombox will suffer.
Others again have really good experiences with the e-bay stuff, so it's your call
The main reason I recommend the amp6b is that I know it uses high quality components and have an almost unlimited lifetime. At least my first one is still playing nicely. I've had several of those cheapo e-bay T-amp suddenly die on me and other people. Probably because they're not built to endure the extreme temperature and moisture conditions that a boombox will suffer.
Others again have really good experiences with the e-bay stuff, so it's your call
ok I am getting the hang of this WINISD thing now, but the weird thing is that there is no Qtc field. I know it should be under the Box-tab, but here is only Volume and Tuning freq., and I've seen screenshots of where it should be, but I don't have it. I've entered all information from the HP-10W datasheet, still no box with Qtc. Well...I might just go with the old 23L 82Hz then.