your battery is going to be 12v. theres only so much volume you can create with 12 volts. so the thing to do is get really sensitive speakers, that way you can maximise the volume output from 12 volts.
theres an article here on speaker sensitivity -
http://en.wikipedia.org/wiki/Loudspeaker#Efficiency_vs._sensitivity
read the paragraph below the bullet points.
then re-read it
theres an article here on speaker sensitivity -
http://en.wikipedia.org/wiki/Loudspeaker#Efficiency_vs._sensitivity
read the paragraph below the bullet points.
then re-read it
NED 209 said:your battery is going to be 12v. theres only so much volume you can create with 12 volts. so the thing to do is get really sensitive speakers, that way you can maximise the volume output from 12 volts.
theres an article here on speaker sensitivity -
http://en.wikipedia.org/wiki/Loudspeaker#Efficiency_vs._sensitivity
read the paragraph below the bullet points.
then re-read it
what about two 12V batteries in series? A lot of these amps are VERY happy at 24VDC.
Weight is not really a huge concern; the thing is going to have wheels.
Anyway, thanks for the lowdown on speaker sensitivity. What's considered a high sensitivity? Wikipedia says around 95 to 102 dB for outdoor speakers, but would e.g. 90dB suffice [1]?
I'm pretty settled on buying a 41Hz amplifier. I just don't know whether to get an AMP6 or an AMP6-basic. Do you have any hints in that direction. And, again, what about the volume knob. Is there any or is the amplifier locked to a certain amplification, so to speak?
[1] http://thansen.dk/product.asp?c=1820525968&n=-2035763586&pn=-2035762707
Anyway, thanks for the lowdown on speaker sensitivity. What's considered a high sensitivity? Wikipedia says around 95 to 102 dB for outdoor speakers, but would e.g. 90dB suffice [1]?
I'm pretty settled on buying a 41Hz amplifier. I just don't know whether to get an AMP6 or an AMP6-basic. Do you have any hints in that direction. And, again, what about the volume knob. Is there any or is the amplifier locked to a certain amplification, so to speak?
[1] http://thansen.dk/product.asp?c=1820525968&n=-2035763586&pn=-2035762707
The difference as I am sure you know is the basic does not have the power supply circuitry built in, and the regular unit does. With the addition of a transformer, you can use the regular model by plugging it into an outlet. To use a battery, you will have to figure out how to separate the power supply part of the Amp 6 from the amplifier part, and put a switch in there that will allow you to go back and forth between the AC and the battery. Part of that circuit would ideally be a battery charger that also works off the AC, so when the switch is flipped to the "AC" position, the battery is also charging.
It comes down to how you plan to use the unit. I used the Amp 6 basic and built a small switching PS. the kind you can get cheap on eBay as an LCD monitor supply, and also a battery charger/conditioner from Batteries.cm:
http://www.batteries.com/productprofile.asp?appid=298436
The setup works well, although to save weight, it would be ideal if the battery charger and amp PS used the same transformer--although I haven't torn into the charger to see if this is feasible. Also, I don't know whether this would "kick back" any noise from the charger, as it does create some HF pulses that help keep the battery in good condition.
--Buckapound
It comes down to how you plan to use the unit. I used the Amp 6 basic and built a small switching PS. the kind you can get cheap on eBay as an LCD monitor supply, and also a battery charger/conditioner from Batteries.cm:
http://www.batteries.com/productprofile.asp?appid=298436
The setup works well, although to save weight, it would be ideal if the battery charger and amp PS used the same transformer--although I haven't torn into the charger to see if this is feasible. Also, I don't know whether this would "kick back" any noise from the charger, as it does create some HF pulses that help keep the battery in good condition.
--Buckapound
Hi guys,
car coaxial speakers have a down side, there is no 'real' filter, it's just a tweeter protection cap. So that shouldn't be a reason not to use a separate woofer and tweeter the same way. From there you can work out a better functioning filter. Making it better than just a cap isn't going to be hard
The sensitivity a manufacturer publishes in the specs sheet is nothing reliable, when it says 93db it is possible that this is just at a given frequency. It is therefore wise to have a look at a frequency spectrum diagram.
Here you can see exactly where the driver has good sensitivity.
Another misunderstanding is speakers don't draw power, they merely receive and convert it into motion and heat. The only thing drawing power here is the amp and auxiliary equipment.
If weight is no issue than that's a big bonus, you CAN use a car battery, although there are issues with the risk of acid pouring out (yes they all do, especially during the charging) and the gas that comes free when charging is more or less flamable. (can be explosive!
) So you can have holes burnt in your creation from the burning acid (or worse in your fingers or your favorite T-shirt)
I would certainly advise the use of SLA...
Than the amp, if you still contemplate on them than the AMP9-B is still an option, it does use more power than an AMP6, but with 24V and 2 ohm speakers it's really loud....
I do think that if money is an issue you shouldn't overdo it and go the same route as Saturnus did, get the AMP6 which is the easiest to build T-amp and go for really sensitive speakers.
Note: Placing two speakers really near eachother raises the sinsitivity by about 3 db! So that doubles the loudness! Just make sure that the AMP can handle the load...(two speakers in parallel halves the impedance)
car coaxial speakers have a down side, there is no 'real' filter, it's just a tweeter protection cap. So that shouldn't be a reason not to use a separate woofer and tweeter the same way. From there you can work out a better functioning filter. Making it better than just a cap isn't going to be hard
The sensitivity a manufacturer publishes in the specs sheet is nothing reliable, when it says 93db it is possible that this is just at a given frequency. It is therefore wise to have a look at a frequency spectrum diagram.
An externally hosted image should be here but it was not working when we last tested it.
Here you can see exactly where the driver has good sensitivity.
Another misunderstanding is speakers don't draw power, they merely receive and convert it into motion and heat. The only thing drawing power here is the amp and auxiliary equipment.
If weight is no issue than that's a big bonus, you CAN use a car battery, although there are issues with the risk of acid pouring out (yes they all do, especially during the charging) and the gas that comes free when charging is more or less flamable. (can be explosive!
) So you can have holes burnt in your creation from the burning acid (or worse in your fingers or your favorite T-shirt)I would certainly advise the use of SLA...
Than the amp, if you still contemplate on them than the AMP9-B is still an option, it does use more power than an AMP6, but with 24V and 2 ohm speakers it's really loud....
I do think that if money is an issue you shouldn't overdo it and go the same route as Saturnus did, get the AMP6 which is the easiest to build T-amp and go for really sensitive speakers.
Note: Placing two speakers really near eachother raises the sinsitivity by about 3 db! So that doubles the loudness! Just make sure that the AMP can handle the load...(two speakers in parallel halves the impedance)
Actually I had bought the AMP6-BASIC before your answer. I plan on running it on a ~60Ah car battery. Some guy earlier in this post said that he got 6 hours of play time on a battery holding 4 Ah.
I'm still a bit in doubt about what kind of speakers I need. It's a jungle! Anyway, the amp specifications state 2x25W 4Ohm. Most of the car speakers I see are >200W, so how is that possible? What kind of speakers should I buy? NED 209 told me I wanted something with high sensitivity, so I guess that's right. Should I just go for one of those >200W speakers?
I'm still a bit in doubt about what kind of speakers I need. It's a jungle!
Anyway, the amp specifications state 2x25W 4Ohm. Most of the car speakers I see are >200W, so how is that possible? What kind of speakers should I buy? NED 209 told me I wanted something with high sensitivity, so I guess that's right. Should I just go for one of those >200W speakers?jchillerup, you should be aware that car batteries are not designed to be drained down very far from their maximum charge. So, in a portable power situation, repeated deep use and charge cycles will result in shorter life.
Marine batteries, usually described as "deep cycle" and/or gel-cell type batteries are more expensive per hour but will work longer than a car battery, and don't have the potential to spray acid in anyone's face.
--Buckapound
Marine batteries, usually described as "deep cycle" and/or gel-cell type batteries are more expensive per hour but will work longer than a car battery, and don't have the potential to spray acid in anyone's face.
--Buckapound
it doesnt really matter what wattage the speakers are, your only going to be putting 25 watts into each one. your supposed to leave a bit of leeway, so speakers that can handle 50 watts or above will be fine. theres a bit written here about it
http://reviews.ebay.co.uk/Buying-Speakers-on-eBay-RMS-vs-MAX_W0QQugidZ10000000000063388
http://reviews.ebay.co.uk/Buying-Speakers-on-eBay-RMS-vs-MAX_W0QQugidZ10000000000063388
Guys, you're all awesome.
As I said, I've already settled on an AMP6 for this first project. Instead of using a car battery, I'm going for a 17Ah 12V lead battery, which is also cheaper than the car battery I was looking at (albeit that was 95Ah, but I've figured that charging won't really be a problem). I think I'm going to go for two of those in parallel. I couldn't find any easily accessible boat battery vendors anywhere near me (with a home page at least).
So that leaves the amp and battery handled. Nice. That leaves only the speakers. Thanks for the lowdown on speaker wattage, NED, it was very helpful. So I'm going for some high sensitivity, not necessarily high wattage speakers. v-bro, who's exceedingly awesome topic I must have missed before posting my previous post, says that car speakers might not be the way to go. Do you guys have any suggestions, perhaps even with an ebay link
As I said, I've already settled on an AMP6 for this first project. Instead of using a car battery, I'm going for a 17Ah 12V lead battery, which is also cheaper than the car battery I was looking at (albeit that was 95Ah, but I've figured that charging won't really be a problem). I think I'm going to go for two of those in parallel. I couldn't find any easily accessible boat battery vendors anywhere near me (with a home page at least).
So that leaves the amp and battery handled. Nice. That leaves only the speakers. Thanks for the lowdown on speaker wattage, NED, it was very helpful. So I'm going for some high sensitivity, not necessarily high wattage speakers. v-bro, who's exceedingly awesome topic I must have missed before posting my previous post, says that car speakers might not be the way to go. Do you guys have any suggestions, perhaps even with an ebay link
Yes, his design is cool indeed. I'm just worried; won't this be a waste of money. Isn't the AMP6-BASIC kind of petty to that kind of speakers? If not, then would this be a bad trade:
2x HP10W (bass)
1x G-1045 (mid/high)
And what about the battery life? You say the speakers themselves don't consume power. But doesn't the amplifier eat more energy when it's set to load three speaker modules? (sorry if that was a stupid question)
2x HP10W (bass)
1x G-1045 (mid/high)
And what about the battery life? You say the speakers themselves don't consume power. But doesn't the amplifier eat more energy when it's set to load three speaker modules? (sorry if that was a stupid question)
Hi,
these drivers look pretty cheap, what budget were you aiming for.
Still Saturnus put a lot of thought in the design, and wise thought if I might say. The AMP6 will operate fine with such a speaker configuration (although I believe he used two in one boombox?)
I'll get back on this, no more time.....
these drivers look pretty cheap, what budget were you aiming for.
Still Saturnus put a lot of thought in the design, and wise thought if I might say. The AMP6 will operate fine with such a speaker configuration (although I believe he used two in one boombox?)
I'll get back on this, no more time.....
youll be amazed at the volume levels you can get out of a low powered amp with the right speakers. here, read through this thread, i found it very educational, if a little costly
http://www.diyaudio.com/forums/showthread.php?s=&threadid=118633
http://www.diyaudio.com/forums/showthread.php?s=&threadid=118633
Thanks for the link, NED. I read it but I didn't get that much from it, though; too much "moonspeak"
Anyway, I reexamined the dB-to-tone-frequency chart again and figured I wouldn't really need anything else than the HP10Ws. Mind you, I'm trying to do this project on a rather strict budget -- not saying as cheap as possible, though. The chart for the G-1045 looks a bit more intriguing, so I'm considering going for just two of those (and no more -- DO complain if that is just ridiculous, please).
What else will I need, aside from the apparent stuff:
I owe you guys a huge _thank you_ for all your time explaining this to me. I sincerely hope it's not been too much of a burden.
Anyway, I reexamined the dB-to-tone-frequency chart again and figured I wouldn't really need anything else than the HP10Ws. Mind you, I'm trying to do this project on a rather strict budget -- not saying as cheap as possible, though. The chart for the G-1045 looks a bit more intriguing, so I'm considering going for just two of those (and no more -- DO complain if that is just ridiculous, please).
What else will I need, aside from the apparent stuff:
- Storage box
- Battery
- Amplifier
- Drivers
- Cables from battery to amp
- Cables from amp to drivers (I know speakers should not be connected with the same cables as from the battery to the amp)
I owe you guys a huge _thank you_ for all your time explaining this to me. I sincerely hope it's not been too much of a burden.
You'll also need:
- Power supply/transformer
- Charger/conditioner for batteries.
- Pot for volume control. You can get by without this if you use the headphone jack from an Ipod or walkman, but you'll generally get a better-sounding signal through a line-out (through the dock connector on an iPod).
Don't forget to fuse the battery. Those things can put out a lot of current in a short situation.
--Buckapound
- Power supply/transformer
- Charger/conditioner for batteries.
- Pot for volume control. You can get by without this if you use the headphone jack from an Ipod or walkman, but you'll generally get a better-sounding signal through a line-out (through the dock connector on an iPod).
Don't forget to fuse the battery. Those things can put out a lot of current in a short situation.
--Buckapound
The power supply is all right. Battery supplies 12V which is what the amplifier takes.
I forgot to write charger on that other list, but yeah, that is definitely needed.
Where do I get a volume pot. Is it something I can get in any Radio Shack?
The amp already has a fuse. I suppose that's for the battery. Won't that be enough?
I forgot to write charger on that other list, but yeah, that is definitely needed.
Where do I get a volume pot. Is it something I can get in any Radio Shack?
The amp already has a fuse. I suppose that's for the battery. Won't that be enough?
I could be ousted from this forum for saying so, but a Radio Shack pot should work fine. If you are feeling overburdened with cash, there are solutions out there ranging up to a several hundred dollar stepped attenuators. Myself, I'm using a counterfeit Alps bought off eBay.
The real Alps, BTW, seems to be what people consider to be a choice with a good price/performance ratio:
http://cgi.ebay.com/ALPS-Potentiome...ryZ39997QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
If there's a fuse on the board, as long as it's between the board and the battery, you should be good.
--Buckapound
The real Alps, BTW, seems to be what people consider to be a choice with a good price/performance ratio:
http://cgi.ebay.com/ALPS-Potentiome...ryZ39997QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
If there's a fuse on the board, as long as it's between the board and the battery, you should be good.
--Buckapound