Hello Class D section of DIY audio!
Im in the process of building a sound system. It has two upper bass/mid/high range speakers and one bass/sub bass speaker. Also they have lights reacting to the music
The upper bass/mid/high speakers have been created. Im using a transducer rather than a cone. The amp is (Mini Battery Powered Class D Audio Amplifier) and so far am happy with the results. If any one has opinions about this amp let me know. I have not gotten any answers from my questions to the amps costumer service..
I am now starting the process of building the sub. I was looking at a few different drivers. I really want it to be close to 20hz to get good sub bass but its going to be battery powered so it cant take too much power. This is the best driver I could find for lowest wattage but that price is so high! (https://www.parts-express.com/peerless-830452-10-xls-subwoofer--264-1108).
Anyway... The question is: whats a good class D amp module that I could use to make a portable sub w/out a generator? It probably needs to be below 100watts but NEEDS to handle 20hz nice and clean.
Im in the process of building a sound system. It has two upper bass/mid/high range speakers and one bass/sub bass speaker. Also they have lights reacting to the music
The upper bass/mid/high speakers have been created. Im using a transducer rather than a cone. The amp is (Mini Battery Powered Class D Audio Amplifier) and so far am happy with the results. If any one has opinions about this amp let me know. I have not gotten any answers from my questions to the amps costumer service..
I am now starting the process of building the sub. I was looking at a few different drivers. I really want it to be close to 20hz to get good sub bass but its going to be battery powered so it cant take too much power. This is the best driver I could find for lowest wattage but that price is so high! (https://www.parts-express.com/peerless-830452-10-xls-subwoofer--264-1108).
Anyway... The question is: whats a good class D amp module that I could use to make a portable sub w/out a generator? It probably needs to be below 100watts but NEEDS to handle 20hz nice and clean.
Hello Class D section of DIY audio!
Im in the process of building a sound system. It has two upper bass/mid/high range speakers and one bass/sub bass speaker. Also they have lights reacting to the music
The upper bass/mid/high speakers have been created. Im using a transducer rather than a cone. The amp is (Mini Battery Powered Class D Audio Amplifier) and so far am happy with the results. If any one has opinions about this amp let me know. I have not gotten any answers from my questions to the amps costumer service..
I am now starting the process of building the sub. I was looking at a few different drivers. I really want it to be close to 20hz to get good sub bass but its going to be battery powered so it cant take too much power. This is the best driver I could find for lowest wattage but that price is so high! (https://www.parts-express.com/peerless-830452-10-xls-subwoofer--264-1108).
Anyway... The question is: whats a good class D amp module that I could use to make a portable sub w/out a generator? It probably needs to be below 100watts but NEEDS to handle 20hz nice and clean.
20 Hz outdoor is always a huge problem... (Oops, you didn't tell where you want to use it, neither if you want it to be portable...)
What you really need, is not low power rating, but high sensitivity at low freq, with probably a very limited size (but you didnt specify this most important factor either).
I don't know your battery (an other unspecified point) nor your intended continuous play time, but probably the accumulator can weight as much as bass speaker. Provided this I assume you can go up to 100 W, but 12 V (we don't know, but I assume this is the voltage) is too small to produce significant power on 8 ohms. I suggest you to use a 2x2 ohm speaker, each coil connected to a bridged channel. This will receive 8 times higher power from the same voltage...
Maybe I would choose this from 10 coll 2+2 ohm at partsexpress:
https://www.parts-express.com/dayton-audio-um10-22-10-ultimax-dvc-subwoofer-2-ohms-per-coil--295-510
This is said to be the most powerful and sensitive (88.7 dB 1W/1m), but not too deep, and very poorly specified:
https://www.parts-express.com/re-au...-frame-dvc-subwoofer-driver-2-2-ohm--268-8070
But definitely this has the best price/performance ratio:
https://www.parts-express.com/kicker-cvr102-compvr-series-10-dvc-subwoofer-2-2-ohm--267-6920
The key to deep bass is the enclosure and environment. If you can use the environment wisely, you can get good bass.
Description of MINI CLASS D AUDIO POWER AMPLIFIER is stupid (the power spec part), and the product itself is very overpriced. For 18 USD you can get a more powerful one on eBay. 20 Hz is not a problem for almost any of the ClassD modules.
This is a question impossible to answer to. No direct relationship between frequency limit and power. It depends on what SPL do you need at 20 Hz, with what speaker and enclosure and environment, at what distance. Do you know what do you expect? I guess not.
But if you change 20 Hz to 30 Hz, you will need about 4th to 10th part of the required power for the same SPL.
Limiting upper freq. to 80 Hz also helps somewhat.
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Thank you for all of the replies
DoctorMord, nice job on finding that information. Have you used their products before?
The reason I went with Class D Audio is they are made in America and it looked like a solid amp for my application. Most modules I have found online had very mixed reviews. Class D Audio only has good reviews on their site... I have now learned this is because they approve the comments before they are shown. I don't know what to look for when searching for a quality amp module and the higher price and good looking design made me think they used good components.
This is my first speaker build so I am new to this. The speaker already made that Im looking to compliment with a sub starts picking up strong at 100hz so I am looking to get 20 - approximately 100hz or higher for the sub.
Pafi, Thank you for all of that information. The system is intended to be portable for inside and outside use. I am finishing up the first speaker still. Its functioning just fine but all of the parts for the lights / amp module are not attached and still are on the bread board. I have not purchased the battery yet so its running off of my bench power supply at 12v. Normal listening pulls .15A and full volume is averages out at about .5A. Something that confuses me with those numbers are that they don't equal 30 watts which is what the amp is rated for. The speaker is pretty loud and sounds nice to my ears and others who have heard it.
Batteries! So many batteries to choose from... cost / weight / power all play a role. For the speaker I made I am seriously considering getting this battery at 12v 7.5Ah (12V 7.5 AH (amp hour) Lithium Iron Phosphate battery packs for sale direct replacement for 12V7AH sealed lead acid batteries.) With the amount of power it pulls, according to my power supply, I should be able to get more than 15 hours of play time full volume. A larger battery could be purchased for the sub to match that play time. Adding a solar panel charging station and we could be looking at endless playtime in the summer.
This is my first time hearing about dual voice coils. Thats awesome information and thank you for those links. Would I use a 4ohm amp with the 2+2 driver bridged to get the most power that you mentioned?
I have not gotten into researching enclosures yet but I have found from shows the deepest and cleanest bass comes from a fully enclosed driver. When I first noticed a stack of subs like this at a show I spent a while trying to understand how it worked. I am excited to research these enclosures as I still don't understand them.
"...Loudspeaker Measurement System (LMS) to plot the result. The plot, commonly know as a frequency response graph, shows frequency on an x-axis (in Hz) versus SPL on a y-axis (in dB)." -(Understanding SPL | Eminence Speaker)
I imagine this must be the "sensitivity" part of the specs. So this means that at 88.7 dB 1W/1m the speaker puts out 88.7dB with one watt of power from a distance of a meter? That is loud. What does that mean if 100watts are pushed into it? I would like to get it down to 20Hz for a full range system but 30hz could be livable, especially if it gives me 10x the battery life. The distance I am aiming to achieve for out door listening is about 15 to 20 meters.
DoctorMord, nice job on finding that information. Have you used their products before?
The reason I went with Class D Audio is they are made in America and it looked like a solid amp for my application. Most modules I have found online had very mixed reviews. Class D Audio only has good reviews on their site... I have now learned this is because they approve the comments before they are shown. I don't know what to look for when searching for a quality amp module and the higher price and good looking design made me think they used good components.
This is my first speaker build so I am new to this. The speaker already made that Im looking to compliment with a sub starts picking up strong at 100hz so I am looking to get 20 - approximately 100hz or higher for the sub.
Pafi, Thank you for all of that information. The system is intended to be portable for inside and outside use. I am finishing up the first speaker still. Its functioning just fine but all of the parts for the lights / amp module are not attached and still are on the bread board. I have not purchased the battery yet so its running off of my bench power supply at 12v. Normal listening pulls .15A and full volume is averages out at about .5A. Something that confuses me with those numbers are that they don't equal 30 watts which is what the amp is rated for. The speaker is pretty loud and sounds nice to my ears and others who have heard it.
Batteries! So many batteries to choose from... cost / weight / power all play a role. For the speaker I made I am seriously considering getting this battery at 12v 7.5Ah (12V 7.5 AH (amp hour) Lithium Iron Phosphate battery packs for sale direct replacement for 12V7AH sealed lead acid batteries.) With the amount of power it pulls, according to my power supply, I should be able to get more than 15 hours of play time full volume. A larger battery could be purchased for the sub to match that play time. Adding a solar panel charging station and we could be looking at endless playtime in the summer.
This is my first time hearing about dual voice coils. Thats awesome information and thank you for those links. Would I use a 4ohm amp with the 2+2 driver bridged to get the most power that you mentioned?
I have not gotten into researching enclosures yet but I have found from shows the deepest and cleanest bass comes from a fully enclosed driver. When I first noticed a stack of subs like this at a show I spent a while trying to understand how it worked. I am excited to research these enclosures as I still don't understand them.
"...Loudspeaker Measurement System (LMS) to plot the result. The plot, commonly know as a frequency response graph, shows frequency on an x-axis (in Hz) versus SPL on a y-axis (in dB)." -(Understanding SPL | Eminence Speaker)
I imagine this must be the "sensitivity" part of the specs. So this means that at 88.7 dB 1W/1m the speaker puts out 88.7dB with one watt of power from a distance of a meter? That is loud. What does that mean if 100watts are pushed into it? I would like to get it down to 20Hz for a full range system but 30hz could be livable, especially if it gives me 10x the battery life. The distance I am aiming to achieve for out door listening is about 15 to 20 meters.
Never heard of this company before.
100W is +20dB to your 1W rating.
Battery looks good to me if you don't to struggle with multicell LiIon/LiPo packs (like 6-8s packs) with their need of balanced charging etc.
But keep in mind that getting 100Wrms at 12V isn't working, min. 30V if running single supply BTL into 4R. (Or 24V if pumping into 2R)
100W is +20dB to your 1W rating.
Battery looks good to me if you don't to struggle with multicell LiIon/LiPo packs (like 6-8s packs) with their need of balanced charging etc.
But keep in mind that getting 100Wrms at 12V isn't working, min. 30V if running single supply BTL into 4R. (Or 24V if pumping into 2R)
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How are you getting these numbers?
That's why I like this battery. It's all packaged up. I have been looking into stacking cells too but I'm concerned about it blowing up...
2x loudness = 10dB = 10x power, so:
88dB = 1W
98dB = 10W
108dB = 100W
For every 3dB, you need 2x the power.
88dB = 1W
91dB = 2W
94dB = 4W
97dB = 8W
100dB = 16W
103dB = 32W
106dB = 64W
109dB = 128W
etc.
So having efficient/sensitive speakers gets you dB/loudness for "free". Easily seen when doing the math for I.e. 103dB/W/m speakers.
88dB = 1W
98dB = 10W
108dB = 100W
For every 3dB, you need 2x the power.
88dB = 1W
91dB = 2W
94dB = 4W
97dB = 8W
100dB = 16W
103dB = 32W
106dB = 64W
109dB = 128W
etc.
So having efficient/sensitive speakers gets you dB/loudness for "free". Easily seen when doing the math for I.e. 103dB/W/m speakers.
wow that is cool. Thank you for laying that out for me. So different speakers dB/loudness is relative to their sensitivity and wattage input. I was under the assumption that it was based off of wattage alone.
When pairing a speaker to an amplifier at first I was looking at the wattage of the speaker and the amplifier. If the ohms the amplifier can handle match that of the speaker does it matter if the wattages match or could the amplifier be lower watts than the speaker? Im using a 40watt speaker with a 30watt amp and it seems to be doing just fine. If I were to go with the kicker sub that Pafi referenced its rated at 400watts of power handling. Would a 100watt amp work for a speaker like this if the amp could handle its resistance?
When pairing a speaker to an amplifier at first I was looking at the wattage of the speaker and the amplifier. If the ohms the amplifier can handle match that of the speaker does it matter if the wattages match or could the amplifier be lower watts than the speaker? Im using a 40watt speaker with a 30watt amp and it seems to be doing just fine. If I were to go with the kicker sub that Pafi referenced its rated at 400watts of power handling. Would a 100watt amp work for a speaker like this if the amp could handle its resistance?
doctormord, I was looking at your website in regards to your class D amp builds. You have a professional understanding of how to build one and test it. Do you sell your amps? I understand the basics of how a class D amp works. I have built one for input to a microcontroller with a small op amp to react to music. I don't understand all of the details involved in making one for large amplified clean sound. I hope to make my own in a few years but its going to take a lot of learning to get to that level.
This looks like a good enclosure for a portable sub AutoTuba and TruckTuba
earlier when I wrote fully enclosed enclosure I think what I meant was folded horns designs.
earlier when I wrote fully enclosed enclosure I think what I meant was folded horns designs.
Amp could be lower watts, no problem. The speakers Pafi refered to are all "big diplacement" drivers for smaller enclosures. Getting "ompf" out of these drivers needs alot of power as they trade in displacement for enclosure size. It's all about pumping air around. So having a bigger diaphragm needs less power to pump the same amount of air than these smaller ones with big displacement as efficiency is increased due to a better coupling factor to the surrounded air.
100watts isn't enough and getting something around 20Hz in free-air? No way. This might work in a car due to the fact that the car is acting as a sealed enclosure too.
You'll have to live with a higher low-end-frequency in free-air, even 50Hz outside needs much energy if you want "ompf".
I got my bike-sub tuned to something 80Hz, but getting 104dB/W/m with a 15" 4Ohm PA-chassis in a 130 liters BR enclosure.
The smaller wattage amps are avail on request, the TPA3251D2 isn't available yet.
You have a sub for your bicycle? It must be fun to ride around town with that. Does the BR enclosure mean a ported sub? When the sub is tuned to 80hz does that = great 80hz response. How much variance comes from this tuning?
The ported sub designs look like they might be a good option. The description of them says they have better frequency response than a closed box exclosure. The Folded Horns type of designs are awesome but they look like they need to be large not making them portable.
I thought we were saying that the speakers Pafi referenced had great SPL and would respond well with low power. Wouldn't one of them Work well in a Folded Horn design or ported sub at low power?
When you say free air are you referring to being outside or not having an enclosure?
How much are the TPA3116's running for? It would be nice to try out a higher power amp on the speaker I have going already.
The ported sub designs look like they might be a good option. The description of them says they have better frequency response than a closed box exclosure. The Folded Horns type of designs are awesome but they look like they need to be large not making them portable.
I thought we were saying that the speakers Pafi referenced had great SPL and would respond well with low power. Wouldn't one of them Work well in a Folded Horn design or ported sub at low power?
When you say free air are you referring to being outside or not having an enclosure?
How much are the TPA3116's running for? It would be nice to try out a higher power amp on the speaker I have going already.
Ok, I was just checking because I saw that "free air" is an enclosure type and I wanted to make sure I understood you right.
The power now is 30 watts to a 40watt power handling speaker. I'm going to be making more of these so finding a quality class d amp for a good price will be nice. Going back to the calculations you laid out for me I see that their should not be too much of a difference from 30 to 50watts on the amp. It's possible it might sound better though?
The power now is 30 watts to a 40watt power handling speaker. I'm going to be making more of these so finding a quality class d amp for a good price will be nice. Going back to the calculations you laid out for me I see that their should not be too much of a difference from 30 to 50watts on the amp. It's possible it might sound better though?
Mostly yes, a 30W amp at full 30W will normally more distort than a 50W at 30W. Amps distortion quickly rise at the upper limit.
So if you want to have an amp which will do twice as loud, you'd need to go for 300W. (As seen from the calculation earlier. 10dB more = twice as loud = 10x times the power needed)
So if you want to have an amp which will do twice as loud, you'd need to go for 300W. (As seen from the calculation earlier. 10dB more = twice as loud = 10x times the power needed)
I am interested in quality sound. I don't want this speaker to be twice as loud, that's too much for my application. Both in dB and power consumption.
I will be making more of these. How many more I'm not sure. Could be 10 could be 100, only time will tell. I would like to find a good class d amp for it that preferably cost less than 60$. I only plan on making one sub and I want to get a good amp for that too.
I will be making more of these. How many more I'm not sure. Could be 10 could be 100, only time will tell. I would like to find a good class d amp for it that preferably cost less than 60$. I only plan on making one sub and I want to get a good amp for that too.
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