I would like to build a high quality small powered speaker. To save the cost (and design and build complexity) of a crossover, I'd like to use an amplifier to serve as the amplifier and crossover for the speaker.
I'm a complete noob to amplifiers for powered speakers, but I'm willing to learn as much as I have to.
I'm thinking of using a class D amplifier for the efficiency, high power, and small size. I need an amplifier that can output 50-100 watts total. I'm thinking of a two channel amplifier, one channel for the tweeter, one channel for the woofer?
What amplifier should I use? The budget is under $100. I'd like an amplifier with a DSP to tune the crossover point and to boost the bass while having a limiter in place.
Thanks
I'm a complete noob to amplifiers for powered speakers, but I'm willing to learn as much as I have to.
I'm thinking of using a class D amplifier for the efficiency, high power, and small size. I need an amplifier that can output 50-100 watts total. I'm thinking of a two channel amplifier, one channel for the tweeter, one channel for the woofer?
What amplifier should I use? The budget is under $100. I'd like an amplifier with a DSP to tune the crossover point and to boost the bass while having a limiter in place.
Thanks
I would recommend to buy an TK2050 or TPA3116 amp (TK2050's from HiFimeDIY.com have really excellent sound quality, but boards from Sure, Muse and others are also recommendable - all starting between 20-30US$ for 50-100W/channel) and an 2x4 DSP module from miniDSP.com (~70$ for unboxed version if I remember correctly)
Theoretically you could use one 2x4 miniDSP for two 2-ways speakers and save costs, though it would need additional cables of course 😉
Several people have build really awesome speakers with these miniDSP's, also 4-way etc.
https://www.youtube.com/watch?v=bQPK-5lAIFY
As power source you could use an universal 24V 150W power supply like that one (15-20$) with a secondary 5V USB output
http://xtc.images.dp-tech.de/images/product_images/original_images/28564823_0.jpg
With the 5V 1A USB output you can power the DSP directly and they have low idle power consumption.
I don't know any cheap(er) solutions which contain an easily adjustable DSP and have good sound quality.
Texas Instruments and others have cheaper DSP's but you need a lot good informatical know-how (they are coming without any software etc.), some additional hardware to connect them to your computer and good soldering skills. The DSP's by MiniDSP can be programmed with provided software with an easy guided user interface and simply connected with USB. Even if you have the know-how how to program and setup plain DSP chips I would recommend to buy the DSP modules from miniDSP unless you want to build dozens of speakers.
Do you already have a calibrated mic for measuring to adjust crossover and ironing frequency response with the DSP? The UMIK-1 from MiniDSP.com is really excellent and very cheap for what you get and it has build-in power supply and USB-DAC, so you don't need a calibrated sound card and expensive additional power sources which you need for most other calibration mics. Every mic comes with unique calibration file. If you don't have one I do highly recommend it.
Theoretically you could use one 2x4 miniDSP for two 2-ways speakers and save costs, though it would need additional cables of course 😉
Several people have build really awesome speakers with these miniDSP's, also 4-way etc.
https://www.youtube.com/watch?v=bQPK-5lAIFY
As power source you could use an universal 24V 150W power supply like that one (15-20$) with a secondary 5V USB output
http://xtc.images.dp-tech.de/images/product_images/original_images/28564823_0.jpg
With the 5V 1A USB output you can power the DSP directly and they have low idle power consumption.
I don't know any cheap(er) solutions which contain an easily adjustable DSP and have good sound quality.
Texas Instruments and others have cheaper DSP's but you need a lot good informatical know-how (they are coming without any software etc.), some additional hardware to connect them to your computer and good soldering skills. The DSP's by MiniDSP can be programmed with provided software with an easy guided user interface and simply connected with USB. Even if you have the know-how how to program and setup plain DSP chips I would recommend to buy the DSP modules from miniDSP unless you want to build dozens of speakers.
Do you already have a calibrated mic for measuring to adjust crossover and ironing frequency response with the DSP? The UMIK-1 from MiniDSP.com is really excellent and very cheap for what you get and it has build-in power supply and USB-DAC, so you don't need a calibrated sound card and expensive additional power sources which you need for most other calibration mics. Every mic comes with unique calibration file. If you don't have one I do highly recommend it.
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Thank you for your recommendation. The TK2050 seems great.
I don't have a mic for a crossover. Why would I need one? I was thinking of just a simple 2500Hz or something, whatever that sounds good for my driver selection. The 2 channel amplifier is acting like an active crossover with one channel for each driver.
The MiniDSP is great, but it is an external solution. I'm looking for an internal DSP solution for this project. This is going to be a small speaker I'm bringing with me whenever I'm traveling, so the amplifier and DSP has to be in one package that'll fit inside a speaker.
I don't have a mic for a crossover. Why would I need one? I was thinking of just a simple 2500Hz or something, whatever that sounds good for my driver selection. The 2 channel amplifier is acting like an active crossover with one channel for each driver.
The MiniDSP is great, but it is an external solution. I'm looking for an internal DSP solution for this project. This is going to be a small speaker I'm bringing with me whenever I'm traveling, so the amplifier and DSP has to be in one package that'll fit inside a speaker.
Of course you could put one miniDSP into each speaker 😉 Problem solved 😉 the non-boxed 2x4 version a only about big as a package of cigarettes, you can easily fit them into almost any speaker
http://www.minidsp.com/products/minidspkits/2-x-in-4-x-out
(PS 80$, not 70$ 😉)
Also I think there's no serious alternative for you unless you want to spend much more or have serious skill in programming etc. to program and solder your own DSP chip
And about the mic - it depends a bit on your demands if you really need it. The great advantage of an measuring microphone ist that you can measure both distortion and frequency response of your drivers and also influence of housing - and with these infos and miniDSP you can optimize them all within minutes without opening the speaker (altering the volume inside etc.), soldering around on crossovers etc. and hours of tests with your ears 🙂
Some free software like REW can even automatically produce calibration files (maybe it can also even automatically generate files for optimal crossover, I don't know) which you can upload directly on your miniDSP which highly optimizes the frequency response (linearisation) and so on. And it can even help to put woofers into much smaller housings than they usually need to sound good - but it would take months to make it by hand without a mic. - a miniDSP and a calibration mic can make the difference between a "only usable speaker" and a high-end super-linear monitor HiFi speaker 😉
If you don't have high demands and it's all about a simple lets say 2500hz crossover only it would be much cheaper if you solder an simple passive 2-way crossover - it would only need a very few parts which are easy to solder together and cost only a few $.
http://www.minidsp.com/products/minidspkits/2-x-in-4-x-out
(PS 80$, not 70$ 😉)
Also I think there's no serious alternative for you unless you want to spend much more or have serious skill in programming etc. to program and solder your own DSP chip
And about the mic - it depends a bit on your demands if you really need it. The great advantage of an measuring microphone ist that you can measure both distortion and frequency response of your drivers and also influence of housing - and with these infos and miniDSP you can optimize them all within minutes without opening the speaker (altering the volume inside etc.), soldering around on crossovers etc. and hours of tests with your ears 🙂
Some free software like REW can even automatically produce calibration files (maybe it can also even automatically generate files for optimal crossover, I don't know) which you can upload directly on your miniDSP which highly optimizes the frequency response (linearisation) and so on. And it can even help to put woofers into much smaller housings than they usually need to sound good - but it would take months to make it by hand without a mic. - a miniDSP and a calibration mic can make the difference between a "only usable speaker" and a high-end super-linear monitor HiFi speaker 😉
If you don't have high demands and it's all about a simple lets say 2500hz crossover only it would be much cheaper if you solder an simple passive 2-way crossover - it would only need a very few parts which are easy to solder together and cost only a few $.
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I never knew the miniDSP is available in a board. So far I know knew it as a "in a box" solution!
I think the miniDSP is overkill for my applications, but I think I need a DSP. Besides using it as an active crossover, I want to boost the bass response, apply a high pass filter, and apply a limiter to protect the driver and limit distortion.
EDIT: Can't I use one miniDSP for both speakers? $80 is a stretch, but its a lot more tolerable than $160 for 2 speakers.
I think the miniDSP is overkill for my applications, but I think I need a DSP. Besides using it as an active crossover, I want to boost the bass response, apply a high pass filter, and apply a limiter to protect the driver and limit distortion.
EDIT: Can't I use one miniDSP for both speakers? $80 is a stretch, but its a lot more tolerable than $160 for 2 speakers.
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Noob detected 😀
You have lots of options available to you.
Why do you need that much power? Have you already purchased drivers?
If you're looking for a simple portable have you considered a full range speaker solution?
No crossover, one stereo amp, easy and cheap 🙂
If you want more power handling just make a castle style arrangement (one driver at the front and one on top) or bipole (one driver at the front and one at the back)
You have lots of options available to you.
Why do you need that much power? Have you already purchased drivers?
If you're looking for a simple portable have you considered a full range speaker solution?
No crossover, one stereo amp, easy and cheap 🙂
If you want more power handling just make a castle style arrangement (one driver at the front and one on top) or bipole (one driver at the front and one at the back)
Noob reporting in!
I was thinking of 100 watts because realistically I only need about 60 watts, but a 100 watt amp should be able to provide a clean 60 watts to the drivers.
The driver I'm thinking of is 2 Dayton Audio ND105 in a dual opposed configuration. Each of them can handle 30 watts. The tweeter is undecided so far.
I can't use full range speakers. One of the main reasons for this project is to build a small speaker with as much usable bass to about 50Hz as possible. They will be in an undersized enclosure for sure, but they will have passive radiators supporting them. However, even with PRs, they still need some EQ to be flat to around 50Hz.
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Do you want to make portable (battery powered) speakers? Than there would be better options than TK2050 boards.
Yes you can use one miniDSP for 2 speakers - you could build in the miniDSP into one speaker and connect both speakers with any simple stereo cable.
And as said I don't know any cheaper DSP's which can be handled by normal amateurs.
PS: I've just seen that the miniDSP is working from 4.5-24V, so you could use any power supply with <=24V and enough A and don't need one with an additional 5V out or step-down module etc.
Yes you can use one miniDSP for 2 speakers - you could build in the miniDSP into one speaker and connect both speakers with any simple stereo cable.
And as said I don't know any cheaper DSP's which can be handled by normal amateurs.
PS: I've just seen that the miniDSP is working from 4.5-24V, so you could use any power supply with <=24V and enough A and don't need one with an additional 5V out or step-down module etc.
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No. This will be outlet powered. It might be an interesting project after I have the outlet powered version working. Having a miniDSP controlling both speakers would be ideal for many reasons.
You can use miniDSP all the way with the MiniAmp. 4 channels 10W's each. can be bridged, all with one power supply (or battery)
Side info:
If you want to build battery powered speakers you need an amp with high efficiency and low idle power. The TK2050 is very effiecient but only when used at highest volumes, at lower volumes quite high idle power of a few watts (~3-4W or something like that) is draining batteries faster than necessary. For mid-sized and huge mobile battery powered speakers I would recommend TK2020 based boards like that from Muse (22,5WRMS/Channel from 12V) - they need much less idle power.
Do you know about connectivity from watts to loudness?
50W upgrade to 100W brings only +3db while double loudness for human ears is about +9db (=400W!!!), so you need about exponentially more watts eg you get exponentially less battery lifetimes for double loudness.
That's also why when you attach a second speaker it doesn't sound double as loud, it's only +3db aswell.
If you want to play loud it's better to a) buy more efficient drivers (some have 80db/W, others have 95db/W - so with more efficient drivers you can get the same out of 20W amp what other get out of their 500W amp) or b) use more driver within the same speaker (two 8ohm drivers in parallel are bringing +6db, in a row +3db) or c) use bass reflex housings (usually around +4db, theoretically up to +6db)
With a pair of drivers/speakers with good efficienciy like 89db/1W/1m or more with a "small" 2x22WRMS amp is more than enough indoors in 30m² rooms that you can't talk to each other anymore 😉
A good example for an quite effective mobile speaker is the famous "Boominator" which uses "trick" a) and "trick" b)... here have look what <2x20W can deliver https://www.youtube.com/watch?v=9H6SINd96UY
If you want to build battery powered speakers you need an amp with high efficiency and low idle power. The TK2050 is very effiecient but only when used at highest volumes, at lower volumes quite high idle power of a few watts (~3-4W or something like that) is draining batteries faster than necessary. For mid-sized and huge mobile battery powered speakers I would recommend TK2020 based boards like that from Muse (22,5WRMS/Channel from 12V) - they need much less idle power.
Do you know about connectivity from watts to loudness?
50W upgrade to 100W brings only +3db while double loudness for human ears is about +9db (=400W!!!), so you need about exponentially more watts eg you get exponentially less battery lifetimes for double loudness.
That's also why when you attach a second speaker it doesn't sound double as loud, it's only +3db aswell.
If you want to play loud it's better to a) buy more efficient drivers (some have 80db/W, others have 95db/W - so with more efficient drivers you can get the same out of 20W amp what other get out of their 500W amp) or b) use more driver within the same speaker (two 8ohm drivers in parallel are bringing +6db, in a row +3db) or c) use bass reflex housings (usually around +4db, theoretically up to +6db)
With a pair of drivers/speakers with good efficienciy like 89db/1W/1m or more with a "small" 2x22WRMS amp is more than enough indoors in 30m² rooms that you can't talk to each other anymore 😉
A good example for an quite effective mobile speaker is the famous "Boominator" which uses "trick" a) and "trick" b)... here have look what <2x20W can deliver https://www.youtube.com/watch?v=9H6SINd96UY
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Yes I understand the relationship between power and decibels very well, as well as driver and cabinet efficiency. The battery life wouldn't be very long at all, like under an hour, and I know that, as the drivers and EQ I'm planning on using is just insanely inefficient. That's why that would be a second project, where I would really have to think about the compromises needed to be made for a battery powered speaker.
But right now I just want to get a powered version working.
I'm wondering, are there any amplifiers that don't use a big power brick transformer? Most of the powered speakers/monitors don't use a power brick for their speakers, and I doubt they fit one inside. 2x 100 watt transformers or a single 200 watt transformer would be big, and as a travel speaker, I'd like to minimize the number of components if possible.
But right now I just want to get a powered version working.
I'm wondering, are there any amplifiers that don't use a big power brick transformer? Most of the powered speakers/monitors don't use a power brick for their speakers, and I doubt they fit one inside. 2x 100 watt transformers or a single 200 watt transformer would be big, and as a travel speaker, I'd like to minimize the number of components if possible.
The efficiency of that system is certainly impressive. I'm guessing it is some sort of dual opposed 8'' pro woofers on each side. The efficiency should reach around 96dB/1W/1m or so, but it is massive, and it has effectively no bass response below probably 70Hz or so.
For my build, I don't give a crap about efficiency. I'm sacrificing efficiency for ultra small size and extended bass response because size and good sound quality and bass at normal volumes is what is most important to me. I'm going so far as to planning to contact an OEM to make a custom oval passive radiator for this build. I'm quite limited by maximum SPL (still probably much louder than any sound dock of its size on the market), but with normal playback volume, the bass response should be extremely impressive for its tiny size.
Is there a guide on how to use amplifier boards and hook them up to speakers? I have no idea what to do as I've never dealt with onboard amplification before.
Thanks.
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Dual bipolar 10" pro woofers actually. 101dB/w/m sensitivity and -3dB at E2 or 82Hz. It's got oceans of deep solid bass though.
Aim for -3dB at around A2 or 110Hz then.
If the board has input caps which are large enough a 24V 150W like I've linked a pic of in my first answer should be enough and is compact.
You will rarely listend to sinus-signals at max volume, right? 😉
Real music is using the let's say max. 100W/channel only a a few ms at a time - and a 150W PSU which can be easily enough for 2x100W channels as you have capacitors betwen them which are buffering the energy needed. If you get any problems with such a PSU (which I doubt) you could solder one or two 35V 6800µF Nichion Capacitors in parallel.
I'm going for a F3 of 45Hz through a combination of PR's tuned to 45Hz and EQ boosts and high pass filter around 40Hz.
Yeah as long as the caps can store some power for the peaks then 150 watts will easily be fine. Since there are 2 woofers in each speaker, and I'm running 2 drivers in a single channel, I'd be pushing the limits of the channel driving both woofers, and the other channel driving the tweeter would be mostly idle.
Since there are 2 woofers in one channel, and I'll be adding around 10dB of bass boost on the DSP, it isn't too difficult to max out the 50 watt/channel. I hope it has some good peak power capabilities. I may consider adding another amplifier just for the tweeter so the 2 woofers can each have one channel and get 50 watts each instead of sharing 50 watts, but I may not have the space to do that.
Yeah as long as the caps can store some power for the peaks then 150 watts will easily be fine. Since there are 2 woofers in each speaker, and I'm running 2 drivers in a single channel, I'd be pushing the limits of the channel driving both woofers, and the other channel driving the tweeter would be mostly idle.
Since there are 2 woofers in one channel, and I'll be adding around 10dB of bass boost on the DSP, it isn't too difficult to max out the 50 watt/channel. I hope it has some good peak power capabilities. I may consider adding another amplifier just for the tweeter so the 2 woofers can each have one channel and get 50 watts each instead of sharing 50 watts, but I may not have the space to do that.
For quick/cheap system I'd personally throw together:
- TPA3116 card - can't really make any recommendations, but I'm sure the gang on the TPA3116 thread will have a few. Get one with a standby switch, and try to get one without any status LEDs or other circuitry that'll draw standby power. If you can get one with switchable frequency and BD/1SPW mode, get that one.
- A 6S (21.6V) lipo RC battery pack, make sure it's a protected one. Lots of choices up on Hobbyking.
- Bits to make a power cable with connectors that plug into the battery leads and the amp.
- An Imax B6-AC or similar charger to charge the battery. Pull the battery out of the system to charge it.
I think trying to produce audio content at less than 60-70hz in a portable system is pretty much useless, especially if it's going to be used in an open listening environment. You won't exactly have anyone feeling bass outdoors.
- TPA3116 card - can't really make any recommendations, but I'm sure the gang on the TPA3116 thread will have a few. Get one with a standby switch, and try to get one without any status LEDs or other circuitry that'll draw standby power. If you can get one with switchable frequency and BD/1SPW mode, get that one.
- A 6S (21.6V) lipo RC battery pack, make sure it's a protected one. Lots of choices up on Hobbyking.
- Bits to make a power cable with connectors that plug into the battery leads and the amp.
- An Imax B6-AC or similar charger to charge the battery. Pull the battery out of the system to charge it.
I think trying to produce audio content at less than 60-70hz in a portable system is pretty much useless, especially if it's going to be used in an open listening environment. You won't exactly have anyone feeling bass outdoors.
I agree. I've used a $600 home audio subwoofer outdoors and it just barely had enough bass for normal volume.
However, this speaker is designed to be used in a room, connected to an outlet. The battery would have to be enormous to drive these speakers for just a few hours. Also, with 4 drivers with 20mm of xmech each in vented enclosures, they should have as much bass as a decent 8'' woofer.
Oh, if you're plugging it into a wall - Connexelectronic - plenty of cheap amplifier modules, power supplies and even combos available.
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