I have made a BTL amplifier by the India famous Sanyo LA4440 chip. I used two ICs for stereo operation. Each one is capable of delivering 19W RMS power by operating with 12-0 5A single supply transformer. I am now about to make the boxes for it. Can you suggest that how much wattage of Woofer and Tweeter should be used for this? Any other suggestion regarding speakers are welcome.
Another question is, I want to make small bookshelf type encloser for this project with 4-inch woofer and 1-inch tweeter. Can anyone from India/Kolkata confirm me that do Sweton (speaker maker of Kolkata) have products like 1-inch tweeter? Do anyone have the detailed specification of sweton woofer and tweeter like frequency range, Equivalent volume (Vas), Free air resonance (Fas), Total Q (Qts) etc so that i can design the encloser using these Thiele/Small parameters and as well as the crossovers too?
Another question is, I want to make small bookshelf type encloser for this project with 4-inch woofer and 1-inch tweeter. Can anyone from India/Kolkata confirm me that do Sweton (speaker maker of Kolkata) have products like 1-inch tweeter? Do anyone have the detailed specification of sweton woofer and tweeter like frequency range, Equivalent volume (Vas), Free air resonance (Fas), Total Q (Qts) etc so that i can design the encloser using these Thiele/Small parameters and as well as the crossovers too?
4" Woofers
For a 4"" woofer you have a woofer for sealed speaker 7-12L
(ref: 4" IWAI Woofer Fs=100Hz, Former/Aluminum)
Iwai Electronics Pvt. Ltd.
And a reflex speaker driver for a 6-10L net (BR) plus space for port and internals.
(ref: 4" IWAI Woofer Fs=80Hz, Former/Kapton)
Iwai Electronics Pvt. Ltd.
Tweeters:
Crossing low, Resonance Frequency 950 Hz
Iwai Electronics Pvt. Ltd.
Or with higher Fs (~1400Hz) and round face plate
Iwai Electronics Pvt. Ltd.
For a 4"" woofer you have a woofer for sealed speaker 7-12L
(ref: 4" IWAI Woofer Fs=100Hz, Former/Aluminum)
Iwai Electronics Pvt. Ltd.
And a reflex speaker driver for a 6-10L net (BR) plus space for port and internals.
(ref: 4" IWAI Woofer Fs=80Hz, Former/Kapton)
Iwai Electronics Pvt. Ltd.
Tweeters:
Crossing low, Resonance Frequency 950 Hz
Iwai Electronics Pvt. Ltd.
Or with higher Fs (~1400Hz) and round face plate
Iwai Electronics Pvt. Ltd.
The 4440 is
a) probably fake, Sanyo hasn't made these in 20 years
b) not 19W but closer to 10 decent watts per channel, look at the datasheet
You need a fairly high-sensitivity speaker for an amplifier like this so that you get a lot of acoustic output for the limited amount of electrical power it is capable of.
In a car (where this was meant to be used) you have cabin gain that adds ~6dB. In a room, this small and amp isn't going to get very far. Don't worry about 'watts' in a speaker, it is a figure that has very little to do with actual SPL capabilities or power handling ability. It indicates the maximum thermal handling ability of the speaker voice coil, though in most speakers you will exceed the mechanical suspension limits long before you get there.
Consider using professional speakers. All brands are quite easy to find, and finding data for them should not be too difficult. They are robust and will be able to handle the abusive clipping these little chips are going to subject them to.
Sweton etc would give you strange looks if you asked them about T/S parameters. Those guys just know how to glue a speaker together. And not that well either. Same story for almost any driver you can easily find locally.
I get some of my drivers from sites within India, or distributors of pro drivers - Eminence. Beyma, PRV, JBL Pro, P audio are all available quite easily and for the high end models most distributors will deal with you directly.
a) probably fake, Sanyo hasn't made these in 20 years
b) not 19W but closer to 10 decent watts per channel, look at the datasheet
You need a fairly high-sensitivity speaker for an amplifier like this so that you get a lot of acoustic output for the limited amount of electrical power it is capable of.
In a car (where this was meant to be used) you have cabin gain that adds ~6dB. In a room, this small and amp isn't going to get very far. Don't worry about 'watts' in a speaker, it is a figure that has very little to do with actual SPL capabilities or power handling ability. It indicates the maximum thermal handling ability of the speaker voice coil, though in most speakers you will exceed the mechanical suspension limits long before you get there.
Consider using professional speakers. All brands are quite easy to find, and finding data for them should not be too difficult. They are robust and will be able to handle the abusive clipping these little chips are going to subject them to.
Sweton etc would give you strange looks if you asked them about T/S parameters. Those guys just know how to glue a speaker together. And not that well either. Same story for almost any driver you can easily find locally.
I get some of my drivers from sites within India, or distributors of pro drivers - Eminence. Beyma, PRV, JBL Pro, P audio are all available quite easily and for the high end models most distributors will deal with you directly.
sangram I know about the situation of local speakers available in kolkata. Basically I dont want to spend a lot of money for this outdated amplifier, though its still very famous here. I want a error-less design of box. These parameters can be measured manually. Just searching anyone has done or not. Though, frequency range cannot be calculated
Is it difficult, for you to receive a package from another city in the country?😱 (vasai , near mumbai)
LA4440 obviously provide 19W RMS out when tied with 4 ohm load in Bridge mode. Datasheet clearly state this. Even the graphs of bridge mode operation supports this data.
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In kolkata its a usual practice to use 40W woofer with 40W tweeter (both having unknown specifications) with this system. In this configuration of speakers, it can handle 40Wx4=160W 😱 of power reception in total in stereo configuration. The practice of using 12V-5A transformer is also very common. This transformer gives maximum 60W RMS power, where two LA4440 is capable of using 19wx2=38W energy. The extra 22W 😱 energy is probably kept for transient peak responses, such peak wattage is pretty obscure for this small powered IC. Datasheet is silent about the peak response of this IC. Anyway, if we consider the whole system can deliver max 60W peak power, use of such speaker system which can receive 160W is not a wastage of money? The total speaker wattage should be equal or just higher to the peak wattage of machine. Am I right?
Another thing is the use of same wattage of tweeter and woofer. Tweeter receives less power from amplifier than woofer in presence of crossover. So why to use same wattage rating for both?
For the above two reasons I asked for the wattage of speakers.
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I have not bought any first hand product from outside my city except by online purchase where delivery is guaranteed. Not every retailer entertain by-post delivery
hi anirban,
u can try the IWAI speakers, they look good and are decently made with T/s parameters , i myself is planning on buying some from them ..last time i asked for a quote for subwoofwers they were pretty quick .And some indian and international manufacturer do use their drivers I think...
regards
u can try the IWAI speakers, they look good and are decently made with T/s parameters , i myself is planning on buying some from them ..last time i asked for a quote for subwoofwers they were pretty quick .And some indian and international manufacturer do use their drivers I think...
regards
My usual practice when using local speakers is to buy the cheapest possible, because they are cheap, rubbish and they always break. Its no surprise that no one has tried to measure them. Anyway, since you asked...
Speakers draw power, not 'receive' it. By varying the volume control you increase the voltage across the speaker, and the speaker draws current depending on its impedance. The speaker is therefore a 'consumer' of power.
The power rating on the label usually means the thermal power handling ability of the voice coil. Good woofers usually also have sufficient parameters available to compute the maximum excursion possible with a given air volume in your box, so you will be able to arrive at a mechanical power handling limit. This is usually quite low for small drivers.
A speaker capable of handling 30w may be used with a 100w amplifier most of the time without problems, the other way around may be actually more of an issue. It is far easier to hear a speaker in distress than an amplifier in clipping, and clipping is what kills tweeters.
Tweeter power ratings are usually for system power, not driver power handling. In any case it is fairly easy to hear distortion in speakers. If it's too loud, turn it down.
The LA4440 data sheet show the 19w output with 10% THD I did say it produces 10 good watts, I don't consider 10% THD as good. It is not possible for that chip to swing more than ten volts across the load and there's obviously massive sag when then load dips to 4 ohms.
If the amp is cheap and you don't want to spend, just get a pair of the Boston Acoustic (nee Philips} full range drivers and pop them in a box. Will be cheap and efficient, and the speakers will not be the weak link in the chain. There's worse ways to spend your money.
Peerless India drivers may be purchased from online sites who deliver by courier to this city. Diyaudiocart and Theaudiocrafts come to mind - add the .com suffix. Both sites also have some decent imported drivers. Some Peerless Denmark woofers are also stocked by a store in the Chandni area, but good tweeters are not available anywhere.
Good luck!
Speakers draw power, not 'receive' it. By varying the volume control you increase the voltage across the speaker, and the speaker draws current depending on its impedance. The speaker is therefore a 'consumer' of power.
The power rating on the label usually means the thermal power handling ability of the voice coil. Good woofers usually also have sufficient parameters available to compute the maximum excursion possible with a given air volume in your box, so you will be able to arrive at a mechanical power handling limit. This is usually quite low for small drivers.
A speaker capable of handling 30w may be used with a 100w amplifier most of the time without problems, the other way around may be actually more of an issue. It is far easier to hear a speaker in distress than an amplifier in clipping, and clipping is what kills tweeters.
Tweeter power ratings are usually for system power, not driver power handling. In any case it is fairly easy to hear distortion in speakers. If it's too loud, turn it down.
The LA4440 data sheet show the 19w output with 10% THD I did say it produces 10 good watts, I don't consider 10% THD as good. It is not possible for that chip to swing more than ten volts across the load and there's obviously massive sag when then load dips to 4 ohms.
If the amp is cheap and you don't want to spend, just get a pair of the Boston Acoustic (nee Philips} full range drivers and pop them in a box. Will be cheap and efficient, and the speakers will not be the weak link in the chain. There's worse ways to spend your money.
Peerless India drivers may be purchased from online sites who deliver by courier to this city. Diyaudiocart and Theaudiocrafts come to mind - add the .com suffix. Both sites also have some decent imported drivers. Some Peerless Denmark woofers are also stocked by a store in the Chandni area, but good tweeters are not available anywhere.
Good luck!
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