3mm stroke? 100 cubic feet to get down to 16hz? Doesn't really sound suited to this application.
How do people feel about amps that don't have a power transformer?
I'm poking around, seeing that other people have used the 18" Avalanche driver. Was there a link for that manuf and vendor, did I miss it?
I'm seeing that some people are using amps that don't seem to have a power transformer, unisolated.
I've seen things sold like this.
In my understanding, drivers are not make to provide absolute line voltage isolation.
I guess you could try to provide it in the enclosure. I still feel uncomortable about it. How do other people feel?
I'm poking around, seeing that other people have used the 18" Avalanche driver. Was there a link for that manuf and vendor, did I miss it?
I'm seeing that some people are using amps that don't seem to have a power transformer, unisolated.
I've seen things sold like this.
In my understanding, drivers are not make to provide absolute line voltage isolation.
I guess you could try to provide it in the enclosure. I still feel uncomortable about it. How do other people feel?
Unisolated amplifiers
Although this is a topic for another section of the forum, practically all home PC's do not use power transformers, they use isolated switching power supplies instead. Having a power amplifier supply hooked up directly to the AC mains can be done, but not without extreme attention being paid to isolating the AC mains from the audio feed, and preventing human contact with the high voltage. Speakers are not designed for isolation from the AC mains. Safety would be my main concern. I suppose it can be done, but I would want UL approval on anything I would consider buying.
Although this is a topic for another section of the forum, practically all home PC's do not use power transformers, they use isolated switching power supplies instead. Having a power amplifier supply hooked up directly to the AC mains can be done, but not without extreme attention being paid to isolating the AC mains from the audio feed, and preventing human contact with the high voltage. Speakers are not designed for isolation from the AC mains. Safety would be my main concern. I suppose it can be done, but I would want UL approval on anything I would consider buying.
Don't even think about it. Death is very permanent.please, please, please, explain to me why sy. I am seriously in the dark on this issue and have never had a reply to this question that I respect.
Lay it on me brother.
Lay it on me brother.
Woa! REK, a PC does have isolation from the power mains throughout.
The isolation is obtained by a transformer, but it is a high frequency transformer.
The input part of the switching power supply is not isolated. That does rectification and coarse filtering. Then there is a multivibrator or oscillator. This goes into a transformer which meets UL specs. It is not a laminated core or big transformer. It is little. Everything from there on is isolated.
There is some control information which comes back to the multivibrator, but that control signal has either magnetic or optical isloation. So all the wires coming out of the switching power supply are isolated from the power mains.
Other wise they would not be able to allow people to take the covers off of PCs and plug boards in.
As far as audio power amps, traditionally they have always had isolating power transformers. I am seeing some now that don't seem to. They are always used in powered speakers.
I am not comfortable with this.
The isolation is obtained by a transformer, but it is a high frequency transformer.
The input part of the switching power supply is not isolated. That does rectification and coarse filtering. Then there is a multivibrator or oscillator. This goes into a transformer which meets UL specs. It is not a laminated core or big transformer. It is little. Everything from there on is isolated.
There is some control information which comes back to the multivibrator, but that control signal has either magnetic or optical isloation. So all the wires coming out of the switching power supply are isolated from the power mains.
Other wise they would not be able to allow people to take the covers off of PCs and plug boards in.
As far as audio power amps, traditionally they have always had isolating power transformers. I am seeing some now that don't seem to. They are always used in powered speakers.
I am not comfortable with this.
I thought the Marin Colloms book covered the type of bandpass enclosure used by Bose.
I was wrong.
I think it is in another book by John Eargle. I'm going to try to find it.
Steve, did you post a link for your Avalanche 18" driver?
I was wrong.
I think it is in another book by John Eargle. I'm going to try to find it.
Steve, did you post a link for your Avalanche 18" driver?
I just read this whole post and all I have to say is HOLY S*&%. lol
Brian you could of built 2 LLT subs by now and could of brought your house down into rubble. 🙂
I got to give it up to Steve though, he held in there longer then anyone would of.
Good luck in your search for your new radical design.
peace
Brian you could of built 2 LLT subs by now and could of brought your house down into rubble. 🙂
I got to give it up to Steve though, he held in there longer then anyone would of.
Good luck in your search for your new radical design.
peace
I tried to look up Steve's Avalanche 18" driver. I can't find how makes and sells Avalanche.
I do see that lots of other people are using it.
8hz for the 64' organ octave is an unusual objective. But I think it worth considering.
Audiophile gear is not made according to a good enough, or just meet the specs. approach. It made by finding ways to extend the known limits.
I do see that lots of other people are using it.
8hz for the 64' organ octave is an unusual objective. But I think it worth considering.
Audiophile gear is not made according to a good enough, or just meet the specs. approach. It made by finding ways to extend the known limits.
Im betting that an 18'' Sonosub would do just fine for your application. If you still needed more Dicplacement after building one, you could make another and also enjoy the benifits of the sonic coupling.
I also wish you good luck in your search!
I also wish you good luck in your search!
tade, sorry to be so slow to respond. Travel has been rather intensive the past week.
In any case, a lamp is an insulated device with all wiring totally isolated from any metal touchable by a user. If there's a metal chassis, a three wire system is the only practical safety connection. Double-insulation will allow the use of a two wire system, but that is extremely difficult for a home constructor to do safely.
That said, you can certainly zap yourself by pulling out the bulb and sticking in a finger. But you can kill yourself just as easily with an IEC cord; in both these examples, death occurs by a deliberate act, not by accident.
In any case, a lamp is an insulated device with all wiring totally isolated from any metal touchable by a user. If there's a metal chassis, a three wire system is the only practical safety connection. Double-insulation will allow the use of a two wire system, but that is extremely difficult for a home constructor to do safely.
That said, you can certainly zap yourself by pulling out the bulb and sticking in a finger. But you can kill yourself just as easily with an IEC cord; in both these examples, death occurs by a deliberate act, not by accident.
What is a Sonosub driver??
Where can I find out about the Avalanche 18"
Someone posted a link to Elliot Sound products, which seems like a fascinating company.
But it was to a circuit board they have for going below fs. I can't seem to find that, either on this thread, or their web site.
As far as isolation from power mains: Lamp sockets are made to do such. It is not clear to me that a driver was ever inteded to be used that way. What isolation can you depend on between the voice coil and the metal basket.
Maybe if you depend on the cabinetry and an unremovable grill cloth?
Do you know what UL approvals there have been on such.
I agree, no power transformer certainly cuts the cost down. And if its class D, the power mains are a workable voltage. You still need isolation for the input signal.
You also need an isolation transformer for trouble shooting.
Where can I find out about the Avalanche 18"
Someone posted a link to Elliot Sound products, which seems like a fascinating company.
But it was to a circuit board they have for going below fs. I can't seem to find that, either on this thread, or their web site.
As far as isolation from power mains: Lamp sockets are made to do such. It is not clear to me that a driver was ever inteded to be used that way. What isolation can you depend on between the voice coil and the metal basket.
Maybe if you depend on the cabinetry and an unremovable grill cloth?
Do you know what UL approvals there have been on such.
I agree, no power transformer certainly cuts the cost down. And if its class D, the power mains are a workable voltage. You still need isolation for the input signal.
You also need an isolation transformer for trouble shooting.
heres the link to elliot sound http://sound.westhost.com/project48.htm
try the design it works great.
try the design it works great.
F1 Fan? What is F1? Do you mean the McLaren super car?
Oh, I guess you mean the Formula One class of racing.
I am really enjoying the Elliot Sound Products site.
I don't know why I couldn't find that page on it.
I also have not been able to find the page for the transconductance amp.
I like the way Elliot does things, publishing so much info.
I'm going to learn a great deal from his site.
I wish I was doing what he is doing.😎
Oh, I guess you mean the Formula One class of racing.
I am really enjoying the Elliot Sound Products site.
I don't know why I couldn't find that page on it.
I also have not been able to find the page for the transconductance amp.
I like the way Elliot does things, publishing so much info.
I'm going to learn a great deal from his site.
I wish I was doing what he is doing.😎
Hi Zen, yes the F1 is for the Formula One class of racing.
Rod Elliotts site has to be one of the best sources of audio info on the internet.
Rod Elliotts site has to be one of the best sources of audio info on the internet.
Has anyone seen this ad? They are claiming that it is the largest subwoofer in the world! AND YOU CAN OWN IT NOW!
but do tell if you buy it...
http://cgi.ebay.com/Audiobahn-Subwo...3QQihZ017QQcategoryZ18805QQrdZ1QQcmdZViewItem
Dominick
but do tell if you buy it...
http://cgi.ebay.com/Audiobahn-Subwo...3QQihZ017QQcategoryZ18805QQrdZ1QQcmdZViewItem
Dominick
Wow! That is the kind of driver I've been asking about. Notice, they say it goes down to 10hz. That is lower than most of the other ones that have been discussed here.
I believe there is increasing interest in this type of driver.
I believe there is increasing interest in this type of driver.
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