ultimate low cost FR system

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I guess I mean passives. You would be looking at the same thing as a two-way speaker with an internal crossover, except the Fostex would be in one box and the woofer would be in another, and you would have four speaker wires running from the panny for both channels. The thing I don't know is if the Panny would handle the crossover work. We already know the Panny has bass management in multi-channel use but does it do it in two-channel, bi-amped mode?

As for expense, sure, you could spend $500 building a passive crossover for a two-way speaker. You could also do it for $20. Depends on how much money you have.

Regal, my entire input in this thread is based on the idea of bypassing the plate amp on the subs entirely by using the bi-amp mode on the Panny. Everything you wrote in your first post made excellent sense. I'm just seeing if it can be done even simpler and cheaper.

Doug
 
The Behringer 2496 puts it out of what I consider, budget territory. I looked at buying one previously, but I can't find it for under $230 anywhere and I've got more important things to buy before I drop that kind of money on an equalizer.

As for cheap amplification for the subwoofer, why not use one of the more robust Tripath based designs from 41hz.com? An Amp1 or Amp2 would have plenty of power for a pair of subwoofers. They're pretty cheap and power efficient too.

Considering a budget solution would use a driver along the lines of a 126/127 or 166/167 (which is pushing it for a budget system), you'd want to cross it in the 100-200 range, which means you'd probably want stereo subs. Crossing at 150-200 would make passive affordable, much more so than using a Behringer. Sure, you wouldn't have all the equalization, but you're looking at doubling cost of the system if you go the active route.

Then again, there are always plate amps that do a decent job. Pair it with a Tripath amp for the Fostexes and you're good to go for a pretty small sum of cash.
 
The other issue with using a passive crossover would be matching the SPL og the fostex with a sub it would probably require alot of attenuation which may take some of the majic away from the fostex.

I am going to try this with a plate amp at 150hz but it will be mono but I will using 2 subs one under each speaker so localization won't be a problem. I really don't think there is much stereo material on recordings below 200hz. If I don't like the way it sounds I can lower the crossover to 100hz and build BR boxes for the fostex's in lieu of sealed .


Funny you mentioned the AMP1 at 41hz.com. I looked into it but building a power supply isn't something I am up to. It requires an oddball expensive torroidal transformer (22x2V 300VA) that costs more than the panasonic reciever alone.
 
A cheap Yamaha computer sub I bought off ebay has an adjustable crossover, and it works on both speaker level inputs and line level inputs. So if almost every plate amp ever made has an adjustable crossover, why would it be so hard to build your own and then use the Panny's amps to drive the subs?

This is where I stumble on this whole idea. Why buy more amplification when the Panny (for example) has seven amplifiers?

We're still talking about a low-cost, two-channel music setup, right?

Doug
 
I was thinking a sub amp and T-amp combo, rather than use the Panasonic in combination with another amp. I'd rather not use the Panasonic at all.

But I think amplification is a totally separate issue. I think the main purpose should be to select drivers and enclosure(s). You can amplify the system however you like. At this point the bass driver to be used hasn't even been established yet and the use of the Fostex FE126E/127E is still tentative, and it'll probably be in a sealed, but maybe it'll be in a BR enclosure. Of indeterminate design. And yet crossovers and amplification are already being decided upon. Though no one knows what it's going to be powering yet. I got caught up in it, but shouldn't the drivers and enclosure be decided upon first?
 
I'm trying to get my head around all this. This is what I learned tonight:

For proper bi-amping, the crossover comes before the amp. Example: Source/preamp-->crossover-->amp--->driver.

So unless the panasonic does active filtering in bi-amp mode, it would not work. I was thinking you could just stick the crossover in the speaker wire to each driver, like a passive crossover. This won't work as you lose all the benefits of directly amplifying each driver.

It seems to me the crossover is the all-important link in this chain. After the crossover, you can use any amp for the drivers.

I checked prices on active crossovers. The Behringer is so popular because it is about the cheapest available. There are some kits, however, as low as $75, but you can't just turn a dial with these.

A plate amp with a both a high and low-pass filter would be ideal (you chose which one you want). Four of those, and you would be in business...I think :xeye:

Doug
 
regal said:
I don't think anything can compare to a fostex up to 10x the cost as far as the fostex drivers. This system I propose is not a true single driver system but I believe it makes more sense than TL or horns. The technology is there why not use it?

Start with a panasonic digital reciever SA-XR25,45,50,55,70. These are highly regarded.



I am using the SA-XR30 with the Ciare CH250 and I tried it with the FE126. The Fostex doesn`t come close to the Ciare in detail resulution, no chance. I never heard the larger fostexes, only a 16cm custom made by Fostex for Loth-X and its resolution isn`t so good, either. I don`t have woofers, yet, but I am considering the Eminence Alpha 15 in OB.
 
JWFokker said:
I was thinking a sub amp and T-amp combo, rather than use the Panasonic in combination with another amp. I'd rather not use the Panasonic at all.

But I think amplification is a totally separate issue. I think the main purpose should be to select drivers and enclosure(s). You can amplify the system however you like. At this point the bass driver to be used hasn't even been established yet and the use of the Fostex FE126E/127E is still tentative, and it'll probably be in a sealed, but maybe it'll be in a BR enclosure. Of indeterminate design. And yet crossovers and amplification are already being decided upon. Though no one knows what it's going to be powering yet. I got caught up in it, but shouldn't the drivers and enclosure be decided upon first?


I tested the T-Amp, really not bad for the money, but don`t compare it with a Panasonic. When it has to be the T-Amp the small fostexes are a good solution, better than the Ciares. In contrast to the T-Amp the Panasonic has variable voltage for the output transistors an will sound good at any level.
 
I hope you're not referring to the stock Sonic Impact T-Amp. In it's stock form, it's very good for the money, but not great. The Sonic Impact amp uses pretty cheap parts. You should look into trying a higher quality Tripath amp, along the lines of an Amp3 or Amp6 from 41hz.com or the Tripath based amp from DIYParadise.com.

http://www.41hz.com/main.aspx?pageID=105
http://www.41hz.com/main.aspx?pageID=118
http://www.diyparadise.com/charlize.html

Of course, the Amp3 is primarily SMD based, so unless you're into that sort of thing, it's a PITA. I toasted mine because I don't have the hardware to assemble SMD parts. I did make a number of modifications to a Sonic Impact T-Amp, and the result was considerably better than stock form. With an Amp3/Amp6 or the Charlize amp, no modification would be necessary. I plan on picking one up in a couple weeks to replace my modded T-Amp.


As for the Ciare CH250, the comparable Fostex would be the FE206. It's quite similar in size, design and efficiency. However, it's about 3x the price. I don't doubt the Ciare is better than the FE126. The problem I have with the Ciare is that it's only available in Europe. It looks like it's a good deal at about 50 Euros (what I was able to find), but I can't get it, as I'm in the US. Fostexes are available worldwide however.
 
JWFokker said:
I hope you're not referring to the stock Sonic Impact T-Amp. In it's stock form, it's very good for the money, but not great. The Sonic Impact amp uses pretty cheap parts. You should look into trying a higher quality Tripath amp, along the lines of an Amp3 or Amp6 from 41hz.com or the Tripath based amp from DIYParadise.com.

http://www.41hz.com/main.aspx?pageID=105
http://www.41hz.com/main.aspx?pageID=118
http://www.diyparadise.com/charlize.html

Of course, the Amp3 is primarily SMD based, so unless you're into that sort of thing, it's a PITA. I toasted mine because I don't have the hardware to assemble SMD parts. I did make a number of modifications to a Sonic Impact T-Amp, and the result was considerably better than stock form. With an Amp3/Amp6 or the Charlize amp, no modification would be necessary. I plan on picking one up in a couple weeks to replace my modded T-Amp.




But then you still have the problem that you need the right voltage for your speakers and listening habits, and the player will cost more than a Panasonic plus drive.
 
JWFokker said:

Of course, the Amp3 is primarily SMD based, so unless you're into that sort of thing, it's a PITA. I toasted mine because I don't have the hardware to assemble SMD parts. I did make a number of modifications to a Sonic Impact T-Amp, and the result was considerably better than stock form. With an Amp3/Amp6 or the Charlize amp, no modification would be necessary. I plan on picking one up in a couple weeks to replace my modded T-Amp.


Is the AMP3 really that easy to toast?
 
el`Ol said:



But then you still have the problem that you need the right voltage for your speakers and listening habits, and the player will cost more than a Panasonic plus drive.

What are you talking about with the voltage? The Amp3/Amp6/Sonic Impact T-Amp use 12-13.5V regardless of speakers and listening habits. And I don't know how you figure it'd be more expensive. An Amp3 is $25 and another $20-30 for the power supply. The cheapest Panasonic XR25 I found was $210. I think you can find a good player for under $160.

soongsc said:


Is the AMP3 really that easy to toast?

Only if you try to build it with a 30W iron that wasn't ever intended for use with SMDs. I got it about halfway done, then got a couple parts stuck to the iron and toasted them. I should really have used epoxy and an iron meant for SMDs, but I was impatient.
 
A class D amp works like a DAC. It has full dynamic range only when it is used at full volume. The volume control of a Tripath amp is done with a preamp or a potentiometer, the rail voltage is constant, and you have full dynamic range only when your desired max. output voltage is close to the rail voltage. The TacT Millenium and the Panasonics derived from it change the volume by changing the rail voltage and make use of the full dynamic range no matter what the desired max. output voltage is.
I would be curious to hear about good players for 150$.
 
el`Ol said:
A class D amp works like a DAC. It has full dynamic range only when it is used at full volume. The volume control of a Tripath amp is done with a preamp or a potentiometer, the rail voltage is constant, and you have full dynamic range only when your desired max. output voltage is close to the rail voltage. The TacT Millenium and the Panasonics derived from it change the volume by changing the rail voltage and make use of the full dynamic range no matter what the desired max. output voltage is.
I would be curious to hear about good players for 150$.

Which Panasonic models use class D?

I wonder if the 41Hz amps can be modified to do that easily.
 
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