Several people have already provided explanations, but sometimes a picture helps the understanding.
The figure was created for a 4 ohm discussion in another forum, but the same principle applies for 8 ohm.
What the manual is saying is that the effective load on each amplifier channel is half of the load applied to the bridged configured amplifier.
Attached is a figure that compares voltage, current, and power output for stereo and bridged configurations.
Each channel still puts out the same voltage, but current has increases 2x.
Ohms Law for AC circuits tells you that the effective load on each amplifier channel has been halved.
With the 4 ohm load driven by equal and opposite voltages at its ends there is a virtual ground at the midpoint of the load.
You can think of it as replacing the 4 ohm load with 2 x 2ohm loads with the center point grounded.
Attachments
I bought several good quality quiet PC fans and found an old 12 volt power supply to power them and have them set on top of the amp, but I have had the thermal protection kick on on this amp if I'm not using the fans.
On a side not, are there any crossover layout pictures...I am kind of a "paint by numbers" kind of guy when it comes to wiring crossovers. 😉 I can figure it out but I was just wondering.
On a side not, are there any crossover layout pictures...I am kind of a "paint by numbers" kind of guy when it comes to wiring crossovers. 😉 I can figure it out but I was just wondering.
You've explained it better than I did. I guess the real implication is that an amp capable of say 100W per channel in non bridged mode cannot realistically be able to suddenly produce 400W in bridge mode. It would be unlikely that it's power supply would be capable of this. It's all about how much current it can deliver. You can't get something for nothing.
I guess I'm thinking that running one sounds sooo much better than any other amp I've used, will two be even better! So so tempting. Might be sending Mr Poon an email.
oh i hear you! after the first evening, i sent him an email letting him know i'd most likely be getting a 2nd this fall. pro'ly will, i mean if i'm thinking about it now, it's not likely that the bug will go away or lessen. that's not how this audio disease works...it's why i'm building a new subwoofer every year it seems.
'this is great, if i could just get a teeny bit more of it....'
cheers,
Scott
'this is great, if i could just get a teeny bit more of it....'
cheers,
Scott
So I've been going over your articles on your website Joe, because I have some basic crossover questions. The 1.8 uf cap I'm going with the Intertechnik Audyn True Copper Cap...it's a $70 cap I can get for $50... from Humble Homemade Hifi ( Very nice indeed and one of my personal favourites!)
So that's not a question... 😀
Here's my first question...does "bi-polar" mean "electrolytic". Example- https://wholesale.parts-express.com...ic-non-polarized-crossover-capacitor--027-360
Second question...this one is two parts...is the bottom pair of "midbass" the bass section?
I saw in the FAQ that "steel laminate" coils works fine for the bass section. Does that include all coils in the bass section? As I understand xovers...and again I know I may be wrong, 2 coils on the upper midbass are "LCR" circuits.
Here's the short question....where should I be most concerned about quality xover components besides the tweeter cap? (You can exclude resistors, I got that part... 😉 )
So that's not a question... 😀
Here's my first question...does "bi-polar" mean "electrolytic". Example- https://wholesale.parts-express.com...ic-non-polarized-crossover-capacitor--027-360
Second question...this one is two parts...is the bottom pair of "midbass" the bass section?
I saw in the FAQ that "steel laminate" coils works fine for the bass section. Does that include all coils in the bass section? As I understand xovers...and again I know I may be wrong, 2 coils on the upper midbass are "LCR" circuits.
Here's the short question....where should I be most concerned about quality xover components besides the tweeter cap? (You can exclude resistors, I got that part... 😉 )
It is a type of electrolytic, but not the same. Electros are normally polarised "+" and "-" and bi-polar are not. They are also sometimes called non-polar. Do NOT use a normal electro cap.
It's the bottom two drivers and they come in around 400 Hertz and below.
Air-cored coils would be huge and wasted money. 1) They are in series with an additional resistor, so low DC resistance is not required. 2) Each leg is nominally 16 Ohm and hence saturation/headroom very high. 3) Overall sensitivity is high. 4) They are effectively conjugates driven by the amplifier.. there are multiple reasons why laminated or cored coil is just fine.
Any component that is in series are the critical ones. You have identified the 1.8uF (and the 2R resistor after that), then the series 0.47mH coil, then the 4mH coil. In that order I would consider most important.
Cheers, Joe
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Excellent answer....thank you. ( I had to read it several times...but I got it!!!!)
I was only able to get one 1.8uf cap because it was the only one Parts Express had in stock, they are due in of the 19th of this month but I'm in no hurry!
I've decided I'm going to buy the best crossover parts I can where they matter! So thanks....3 good xover parts per side...wow...that's great!
Spend big (as you can) on those parts and less on the others. Everybody has a limit to their budget, so rather waste money on less important parts, better to put that on the more important parts.
I have to say that the Jantzen Superior Z-Cap is just great - especially shines with speakers. So I would go for that and it's not expensive.
Jantzen Superior Z-Cap 1.8uF:
Jantzen also makes a nice flat coil - get the 0.47mH:
Then I have used this P-Core 3.9mH and even though it is not air-cored, it works well and into a 16 Ohm leg - so I can't see it saturating:
Of course, they also make an air-cored 3.9mH, but it is quite pricey:
For the series 2R resistor to the Tweeter, I am using Dale CW-5 and again they are very reasonably priced.
There are of course other options, but the above I have actually used and can give the thumbs up.
You really don't have to pay crazy money to get top sound - lacking nothing.
For those in Australia, you can buy Jantzen from www.speakerbug.com.au
Cheers, Joe
.
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Spend big (as you can) on those parts and less on the others. Everybody has a limit to their budget, so rather waste money on less important parts, better to put that on the more important parts.
I have to say that the Jantzen Superior Z-Cap is just great - especially shines with speakers. So I would go for that and it's not expensive.
Jantzen Superior Z-Cap 1.8uF:
Jantzen also makes a nice flat coil - get the 0.47mH:
Then I have used this P-Core 3.9mH and even though it is not air-cored, it works well and into a 16 Ohm leg - so I can't see it saturating:
Of course, they also make an air-cored 3.9mH, but it is quite pricey:
For the series 2R resistor to the Tweeter, I am using Dale CW-5 and again they are very reasonably priced.
There are of course other options, but the above I have actually used and can give the thumbs up.
You really don't have to pay crazy money to get top sound - lacking nothing.
For those in Australia, you can buy Jantzen from www.speakerbug.com.au
Cheers, Joe
.
I've already bought the flat .47mh coils...and I went with the Audyn True Copper Cap...https://wholesale.parts-express.com...18uf-630v-copper-foil-capacitor--027-160...as I said at this review they gave it one of the highest rating for caps...Humble Homemade Hifi
I will most likely go with the P-core 3.9 mh...and Madisound has nice Mundorf resistors and Parts Express has nice Mills resistors...I've used both.
Thanks so much for the excellent suggestions....I hope I don't regret the expensive caps...but I can always try the Super Z-Caps...I can get those for $30 a pair. I might do that just so I know the difference! I have a wholesale account at Parts Express and I get good deals on some products!
I still need to buy the rest of the drivers....my wife has a complete melt down if I spend more than $100...she's cheap!
Resistors can make a huge difference depending on how revealing your amplifier is.
Try winding your own with soft annealed copper wire. 😉
https://www.google.com/search?q=ayr...v&sa=X&ei=lV1yVeCoFMmGsAWBzoO4Aw&ved=0CCUQsAQ
..or even soft silver if you don't need that much resistance.
I got my wave guides today...wow these things are sweet!!!! Well worth the price!
Joe check your PM, just wanted to tell you something...no big deal!
These wave guides are very professional...I am very impressed! I do auto paint & body and these things are very professional!
Very stoked! It will be a few weeks before I get started, but I'll keep everyone posted!
Joe check your PM, just wanted to tell you something...no big deal!
These wave guides are very professional...I am very impressed! I do auto paint & body and these things are very professional!
Very stoked! It will be a few weeks before I get started, but I'll keep everyone posted!
Great !!!
Price adjustment:
One pair USD $150 or AUD $190 from now on.
This includes PayPal Fees and Air Shipping anywhere in the World.
If more than one pair, email me.
Cheers, Joe
.
I am looking at ports on Parts Express...I can get a 3 3/4 in internal dia. port which is about 95 mill...according to my math that means it needs to be about 95 mill long?
Is that correct?
Is that correct?
It would be reasonably close, but I would make it a little longer than that at 110mm.
.
Spend big (as you can) on those parts and less on the others. Everybody has a limit to their budget, so rather waste money on less important parts, better to put that on the more important parts.
I have to say that the Jantzen Superior Z-Cap is just great - especially shines with speakers. So I would go for that and it's not expensive.
Jantzen Superior Z-Cap 1.8uF:
Jantzen also makes a nice flat coil - get the 0.47mH:
Then I have used this P-Core 3.9mH and even though it is not air-cored, it works well and into a 16 Ohm leg - so I can't see it saturating:
Of course, they also make an air-cored 3.9mH, but it is quite pricey:
For the series 2R resistor to the Tweeter, I am using Dale CW-5 and again they are very reasonably priced.
There are of course other options, but the above I have actually used and can give the thumbs up.
You really don't have to pay crazy money to get top sound - lacking nothing.
For those in Australia, you can buy Jantzen from www.speakerbug.com.au
Cheers, Joe
.
Ok cool...is there room then for 110 mm with the internal brace? If so perfect!
progress pics
Hi guys. irext has been pushing me to put some pics of the progress of my speakers on the forum. i have taken a few liberties with the layout of the cabinets. I have extended the sides below the cabinet to create a foot in which to house the crossover. i also made the 18mm front panel the full width and height so i could black french polish the panel haing no joint lines visible through the polish. i am also adding curved side and top panels to clad the speaker box to give a similar look to naim ovators. These panels were then covered with 2mm (1/16") Tasmanian Blackwood Ply. i hope the pics appear.
OZmOZis
Hi guys. irext has been pushing me to put some pics of the progress of my speakers on the forum. i have taken a few liberties with the layout of the cabinets. I have extended the sides below the cabinet to create a foot in which to house the crossover. i also made the 18mm front panel the full width and height so i could black french polish the panel haing no joint lines visible through the polish. i am also adding curved side and top panels to clad the speaker box to give a similar look to naim ovators. These panels were then covered with 2mm (1/16") Tasmanian Blackwood Ply. i hope the pics appear.
OZmOZis
