N1600 crossovers for my 604Ds

**donaldpatten** · March 9th, 2013, 09:07 AM

Alancohen

I recommend you change the 16 uF cap in each N-1600 . Then if you do build new XOs you will have a base line to compare to.
The old caps are in cardboard boxes with a pair of wires coming out. Cut these wires very close to the box and splice them to the new 16 caps.
Dig out the old caps to make room for the new ones. If the new 16s are tight, or too large, sub two 8 uF caps in parallel . If you want to repot the XOs you could use candle wax.

Don

**alancohen** · March 16th, 2013, 08:55 AM

Don: thanks for the suggestion, but I think I'd rather not bother with these XOs at all. The small one has the L-pad shaft snapped clean off and it just seams like too much trouble when making a new one is relatively easy.

On the subject of making new ones I started doing a little homework and getting my big toe wet in the huge learning curve pool. I have a question. In looking at JM's work with his 604B/E-cone design here:

He specifies a 1.6mH air core inductor @ .3 Ohms made from 16 AWG wire. However, when I look at this inductor calculator Shavano Music Online - Cross-Over Network; Air Core Inductor Calculator and plug in 1.6mH you get this result:

My confusion is that in order to get a .3 Ohm value you need 14 AWG wire, not 16.

Same with the 1.1mH. In order to get to his stated value of .235 Ohms, you also need 14 AWG wire.

Inquiring minds want to know what I'm missing.

- - - Updated - - -

Things get dicey when you get to the 4.7mH. He calls for 14 AWG. Again, plugging into the calculator it seems I would need 230' of 14 AWG wire to make this inductor. That's a lot of copper.

If I make this 4.7mH inductor from 18 AWG wire, I only need 191' of much cheaper wire, but my DCR doubles from .58 to 1.22 Ohms.

The question is: what effect will that have on the whole loudspeaker package? I assume that more resistance will generate more heat and it will also absorb a percentage of the wattage available to the driver. Since I will likely be driving my 604s with 1.5W monoblocks, I would like to retain all the power I can.

So the bigger the gauge the better for this purpose? And at what point does the sublime meet the ridiculous?

BTW, after starting to shop for wire it made me realize that Bill's price for his 1600 XOs at $178 are quite reasonable: Altec Lansing GPA N1600 16 Crossover New | eBay . Copper t'aint cheap.

**donaldpatten** · March 16th, 2013, 09:36 AM

alancohen
If I were making this XO, I would use # 15 AWG and shoot for an average of 0.5 Ohms per coil.
Buy 10 # ( pounds ) of magnet wire.
The bigger the wire the lower the loss. We are talking a few tenths of a dB.

Don

**alancohen** · March 16th, 2013, 11:00 AM

Big thanks, Don. The words "If I were making this XO, I would use..." from someone of your experience are like fine music to my ears. I guess I have some coil winding in my near future.

BTW, this is where they are going...with a couple of 300B monoblocks on the mantle.

**alancohen** · March 17th, 2013, 06:04 PM

The 604s have been just laying around the LR so I thought I'd get them out of the way and install them back into their old home. Not much else to do while I wait for my inductor wire.

Some decent grille covers came with the cabs, but it sure is a shame to cover them up.

Now the cabs officially weigh a ton. I know the black and wood grain look is a bit tacky, but my whole living room is wood floors and ceilings with black furniture. They oddly fit right in.

**VolvoHeretic** · March 17th, 2013, 09:13 PM

Hate to say this, but if that were my room, I would tear that fireplace the hell out of there. Sorry, that's just me, but what a mess.

**cradeldorf** · March 17th, 2013, 10:18 PM

I don't know about tearing out the fireplace but I would seriously think about sliding them to the opposite side of the step from the fireplace. Having them up tight to the side of the fireplace might not be an optimum placement.

**alancohen** · March 17th, 2013, 10:45 PM

Originally Posted by VolvoHeretic

Hate to say this, but if that were my room, I would tear that fireplace the hell out of there. Sorry, that's just me, but what a mess.

Well considering my house is heated predominantly by that fireplace, it is not likely.

I don't know about tearing out the fireplace but I would seriously think about sliding them to the opposite side of the step from the fireplace. Having them up tight to the side of the fireplace might not be an optimum placement.

That is certainly an option, but too far apart will likely destroy the stereo image. I'm thinking about building a little riser in between the step and the base of the fireplace which will allow moving the speakers forward about a foot. At least that would get the baffle about 4" in front of the fireplace. We'll see.

**cradeldorf** · March 18th, 2013, 02:07 AM

That was gonna be my second suggestion.

you might want to check how hot it gets there with a roaring fire before you find your horns drooping.

**alancohen** · March 18th, 2013, 10:28 AM

Originally Posted by cradeldorf

That was gonna be my second suggestion.

you might want to check how hot it gets there with a roaring fire before you find your horns drooping.

Why shouldn't my horns start drooping. Everything else has.

There's a fan built in to the stove that blows straight out. The stone is so big that it just gets warm, but never hot. Even the back side where I sit gets nicely warm. Pretty creamy, but not ideal for a recording studio.