AlphaCore Copper Foil or Solen Hepta-litz ???

[bbaker6212]

which would you use/prefer for speaker crossovers?

 

[planet10]

which would you use/prefer for speaker crossovers?

They are both good. Depends on the R you can live with. The flat foil ones are strongly suggested for series XOs.

dave

 

[Eric]

Dave, I'm interested in your rationale as to why a foil crossover is better for series crossovers... I'm currently gathering parts for a small speaker system that calls for a series crossover.

Thanks, Eric

 

[AGGEMAM]

which would you use/prefer for speaker crossovers?

Neither, I use Jensen AirCore CopperFoil (or SilverFoil), but the foil inductors are extremely good for mid- and hi-range, and (as said above) for series crossovers.

Check this link for more info, especially note the dielectric material:

http://www.jensencapacitors.com/audio/products/aircore.html

 

[AGGEMAM]

Dave, I'm interested in your rationale as to why a foil crossover is better for series crossovers... I'm currently gathering parts for a small speaker system that calls for a series crossover.

Sorry if I answer this at least partly, foils have extremely AC/DC resistance resulting in less complecated XO calculation.

 

[planet10]

I'm interested in your rationale as to why a foil crossover is better for series crossovers...

Low R. Any R in the inductor shelves the high pass at low frequencies so lower R means better tweeter protection.

dave

 

[Eric]

Thanks for the explanation, Dave, this makes sense to me. I'm wondering if the recommendation of foil vs. "traditional" inductors for low R is brand-specific...

For example, I need two inductors 0.47 and 0.68mH, 12 ga. If you look at NorthcreekMusic.com, the resistance of these coils is .04 and .06 ohms, respectively. If you look at the Alpha-core foil inductors that Michael Percy stocks, the resistance of similar inductors is .11 and .13 ohms, respectively.

In this case, it appears that the more traditional coils from Northcreek have lower R... curious.

 

[AGGEMAM]

I'm wondering if the recommendation of foil vs. "traditional" inductors for low R is brand-specific...

Any value of less than a quater of an ohm should suffice for most modern tweeters. As I wrote earlier, foil inductors simply sound better as well especially if it is the mid- or hi-range we are talking about. Ah well ... what can I say but 'just try it'.

Have you checked the link I provided?

 

[Eric]

AGGEMAN, yes, I have read the link you provided, thanks! I hadn't considered Jensen inductors, I'll have to poke around and learn a little more.

I suspected there was some "threshold" value, beyond which the R would not matter too much - I just didn't know what it was.

Eric

 

[promitheus]

The foils are a lot better due to very low series resistance.
This means the crossover is not effected by the resistance of the coil.

 

[AGGEMAM]

Besides the one I already linked to earlier here is another link to a Danish producer of copper-foil inductor, these are, IMHO, of lower quality than the Jensen once, but then again everything is, however they are cheaper:

http://www.jantzen-audio.com/

Note: Don't confuse the similar names of 'Jantzen' and 'Jensen'.

 

[sianturi]

For example, I need two inductors 0.47 and 0.68mH, 12 ga. If you look at NorthcreekMusic.com, the resistance of these coils is .04 and .06 ohms, respectively. If you look at the Alpha-core foil inductors that Michael Percy stocks, the resistance of similar inductors is .11 and .13 ohms, respectively.

In this case, it appears that the more traditional coils from Northcreek have lower R... curious.

Talking about NorthCreek Crossover.... they boast that using foil coil will surely degrade low frequency sound quality. Well... actually I bought couples of 1 mH inductor (12 AWG) & 0.3 mH inductor (12 & 14 AWG) from Northcreek but haven't tried them yet.

If you want, I can measure the DC resistance of my northcreek coils so that you can compare if it fits the specs published by northcreek. ....Anyway... I think you're right. I never compare the dc resistance of foil coils to traditional coils (northcreek in this case). So, I will let you know the measurement, and see if northcreek produce the "true-to-the-spec" product. Just give me couple days, and I will post my measurement.

Actually, the reason I bought NCMS coils because Lynn Olson's recommendation for his Ariel crossovers.

Regards,

 

[Eric]

If you want, I can measure the DC resistance of my northcreek coils so that you can compare if it fits the specs published by northcreek.

That would be great, I suspect they will measure close to spec...

AGGEMAM, I didn't see any prices on the Jensen web page - how do their prices compare? Just wondering since they weren't immediately apparent.

Brad, you still around? Sorry to have hijacked your thread

Eric

 

[AGGEMAM]

AGGEMAM, I didn't see any prices on the Jensen web page - how do their prices compare?

Just take the price of the most expensive foil coil you can find and multiply that price with 2 or 3, including freight and taxes in the US, probably 4 or 5 times more expensive.

However it is worth it!!! Now I do not have any commercial interest in any company in what-so-ever, but I can safely that the Jensen components (foil inductors and paper-in-oil capacitors) are unsurpased by anything else in the entire industry (even the highly renowned Black Gate capators).

The reason for this, I believe is fourfold:

1) They are handmade by skilled craftsmen.

2) They are made without any plastic or other artificial parts, only pure metal and organic material is used.

3) The engineers designing are not hi-fi freaks themselves, going by any whim of the day, but rather use good old fashioned tested-and-true methods of production.

4) The testers are however hi-fi freak, or at least 'golden-ears', and no design gets to the production stage without the approval of them.

 

[Eric]

AGGEMAM,

I've been doing some searching on the web and it seems that the Jensen caps and coils are very well received. At their price point, however, I don't think match the current speaker system I am building.

I'm working on a set of HATT speakers designed by Tony Gee. They consist of a Seas 19TAF/D (H561) tweeter and a Seas L11RCY/P mid-woofer. The total cost of the drivers is only $150 USD. The cost of Jensen caps and coils would be many times the cost of the raw drivers. These speakers are my first attempt at a "kit" and the requisite wood working. After I complete these, I'll likely work on a floor-standing set using better drivers, so I'll probably use Jensen parts in my next pair...

Thanks for all of your input! I appreciate the insights!

Eric

 

[AGGEMAM]

You're right, one should not spend more money on the XO than on the drivers.

I have a rule of thumb regarding that, actually, spend an equal amount of money on the three parts, that being the drivers, the XO, and the cabinet.

I have just looked at the HATT project, looks good. But why the series filter, IMO, a series filter is only an advantage if it is a 1st order XO, or if you have a current amplifier.

 

[Eric]

The XO is a second order series filter designed by Tony Gee (see picture below). The cross over point is 4500Hz and seems to tame the 12kHz peak pretty well. The parallel caps for the tweeter is just to arrive at 4.0uF.

The drivers cost about $150, so I figured on using AudioCap PPMF caps, Air Coil Foil Inductors, and Mills non-inductive wire wound resistors. The total for cross over parts (I don't have them yet) is about $145. A fairly close balance, I too believe in matching driver and crossover costs.

I'm still in the learning phase, buidling my first DIY amp and next a set of speakers to go with it. My first amp is a Pass Labs a40 and I figure the HATT speakers will go nicely with it. I've also got a few parts for a Pass Aleph 2 on hand and eventually I'll build a floor standing set of speakers to go with that. I also keep eyeing a few tube amp kits and projects - but one thing at a time!

All of these projects are moving slowly becuase I just made my first mortgage payment on a new house, so my toy budget will be a little thin for the next while...

 

[sianturi]

Multimeter problem...

uhhh.... Sorry. I just realized that my multimeter only have 0.1 ohm precision. So I cannot measure my northcreek coils. When I tried to measure 0.3 mH (14 awg), the reading goes alternating betwen 0 & 0.1 ohm. Unfortunately, I also cannot test the quality of these coils if used in the real loudspeaker, because I'm still saving money for the caps to be used in the crossover.

Hmmmh, probably we just have to trust ncms being honest bout their product and trust Lynn Olson recommendation.

Sorry guys

 

[Eric]

Sianturi, thanks for the efforts, sorry to hear that it didn't work out. Oh well...

 

[nicoch58]

HI I have tested some caps an my scanspeak ,the difference are big, not tested coil but I have mundurf ofc flat wire ,some people spend a lot money in cable ,silver-ofc , but in series at woofer the coils have a lot of wire,meters......the connector are in brass....

good gear need a bilanced component and fine tweeking....good speakers good component ,the problem are audio marketing (cu price fly) audio component cost double or triple.....but rulez!


try one 0,47 mundurf silver/oil on tw ,never came back!


do not put the xo in the box.....