Where to save money on crossover components

Hi All

I'm looking at building Troel's Amish speaker (I already have the driverrs) but his crossover looks like it will bankrupt me!

http://home1.stofanet.dk/troels.gravesen/index_b/8545_9500_series_v2.GIF

Where could I use cheaper components to bring the crossover cost to a more WAF level? Or should I just start saving and use decent spec components troughout?

Anybody got any cheaper designs using the 8545 and 9500 drivers?

Cheers

Al
 
Thanks for the replies. I suppose £30 per speaker is not over the top but any money saved would be helpful. E.g. Do all caps have to be polyprops or can some be an electro and poly in parallel? Can I substitute large air cores with iron cored inductors with similar DCRs? If I'm buying a few better quality caps, where should they go? etc, etc.

I'm looking at sourcing the components from http://www.lautsprecher-shop.de/ .

They seem pretty reasonable on quality and cost (apart from 17 euro delivery to UK). Certainly much cheaper than UK suppliers.

Al
 

Jay

Banned
2003-02-11 9:02 am
Jakarta
You can use ferrite-cored inductor in 4.7mH. Not only because it is the biggest, but as a compensation circuit it works on narrow frequency range.

0.15 and 0.22 do not need to be high end. Often when I build a crossover (series), the prototype is using cheap (smaller value) inductor and when finished I tried to replace with quality one (I measured the inductance) but the cheap inductor sounded better. May be because of different DCR I don't know. But if so, then lower DCR doesn't mean better, and may be keeping the DCR as the original design is more important.

Worse cap (electrolytic) may be used in the compensation circuit (11.5uF). Quality ones might go for the 6.8uF ones.

Also, I often found that electrolityc (axial NP) while not as detail as Solen cap, they are easier on ears. And, they are not as critical as in parallel crossover. Last night I tried to use Black Gate N (electrolytic) in parallel crossover, and they were absolutely worse than Solen MKP, but I believe there's a possibility they turn out to be better since normally it takes very long time for such Black Gate to burn-in.

From others' advices/comments below, I read a message saying that when you use high quality expensive drivers like SS, why bother trying to save very little amount of money for the crossover parts???

But let me tell you something important about crossover. Correct crossover (hence correct values) is a LOT LOT more important than quality parts. The good news is series crossovers are very very tolerable. But still you better use exactly the same values (hence unwinding some inductors?) IMO.
 

jomor

Member
2004-02-20 1:36 pm
Athens
I m not sure about using a cored inductor, in such case an accurate measuring equipment is required to make sure the desired value is maintained in the frequency of interest (where the notch is tuned), since the inductance of core inductors vary with frequency. Most inductor values are measured at 1Khz so if the notch is close to 1Khz you can trust the nominal value of the cored inductor you re going to buy.

I couldn't agree more with the rest though, a slight change in a component (DCR of an inductor for example) will not affect the magnitude of frequency response noticably, but it will mess up the phase response very much. Use exactly the suggested
by the designer values. Besides, cutting cost on crossover while using scanspeak drivers is really a pity.
 
Jennice said:
Hey,

I'm in DK too... I could need suggestions on fair-priced X-over component sources, although i'm thinking of DK / scandinavian suppliers.

Jennice


waltona said:


I'm looking at sourcing the components from http://www.lautsprecher-shop.de/ .

They seem pretty reasonable on quality and cost (apart from 17 euro delivery to UK). Certainly much cheaper than UK suppliers.

Al

You should look at suppliers like Elfa and other industrial suppliers, any company with a name that suggests audio or the like is a very expensive solution.

for caps you could choose Rifa PHE426, those are very high quality and quite cheap. I personally don't use anything but air core inductors, they don't cost much for xo purposes.


Magura :)
 
imo the most money you will save is on winding your own inductors..

Unless you have some cheap source for air cores (havent seen one yet, dont care either).

Next is caps, PP shouldnt be too expensive as long as you dont go all out on some fancy brands. You could check a surplus store as well, they may have something.
 

andy2

Member
2004-11-17 4:46 pm
thomas997 said:
imo the most money you will save is on winding your own inductors..

Unless you have some cheap source for air cores (havent seen one yet, dont care either).

Next is caps, PP shouldnt be too expensive as long as you dont go all out on some fancy brands. You could check a surplus store as well, they may have something.



Not a bad idea since I can borrow an inductance meter from work. My question is where can I purchase raw ofc cable for winding my own inductor?
 
andy2 said:




Not a bad idea since I can borrow an inductance meter from work. My question is where can I purchase raw ofc cable for winding my own inductor?


OFC wire for inductors is pointless AFAIK. I make inductors, and my inductors are highly regarded by severel members on this board. All were made of good quality magnet wire.

Magura :)
 
Bipolar electrolytics are maybe an option, but I don't like them, as the quality of the cap turns into an issue. I have recently played around with bipolars in my XO, and the difference between nichicon bipolars and PP film caps was night and day for all applications. I had a hard time telling the difference between PP and PTFE film caps. This may be different for other types of bipolars.

Magura:)
 

Jay

Banned
2003-02-11 9:02 am
Jakarta
rcw,

They say audio-electronics is half science half art. There are many engineers here that know almost only the science only. There are some who knows the art part. And there are balanced people.

To master the science what you need is only to take the correct courses or reading the correct books. You don't have to be smart to master the science. But art, you have to be smart to have a great sense of art (and part of this is psychology). Even if you sing a song, you don't need to have a good voice, you just need your brain to control your voice to sound so enjoyable to your ears. You don't try to measure the lambda at all (to create 2nd order harmonics). Doesn't this has something to do? :cool:

You CANNOT even use blind test to prove that A and B is equal. But many will be able to differentiate Solen to Dynacord. Whether it is because of the build quality or the oxygen content, or worse, unequal inductance between left and right, the science people may have the answer. But AFAIK, people don't use solen for the oxygen content reason. They use it because it 'sounds' better :D

But okay, I'm agree. The price-to-quality ratio is almost always forgotten...
 
re capacitors

As i said previously no one has ever showed that film capacitors have a sonic advantage over bipolar types, bipolars do however have greater value tolerance limits than film types, and any sonic difference can be firmly attributed to this.
In the historical sense crossovers that needed 5% tolerance components used large value bipolars paralleled with small value film types to bring the total value into tolerance, and upon hearing about the measurable differences between bipolars and film capacitors the marketing department parlayed it into a sonic advantage. No one has however published a correctly done double blind test to proove this advantage for the reason that so many of these tests, such as the ofc one haven't been either done or published, they show no audible benefit.
Since ferrite is non conductive and iron powder epoxy coated you can use non enamelled wire for single layer windings.