Cheap analog electronic crossover

[Sokel]

Additional "asking for a friend" questions:
Would the DC PSU Motronix sells be quieter than an AC transformer?
Should the PSU be kept separate from the crossover (mounted in a separate box)?
Should the box be metal or is plastic OK?
Are there other considerations for keeping things quiet (hum free etc.)?

Have a look at my edited post.
1. I'm not sure but a nice PSU is always better.
2. No,same box is ok
3.Metal for some shielding and grounding the components.
4. Proper grounding (nothing extreme,just nicely bolted to the case twisted cables and an IEC socket which has a ground (so no 2 prong ones)

 

[Sokel]

@hdw @JohnnyNG ,alternatively,if you want a SMPS,this will do fine:

Mean Well PD-2515

Mean Well PD-2515 AC-DC Dual output Open frame Power supply; Output 15Vdc at 1A -15Vdc at 1A

www.meanwell-web.com

 

[Short38]

There are two dbx models and one behringer analog crossover. Relatively inexpensive. The dbx units (I own two) from three years ago hummed - physical box not outputs. I took the cover off and found that the power supply was “shielded” with a thin strip of metal. Removed strip and no more hum. I believe the dbx 234 was reviewed here and deemed ok.

 

[Sokel]

There are two dbx models and one behringer analog crossover. Relatively inexpensive. The dbx units (I own two) from three years ago hummed - physical box not outputs. I took the cover off and found that the power supply was “shielded” with a thin strip of metal. Removed strip and no more hum. I believe the dbx 234 was reviewed here and deemed ok.

I had a look and they seem nice,are balanced,are highly configurable,etc.
But not comparable to price,or simplicity,you can put this little think in a small box along with its PSU and totally forget it for about 60 euro all included.

And another,all these pro cheap xovers like the Behringer are close to impossible to exactly match levels,filters,etc (and I mean exactly,down to the last mV) because of their pots.
That's why I suggest everyone who may want this little thing I posted to order it without the pot soldered and solder some good quality trimpots instead.
That allows you to match everything to be identical between channels :

Have a look here,all channels:

Slopes

Phase

IR

That's with filters in place of course (there can't be any other way,it's fixed)

 

[computer-audiophile]

There are two dbx models and one behringer analog crossover. Relatively inexpensive. The dbx units (I own two) from three years ago hummed - physical box not outputs. I took the cover off and found that the power supply was “shielded” with a thin strip of metal. Removed strip and no more hum. I believe the dbx 234 was reviewed here and deemed ok.

You have to have good reasons to build such a crossover yourself. (What are they?)

BTW: I have had very good experiences with this Behringer crossover, which I once used to build a large three-way horn system. Good sound and absolutely no audible noise.

Own photo:

 

[Sokel]

You have to have good reasons to build such a crossover yourself. (What are they?)

BTW: I have had very good experiences with this Behringer crossover, which I once used to build a large three-way horn system. Good sound and absolutely no audible noise.

Own photo:

View attachment 321904

You have to be REALLY patient with this one to exactly match everything,I mean REALLY.
Putting the pots at the exact same position can be as far as 2-3db,and on top of this that changes during the operation.
Ok,no one expects 15 or so pots to be top quality and precise at that cost,but for precise applications is hard and you need to measure it constantly.

(I have tried one,I also have one somewhere,I know,maybe I'll measure this parameters for fun and post them here when I get back to my rig tomorrow)

 

[Sokel]

To put things into context,the highly regarded (and really nice sounding,my type of nice in terms of highs) Genelec 80xx series uses something like this and it's a set once and forget thing.
It's not as good as the DSP stuff,nor as configurable,but look how it also reflects to the price of the analog Genelecs' compared to the DSP controlled ones (along with all the other stuff involved )

That's NOT for high demanding application and one must know exactly what he needs before getting it.

 

[computer-audiophile]

OK, of course you can't rely exactly on the scales of the knobs if you have such high measurement requirements for level accuracy.
This is the case with many analogue potentiometers on hi-fi equipment. I have not noticed any instabilities during operation, e.g. temperature drift, etc. I would use this crossover again today.

But there are also similar cheap digital crossover units or speaker management systems if this is an argument.

 

[Sokel]

OK, of course you can't rely exactly on the scales of the knobs if you have such high measurement requirements for level accuracy.
This is the case with many analogue potentiometers on hi-fi equipment. I have not noticed any instabilities during operation, e.g. temperature drift, etc. I would use this crossover again today.

But there are also similar cheap digital crossover units if this is an argument.

We're not talking that high requirements and I'll give you an example using only two pots,the one that controls x-over frequency and the one that controls low's level.
Let's say you put them all at the same position.

Setting the xover you already have a difference in the crossing frequency,doesn't matter how much,just an example.
Now,setting the level,you not only have level difference between the two speakers but the crossing frequency also shifts some more back or forth (imagine the whole driver area up or down where the two drivers cross,first graph of my above post helps visually) .

That way you can easily end up with two different speakers and that's without taking the rest of the settings into account.
Level difference is very-very audible.

 

[computer-audiophile]

All right, if you want to be very precise, you have to make a corresponding effort. I didn't do it, but for me the Behringer crossover was good enough to build a big horn system and play it to a group of audio friends. Today I see little point in building 'normal' speakers myself anyway, because there is such a great range of everything on the market that is hard to beat. It would have to be very special to make sense for me and I can't think of anything else for that.

But - sorry - please don't feel disturbed by my aberrant thoughts in the thread.

 

[Sokel]

But - sorry - please don't feel disturbed by my aberrant thoughts in the thread.

No worries,everyone has different goals and as long as you have fun everything is in the right place.

(concerning cost,one can use no device at all,just the PC and a multichannel DAC,etc.Not for the paranoid about safety ones like me obviously but totally doable,high performance,configurable,etc)

The one good upside of the analogs is that they don't need a PC at all,you play everything,CD,vinyl,etc fully detached without the need of extra ADC,etc.

 

[Schollaudio]

You have to be REALLY patient with this one to exactly match everything,I mean REALLY.
Putting the pots at the exact same position can be as far as 2-3db,and on top of this that changes during the operation.
Ok,no one expects 15 or so pots to be top quality and precise at that cost,but for precise applications is hard and you need to measure it constantly.

(I have tried one,I also have one somewhere,I know,maybe I'll measure this parameters for fun and post them here when I get back to my rig tomorrow)

I've used prosound crossovers for years and the small knobs were all finicky to adjust. I rely on REW to adjust active similar to the way I adjust passive but tweak knobs instead of swap inductors and caps. A DIYer can get prosound rack gear for 20-200 bucks in local listings.

 

[Short38]

I had a look and they seem nice,are balanced,are highly configurable,etc.
But not comparable to price,or simplicity,you can put this little think in a small box along with its PSU and totally forget it for about 60 euro all included.

And another,all these pro cheap xovers like the Behringer are close to impossible to exactly match levels,filters,etc (and I mean exactly,down to the last mV) because of their pots.
That's why I suggest everyone who may want this little thing I posted to order it without the pot soldered and solder some good quality trimpots instead.
That allows you to match everything to be identical between channels :

Have a look here,all channels:

View attachment 321899

Slopes

View attachment 321900

Phase


View attachment 321901

IR

That's with filters in place of course (there can't be any other way,it's fixed)

I see your points. Better performance and lower price. Thanks

 

[Sokel]

You have to have good reasons to build such a crossover yourself. (What are they?)

BTW: I have had very good experiences with this Behringer crossover, which I once used to build a large three-way horn system. Good sound and absolutely no audible noise.

Own photo:

View attachment 321904

As promised this is couple of measurements of this exact model Behringer CX3400:



The rig is the same as with thread's x-over,just a loopback.





Highs



Lows

It took me a while to get there,pots are a pain and different combinations bring different results.
At the specific measurements x-over was at about 200Hz.

(that's some tube distortion profile at lows! )

Probably ok for it's intended but not for hi-fi,the little one I tested for this thread is WAY better.