Crossovers? How do you evaluate if crossover is any good?

Thank you. You should  enter a virtual system here! 😎 What speakers are you running?

How a particular tube sounds varies a bit from circuit to circuit, plus is highly subjective. I suspect many would agree that your Telefunken 12AX7 are a great option. JJs maybe not so much. Lots and lots of choices! Replacing the KT88s could get expensive, but playing with some 12AT7s could be reasonable to experiment with. I don’t run any 12AT7s, so suggest any from experience, but I have been pleased with the Mullard reissue CV4004/12AX7....many, many audio buffs like the original British Mullard 12AT7 and 12AX7 equivalents. Same with the Holland Amperex. Those get a little pricey too, but should last for many thousands of hours. Tube rolling is all part of the fun of tailoring your system. Enjoy!

-Scott

@knotscott

Awesome comment above especially middle paragraph where you talk about parts.

You have a great space and all the details related to those components you have. So much knowledge about all that goes on. Especially biamp mixture of tubes and solid state. I became a member of the exclusive fraternity and while I wanted to do it with my existing solid state mono amplifiers by adding a couple tube amplifiers it was a bit of a challenge for me. So I purchased a pair of McIntosh 901s which seem to do what I was looking for while sparing me of all the aggravation of doing it myself but you seem to have handled things well. I added 4 telefunken 12ax7 nos tubes at the top of the food chain and now debating whether I want to replace  eight 12at7 jj tubes with Telefunken and leave the remaining 16 kt88 jj Power tubes alone until they die.  Lots of tubes but some comfort that the tele nos Will live a very very long life. Interested in any thoughts you might have about whether the 12at7 tubes are worth changing out.

Thanks

Crossovers are as critical as any component in the speaker. Sometimes the most critical, but that depends. They have to be designed specifically for the drivers being used, to optimize what they do well, and to minimize what they don’t do well. They also have in consider and compensate for contributions of the cabinet and driver layout. The crossover points, slopes, and any compensation networks all have an impact. Calculations and computer simulations provide a place to start, but crossovers also need to be fine tuned to sound right, and that usually requires some subjective adjustments...some are better at it than others. Even the system and room that the speakers are in during the design phase has an impact...potentially a significant impact.

Regardless of the circuit, the parts quality matters too. All those little things that some claim can’t be heard all add up little by little. Many, many companies use components chosen by the accountants at the bidding of the board of directors/shareholders to increase profits. Others use the very best components they can find. Many sand cast resistors and cheap caps have steel in the leads. Many resistors have a notable amount of inductance due to the way their wound. Air core inductors are certainly a step ahead of iron core, and litz wire or foil are arguably a step above standard air core. Wire, connectors, physical layout all matter at some level. Do capacitors matter? 🤣

How far is the designer of a speaker willing to go with the crossover, and how many minor adjustments are they willing to make? At what point do they said "good nuff" vs peeling back another layer? It takes longer to make and evaluate changes....not all designers have as much time as they’d like with a crossover. All are factors in the end result. Yep...crossovers matter, and can be radically different from one speaker to the next.

Speaker designers choose crossovers not on which is best but which is best suited for the job.

@emergingsoul: Head over to YouTube and watch the GR Research videos by well-known crossover expert Danny Richie. In them you will learn ALL about crossovers.

@emergingsoul -- I know you like stirring the pot, but why are you posting a question about speaker crossovers on the amp forum and not the speaker forum?

I stopped using crossovers 20+ years ago, though the whizzer cone is sort of a mechanical crossover.

DeKay

Hey.... psst.... buddy, don’t you really want to make your own speaker?? You really do.... :D Check out Madisound or Parts Express for a number of pre-designed kits.

The cabinet, drivers and crossover form an integrated system. Voicing is important and can make one speaker have a distinct personality from another. As a consumer, what matters most for you is the end result.

After voicing, the next things you might care about is the impedance curve, and the off-axis response to tell you something about the drivers and how well they were put together.

Somewhere in here part quality matters as well, with a very wide range in cost and quality.  Some basic speakers, like Wharferdale Diamonds or low-end Focals really benefit a lot from tweeter cap upgrades in the neighborhood of $10-20 a speaker. 

Caps are probably the part of the crossover that can impart the most character.  Top end Mundorf is used by Magico and B&W for a reason, and while colorful not for me, per se. 

Experimenting with caps early on is best done with self-made kits rather than expensive store bought speakers, and I think it's fun and you can learn a great deal more that way than by reading.