How good is the crossover in your loudspeakers?


 

I just watched a Danny Richie YouTube video from three weeks ago (linked below). Danny is the owner/designer of GR Research, a company that caters to the DIY loudspeaker community. He designs and sells kits that contain the drivers and crossover schematics to his loudspeakers, to hi-fi enthusiasts who are willing and able to build their own enclosures (though he also has a few cabinet makers who will do it for you if you are willing to pay them to do so).

Danny has also designed crossovers for loudspeaker companies who lack his crossover design knowledge. In addition, he offers a service to consumers who, while liking some aspects of the sound of their loudspeakers, find some degree of fault in those loudspeakers, faults Danny offers to try to eliminate. Send Danny one of your loudspeakers, and he will free of charge do a complete evaluation of it's design. If his evaluation reveals design faults (almost always crossover related) he is able to cure, he offers a crossover upgrade kit as a product.

Some make the case that Danny will of course find fault in the designs of others, in an attempt to sell you one of his loudspeaker kits. A reasonable accusation, were it not for the fact that---for instance---in this particular video (an examination of an Eggleston model) Danny makes Eggleston an offer to drop into the company headquarters and help them correct the glaring faults he found in the crossover design of the Eggleston loudspeaker a customer sent him.

Even if you are skeptical---ESPECIALLY if you are---why not give the video a viewing? Like the loudspeaker evaluation, it's free.

 

 

https://youtu.be/1wF-DEEXv64?si=tmd6JI3DFBq8GAjK&t=1

 

And for owners of other loudspeakers, there are a number of other GR Research videos in which other models are evaluated. 

 

 

bdp24

@curiousjim Wrote:

There’s no doubt that an active crossover is better than a passive one.  But why then do so few active crossovers exist?  And why do so few speaker companies even offer them? I have an old ARC crossover that I had set at 100hz and it made a huge difference with some electrostatic speakers I have. 

When I bought my speakers the manufacturer gave you the option to buy the active crossover and bypass the passive crossover in the speakers. Two years later I bought the active crossover. With the active crossover the sound quality was way above the passive crossover see here last page bi-amplification. @russbutton is correct. smiley

Mike

 

@texbychoice wrote:

Russbutton describes an active crossover providing signal to an amplifier for each driver.  For a three driver speaker, three separate amps required.  Six amps total for a typical 2 channel system.  That is increased complication. In no way is replacing a passive crossover with that an equal exchange.

Ask yourself what a passive crossover, not least a complex one, does with the amp to driver interfacing as it actually impedes with the power transfer with all that entails with lesser driver control. And then ask yourself what a dedicated, frequency limited amp channel directly connected to each driver section does by comparison. Any which way you want to bend this the former scenario is the real complexity and hindrance; not merely adding up on amp channel in parallel count actively for what’s already described. 

Numerous paths to problems include more connection points, more cabling, higher parts count=less reliable, multiple paths for EMI/RFI, matching amps to drivers, level adjustment for each driver to name a few. 

Forest for the trees; per earlier paragraph of mine, adding up on amp channels is just that, and they’re working less hard to boot - meaning they’re less likely to fail. Level adjustment actively is the far better and easier option vs. using resistors and trying to match driver sensitivity passively. And, paradoxically, why so many get riled up about amp matching actively boggles the mind. The real need for amp matching is with passively configured speakers, as the harder load they present to the amps makes the amps sound much more different with different speakers. Matching amps to drivers actively is a potential bonus, but no one tells you to. Using the same amp topology/brand top to bottom into the subs to my mind is the preferred scenario. 

The power transfer from amp to each driver is not vastly improved. 

Yes it is, the more so the more complex/load heavy the passive crossover.

A passive crossover does not consume unreasonable power as has been implied either.

Again, depending on the the complexity of the XO, it most certainly can.  

No doubt Class D amps will be recommended.  This recommended path is supposed to produce superior sound quality, right.  Six cheap Class D amps are the exact opposite of quality and reliability.  Better have a couple spares on hand at all times.

Outboard actively any amp topology can be had. Bundled active speakers usually resort to Class D amps, but they also come in different qualities where reliability needn’t be an issue. 

If an individual wishes to pursue active crossover, DSP, multiple amps, etc. that is just as acceptable as improving a passive crossover.  However, fact is the active path is not as simple or vastly superior as the claims made in this thread.  Pick your poison.

If you choose to go about a DIY-approach with active and filter settings, then no - it’s not plug and play. The fact of the matter is though that you have the more optimal outset with the amp to driver interfacing actively, and sitting in the listening with a laptop and doing filter settings on the fly is vastly preferred vs. running back and forth with a soldering iron replacing filter components. Pick the poison, or the nutritious meal that’s good for your tummy ;) 

I have been a GR follower for some time and did choose to install the Magnepan LRS+ kit of parts he sells and I'm happy with the result. Better top-end, more definition  - just  "nicer" to listen to and no more $2 fuse in the signal path. It is no secret that Magnepan choose to now offer most of their range in an "X" version, with vastly improved (and costly) crossover components, so it seems both see a market for these types of upgrades.

As Danny points out and I'd tend to agree - many companies build their speakers to a price point, and a glossy wood grained exterior seems to sell better than a fancy crossover - the latter often seems to get the accountants eye the most. Even a cheap but well designed crossover can measure good, but a simple measurement does not have anywhere the discernment of the human ear. 

A good quality crossover can significantly increase the cost to build in a cheaper speaker and this is why we often get what Danny refers to as "cheesy" parts.

I'm on the side of better parts matter - not all will agree of course!

 

 

For about a week I’ve been down with a serious bout of a rare form of migraine headache known as a "cluster" headache (I started getting them forty years ago). Imagine getting a bolt of lightning to your brain, and waiting for the next one to hit. Sometimes it’s in a matter of seconds, other times minutes. My clusters usually last about three days (most often starting just above one ear, making it’s way across my head to the other ear), this time the longest ever. The prescription drug I take usually helps, but this time didn’t. People have been known to commit suicide to end the pain of their clusters.

Anyway, catching up with this thread has been for the most part delightful; lots of great comments from knowledgeable, informed audiophiles. As for the others, oh well.

As others have already said, upgrading the crossover in your loudspeakers can be done without resorting to buying a kit from GR Research. And if you like a deep hole in the frequency response they may produce (due to two drivers being out-of-phase at the x/o point, or as in the original version of many of the Klipsch models, the woofer and tweeter not even reaching each other until their respective outputs have dropped way below the mean response of the speaker), that is of course your right. But to call that defect a "voicing choice" is just silly. What it really is, is poor engineering. Klipsch corrected the poor x/o filters in the Mk.2 versions of some models. That is not a matter of a natural evolution (or tighter parts values control), it is correcting a mistake. It was obviously done in response to Danny Richie’s evaluations.  

There is no doubt that Magnepan’s introduction of the X Series versions of their models was also made in response to Danny Ruchie’s evaluation of a few models. I mean, Magnepan has been making all their models with the same crossovers since 1970, the X Series upgrade appearing only after Danny’s videos aired.

Here’s something to consider: I don’t know the prices, but it could be that the GR Research upgrade kit for the, say, Magnepan 3.7i, might be about the same price as the cost to get the X Series version instead of the standard 3.7i. But here’s the deal: Magnepan uses all better parts in the X crossover, but the x/o filter characteristics are no different from those in the standard model. It in no way "corrects" the problems Danny Richie found in his examination of the 3.7i.

What problems, you ask? The same problems John Atkinson found in the last Stereophile review of a Magnepan he did, decades ago. Magnepan has never sent another speaker to the mag, Wendell Diller saying it was because Magnepan’s can’t be measured like other speakers. Both Atkinson and Richie found the drivers played "over each other", a result of the shallow x/o filters and the chosen crossover frequencies. That creates serious problems of comb filtering, a phenomenon known to speaker designers for many, many years. It’s a testament to the quality of the Magnepan planar-magnetic drivers that the speakers sound as good as they do in spite of the flaws in their crossovers!

The beauty of the old Maggies (like the 3.6) is their series crossovers. With a good active crossover (like the First Watt B4 I mentioned earlier), you can create your own filters. I don’t remember what filter characteristics Danny came up with for the 3.7, but with a x/o like the B4 you can try 4th-order low- and hi-pass filters at 400 Hz. If you don’t like it, try something else.

Or, you can just buy a pair of Eminent Technology LFT-8c’s. A single push/pull planar-magnetic driver (magnets on both sides of the Mylar diaphragm) for 180Hz up to 10kHz, a ribbon tweeter for 10kHz up, and a dipole woofer for 180Hz down. Wendell Diller has been insisting forever that a monopole woofer "does not work" with a dipole loudspeaker, and Magnepan has been working on a dipole woofer system for a number of years. Why so long? No need to wait any longer, Eminent Technology already has one.

Or even better, add to your dipole loudspeakers a pair of the unique OB/Dipole Servo-Feedback Woofer that Brian Ding of Rythmik Audio and Danny Richie collaborated on. Open Baffle (2 or 3 12"  woofers in an open baffle frame), dipole output, and servo-feedback control of the woofers. It will play up to 300Hz, unique for a sub. It comes with a plate amp that contains a dipole cancellation compensation circuit, and all the controls you want and need, and in the analogue domain.

        

@bdp24 Very well said summary.  For a DIY person crossover modifications or going the amp for each driver route would not be difficult.  If one can't handle a soldering iron, stay away from DIY.  

Passive crossover or all active can result in a system that measures well.  Measurements do not tell the entire story.  For those of us that have over the years tried many of the latest bright shiny audio gizmos or idea we know that fact all too well. Separate amps for each driver is nothing new and revolutionary.  There are trade-offs for any approach.  

Claiming an all active system to be superior is a broad generalization, not a universal truth.  Previously noted potential problems cannot be explained away by opinion.  Parts count increased by dozens and more interconnections decrease overall reliability and introduce new variables.  That is engineering fact that can be calculated.  When a complex system works it can be great.  When a problem appears, it can be a nightmare.