True high-end Speakers need a midrange
To be clear, I don’t mean expensive, I mean high performing.
I recently built a new center speaker for my home theater and as I was comparing/contrasting design alternatives between a variety of designs, everything from expensive DIY designs to Wilson, Legacy, ATC and Focal and others the thing that stood out the most was this:
I say this as a person who has had pretty good success with 2-way speakers and really admire 2-ways from Fritz and others, but when push came to shove, there was no way to make a 2-way with very high output AND low distortion AND excellent off-axis performance without a midrange driver.
You can push many tweeters down to 2kHz or even a tad below but it is very hard to find a tweeter that will do so with low distortion at high volume. On the other hand there are many 1" domes which will perform excellently when crossed over at 3 kHz or higher even when driven hard, things you don’t see from a frequency response plot, or really any measurements from Stereophile which never plots dynamic range charts. It’s not just about the frequency response and imaging, sometimes it is about doing all of that under pressure that matters.
Similar, complementary issues are true for the woofer in a 2-way design. First, good mid-woofers with good frequency responses through 2-4kHz are expensive, but as you push the crossover up 7" drivers and larger have to beam, right in the middle of the midrange. Instead of a wide open sound stage you can hear anywhere they restrict where you can sit.
In a large, full range speaker you can push your design for high output even further by going with a 5" midrange for instance. Not quite as wide as the 4" counterparts but lots of power handling and plenty of overlap with the tweeter and woofers.
To make things clear, I don't actually believe you must use a 3 way or even a multi-way speaker to achieve excellent results. Sorry if it seemed I was trying to denigrate other designs. I really just meant to elicit technical responses, which have been fascinating, especially the horns. My own stereo uses 2-way mains with pretty good results. :) |
Hi @fsonicsmith
As I pointed out earlier, the intent of this post was really to elicit technical replies. Much like great art is often done as a reply to what has gone before, I thought that posting the merits of a 3-way design, and the challenges it solves would also cause others to come up with "but what about...." replies, and it has, rather beautifully. Apologies if that sounded like absolutism, but given how this board functions I thought it would be understood. Now, for this...
I’ve never said anything like that. I have said that I wish more audiophiles would build (cables, amps, whatever, not just speakers) so we’d have more arguments built on practical experience rather than either relying on manufacturers, myths, or reviewers. Arguments over capacitor sound quality and break-in are a great example. More builders = more actual experience.
Now you are downright making stuff up. I am however always happy to troll anyone over the use of the "high-end" moniker. We get far too wound up over what it is/is not and who has it and how much it should cost. I am also very amused at how many "high end" audiophiles get all wound up over the idea of participation in this hobby that is something other than going to the store and spending a lot of money. Tinkers built this hobby and the brands you so admire. I have no issue with consumers spending lots and lots of cash on stereos. I just want to encourage the remaining 99% to get their hands dirty now and then as a satisfying way to enjoy the hobby as well. |
@snapsc All drivers (from tweeters to subwoofers) have a distortion profile which gets worse the lower in frequency and higher in amplitude you get, the question is whether you can keep it out of your operating range so for any given device it depends on how low the distortion remains when the output levels are increased and when you plan on crossing over. This is where a midrange can really come in handy. By raising the crossover frequency from say 1.8kHz to 3kHz the high distortion area of the tweeter is avoided and the very low distortion area of the midrange is used, but as we know, no two parts are the same, and we don't all hear distortion in the same way. If you want to minimize distortion, maximize dispersion and output levels, then going from a 2-way to 3-way design is often the solution. There are a number of ring or dome tweeters between 1" and 1 1/2" which have a claimed sub 2 kHz operating range they are still limited in output. Often these models have unusually large rear chambers or like the legendary Scanspeak R2604 (Peerless had a very similar model) the bottom end of the tweeter will show increased distortion with output. Perhaps the secret lies in the crossover though. I’ve read commentary that says you can get fabulous output from a tweeter if you use high order (i.e. 4th or higher) high pass filters, something I personally am loathe to attempt without an active crossover.
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Hi @unreceivedogma , I must beg your forgiveness and indulgence. Truthfully I thought this was an interesting discussion topic and wanted to read what others thought about solving the issue. It's been very interesting reading for me, for sure. |
