What goes on between 2kHz and 4kHz is key to speech recognition. Having a dip around 3kHz lessens fatigue, maybe something to do with the ear canal resonance? Having a rise around 5khz in the presence range is good for clarity. Sibilance range is around 7-9 kHz.
Imo, it's (fatigue and unnatural sound) all about distortions. Anywhere there is distortion, whatever the frequency, having a dip will always lessen fatigue...
A common problem is at frequency where wavelength is equal to the position of the rubber surround (around 1kHz). Making a dip here will lessen fatigue (applies to probably all 5-6 inch drivers)...
It's all about distortions. Start with choosing drivers with low distortion and/or cross them based on their (non-linear) distortion performance. Crossing below 2kHz for the sake of it (sensitive region) will not help.
It is a critical region not only because ears are more sensitive but more importantly because most drivers (midwoofers and tweeters) have weaknesses at this frequency. So either choose drivers with no weaknesses (in simple language: where notch filter is not required) or fix the weakness appropriately.
Speech recognition also requires that multiple drivers to be "in phase". Getting good phase tracking at HF (4kHz) is more difficult than at LF (300Hz), that's why crossing very low is imo not preferable.
Interesting stuff
Thanks Line Source,
As always you come up with opinion and observations backed by testing and studies...Thanks!
All the best
Derek.
Thanks Line Source,
As always you come up with opinion and observations backed by testing and studies...Thanks!
All the best
Derek.
If you listen to a stereo loudspeaker in the commonly used 30 degree triangle and have an averaged sized head, in the sweet spot you will get combing from the left speaker reaching the right ear and the right speaker's direct sound. Obviously also the right speaker reaching the left ear and the left speaker's direct sound.
If you look at what that comb pattern looks like:
It might explain why a dip at 3-4 KHz is favorable. A peak at ~5.5 KHz lines up perfectly too. Throw in a mild Q peak at 1850 Hz and it gets even better.
The higher frequency dips and peaks get more head shading and won't be anything as severe, what I show here is a worst case scenario.
Look at a measurement from Toole measured with a dummy head at the sweet spot of a stereo triangle:
This is an average of the frequency response of the direct and the following combing. Do you see the dips and peaks at the same places? Thanks to BYRTT for tracing Toole's measurement. (I believe this one was recorded in a reflective room, according to Toole's standards)
Remember, the upper graph I posted represents what happens at the sweet spot after about 0.270 ms. The direct sound has already hit your ears. Move out of the sweet spot and things change rapidly. The left and right ear get different comb patterns. Only in the sweet spot both ears get the same dips and peaks for all phantom center info.
Some mild variations at these frequencies are favorable, countering the dips and peaks seen here, especially in the phantom signal with both speakers playing the same material.
From another thread started recently we can see some speakers actually use these variations to their benefit:
I think the Wilson Sabrina will probably be praised for natural sound and good imaging capabilities.
For those with EQ, try it, you might like what you hear 🙂.
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You are highlighting the importance of FLAT frequency response...
While I agree that flatness contributes to naturalness, many other things (distortions) will trump on it...
(Regarding the relationship with imaging, I have no idea...)
But FATIGUE may appear regardless of FR flatness. It cannot be seen from FR chart. But an impedance chart might show one or two hints. But most is in driver's NLD and the crossover works.
I think you are missing my point, Jay...
I'm actually promoting non flat frequency response for speakers used in a Stereo triangle.
Bump at 1850 and 5500, dip at 3700 and 7400, not much is needed, but try it and listen.
We have two ears, if they both work as advertised you'll hear the difference in imaging.
You'll also notice an improvement of intelligibility in the phantom center.
Distortions shouldn't have to be a problem in this particular range. (unless something went terribly wrong 😀) Flat frequency response might be a bit less ideal than you might think. As long as we are listening with two ears.
It gets even better if you only EQ the phantom signal (mid-side processing). As the side signals (panned hard left or right) don't suffer from that same comb effect. There's no opposing signal to comb with.
I'm actually promoting non flat frequency response for speakers used in a Stereo triangle.
Bump at 1850 and 5500, dip at 3700 and 7400, not much is needed, but try it and listen.
We have two ears, if they both work as advertised you'll hear the difference in imaging.
You'll also notice an improvement of intelligibility in the phantom center.
Distortions shouldn't have to be a problem in this particular range. (unless something went terribly wrong 😀) Flat frequency response might be a bit less ideal than you might think. As long as we are listening with two ears.
It gets even better if you only EQ the phantom signal (mid-side processing). As the side signals (panned hard left or right) don't suffer from that same comb effect. There's no opposing signal to comb with.
I always thought moving the crossover up as high as possible was beneficial, at least for a two way.
Now I see a 2khz or just under X/0 is good for 2 reasons. Beaming and keeping out of that sensitive ear area
Now I see a 2khz or just under X/0 is good for 2 reasons. Beaming and keeping out of that sensitive ear area
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No, I believe you are actually promoting a FLAT frequency response...
Except that you are looking for flatness at different position (at ear at listening position)...
Hehe. When people observe the Fletcher-Munson curve, they might think, hey why not change the response to suit our ears? But it has been done by the recording engineer when he/she uses the studio monitor, so pure flatness is actually what we want from this POV...
When musicians perform live, what adults hear is not the same with what teenagers hear (because they have different ears FR)... So which one do we want? Because the musicians are adults so we want what the adults hear? But the musicians get feedback from amplified control speakers when they are playing...
My point is simple: I don't put importance in FR flatness!
May be you should say the opposite? 😀
No, I don't think so.
I think it is not that hard to imagine that there will be more market for drivers that can do a wide range than a shorter range of equivalent price...
Beaming is a function of cone size (distance to the HF transducer). The bigger the cone, the lower you want to cross them (to avoid beaming). But it is rarely a limiting factor (you can even cut a tweeter flange if necessary)...
Most often, the limiting factor is the tweeter ability to be crossed low!
Keeping XO frequency below sensitive ear region is a fallacy. Yes, most midrange have peak just before roll-off. If bringing the XO low will avoid the necessity of using a notch filter, then it is a benefit. But how many times you meet this situation? None in my experience.
The common good reason you want to cross low is simply because you want to make wide band speaker with only 2 drivers. Big woofer will give you low frequency (bass) and xmax (watt), but you have to avoid beaming (hence crossing low)... Not to mention non-linear distortion that get worse with increasing frequency...
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Why not? Since it would make it a higher performing midrange it appear to be the obvious thing to do. How many people on here look at that dip and say yuck regardless of how audible it is likely to be? There seems to be no reason for it to be present in a conventional midrange.
They already have a midwoofer and so why opt for something half way between a midrange and a midwoofer rather than a midrange? I am not saying they don't have a good reason just that I cannot see what it is. Perhaps the next release will include a change like a new motor better suited to a conventional midrange and they didn't want this driver to be immediately superseded. Perhaps they see an opening in the market for a driver that is able to cross at a frequency below a conventional midrange to the extent it is worth sacrificing some upper midrange performance. I don't know but it seems a bit odd.
I can see a big commercial market for this driver. The midbass it's based on has a very good midrange, so it's an obvious addition to add a high sensitivity mid
Yes, except that it is not a midrange. They just haven't decided on producing a midrange yet. There are just too many possible sales&marketing reasons for this...
If you own a high end speaker company and would like to purchase at least a thousand of such midrange from them, I believe we will see the product very soon...
And why do you need them to produce the midrange, are the Scan-Speak too expensive for you? May be it is expensive because there is no demand.
SB Acoustics are calling it a midrange and putting it in their midrange section. You have twigged this is what is being discussed and not the midwoofers that have been around for a while?
I don't need to order a thousand to get SB drivers built to my spec. This is a batch of custom SB Acoustic midwoofers ordered by a small speaker manufacturer.
I am interested in midrange drivers because I am interested in high fidelity sound. The Scan-Speak midranges have their pros and cons as do the SEAS midrange drivers. It would be good to see conventional midrange drivers from SB Acoustics (and Dayton and one or two other manufacturers) because there are not many on the DIY market. And yes I expect this is because the demand is low given the number of 2 ways sold compared to the number of 3+ ways,
A mid with a minimal or fabric surround similar to those seen in B&W's would be nice.
I can see another obvious niche in SBs range for a type of mid which I'm sure would be very popular.. If they haven't thought of it already.
I can see another obvious niche in SBs range for a type of mid which I'm sure would be very popular.. If they haven't thought of it already.
Aren't you asking for a driver specialized for midrange duty? Whatever they call the drivers, they are intended for wide band capable of 2-way, so not really a midrange.
Driver design is all about compromise. It is easy to get a high quality midrange if LF performance is sacrificed.
Why not order your underhung midrange driver? 😉
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