What are benefits of adding HF driver 7khz up?

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I have the following system with vertical LowMidTweeterMidLow arranged speakers:
Mid-HF – Radian 950PB in PAudio 4525 bi-radial horn – Wright 3.5 2A3 amp
Low-Mid – Hawthorne Sterling Mid-woofers – open baffle – Quicksilver Mid-mono EL34 amp
LF – Hawthorne Augie woofers – open baffle – Crown K1 amp
Marchand XM126 3-way tube crossover with 24db slopes at 60hz and 500hz
Cary 306 SACD, Cary SLP-05 with Mundorf S/G/O, V-Cap CUTF on other amps coupling caps, MAC Reference, Mystic, and UltraSilver cables.

I am 50 years old and would like to know what benefits I would see if i add another amplifier, driver, and crossover at 7000hz? The response of the 950PB is fairly linear up to 15khz. Will there be more "air" or will I hear more of the room acoustics where music was recorded? Will it allow the 950PB to perform better? I can only hear tones up to about 15khz.

Thank you, Mike
 
Two problems with additional drivers:

1. You physically displace and muddle the source of sound especially in the crossover frequency range.

2. You need another crossover with all the assorted issues with crossovers.

I suspect that you may be at, or possibly even beyond the plus/minus tradeoff point of more drivers already.
 
I have the following system with vertical LowMidTweeterMidLow arranged speakers:
Mid-HF – Radian 950PB in PAudio 4525 bi-radial horn – Wright 3.5 2A3 amp
Low-Mid – Hawthorne Sterling Mid-woofers – open baffle – Quicksilver Mid-mono EL34 amp
LF – Hawthorne Augie woofers – open baffle – Crown K1 amp
Marchand XM126 3-way tube crossover with 24db slopes at 60hz and 500hz
Cary 306 SACD, Cary SLP-05 with Mundorf S/G/O, V-Cap CUTF on other amps coupling caps, MAC Reference, Mystic, and UltraSilver cables.

I am 50 years old and would like to know what benefits I would see if i add another amplifier, driver, and crossover at 7000hz? The response of the 950PB is fairly linear up to 15khz. Will there be more "air" or will I hear more of the room acoustics where music was recorded? Will it allow the 950PB to perform better? I can only hear tones up to about 15khz.

Thank you, Mike

There is no way for anyone on this site to know in advance what you will or won't hear. I recently tested my hearing and it is good to at least 16 Khz, the limit of the test I performed. I'll be 64 years old in July. The notion that age automatically means hearing impairment especially at higher frequencies is a myth. About 30 or 40 years ago I saw a report of hearing tests performed in what was once one of the quietest places in Africa. Tribal elders in their 70s had hearing accuity equal to teenagers.

Factors which contribute to hearing impairment include exposure to loud noises, drugs, illness, injury, and genetic factors sometimes where age is a consideration. If you have been exposed deliberately or accidentally to very loud noises even once your hearing may be impaired. A competent audiologist can perform a test or you can perform it yourself but you must be certain that the equipment you use has the range for it. For example the test I used was the mosquito ring tone web site. The speakers in my PC display are good to only 12 khz, above that I heard nothing. With Sony MDR-V6 headphones I heard to 15 khz. with Radio Shack Pro 25 I heard to 16 khz. While there are higher test tones on the web site I was unable to tell if I couldn't hear them because of my sound card, the earphones, or my hearing. I may try again using tweeters with known response to 20 khz or higher. Being able to hear the entire normal range of audible sound adds much enjoyment to listening to music and to life in general. It's a shame so many people foolishly and carelessly damage themselves permanently with very loud music, an impairment they'll suffer for the rest of their lives.
 
I find crossing in a piezo (with a 4.5khz resonance) at 5khz@24db to be extremely revealing of exactly what the recording monkies do in a recording. Like headphone revealing.

Your super highs will be cleaner than what that horn is giving you.

If I remember, someone was using a piezo with his tad driver and horn over at the audioasylum.

But yes, you need another crossover, another amplifier channel, and you get phase shift up there. But ideally you try and make a decision for what you think is best.

Norman
 
To me adding drivers is a classic engineering trade off.
An additional driver gains you:
1 Lower IM distortion.
2. Lower thermal compression
3. Lower excursion / Lower Harmonic Distortion.
4. Narrow Pass-band with the potential to have more ideal drivers.
5. Drivers that are the correct size to reproduce the frequencies without beaming.

The Costs are:

1. More phase issues do to the additional crossovers
2. Compromises in driver spacing to obtain at least 1/2 wave at crossover
3. Cost
4. Complexity
5. Difficulty of design

I encourage you to think about it in these terms.
What problems does this solve?
What problems does this create?

Observing what other people have done with loudspeakers, the range is from single driver speakers to 10 way.
Most designers feel that 2 way or 3 way (often with a sub) is a good compromise.
So my observation is the additional benefits diminish greatly as more drivers are added.

HTH

Doug
 
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Its really hard to do a 7kHz crossover without suffering from lobing issues that will generally depress the 7k area, unless you can very carefully control the listening axis and the phasing between the units. The biradial horn will give you fairly flat power response up to beyond 10kHz, so it isn't like it is overly direction.

I'd go without.

David
 
To those who can hear the highest two octaves between 5 khz and 20 khz, components of sound in this region are extremely critical in both quantity and quality. Even though as a percentage of the total sound it is usually relatively small, its importance is way out of proportion to the quantity. That may explain why there are probably more kinds of tweeters than all other types of drivers combined and why they attract so much interest. To those who can hear in this region, if this part of the spectrum is poorly reproduced, nothing else matters, nothing else is sufficent to compensate for it.
 
To those who can hear the highest two octaves between 5 khz and 20 khz, components of sound in this region are extremely critical in both quantity and quality. Even though as a percentage of the total sound it is usually relatively small, its importance is way out of proportion to the quantity. That may explain why there are probably more kinds of tweeters than all other types of drivers combined and why they attract so much interest. To those who can hear in this region, if this part of the spectrum is poorly reproduced, nothing else matters, nothing else is sufficent to compensate for it.

I will have to disagree with you on this one.

I would worry about everything else first before I got concerned about the top octave. It is way down on the list of priorities
 
To those who can hear the highest two octaves between 5 khz and 20 khz, components of sound in this region are extremely critical in both quantity and quality. Even though as a percentage of the total sound it is usually relatively small, its importance is way out of proportion to the quantity. That may explain why there are probably more kinds of tweeters than all other types of drivers combined and why they attract so much interest. To those who can hear in this region, if this part of the spectrum is poorly reproduced, nothing else matters, nothing else is sufficent to compensate for it.

Lets say sound is a cake which has a crust, filling and icing on top.

The filling (midrange) is the part you taste the most, and imo, the most important. But that said, awful icing (high frequencies) can certainly ruin a cake that is great otherwise. Same said for a terrible crust (bass).

But personally, I can enjoy a cake that has mediocre crust and icing if the filling is engaging.

Addressing the topic.....if what you are hearing 7k and up is dissatisfying, then I might ask this question also. It depends on what you are hearing that is unsatisfactory. Is it dispersion? Intensity? Smoothness (lack of)? Answering this would help me anyway make a recommendation or determine if adding a super tweeter would help.
 
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To those who can hear the highest two octaves between 5 khz and 20 khz, components of sound in this region are extremely critical in both quantity and quality. Even though as a percentage of the total sound it is usually relatively small, its importance is way out of proportion to the quantity.
I'd agree with that to some extent, certainly the smoothness of response from 5-20Khz is extremely critical, more so than at lower frequencies. It doesn't take much in the way of narrow lumps and bumps in that range to cause harshness.

Yesterday I had an amusing reminder of how important and fussy high treble can be, I had been listening to some music for an hour or so and something was bothering me - the phantom channel image was considerably off to the right, maybe about half way between the centre line and the right speaker, with the overall presentation being a bit lacking in air and a poor, compressed stereo spread to the image.

I was checking the balance control, the cables and all manner of other things, and finally found the problem. Turns out I'd bumped the knob on the graphic EQ and accidentally put a 2dB 1/6th octave notch at 16Khz in only the LEFT channel. :eek: Fixing this restored the phantom channel location to the centre, improved the air and realism and broadened the stereo image spread again.

Considering my hearing only goes to 17.5Khz the effect of this small notch in one channel over a rather small frequency range at the extreme end of my hearing range was WAY out of proportion to what you might expect.

So to those who think that above 10Khz doesn't really matter that much, it really does if you have hearing that can hear it, and very accurate matching of the treble frequency response between left and right channels is also critical, as image location at treble frequencies is almost entirely amplitude balance related.
 
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couldnt have said it better. I have two different speakers for my stereo hack n slash hifi of the moment. Same tweeter, but different woofers, tweeter HP crossover 2.5k and 3k. It never quite sounds right. the mids arent matched due to the differing woofers, but with tinkering they have a very similar response, except in bass; but honestly its the tweeters that make it noticable. maybe the difference in phase due to different crossover points? either way I also hear to maybe 17k at best (using winISD sine generator) but even the slight mis match in tweeter crossover, and baffle width(3/4" difference), I can easily hear the stereo image sinking to the right...
 
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I would worry about everything else first
Agreed, but once you get there...

if this part of the spectrum is poorly reproduced, nothing else matters
I find this region needs to be in line with the octave before or else it seems to 'unmask' it, e.g. I can find sibilance issues if the upper octave is too low in level and vocalists (for example) will potentially fall back slightly, almost to get lost into the mix. Too high a level will also introduce a sibilance that sounds an octave higher in nature, combined with sizzle. Just right and it keys in like a focus adjustment meaning the vocalists are right there and sounding clean.
 
I find this region needs to be in line with the octave before or else it seems to 'unmask' it, e.g. I can find sibilance issues if the upper octave is too low in level and vocalists (for example) will potentially fall back slightly, almost to get lost into the mix. Too high a level will also introduce a sibilance that sounds an octave higher in nature, combined with sizzle. Just right and it keys in like a focus adjustment meaning the vocalists are right there and sounding clean.
If by upper Octave you mean 10-20Khz then I agree, thats exactly what I notice.

The balance between 5-10Khz and 10-20Khz is pretty critical, a lack of 10-20Khz response can indeed cause apparent sibilance in the 5-10Khz region even if the response is actually flat before starting to roll off at 10Khz.

My guess is this is due to some sort of hearing masking effect between adjacent octaves - presence of 10-20Khz content partially masks 5-10Khz content so if 10-20Khz is missing the 5-10Khz region is "unmasked" and is perceptually exaggerated.

On the other hand I find excessive response from 10-20Khz can lead to an overly airy and thin sound that sounds impressive for a short time but is ultimately unsatisfying and lacking in body.

In my experience the exact shape of the treble response in the top 2 octaves does seem rather critical to get the "focus" just right, making small tweaks in the network to shape the response optimally quite worthwhile.
 
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The ability to reproduce the highest overtones of acoustic instruments accurately to recreate their exact timbre is beyond the current state of the art. Careful examination of the way musical instruments propagate sound into space and the way loudspeaker systems propagate sound shows radical differences that explain why. To a critical listener there are no commercially available loudspeakers that can satisfactorily reproduce the sound of most musical instruments. The conventional notion of how a loudspeaker system should perform in what is purported to be a high fidelity sound reproducing system is basically badly flawed. Experimental designs that address this problem have yielded much better results.
 
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