Hello Camplo
With reference to low excursion I am not seeing this as an issue in real life using a pair of inexpensive near field monitors. I have a pair of JBL 308Mk 2 with a subwoofer I listen to all day at work. They are 92db @ 1 meter. I listen to them @ 1 meter and once you add a sub even stupid loud, which doesn't take much power@ 1 meter, there is no significant excursion in the 8" drivers. Using a stand alone active 24dB analog L/R crossover @ 80Hz for the crossover.
Carry on.
I just think you are making this much harder than it needs to be by some of the choices you are making. Do you have any practical experience with any near fields combined with subs?? I don't understand why you are putting such a premium on excursion. In my experience it's a problem that simply doesn't exist @ your proposed listening levels. JMHO
Oh and a little something on cone stiffness and break-up vs profile.
Rob
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My system that this new system will replace, is a krkS4V4 strapped to the top of 12" krk 12"s in a boxes I designed. You can get the krk 12 and plate amp on Apex Jr for pretty cheap....I got tired of not being satisfied with the bass performance. 200watts into 4ohms rms, per sub. I had the krk V8's previously, and I miss the midbass, so I thought. Technically I just missed the the amount of Sd I had. Been listening to this system for several years now.
I'm creating the largest System I can, that theoretically, I could use nearfield, even if only by my own unorthodox logic.....and then settling for what ever materializes and what ever real life limitations that comes with it. So yes, I want to use the system nearfield....but I also want to use it from about 6-7 feet away.....and in the event that I ever have a larger basement maybe 10 ft away....and its nice to know that most of the system will still be able to keep up.
My reasons for using so much Sd, are more than just excursion. I am trying to create the most Direct Energy I can, also....
I'm creating the largest System I can, that theoretically, I could use nearfield, even if only by my own unorthodox logic.....and then settling for what ever materializes and what ever real life limitations that comes with it. So yes, I want to use the system nearfield....but I also want to use it from about 6-7 feet away.....and in the event that I ever have a larger basement maybe 10 ft away....and its nice to know that most of the system will still be able to keep up.
I want my system to play flat to 115db/1m/30hz, how do you achieve this with an 8"???
My reasons for using so much Sd, are more than just excursion. I am trying to create the most Direct Energy I can, also....
(The pic actually includes an allpass, on the lower woofers. In XO pic its showed, as turned off.....with it off, GD is better (13ms at 30hz) and FR the same.)
I still do not know everything I want to know about critical Q.
I pulled up WinISD and an AEtd15H ina sealed Box....Adjust box size till qtc says 0.5....
As long as the bass roll off, is the same exact shape as what I see here? Thats the goal?
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That could be argued if you weren’t also applying a +24 dB gain to the passband.
I’m also not sure what the other simulation parameters such as driver diameter and baffle placement are entered as, but right now you appear to have a speaker with 180 degrees of coverage - apart from some bad waist banding through the midrange to HF transition and narrowing of coverage above 10 kHz.
Being polite, I would call the model ‘untrustworthy’.
I’m also not sure what the other simulation parameters such as driver diameter and baffle placement are entered as, but right now you appear to have a speaker with 180 degrees of coverage - apart from some bad waist banding through the midrange to HF transition and narrowing of coverage above 10 kHz.
Being polite, I would call the model ‘untrustworthy’.
I'd agree, HP at 27 Hz. and + 24 dB gain?
And the data that Camplo has been showing is either a different format than I am used to, or these results are pretty bad - by my design intent. Do you (Camplo) really think that high SPL and directivity is going to make up for a bad frequency (axial and/or power) response? Or is the idea to EQ it all flat for near field and not worry about anything else.
And the data that Camplo has been showing is either a different format than I am used to, or these results are pretty bad - by my design intent. Do you (Camplo) really think that high SPL and directivity is going to make up for a bad frequency (axial and/or power) response? Or is the idea to EQ it all flat for near field and not worry about anything else.
Without full measured data the only part of camplo's system that can be simulated to any degree of accuracy in Vituix is the mid woofer.
Did you guys read the part about the horns polar being a rectangle made with vituixcad? I have to wait to get the horn to get accurate data.
The gain staging is so random. I will try to clean it up...to take an actual 1 meter measurement atm, would include room, so I stuck with measurements from about 1"
The gain staging is so random. I will try to clean it up...to take an actual 1 meter measurement atm, would include room, so I stuck with measurements from about 1"
mid woofer and sub...
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The above is almost +\-2db. Power response, is a room calculation isnt it? I thought we were not to trust room calculators? With a typical tractrix horn tweeter system the top end is going to beam...in respect to what is known as the "better" polar, achieved with a constant directivity waveguide, this set up will have a smooth off axis transition but the beaming up top, is what it is.
I also intend to develop a waveguide for the Axi2050. If there were a particular model of waveguide you wanted to point me to, especially one that has already ben shared in mabats thread....I could probably get it printed rather soon...any suggestions?
No midwoofer only, the slot loaded sub has more going on than a nearfield and basic baffle diffraction can predict. If you are crossing at 80Hz you could probably get away with simulating it like an omni source on a big baffle and not worry about the rest.
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The power response is not a room calculation it is the total sum of all radiated sound from the speaker.
Ty!
Is there a source of data showing various power responses of different systems?
How do you personally feel about power response...the article the above pic is from, suggest that, some say it is an outdated concept. "Outdated" sometimes can seen as "neglected" lol so I tread lightly
Lets consider the power response of my 350hz tractrix...I listen to it pointed at the ceiling...when I put my ear on axis....I hear no "power response" per say....lets say I do... I'd think its the "airiness" of the reverb, using my dome tweeters...the lower the power response the less reverb....
If I were to theorize; Power response, no less than off axis transition, should be smooth and without peaks or nulls....and as uniform, as in constant, as possible. To which one could apply that, just like off axis transition, having a smooth transition devoid of peaks/nulls, is most important.
Is there a source of data showing various power responses of different systems?
How do you personally feel about power response...the article the above pic is from, suggest that, some say it is an outdated concept. "Outdated" sometimes can seen as "neglected" lol so I tread lightly
Lets consider the power response of my 350hz tractrix...I listen to it pointed at the ceiling...when I put my ear on axis....I hear no "power response" per say....lets say I do... I'd think its the "airiness" of the reverb, using my dome tweeters...the lower the power response the less reverb....
If I were to theorize; Power response, no less than off axis transition, should be smooth and without peaks or nulls....and as uniform, as in constant, as possible. To which one could apply that, just like off axis transition, having a smooth transition devoid of peaks/nulls, is most important.
The power response is the inverse of the directivity Index/DI of the system. Go look up the JBL M2 brochure it's all in there. On axis, listening widow, power response, first reflection and system DI.
Rob
You will hear the power response differences in speakers if you listen in a normal room..
Here is a gallery of Spinorama (ANSI-2034) data for various speakers. Power response is one of the curves. https://pierreaubert.github.io/spinorama/index.html
You can get the standard for free from CTA : https://members.cta.tech/ctaPublicationDetails/?id=367c1410-7212-e811-90ce-000d3a004988&reload=timezone &reload=timezone
Here is a gallery of Spinorama (ANSI-2034) data for various speakers. Power response is one of the curves. https://pierreaubert.github.io/spinorama/index.html
You can get the standard for free from CTA : https://members.cta.tech/ctaPublicationDetails/?id=367c1410-7212-e811-90ce-000d3a004988&reload=timezone &reload=timezone
Ive been spending time listening to the axi2050+350hz, playing bird songs and female vocals....mostly off axis
Listening to the birds in the basement (krks5v4) the treble has much more reverb. The axi2050+horn have a dryer top end. I feel like I could approach this way more scientific
Still
I'm pretty sure this is the difference in the power response but I don't know why I'm supposed to care... I think I hear the difference but it does not concern me, if my feelings change in the future I will express it
Listening to the birds in the basement (krks5v4) the treble has much more reverb. The axi2050+horn have a dryer top end. I feel like I could approach this way more scientific
Still
I'm pretty sure this is the difference in the power response but I don't know why I'm supposed to care... I think I hear the difference but it does not concern me, if my feelings change in the future I will express it
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Not exactly correct.The power response is the inverse of the directivity Index/DI of the system. Go look up the JBL M2 brochure it's all in there. On axis, listening widow, power response, first reflection and system DI.
Rob
The DI(theta) is the power response normalized by the "theta" response. In other words, the DI is dependent on what is chosen as the listening axis.
The listening axis response is what the direct field response will be, and the DI indicates what the relationship will be between the direct sound and the reverberant sound. If the DI is flat, then the reverberant field will have the same timbre as the direct sound. If it rises, then the direct sound will be "bright". This holds above say 300-400 Hz where the ears integration time is such that it cannot distinguish between the direct sound and the reverberant sound. But always remember that this is dependent on what one chooses as the listening axis. I choose and design my systems for a flat DI along about 20-25 degrees and toe-in the speakers. Thus, my direct field has the same timbre as the direct sound.
The software on my website shows many speakers listening axis response and the DI as the angle is changed. It also shows the power response. So there are many examples available.
Your "theory" is exactly the reverse - the higher the power response the greater the reverberation will be. The higher the DI, the lessor the reverb field will be and, which is very important, the more delay there will be in the onset of the reverb field.