4” 400/500 - 4000 Hz
The Max Fidelity PR4 neo8 could be ideal - badman how was it's clarity, what range did you use it over?
Any other suggestions for a low distortion 4” 97+ dB mid for 400 or 500 to – 3500/400 Hz?
For me, it's to extend the upper range of dipole radiation pattern of an open baffle system, beyond what you get with 6.5 or 5.25 inchers (per cuibono and Rudolf Finke).
The Max Fidelity PR4 neo8 could be ideal - badman how was it's clarity, what range did you use it over?
Any other suggestions for a low distortion 4” 97+ dB mid for 400 or 500 to – 3500/400 Hz?
For me, it's to extend the upper range of dipole radiation pattern of an open baffle system, beyond what you get with 6.5 or 5.25 inchers (per cuibono and Rudolf Finke).
Or as Scott pointed out, 2 in parallel
The linked Dayton is 5", but more important I want to use something really good
Vifa's PL11WH09-04 is about 91 db, but Zaph's Small Driver Comparison (Zaph|Audio) found distortion was pretty ordinary
. . are there any good 4” mids of 91 dB? (Visaton, Selenium, Beyma, Volt?)
The linked Dayton is 5", but more important I want to use something really good
Vifa's PL11WH09-04 is about 91 db, but Zaph's Small Driver Comparison (Zaph|Audio) found distortion was pretty ordinary
. . are there any good 4” mids of 91 dB? (Visaton, Selenium, Beyma, Volt?)
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Very cool driver finds.....
Very interesting driver. Will clearly be checking this one out more closely. Thanks
chlorofille- whoa- price sticker shock! Thanks for the link! Very curious company and products. Reading their webpage was very interesting. Feastrex
Thanks to contributors
this thread is turning into a treasure trove of unique and efficient drivers. Useful and informative.
badman- as a few have done repeatedly on DIYaudio- set themselves up as an (claimed) expert and then belittle and argue with anyone who does not agree with their (limited) perspective and then refusing to stick to the thread topic which is identifying existing drivers, I kindly ask you to stay off this thread. You have had your "minute of fame" on this thread and enough is enough. If no one is wants it or is interested why does this thread keep going? Another (typical) wrong conclusion based on assumptions by you. Stay on topic or clear out. Your worthless (ignorant?) opinions do not belong here.
Very interesting driver. Will clearly be checking this one out more closely. Thanks
chlorofille- whoa- price sticker shock! Thanks for the link! Very curious company and products. Reading their webpage was very interesting. Feastrex
Thanks to contributors
this thread is turning into a treasure trove of unique and efficient drivers. Useful and informative.badman- as a few have done repeatedly on DIYaudio- set themselves up as an (claimed) expert and then belittle and argue with anyone who does not agree with their (limited) perspective and then refusing to stick to the thread topic which is identifying existing drivers, I kindly ask you to stay off this thread. You have had your "minute of fame" on this thread and enough is enough. If no one is wants it or is interested why does this thread keep going? Another (typical) wrong conclusion based on assumptions by you. Stay on topic or clear out. Your worthless (ignorant?) opinions do not belong here.
Very interesting driver. Will clearly be checking this one out more closely. Thanks
chlorofille- whoa- price sticker shock! Thanks for the link! Very curious company and products. Reading their webpage was very interesting. Feastrex
Thanks to contributors
badman- as a few have done repeatedly on DIYaudio- set themselves up as an (claimed) expert and then belittle and argue with anyone who does not agree with their (limited) perspective and then refusing to stick to the thread topic which is identifying existing drivers, I kindly ask you to stay off this thread. You have had your "minute of fame" on this thread and enough is enough. If no one is wants it or is interested why does this thread keep going? Another (typical) wrong conclusion based on assumptions by you. Stay on topic or clear out. Your worthless (ignorant?) opinions do not belong here.
You're out of line. Argue the point and keep personal attacks out. Look at the Faital spec sheet. It's 85dB at the cutoff frequency you specified, as (approximately) are all drivers this size and efficiency. It will take several times xmax (though not quite reaching Xdamage) and more than its full power handling to reach your 109dB target at 150. This is true of ALL DRIVERS OF THIS STYLE. Wake up and smell the excursion.
I didn't use the PR4, due to the price, only the PR65Neo, which has a manageable breakup. QC and build quality was not as nice as I'm used to, however. I don't know if that's still the case as it's been a few years since I got mine. Directly to the point of this thread, I ran it in a sealed box trying to maximize the bandwidth at the bottom end for approximately a 150Hz cutoff. It managed (being 2x as big as but definitely was obvious when running out of steam when driving loud in the bottom end as Xmax was exceeded. Performance increased quite a bit when I moved the XO up closer to where it was intended, 300-500. The same was true with other 6.5" high eff mids incl. Audax PR17OMO, and also with the smaller JBL LE5 when I briefly played with it. One could push a high output small driver to 200 or even lower (good luck with managing the overdamped bottom end) in a low output system but that's not what's being demanded here. Even at high home listening levels this is a constraint. A lot of dynamic energy is centered around and about 150Hz.
A thread somewhat related just popped up: http://www.diyaudio.com/forums/mult...l-15cm-scan-speak-revelator-based-driver.html
Have a look
Have a look
It's very cool but misses your sensitivity requirements and then some. You were very specific about the high efficiency and output level demanded, and huge travel and power handling go against the high efficiency in real world driver designs. I do also wonder about long term power handling, that's an awful lot of heat to cram in a tiny box. I've seen peoples drivers fail every which way and they all give up the ghost when pushed to the limits. It's one click of the volume control or one ac compressor kicking on and poof, when you're demanding action at the limits of real world constraints. Also of note is fidelity. While he obviously did a great job on the DIY of it, that is going to be a distortion monster (at high output), most notably, Le/X is going to be all over the map.
This should be probably another thread, re the maximum SPL of drivers, related to their size and Xmax:
While this is written re subwoofers, the same principles apply to all size drivers:
Electrical and mechanical limits
While this is written re subwoofers, the same principles apply to all size drivers:
Electrical and mechanical limits
Thanks for your experience with the PR65Neo badman
I think I might be better going active and SS: needing just say 88 dB, I can find a really good driver
I think I might be better going active and SS: needing just say 88 dB, I can find a really good driver
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I just have not experienced the issues so many talk about as "problems." This is why there are so many custom drivers here rather than off the shelf products. Me and the other driver designer get together and decide how it needs to be and have it made that way. Sure we get lots of "that won't work" and "you cannot do it that way" but, you know what? It can work and it does work that way every time. Ah, the difference between knowledge and theory. There are many with theories and babble on about this and that having never built even one driver from scratch. And the guys with a computer modeling program are far worse believing a click of the mouse and the "correct" answer will be calculated. On the other hand drivers developed here have occasionally been widely copied by several of the bigger players. Flattery for a well conceived design. Driver design covers a lot of different aspects with always the case of optimization for a particular application required. I honestly wonder why so many of the drivers made are even made in the first place? So many drivers seem to not be optimum for anything. For high efficiency and small size, weight of the moving parts is the main number to make smaller. In a woofer weight can well be a friend but in mids, tweeters, and compression drivers for high efficiency weight is much more like obesity- never good for efficiency of motion.
I am certain a driver will eventually emerge from this effort as all the help from DIYaudio people bringing out others design efforts (those who are kind enough to share there knowledge of off the shelf drivers) and the manufacturers who have taken an interest in this. Maybe once again we will be blessed with (have available) efficient mids and tweets that will play very loud without the need for a lot of watts and we who use them can enjoy the dynamics that only high efficiency can give.
One more thing- Xmax is about the most useless driver spec there is. In no way does this single number tell anyone what amount of distortion a specific driver will make at a given SPL. Yes when Xmax values are exceeded we all know distortion will increase but in no way does Xmax provide a clear limit. Suspension (spider and surround) and air motion around all the moving parts tend to dominate the linearity at excursion exceeding 2mm for many of the driver I have seen. Likewise I have seen suspension combined with small Xmax where even though the Xmax was exceeded by factor of 1.5 the distortion curve showed no clear change in slope at the transition. JBL even had a name for this as it was their driver. Saying Xmax is automatically the limit simply shows lack of both knowledge and experience with emphasis on mathematical models and theory and not of what actually happens in the real world with real transducers. I likewise suppose if a theoretical only approach works well then theoretical only music should sound likewise as well.
Keep bringing those off the shelf speakers to this thread. Have seen a lot of interesting things. Thanks-😀
I am certain a driver will eventually emerge from this effort as all the help from DIYaudio people bringing out others design efforts (those who are kind enough to share there knowledge of off the shelf drivers) and the manufacturers who have taken an interest in this. Maybe once again we will be blessed with (have available) efficient mids and tweets that will play very loud without the need for a lot of watts and we who use them can enjoy the dynamics that only high efficiency can give.
One more thing- Xmax is about the most useless driver spec there is. In no way does this single number tell anyone what amount of distortion a specific driver will make at a given SPL. Yes when Xmax values are exceeded we all know distortion will increase but in no way does Xmax provide a clear limit. Suspension (spider and surround) and air motion around all the moving parts tend to dominate the linearity at excursion exceeding 2mm for many of the driver I have seen. Likewise I have seen suspension combined with small Xmax where even though the Xmax was exceeded by factor of 1.5 the distortion curve showed no clear change in slope at the transition. JBL even had a name for this as it was their driver. Saying Xmax is automatically the limit simply shows lack of both knowledge and experience with emphasis on mathematical models and theory and not of what actually happens in the real world with real transducers. I likewise suppose if a theoretical only approach works well then theoretical only music should sound likewise as well.
Keep bringing those off the shelf speakers to this thread. Have seen a lot of interesting things. Thanks-😀
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Care to give a few examples of your drivers and how they "break the rules"?
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From one manufacturer, good news:
Good day.
You must have been endeavoring in speaker industry for decades. In deed, time changes, high efficiency drivers aren’t that common now. However, we’re capable to produce high efficiency speaker which could meet your standard. Kindly let us know your estimated quantity for us to study.
Good day.
You must have been endeavoring in speaker industry for decades. In deed, time changes, high efficiency drivers aren’t that common now. However, we’re capable to produce high efficiency speaker which could meet your standard. Kindly let us know your estimated quantity for us to study.
A few posts have been removed along with some collateral damage. Let's stay on topic and try to pocket your attitudes.
Thanks Cal!
How does the XT25 play 110dB? It does not have too?
How does a 4" driver play 110dB cleanly below 200Hz?
How does the XT25 play 110dB? It does not have too?
How does a 4" driver play 110dB cleanly below 200Hz?
Thanks for the cleaning- it was needed.
As a reminder, the very narrow topic is outlined in post #1. 🙂
doug20- could you define "cleanly" in terms of THD or some other standard? I find 5%THD at 110dB not a problem at at all near 200Hz. Indeed, I have seen zero single woofer systems which are less than 5% distortion at 110dB through their pass band.
badman- as often is the case rules are more imagined than real and hard fast. Please realize the models are at best a poor approximation for what really happens in a wide band transducer. Having reviewed load cell testing of about 100 suspensions at Nuway and done many more myself I have seen everything but constant K behavior for a spider. Spiders are often used to correct other problems such as general non-linearity and the region where the voice coil is not fully in the gap thereby causing a linearized result from the combination of non-linear behaviors. I do this exact thing, addition of non-linear elements, in my sub-woofer resulting in a change in THD from about 15% at 30Hz and 105dB to less than 3%. Much the same thing applies to any wide band transducer.
Does anyone feel like making a spreadsheet showing effective piston size, frequency, SPL, and length of stroke required? That might be a handy reference for every DIYaudio participant and would certainly help move every discussion away from the need for Xmax numbers
As a reminder, the very narrow topic is outlined in post #1. 🙂
doug20- could you define "cleanly" in terms of THD or some other standard? I find 5%THD at 110dB not a problem at at all near 200Hz. Indeed, I have seen zero single woofer systems which are less than 5% distortion at 110dB through their pass band.
badman- as often is the case rules are more imagined than real and hard fast. Please realize the models are at best a poor approximation for what really happens in a wide band transducer. Having reviewed load cell testing of about 100 suspensions at Nuway and done many more myself I have seen everything but constant K behavior for a spider. Spiders are often used to correct other problems such as general non-linearity and the region where the voice coil is not fully in the gap thereby causing a linearized result from the combination of non-linear behaviors. I do this exact thing, addition of non-linear elements, in my sub-woofer resulting in a change in THD from about 15% at 30Hz and 105dB to less than 3%. Much the same thing applies to any wide band transducer.
Does anyone feel like making a spreadsheet showing effective piston size, frequency, SPL, and length of stroke required? That might be a handy reference for every DIYaudio participant and would certainly help move every discussion away from the need for Xmax numbers
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Again, what drivers did you design that were revolutionary in not following the "rules" of the driver designers? You said you've been copied by Seas, what drivers? This is important to the conversation because you're making claims of capability that far exceed what's recognized as the limits of driver capability, so if you have indeed got good results that don't fit current "best practice" for either driver or system designs please put them forth.
More of an issue than the THD (which with a ~7mm sweep would be substantial and likely far over 5% at 200Hz 109dB in a current production 4") would be modulation artifacts. You don't want large excursion in a cone trying to also do frequencies with quarter wavelengths less than the stroke!
I just do not know what "rules" you are talking about. Never said I designed drivers for Seas, I made recommendations for substantial changes to drivers made by Seas which were all implemented. This is one that was changed: https://www.madisound.com/store/product_info.php?cPath=45_234_265&products_id=8706 and is a classic still sounding and testing very well so many years later.
Have no idea who recognized the limits or what those limits are you mention. Could you come up with some reference or make a list? I just do not know of any limits in particular which interfere with the driver I have in mind. As noted one manufacturer has already stated it is within their capacity. What else do you require as proof? When you say "modulation artifacts" are you speaking of IM distortion, self noise, or what? Please clarify this nebulous statement. Never have said anything about a 7mm stroke, that is your assumption. I said Fs near or below 100Hz and usable at 99dB to 200Hz or lower and able to handle 10 watts or more. My intent though that may not have been perfectly clear. By your word the 7mm stroke leads to an upper frequency limit of 12,246Hz. Is that really important for a 5" driver? No. The rest you invented so cannot really address your inventions. You must do that.
One more thing... the main reason the interest is in smaller drivers is they are to be used to 2kHz crossover or higher. It is well established directivity of a piston type transducer begins to collapse, increasing directivity, when the piston is 1/2 the radiated wavelength. With a piston equal to the wavelength the radiation angle becomes quite a bit less, 45 degrees as I recall but could be incorrect. For the Panasonic 5 inch the piston is near 3.7 inches which gives an upper limit for avoiding this effect of 3649Hz. To me this means an upper crossover point no greater than wavelength equal to 1.5 times the piston diameter or 2432Hz.
PA drivers are often used far beyond these limits. The PA drivers though high efficiency are almost always used well beyond these frequency limits. As example 10", 12", and 15" drivers are commonly used in two ways with smallish horns or waveguides. With the limit in mind a 10 would only play to (1.5 times piston size and 8.3" piston size) to 1084Hz. Far to low for any smaller horn. Of course the larger drivers have lower limits. Even a common open dome (no lens or waveguide) 1" tweeter has an upper limit using this definition of 6750Hz (one wavelength) which is very close to what I have found using emperical testing. With these limits in mind it is easy to see why here for PA a 6.5 inch down to 120Hz is used in the PA cabinets with output to 122dB peak. This is a rule I am familiar with.
There are a lot of compromises required for any loudspeaker. Am just seeking what I consider to be the most important aspects first. Controlled directivity is very high on the list of importance. THD is further down the list but still in the top ten.
PA drivers are often used far beyond these limits. The PA drivers though high efficiency are almost always used well beyond these frequency limits. As example 10", 12", and 15" drivers are commonly used in two ways with smallish horns or waveguides. With the limit in mind a 10 would only play to (1.5 times piston size and 8.3" piston size) to 1084Hz. Far to low for any smaller horn. Of course the larger drivers have lower limits. Even a common open dome (no lens or waveguide) 1" tweeter has an upper limit using this definition of 6750Hz (one wavelength) which is very close to what I have found using emperical testing. With these limits in mind it is easy to see why here for PA a 6.5 inch down to 120Hz is used in the PA cabinets with output to 122dB peak. This is a rule I am familiar with.
There are a lot of compromises required for any loudspeaker. Am just seeking what I consider to be the most important aspects first. Controlled directivity is very high on the list of importance. THD is further down the list but still in the top ten.
Your definition is fine. Just looking for clarifaction on the requirements. I posted earlier that I was interested in this project since I have built high sensitivity 3 ways and 2-way waveguides. Im curious about a 4" high sensitivity option and nothing else.
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