4" (3.5"-5") high efficiency wanted please

[otto88]

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).

[otto88]

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?)

[sumaudioguy]

Originally Posted by SunRa

FaitalPRO M5N12-80

Anyone mentioned it?

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.

[badman]

Originally Posted by sumaudioguy

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.

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.

[badman]

Originally Posted by otto88

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).

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.

[sumaudioguy]

A thread somewhat related just popped up: Most powerfull 15cm Scan Speak revelator based driver

Have a look

[badman]

Originally Posted by sumaudioguy

A thread somewhat related just popped up: Most powerfull 15cm Scan Speak revelator based driver

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.

[otto88]

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

[otto88]

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

[sumaudioguy]

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-