Thank you for that, it is very interesting to see all the measurements that you took. I particularly like the directivity information; I think that would suit me quite well. So the small upper-mid-tweeter continues to seem like a very viable answer, if one can accept the small compromise of a crossover at that point (which I believe that I can).
It would really come down then to distortion (power compression etc) of the chosen small driver at the intended SPLs. That might dictate any need to move up to compression drivers or other costly options (or a change in strategy), or it might not.
Thanks again,
Kev
It would really come down then to distortion (power compression etc) of the chosen small driver at the intended SPLs. That might dictate any need to move up to compression drivers or other costly options (or a change in strategy), or it might not.
Thanks again,
Kev
Without even considering the cost of them, for CD/HL tweeters you would be operating near their lower limits, seems like it misses the entire point of your original idea of using FR/WB from 800 up (which from my experience I think could be a good direction to go, with the right driver combo).
I didn't care for the TPL150h crossed any lower than about 2kHz personally. Also found the very limited vertical dispersion difficult to live with..
Not that I move up & down whilst listening but the overall power response in the room was all wrong. Other than that it's a very resolving driver.
Not that I move up & down whilst listening but the overall power response in the room was all wrong. Other than that it's a very resolving driver.
You're welcome!
OK, though is a bit too small at best based my understanding of the fundamentals of acoustical engineering with effective diaphragm diameter = ~3", not frame size and presumably why small true coax drivers start at 4" frame size and seems the best overall choice for this type app.
Correct based on this hearing sensitivity chart.
OK, re current point source drivers, only familiar in general with the TB brand and at a glance this 3" looks like a good choice for ~ equally dividing the 800-20 kHz BW with a ~4300 Hz XO, leaving lots of options such as the TPL150h for the (super) tweeter.
Why not four small WR instead of one? Like in classic EJ Jordan linear array?
https://rasenkan.c.blog.ss-blog.jp/_images/blog/_470/rasenkan/IMG_1049.JPG
One day I shall try a line array or linear array; I did wonder about it for this project, but that would be a separate thread. They are certainly interesting and I'm quite attracted by them, though (as always) still with compromises and I need to learn more about those first.
For now though, I have certain components that I'd like to make use of, which would lend themselves to a multi-way. Two good 10" bass drivers, and a decent multi-way DAC, for instance. I also have a soft-spot for 3-ways, since they were what I lusted after but could not afford in my youth.
Probably I shall end up making both in the longer term, and so being able to compare directly.
For now though, I have certain components that I'd like to make use of, which would lend themselves to a multi-way. Two good 10" bass drivers, and a decent multi-way DAC, for instance. I also have a soft-spot for 3-ways, since they were what I lusted after but could not afford in my youth.
Probably I shall end up making both in the longer term, and so being able to compare directly.
...or why not a nine of them?
Here is German HobbyHiFi's Vi-Line with 9 Visaton BF32 small WRs
Here is German HobbyHiFi's Vi-Line with 9 Visaton BF32 small WRs
Thank you again, GM. Hmm, possibly my 3" is a slightly outdated number and/or based more on nostalgia than reality. Particularly as I'm considering modern wide-range drivers, which try to manage their high-frequency break-up and off-axis performance, they could be a bit bigger. And if there were to be a tweeter, the choice would be even wider.
As this thread progresses, I'm starting to think more in terms of the dispersion wanted. Certainly from the midrange upwards I'm not wanting particularly wide dispersion, and in fact would like to avoid it for reducing unwanted room reflections. So larger drivers (for their frequency) or waveguides need not be a bad thing within reason, and could certainly have advantages. Given adequate cones and sufficient motor strength to maintain performance, anyway.
Cheers,
Kev
Thanks, and thanks also for the suggestions. It is interesting, and fun, to think of all the ways in which one could make a pair of stereo speakers!
There are some active threads with 10-12" woofers + wide range, or mid tweeters as I sometimes call them.
I got a pair of Alpair 5.3's a while ago — the single suspension design got me curious. But it would also be nice to see some more old-school 'cone' tweeters around. Just based on theory, I'm wary of excessive rocking modes on tweeters with maximum-diameter voice coils, where the surround has very little leverage to keep the coil steady and not oscillating like a coin that just got dropped onto a flat surface.
Since the coils nearly always have spiral windings, rocking modes will be constantly active to some extent, but my thinking is: at least with a larger cone-style tweeter the surround has more leverage.
I wonder if crimped paper style surrounds could be technically a better idea than the far more popular soft-roll polymers? Some energy will be reflected from the edge of the cone, leading to the notorious break-up. But at least the reflected energy won't undergo harmonic distortion and IMD with each reflection.
I've been reading up on soft domes in other threads, but it irks me because it seems like there could be strange "beam steering" effects in the polar response, just from phase shifts on different parts of the dome.
But enough about the hardware. There is also a lot to think about in the crossovers and amplifiers...
I got a pair of Alpair 5.3's a while ago — the single suspension design got me curious. But it would also be nice to see some more old-school 'cone' tweeters around. Just based on theory, I'm wary of excessive rocking modes on tweeters with maximum-diameter voice coils, where the surround has very little leverage to keep the coil steady and not oscillating like a coin that just got dropped onto a flat surface.
Since the coils nearly always have spiral windings, rocking modes will be constantly active to some extent, but my thinking is: at least with a larger cone-style tweeter the surround has more leverage.
I wonder if crimped paper style surrounds could be technically a better idea than the far more popular soft-roll polymers? Some energy will be reflected from the edge of the cone, leading to the notorious break-up. But at least the reflected energy won't undergo harmonic distortion and IMD with each reflection.
I've been reading up on soft domes in other threads, but it irks me because it seems like there could be strange "beam steering" effects in the polar response, just from phase shifts on different parts of the dome.
But enough about the hardware. There is also a lot to think about in the crossovers and amplifiers...
Once you start thinking about arrays, it helps to simulate them to see what effect an array can get you. A variety of array simulations can be found in this thread, with a sample project based on the Peerless/Vifa TC9 FD18-08 (a close relative of the Scan Speak 10F): https://www.diyaudio.com/community/...-corner-placement.337956/page-28#post-6205129
It would be good to look around in that thread a bit, there were a lot of different array setups simulated. You can easily try shorter arrays to see the effect it has on the vertical listening window. It inspired me to turn my unshaded 25 driver array into a frequency shaded array using 25x 10F 8414 G10 per side.
Thanks, both.
Abstract, as it happens I also have a pair of the alpair 5.3s, which I'm using in a small near-field waw/2-way project at the moment - yet to be completed. They're interesting and I have high hopes, though I need to spend a lot more time with them before I reach any conclusions. They are quite sparkly and detailed, but am yet to decide if that sounds entirely 'real' or if it might involve artifacts that could annoy over time.
For this thread/project (if I go with wide-range mid-tweeters), I'd probably need to step up to one of their bigger brothers. Though the MS drivers are less well specified and community-tested than many alternatives, even for things like off-axis performance. Which doesn't mean they aren't great, but doesn't help with initial selection so I'd be more likely to go with other brands.
Wesayso, thanks too. I shall have a look through those links. Arrays are very interesting and something I intend to try at some point, but I've only heard them in PA/concert situations and know quite little about designing them, so they'll be for a future project. It does seem like there is scope for quite a few different approaches to them.
Cheers,
Kev
Abstract, as it happens I also have a pair of the alpair 5.3s, which I'm using in a small near-field waw/2-way project at the moment - yet to be completed. They're interesting and I have high hopes, though I need to spend a lot more time with them before I reach any conclusions. They are quite sparkly and detailed, but am yet to decide if that sounds entirely 'real' or if it might involve artifacts that could annoy over time.
For this thread/project (if I go with wide-range mid-tweeters), I'd probably need to step up to one of their bigger brothers. Though the MS drivers are less well specified and community-tested than many alternatives, even for things like off-axis performance. Which doesn't mean they aren't great, but doesn't help with initial selection so I'd be more likely to go with other brands.
Wesayso, thanks too. I shall have a look through those links. Arrays are very interesting and something I intend to try at some point, but I've only heard them in PA/concert situations and know quite little about designing them, so they'll be for a future project. It does seem like there is scope for quite a few different approaches to them.
Cheers,
Kev
SB12MNRX2-25-04 4" midrange would allow you to hit 107db at 400hz within x-max. You'll get another 6db of help from the woofer at the crossover point. Equal power point in most program material is around 300hz. Orchestra can hit 111db peaks. It's a mid, but sounds excellent fullrange. Even though you could use it to 300hz and still hit over 100db, I prefer running the larger driver up to 400 for dynamic presence.
Kev, we seem to be in a similar boat, then, because my build is slowly progressing in small bursts on weekends.
I was very pleased with the CHN-50 earlier, which inspired me to get the 5.3s. They were originally intended for a small FR project as a gift, but I decided to bump it up to 4 or 5" ( not started yet), so now they're waiting for other parts of my sprawling 12"+3" active speaker project to come together.
The Alpair 5.'s seem to respond well to series resistance, sounding much softer and smoother with 10 ohms connected to a class-D amp, as compared to a direct connection. I've been agonising over amplifier design options for months, and I'm finally getting close to "locking in" what I want and whipping up some PCBs. It's...:
-class-A,
-low negative feedback in the output stage,
-high output resistance,
-low noise, low part count.
They are also getting some wooden wave guide TLC, which I've never done before. This should help keep the amplifier small, too. So it's ALL happening.
I was very pleased with the CHN-50 earlier, which inspired me to get the 5.3s. They were originally intended for a small FR project as a gift, but I decided to bump it up to 4 or 5" ( not started yet), so now they're waiting for other parts of my sprawling 12"+3" active speaker project to come together.
The Alpair 5.'s seem to respond well to series resistance, sounding much softer and smoother with 10 ohms connected to a class-D amp, as compared to a direct connection. I've been agonising over amplifier design options for months, and I'm finally getting close to "locking in" what I want and whipping up some PCBs. It's...:
-class-A,
-low negative feedback in the output stage,
-high output resistance,
-low noise, low part count.
They are also getting some wooden wave guide TLC, which I've never done before. This should help keep the amplifier small, too. So it's ALL happening.
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Diypole Thanks for the recommendation; I like SB and can get them here. It also seems like a 4" (frame) or 3" effective diameter might be the sweet spot for my purposes, so shall look at these with great interest.
Yes, the dynamics are something that I am very keen on too, and are partly behind my initial thoughts on a slightly higher crossover of around 800hz or so, with a ~6.5" for the lower-mid (and upper-bass). I've used a 4" (effective diameter) for the whole midrange before, and it was pretty detailed but I thought a bigger one would have benefited the lower-midrange dynamics somewhat.
The second most tempting plan is still just the more traditional ~5.5" mid driver crossed above the most critical range; tried, tested and popular for a reason, though less interesting perhaps. If I went this way, probably I'd want some kind of waveguide for the tweeter, given my renewed interest in directivity. (I'm still looking into the more unusual/enthusiast options like compression drivers and so on; they have different compromises and some are a lot more costly).
Abstract that sounds like a good project. I haven't even got as far as the amplifiers for mine yet, other than wanting it to be active. It doesn't seem the best time to be sourcing semiconductors, though possibly things are improving at last. I quite like the idea of waveguides too, though size might be a consideration (in my case) for lower ranges.
Cheers,
Kev
I like these above 500 Hz .... just a simple first or 2nd order crossover needed .. very easy to work with esp..if running in open baffle mode ( otherwise you may need to build a rear chamber )
https://www.parts-express.com/GRS-PT6825-8-8-Planar-Mid-Tweeter-8-Ohm-272-126
https://www.parts-express.com/GRS-PT6825-8-8-Planar-Mid-Tweeter-8-Ohm-272-126
Lately I have been using a Fostex 166EN full range driver as the "tweeter" in my system. I had been using a 1" compression driver in a horn over Altec/GPA 414-8c woofers (12") , biamped, crossed over at 1200 hz using a Pass 6-24 crossover set at 24db/oct. ( I have Selenium 220, Celestion CDX1-1746, and Altec 902 compression drivers and Dayton Audio B-52, Dayton Audio 612, and Dr. Edgar 650 hz "salad bowl" horns) I swapped in the Fostex 166EN in a .5 cubic foot box, sealed, without changing the crossover. I am not good at describing sonic differences, but I think that the Fostex full range are very good, if a little "soft" on top. They sound more "full bodied" than the CDs on horns, which may be just a result of less high frequency extension. I plan on doing a shoot-out with the CDs on different horns comparing them to the Fostex to see what stays in the system.
Thank you, Decker. That is useful to hear, especially as I'm considering both full-range or CD for the mid-tweeter. I currently believe that either could work very well, but that the CD might be overkill for my purposes (and age related hearing loss); a reduction off-axis at high frequencies would not be a problem for a number of reasons. But no decisions made yet (or in fact for some time) so I'll look forward to the results of your shoot-outs as you decide for your own system.
The specific widerange driver you're using isn't common over here, neither is zobsky's planar midtweeter (USA dwellers appear to be very fortunate for such things!). But there are alternatives that would have comparable characteristics.
Thanks,
Kev
The specific widerange driver you're using isn't common over here, neither is zobsky's planar midtweeter (USA dwellers appear to be very fortunate for such things!). But there are alternatives that would have comparable characteristics.
Thanks,
Kev
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