I'm in the planning stage of my first multi driver speaker build. I've only ever built subwoofers prior to this so I'm in uncharted waters. I'm wanting to build a pair of 3 way speakers to go with my latest subwoofer build. Its a T-Line , quarterwave (down to the centimeter) and modeled strong well up past 100 Hz so the down low is covered. The initial plan was a 3 way setup 8" woofer, 4" mid and horn tweeter. My question is where it comes to the mids. Is it better to just buy a midwoofer or would a full range driver work better? I'm just trying to make sure every end of the spectrum is covered and aaybe learn a thing or 2 so an explanation of why one or the other would be ideal would be very much appreciated. I'm of the mindset of do one thing, do it well so I question the "full range" would have the same quality sound as a dedicated midwoofer and a tweeter handling the highs. Or am I misunderstanding what full range actually means. Thanks for your time
I have successfully built speakers using a woofer and a small fullranger instead of a 3-way setup. This often allows for the crossover point to be in the 500-700Hz range, but with a FR driver the high end may suffer (especially off axis) depending on which fullranger you use. Have you considered a BMR type driver (e.g. from Tectonic Elements) as the fullranger? That could work out well.
I use in my WWMT 2x8", 1×4" midrange from purifi, and as upgrade path to the still to arrive purifi tweeter a sb26adc with 4" waveguide. Crosses at 433 and 3464Hz, works very fine, and directivity from mid to tweeter is a quite close match. Check my thread: https://www.diyaudio.com/community/...ed-after-15-years.391827/page-10#post-7677790
Best your first attempt be a two way......3 ways with bandpass midrange is VERY difficult to design and implement the crossover.
There are lots of 8" midwoofers that can reach up to a horn tweeter.......the B&C 8pe21 can easily top your T Line subwoofer with an F3 of 120hz and is one of the best sounding mid drivers i've ever used regardless of price or size.
For the midrage of a 3 way neither a wideband driver (1 way) or midwoofer (2 way low end) are an appropriate choice. The appropriate choice is a midrange driver. Broadly when used as a midrange a wideband driver will have too low a power handling and too low an efficiency to keep up with the tweeter and woofer. A midwoofer is a bit less compromised than a wideband driver but will tend to have too low an efficiency (it is fairly common to use 2 midwoofers above and below the tweeter to address this) and will usually be a bit more compromised at the high end compared to a midrange in terms of resonances and radiation pattern.
The objectives for a speaker design can vary widely and trading maximum technical performance to address other factors can be perfectly valid thing to do which could involve midwoofers or, at a stretch, wideband drivers.
OP: In a 3-way, then a good midrange driver should in theory be optimised for covering that frequency band. A general purpose small mid/bass woofer or a full-range driver would both need more excursion in order to cope with lower frequencies (in their intended roles), which can involve compromises elsewjere, potentially around the midrange. Full-range drivers might also make small compromises to improve higher frequencies. So, wider range isn't necessarily 'better' unless you need it.
But in practice, driver's general labels don't necessarily tell how they'll perform in different applications. A good mid/bass woofer might actually have very acceptable levels of distortion in the midrange, for instance. Or it (and or a full-range driver) might allow the use of a simpler shallower crossover and/or crossover frequencies that a dedicated midrange might struggle with. So really, you need to evaluate individual drivers against specific intentions and requirements.
That all said, I can't immediately think of any full-range driver that I would personally prefer for use in a normal midrange scenareo, whilst there are mid/bass drivers that I've happily used in place of dedicated midrange drivers.
But in practice, driver's general labels don't necessarily tell how they'll perform in different applications. A good mid/bass woofer might actually have very acceptable levels of distortion in the midrange, for instance. Or it (and or a full-range driver) might allow the use of a simpler shallower crossover and/or crossover frequencies that a dedicated midrange might struggle with. So really, you need to evaluate individual drivers against specific intentions and requirements.
That all said, I can't immediately think of any full-range driver that I would personally prefer for use in a normal midrange scenareo, whilst there are mid/bass drivers that I've happily used in place of dedicated midrange drivers.
The idea for the 8" woofer ws to handle the 120-350+/-Hz range that when the 4 " would take over handling anything between that and where the tweeter could comfortably take it from there. . Didnt and still don't like the idea of 1 driver handling too wide of a frequency. But like I said, I'm a noob at anything other than subs and I'm learning a buttload. In another 20 years I might actually know a litte something. Thank you for your time
I've heard this a couple times over the past 2 days. Maybe you all are on to something
It's true that most fullrange drivers are not that fit as some dedicated midrange drivers, but some are usable for it, like the 3 to 6" mark audio drivers may fit. Idem with the Faital 3 and 4" fullrange drivers (probally some of the better for the task) and the Scanspeak 10M series.
But many are not that fit. They are to resonant in the wanted passband, or have wizzers (that have disadvantages) or are not sensitive enough (many smaller fullrange drivers). You don't have to look at the nominal description, but see if the specs are fit for a midrange use in combination with the other drivers. And many times you will find better dedicated midrange drivers than fullrange drivers to fit best. But not always...
But many are not that fit. They are to resonant in the wanted passband, or have wizzers (that have disadvantages) or are not sensitive enough (many smaller fullrange drivers). You don't have to look at the nominal description, but see if the specs are fit for a midrange use in combination with the other drivers. And many times you will find better dedicated midrange drivers than fullrange drivers to fit best. But not always...
Depends on what sensitivity you need for the mid.
And what your crossover frequency is.
The larger the mid, it will become directional at a lower frequency.
So the tweeter must be able to crossover lower and be a suitable type to cross low for low distortion.
So larger drivers can be more helpful for higher sensitivity but the tradeoff is a lower crossover point for the tweeter.
Some " midbass" drivers are also designed to have more bass so they take a tradeoff in sensitivity.
Some speakers might be only 83 to 85 dB and do bass well.
But not really needed for a midrange.
Also over time you will be able to see in response charts and recognize the response rises in the highend
or becomes jagged in the topend from cone break up . So be able to determine if they work within the bandwidth you need.
Basically they all eventually break up in the top end, and the crossover removes it anyways.
just depends how soon they breakup.
And what your crossover frequency is.
The larger the mid, it will become directional at a lower frequency.
So the tweeter must be able to crossover lower and be a suitable type to cross low for low distortion.
So larger drivers can be more helpful for higher sensitivity but the tradeoff is a lower crossover point for the tweeter.
Some " midbass" drivers are also designed to have more bass so they take a tradeoff in sensitivity.
Some speakers might be only 83 to 85 dB and do bass well.
But not really needed for a midrange.
Also over time you will be able to see in response charts and recognize the response rises in the highend
or becomes jagged in the topend from cone break up . So be able to determine if they work within the bandwidth you need.
Basically they all eventually break up in the top end, and the crossover removes it anyways.
just depends how soon they breakup.
After many years in the modern era of recorded music, I’ve come to a couple of practical experience conclusions……the art form of excellence in a recording has taken a back seat to efficiency and productivity……..simply because physical media no longer sells.
In that, lies the problem with critical midrange content and how a 2 way reproduces it as opposed to a dedicated midrange driver……think of those as peaking drivers……forcing their way through the wider pass bands of the others, interjecting themselves…..forcing to be heard. And if the quality of the content isn’t there or the phase relationship within the crossover isn’t great ( and it HAS to be with mids) you wind up with a very forward sounding speaker. With a two way who’s crossover typically lies in the 2khz range or lower, while not as clinical, the blending of the content is more homogeneous….easier on the ear so to speak.