I've done quite a bit of loudspeaker measurement work, both in-room and quasi-anechoic. I use a combination of gated sine sweeps and nearfield techniques to get accurate low-frequency data and stitch it together with the farfield response. My main tools are REW and ARTA, depending on what I’m analyzing, and I use a calibrated microphone for consistency. I'm very mindful of time-windowing and mic placement to avoid early reflections corrupting the data, and I typically gate to around 5–7 ms indoors, or measure outdoors when I want cleaner midrange data.
I also take multiple measurements at different angles to build a proper off-axis profile, which helps when refining crossover design and directivity. I'm not just looking at on-axis SPL—power response and DI are just as important to me when voicing a speaker, especially for achieving a balanced in-room response.
Beyond the basics, I typically export polar datasets to VituixCAD for full simulation, including both horizontal and vertical directivity. I measure at 10° increments from 0° to 180°, normalize for mic distance and SPL, and apply frequency-dependent windowing (FDW) to smooth out ripple while preserving resolution where it matters. I compensate for baffle diffraction using simulation overlays from tools like Edge or AKABAK, and I also factor in driver acoustic centers to time-align phase through the crossover region.
When tuning, I evaluate group delay and excess phase to verify that system phase tracking aligns with minimum phase behavior, especially near crossover points. I’ve also been experimenting with burst decay plots and energy-time curves to correlate subjective transients with measurable characteristics. For the low end, I use blended nearfield and port measurements summed with appropriate phase alignment and correction for baffle step loss.
I like to keep an eye on compression characteristics too—multi-level sweeps at various SPLs help identify motor non-linearities and thermal compression, especially in long-gap, low-distortion designs like those from Purifi. And of course, I always check impedance and electrical phase to ensure amplifier friendliness and stability across the entire bandwidth.
Anything else?
The laws of physics limit what can be achieved in terms of sound quality by small 2 way speakers. Expensive drivers cannot overcome this but given the significant limitations of the configuration expensive drivers that are competently engineered may bring small improvements.
As a beginner it may be wise to expect one's first design to be rather less than it could have been with a bit more knowledge. This leans towards starting with good quality standard range drivers rather than expensive prestige ones unless price is not a concern or the use of prestige components is of value in itself. Active rather passive crossovers can help with understanding and developing crossovers efficiently. A removable baffle may be worth considering w.r.t. swapping drivers and baffle shape w.r.t. waveguides given waveguides are used by almost all small 2 ways with a high technical performance (high by the standards of small 2 ways rather than large speakers).
The most impressive small speakers I have heard used motional feedback to get a large linear displacement at low frequencies. Might make a nice DIY project.
Well if at the time...you were clueless, had no measuring equipment, and only planned to build one pair of speakers the rest of your life, then it was a good choice. Has that changed?
Have you ever built your own design?
Do you know the thrill of creating something optimized for your needs, or desires, or do you simply have a nice pair of speakers?
Sometimes it's not just about saving money, but what makes you say that you saved quite a bit of it?
What use is a benchmark?
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What makes a pair of speakers sound BIG:
1. Great dynamics with little or no increase in perceived distortion at higher volume
2. Enough output between 40Hz to middle C -- say 260Hz.
3. Great imaging/sound stage
4. Micro-dynamics, which I take to mean the ability to project fine detail and quieter sounds while simultaneously putting out big loud sounds, also seems important.
The Purifi is a celebrated high performance driver with great linear FR, outsize bass reach & low distortion. Unless you want to be able to listen at very high SPL (let's say >100 dB), There doesn't seem any reason it can't do what you want. Esp if your preferred listening position is close to the speakers (say 2m or closer). A Bliesma T34 would be quite a combo.
1. Great dynamics with little or no increase in perceived distortion at higher volume
2. Enough output between 40Hz to middle C -- say 260Hz.
3. Great imaging/sound stage
4. Micro-dynamics, which I take to mean the ability to project fine detail and quieter sounds while simultaneously putting out big loud sounds, also seems important.
The Purifi is a celebrated high performance driver with great linear FR, outsize bass reach & low distortion. Unless you want to be able to listen at very high SPL (let's say >100 dB), There doesn't seem any reason it can't do what you want. Esp if your preferred listening position is close to the speakers (say 2m or closer). A Bliesma T34 would be quite a combo.
Honestly, I feel the OP needs to change his height dimension to allow the standard 4.125" tweeter to be installed if using a 7" woofer. It opens a lot of options.
That said, I've built 4 designs in such a vented 15ltr box, with more to come, and find my most recent one quite satisfactory....
That said, I've built 4 designs in such a vented 15ltr box, with more to come, and find my most recent one quite satisfactory....
Hello
It was a good choice all around. It gave me a reference to compare in real time. Would do it again 20 years latter just a bit different having learned over the years. Still have them to this day. I had already built my active 4 way set-up my Urie 811C and XPL's by then. Unfortunately at the time measurement set-ups were not really affordable so used a Behringer 1/3 octave RTA until I could afford the real deal a CLIO measurement system.
Yes several times
Yes to both.
Saved about 2/3 of the cost of a used pair of JBL 4344's at the time. Was able to purchase cores and get them re-coned so my clones were using new drivers in comparison to a used system. Ended up a win win as I always wanted a pair of large format monitors and got to use essentially factory fresh drivers.
It's a comparison tool to compare your own builds against. I have a couple of stock systems I use for that.
4344 on the left Active 4 way on the right.
Rob 🙂
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Yes, but not that much. I trust you are able to use measurements to design a loudspeaker. Why did you come up with the Purifi and a small tweeter?
If I wanted to make the most of a 0.5 cu ft box, I think I'd give this one a try in a sealed alignment: https://www.scan-speak.dk/product/18w-8535-01/ If you model it you'll find the F3 of ~53 Hz unimpressive, but the gentler 12 dB/oct roll-off means the bass will be effectively more extended than a vented box with a lower F3 and it will play more nicely with room gain and close to wall placement. Qtc will be around 0.76 (+/- depending on Rs and stuffing) which should provide negligible peaking and a pretty good transient response.
As for the tweeter, how about this one: https://www.scan-speak.dk/product/d3004-602200/ I've never tried it myself but it looks like it's basically a small flange / neo magnet version of the D3004/6600, which I've used in a couple of designs and like very much. It does require a Z-flattening LCR trap but takes a lot of abuse without showing any signs of distress even when cut as low as 1.5 kHz, which gives you a lot of flexibility in your crossover design.
As for the tweeter, how about this one: https://www.scan-speak.dk/product/d3004-602200/ I've never tried it myself but it looks like it's basically a small flange / neo magnet version of the D3004/6600, which I've used in a couple of designs and like very much. It does require a Z-flattening LCR trap but takes a lot of abuse without showing any signs of distress even when cut as low as 1.5 kHz, which gives you a lot of flexibility in your crossover design.