I've got my own theory for why some prefer ports and some don't, which simply relates room modal peaks which can easily ruin impression of speaker system. The modal peaks intensity could depend on speaker positioning, but of course the room itself, which is somewhat different for everyone of us. I've come to this conclusion after building big speakers, I'm on fourth prototype bass boxes currently and these are closed and half the volume of first "box calculator" ported boxes, and only now I do not have to cut room modal peaks with EQ. Bass was simply overwhelming with bigger boxes, while I could just EQ them I could just go smaller and closed to avoid some other issues like port noise, reduced cost and surface area overall, and aesthetics. I had feature of too much bass capability which came with trade-offs and I could just make those go away sacrificing the excess. These still have box volume and volume displacement of several average bookshelf speakers which enables plenty bass without unnecessary trade-offs and gets towards problem free speaker, at least more problem free than it was before.
So, I think there is no universal truth which is better. Given same room and person either closed or ported could work. Even then perhaps small speakers could benefit from ports to have some impact, even if it was from modal peaks, and so on, try out and choose the better more suitable one. One could experiement by blocking a port, or build another better suited set if there is luxury to make prototypes until "optimal to situation". If there is one conclusion from all this is I think EQ really helps, perhaps in all situations. I'll never depart my DSP.
So, I think there is no universal truth which is better. Given same room and person either closed or ported could work. Even then perhaps small speakers could benefit from ports to have some impact, even if it was from modal peaks, and so on, try out and choose the better more suitable one. One could experiement by blocking a port, or build another better suited set if there is luxury to make prototypes until "optimal to situation". If there is one conclusion from all this is I think EQ really helps, perhaps in all situations. I'll never depart my DSP.
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My one-penny-thought: make sure 5khz is not deficient else music won't sound dynamic. My favorite 5" fullrange in a 10L 1.3m tapered transmission line played Karajan's Dvorak bass drum concerto nee 9th so exhilaratingly I could not stay seated. The "drum paper" speakers had a very narrow 5khz sharp peak -- once notched, I could listen to music forever and enjoy every note and nuance -- seated. To me the challenge of classical music is "polyphony" where each musical part "sings" melodiously and with verve, and they all sing together in conversation. This is true for all music not only classical, but even chamber pieces with piano are extremely complex, and difficult for audio.
They Carreras are nice and sound great; They sound even better when crossed to a woofer/sub at 100-150hz.
@Alpigiano : what’s about your room? If you can place speaker outside from front wall then a competent dipole speaker like NaO Note II RS can be better for classical music than any three way box speaker, and they do not require much wood working
I did some homework after your feedback, and modelled a few options for woofers. I have also re-drawn the boxes to be deeper and allow for more volume, up to 55-60 lt. I still prefer the original design but I could live with it.
I attach a table with all the numbers, but this is probably information overload, so I'll try to summarise.
What I did:
Conclusions:
Details and questions:
Thanks a lot again!
I attach a table with all the numbers, but this is probably information overload, so I'll try to summarise.
What I did:
- I modelled a few drivers in my shortlist as either single or 2x, depending on their Vd and Re
- Calculated Closed, BR and also the max LW transform the driver could sustain before running out of linear excursion. The latter is mostly for reference in case I found myself with too much SPL and wanted to extend the range. I used VituixCAD
- Also added expected SPL based on Vd and Small's formulas (i.e. not sensitivity and watts). Cross-checked here.
- Limited the box size to a Vb of 58.3 (that's what approx came out of my drawing)
- Added a pro driver from Eminence that Tekton uses, mostly for reference
Conclusions:
- I don't think a 2x setup will work. Either too much Vb required, too much baffle space or too little Sd. And more expensive
- If I want a lot of SPL, I'll be better off with a sub or two.
- Front runners are SS Discovery 26W/4534G00 (used by Troels in his Discovery 3WC-10, which TBH that's a pretty good design for my use case, I can make the box a little shorter & deeper), Satori WO24 (P or TX), and another SS, Revelator 26W/4867T00, also a Troels pick as it was pointed out by @duvixan
Details and questions:
- I wasn't impressed by the WO24P midrange when I heard it. It didn't sound as musical as a Wavecor to me. But it models well, it's good value and I could cross it low. I've read that the TX version is cleaner, but it's more than twice the price. Worth it?
- 2x 8'' Wavecor WF223BD01 (4 Ohm) in series actually models the best of all 2x here. But it's difficult to justify the cost over the SS 26W/4534G00, unless the higher Qms and lower Rms actually make enough of a difference at low volume. Or if I want to cross it higher (to a dome midrange). Am I missing anything?
- The SS Revelator models really well, it's expensive but still cheaper than 2x configurations. I only wish Qms and Rms were comparatively better. This is where my lack of experience suggests to save my cash. Is this the right approach or am I putting to much weight into T/S parameters?
- The SS Discovery looks like really good value. Even half decent in a closed design, so I could experiment with the safety of using Troels' design if closed doesn't work. It can take a lot more in BR, feels like I'm wasting it a bit.
- The Eminence is a very interesting piece of kit. I will try to listen to it. I'm a bit nervous about using a guitar driver, I worry that it won't be as good on transients. Should I be though?
Thanks a lot again!
I wonder if this is why I liked the Morel dome 'filler' midrange? But yes, I will be careful in the 2-5k range.
While I was modelling all the drivers, I was thinking the same. I need to try them with a high pass. I will do some tests as soon as I get some time. I only have a crappy sub on hand but it may be enough.
