While waiting to finish my learning project (thread link) I am starting to think over what my next project could be. I must be enjoying it!
My mostly used current pair of speakers is Genelecs 6010A in the kitchen - these are playing almost all the time when we are at home. As you know these are very small, the smallest Genelec make - 3in mid-woofer, 25W amps, 20cm tall.
I was thinking to build a small sub to complement them, but another option could be making a new small (abt 35cm tall) 2-way based on a slightly larger (5-6in?) high-excursion midwoofer with Hypex FA122 or FA252. I also thought I could experiment with a box made from multiple 'slices/layers' of MDF, so I can work on them without a workshop and using only small tools on pre-cut small panels. I could even try to make a rounded shape for the box a-la Genelec.
Genelec G4 is about 36cm tall, have 6.5in midwoofer and 90W amps. This sort of size.
Enclosure of 35cm x 25cm x 25cm will roughly have an internal vol of 6-7L and will fit a 6.5in woofer + tweeter and Hypex FA122/252.
Question: What mid woofers should I consider?
If my current project proves Dayton Epiques are good, I was thinking to use the 6.5in (Link) which is for small boxes and just about fits in terms of size and could be paired with SB26stwgc (Link) (which I am also using in the current project) crossing over at about 2kHz.
Looking for a significant improvement in bass extension (high SPL not needed).
Or have I gone mad?
My mostly used current pair of speakers is Genelecs 6010A in the kitchen - these are playing almost all the time when we are at home. As you know these are very small, the smallest Genelec make - 3in mid-woofer, 25W amps, 20cm tall.
I was thinking to build a small sub to complement them, but another option could be making a new small (abt 35cm tall) 2-way based on a slightly larger (5-6in?) high-excursion midwoofer with Hypex FA122 or FA252. I also thought I could experiment with a box made from multiple 'slices/layers' of MDF, so I can work on them without a workshop and using only small tools on pre-cut small panels. I could even try to make a rounded shape for the box a-la Genelec.
Genelec G4 is about 36cm tall, have 6.5in midwoofer and 90W amps. This sort of size.
Enclosure of 35cm x 25cm x 25cm will roughly have an internal vol of 6-7L and will fit a 6.5in woofer + tweeter and Hypex FA122/252.
Question: What mid woofers should I consider?
If my current project proves Dayton Epiques are good, I was thinking to use the 6.5in (Link) which is for small boxes and just about fits in terms of size and could be paired with SB26stwgc (Link) (which I am also using in the current project) crossing over at about 2kHz.
Looking for a significant improvement in bass extension (high SPL not needed).
Or have I gone mad?
Last edited:
This is the thinking for the box construction method:
- Use about a dozen 19mm MDF pre-cut panels as 'slices' glued together
- Cutouts in each to form the internal chamber, bracing and amp box
- Panels pre-cut to approximate the outer curves, then sand down to shape (the square shape on the right represents the largest/smallest panel size, the curve on the left represents the sanded down shape).
- Double thick front panel
- Stand made from MDF (with rubber dots at contact points) to allow adjustment to position, similar to how Genelec isopods work (4-poit support 'cradle').
Model it in VituixCad. You will get a reasonable approximation of what the performance will look like. Whether the two drivers will cross nicely while respecting impedence minimums, in-phase, with a good DI, and finally with good listening window and on-axis linearity. Often one of those factors has to give sufficiently enough to make the driver pairing non-viable (at least in the sense that it's worth building that speaker and not something better).
I think I just about managed WinISD, but I am still to find my way around VituixCAD - will use this project to learn it. After all, this is the first project where I do the box from scratch (i.e. not using an existing box like in the first project).
Assuming a standard box (not any fancy curved things) 35cm x 25cm x 25cm - should have internal volume of ~18L (less drivers, braces, Hypex enclosure). Not sure how you arrived at 6L?
First step - I'd recommend settling on a approximate box size and volume. That will allow you to consider which woofer driver (dimensions and TS parameters) you can use. Which leads to closed/ported decision, and that leaqds to an F3 you can aim for.
As it is a 2way - a reasonable directivty will restrict the woofer size to 6"-5", though a tweeter with waveguide may be able to mitigate that upwards. (Though plenty have made successful projects with a 2way using an 8" woofer)
First step - I'd recommend settling on a approximate box size and volume. That will allow you to consider which woofer driver (dimensions and TS parameters) you can use. Which leads to closed/ported decision, and that leaqds to an F3 you can aim for.
As it is a 2way - a reasonable directivty will restrict the woofer size to 6"-5", though a tweeter with waveguide may be able to mitigate that upwards. (Though plenty have made successful projects with a 2way using an 8" woofer)
I quickly modeled your original idea E180HE-44 + SB26STWGC-4 in the suggested baffle and keeping in mind I am a novice and don't really know how to model the active filters in Vcad -> that combo is not looking too great. Directivity is the main problem. There surely is a better crossover; but I feel directivity is just not solvable between a 7" sub and 1" tweeter. DM me and I'll send you the Vcad project so you can start your exploration.
EDIT: The waveguide on that tweeter probably will make better directivity match than this suggests (I don't know how to model the waveguided response in Vcad); but it will probably still be pretty bad.
EDIT: The waveguide on that tweeter probably will make better directivity match than this suggests (I don't know how to model the waveguided response in Vcad); but it will probably still be pretty bad.
Oh, thank you!
Would using the 5.5in version of the Epique improve directivity in the problem band? And/or using a tweeter with a lower extension and lower crossover point?
I will respond to post 6 tomorrow.
Would using the 5.5in version of the Epique improve directivity in the problem band? And/or using a tweeter with a lower extension and lower crossover point?
I will respond to post 6 tomorrow.
you could try tracing the off axis responses, the data sheet includes 30 and 60°.
It is a bit curved, and accounting for the walls, amp, drivers, bracing I get this estimate:
Working assumption is therefore 'about 6L', which would be the min. Relatively easy to almost double the vol by extending the depth of the cabinet. so say 9-11L max.
Yes, the larger, the less dispersion.
But his one I do not understand. How does a tweeter waveguide mitigate the woofer's lack of dispersion and allow a larger woofer? I lack knowledge here.
I could think of using a larger tweeter allowing a lower crossover, so less beaming from the woofer of the same size. But a larger tweeter will also have worse dispersion.
A waveguide restricts tweeter dispersion, allowing for a better blend between the tweeter and woofer off-axis. Constant directivity is about having reflected sound being even (between woofer n tweeter) as the on-axis sound so the blended of the "off and on" is uniform. If there's a disparity; once the reflections arrive the final blend the ear gets is not the same as on-axis.
I'd say in that 6L box - the E150HE-44 might be OK.
At 5.5" directivity will be better managed than the 7". I'd still look for a tweeter that has a waveguide and can be crossed low. This is a subwoofer after all, you don't want it playing 2KHz and up.
You might also consider SUB120_vHP-8 from Kartesian as the woofer. They have a two way kit with that sub (w passive x-over), which is more or less what you're trying to build.
I'd say in that 6L box - the E150HE-44 might be OK.
At 5.5" directivity will be better managed than the 7". I'd still look for a tweeter that has a waveguide and can be crossed low. This is a subwoofer after all, you don't want it playing 2KHz and up.
You might also consider SUB120_vHP-8 from Kartesian as the woofer. They have a two way kit with that sub (w passive x-over), which is more or less what you're trying to build.
Last edited:
ok, got it. it is not just dispersion of each driver individually, it is both having similar dispersion (at least around the crossover point), so the projected and reflected sound field is more even.
Will check that Kartesian pair. Will also have a go at my first VCad attempt using your starter model. Will try to replace the drivers in it etc.
Will check that Kartesian pair. Will also have a go at my first VCad attempt using your starter model. Will try to replace the drivers in it etc.
Last edited:
Don't forget - the steps for Vcad:
- Take a picture of the graph on the spec sheet of the driver and trace ZR and SPL (Dayton Audio provides files for most drivers so can skip this step)
- Enter the Enclosure tool; add the driver TS parameters; model the enclosure (just use the "auto align" for now); export SPL and Z (impedence doesn't matter for you as you are using DSP)
- Enter the Diffraction tool; create your baffle as per desired dimensions; model the difraction (I add the traced 0degre 1/2 space spl) and export at 10 degree increments
- Merge the Enclosure SPL with the Woofer diffraction export
- Add the drivers; all the SPL files; and the ZR
- Mess about with crossover
That little one (5.5in) looks reasonable to 2Khz, but narrows rapidy afterwards. That THD peak at crossover (1.1Khz) is a 2nd harmonic ~30db down from the fundamental - probably a non-issue. In your idea, I think it's a good candidate in a vented enclosure.
Another option is to use the larger one and go 3-way.
Small tweeter, 4in midrange and the 18cm Epique.
Then xovers become very comfortable, box slightly larger and in horisontal orientation. Box dimensions partly driven by the length of the plate amp.
Small tweeter, 4in midrange and the 18cm Epique.
Then xovers become very comfortable, box slightly larger and in horisontal orientation. Box dimensions partly driven by the length of the plate amp.
The Epiques don't really have the kind of performance you'd really want for midrange duty due to their, unfortunately, high inductance and 3rd order distortion.
The E150 is better in this regard though.
It really puzzles me why they brought them to market with such glaring issues. Especially as Dayton wanted to market these as something like an alternative to the Purifi drivers. As it stands their bass performance is decent but that's about it. Everything else is just mediocre.
The Genelec speakers you've already got might not have much bass/power but, by the sound of things, they go loud enough. Also, if they are in use all the time, they probably sound excellent otherwise you'd want to shut them off. This would not be surprising as all the measurements I've seen of Genelec speakers have been excellent. They are well engineered speakers, in low diffraction cabinets, with good attention paid to directivity control.
Adding a subwoofer, as well as high passing the Genelecs, would be a very pragmatic way to improve the system. Improving upon, what would appear to be, the only area that the system appears to be lacking whilst maximising on what the 6010As are really good at.
Of course if you're wanting to build another pair of speakers have at it!
The E150 is better in this regard though.
It really puzzles me why they brought them to market with such glaring issues. Especially as Dayton wanted to market these as something like an alternative to the Purifi drivers. As it stands their bass performance is decent but that's about it. Everything else is just mediocre.
The Genelec speakers you've already got might not have much bass/power but, by the sound of things, they go loud enough. Also, if they are in use all the time, they probably sound excellent otherwise you'd want to shut them off. This would not be surprising as all the measurements I've seen of Genelec speakers have been excellent. They are well engineered speakers, in low diffraction cabinets, with good attention paid to directivity control.
Adding a subwoofer, as well as high passing the Genelecs, would be a very pragmatic way to improve the system. Improving upon, what would appear to be, the only area that the system appears to be lacking whilst maximising on what the 6010As are really good at.
Of course if you're wanting to build another pair of speakers have at it!