Hello,
I’m looking at a couple of 15” driver options to build a ported subwoofer. Either option results in a similar calculated box size. One driver has a significantly larger Xmax. The more expensive driver of course..
Option 1 - DA DCS385-4 has Xmax of 9.3mm
Option 2 - DA RSS390HF-4 has Xmax of 14mm
I’m going to use the subwoofer for both HiFi and home theatre (more hifi) at moderate listening levels in a large sub optimal room in my house.
I understand in theory the higher Xmax should result in capability to move more air volume for the same surface area.
But in reality will I really notice this difference if I want great bass but not high SPL? I want to “feel” the bass but it doesn’t need to break windows.
I’m looking at a couple of 15” driver options to build a ported subwoofer. Either option results in a similar calculated box size. One driver has a significantly larger Xmax. The more expensive driver of course..
Option 1 - DA DCS385-4 has Xmax of 9.3mm
Option 2 - DA RSS390HF-4 has Xmax of 14mm
I’m going to use the subwoofer for both HiFi and home theatre (more hifi) at moderate listening levels in a large sub optimal room in my house.
I understand in theory the higher Xmax should result in capability to move more air volume for the same surface area.
But in reality will I really notice this difference if I want great bass but not high SPL? I want to “feel” the bass but it doesn’t need to break windows.
Could you go for a pair of 12"s or 10"s?
Reason being that distributed subwoofers will give a more even in-room response, and also less variation between seats.
If you have to go with just one subwoofer, I'd recommend making it the best you can afford. Otherwise, you'll end up spending the money twice when you decide to upgrade from the cheaper option.
Chris
Reason being that distributed subwoofers will give a more even in-room response, and also less variation between seats.
If you have to go with just one subwoofer, I'd recommend making it the best you can afford. Otherwise, you'll end up spending the money twice when you decide to upgrade from the cheaper option.
Chris
My personal favourites are mostly PA drivers. I used JBL GTO1214s for a while, but found they added quite a lot of distortion, even at moderate levels. These days my HiFi speakers produce enough bass, so haven't played with domestic subwoofers for a while.
The Dayton Audio subs have a great reputation, though - how does the pricing work out for you?
I'd recommend reading around a little on AVS Forum - they have a lot of people designing and building subwoofers for domestic spaces, and most of them include measurements etc.
Chris
The Dayton Audio subs have a great reputation, though - how does the pricing work out for you?
I'd recommend reading around a little on AVS Forum - they have a lot of people designing and building subwoofers for domestic spaces, and most of them include measurements etc.
Chris
I agree with Roo2 and chris661 to use multiple subwoofers. A smooth in-room response is one of the primary factors determining bass quality. Four (or more) works best, though two are still a large improvement over a single subwoofer. They have to be distributed around the room.
Strictly speaking, Xmax does not tell anything about the performance of a woofer that is operating below Xmax. High Xmax woofers usually have better distortion performance at a given stroke because they are not being pushed, but there are no hard numbers that this holds for your specific woofers.
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From my limited experience a subwoofer with a higher than usual xmax is useful when one wants high low frequency output from a small volume.
High power subs tend to run out of excursion in the 40Hz and under range. The options for more output at these frequencies are then to increase the cone area or the excursion potential, swept volume either way.
It is harder to make a sub with a high linear excursion potential and stiff enough cone to remain linear in these conditions and so multiple conventional subwoofers tend to sound better than one high excursion sub of the same notional swept volume of similar cost.
In car use is an example of the above, space is limited and the so the subwoofers there have evolved to have high xmax, high power handling and low Vas.
High power subs tend to run out of excursion in the 40Hz and under range. The options for more output at these frequencies are then to increase the cone area or the excursion potential, swept volume either way.
It is harder to make a sub with a high linear excursion potential and stiff enough cone to remain linear in these conditions and so multiple conventional subwoofers tend to sound better than one high excursion sub of the same notional swept volume of similar cost.
In car use is an example of the above, space is limited and the so the subwoofers there have evolved to have high xmax, high power handling and low Vas.
Look into Linkwitz transform if you want a smaller box.
Edit: Sorry, just realised you want ported subs..(ignore the above unless you decide to go sealed)
Rob.
270 liters is a lot for a 15". That size you can a make a tapped or alike. Or use a larger driver or a smaller size br.
Apart from the size of a single enclosure, k totally agree with tbtl that mitigating the effects of room resonances is the main problem and multiple lf sources is the way to go. Therefore you could also consider going for the full Monty and build 4 12" subs. Sealed if you want small, br if you need the output. Dsp for each channel and software to simulate the aggregate response gets the most out of it.
Sealed will be smaller, and there are drivers that go very low sealed like the 12" SB Acoustic SB34NRX75-6. A 75L sealed with this driver should give you all you want (a good response to 23Hz in a room before eq). Make two of those and you can shake the house with less integration and waf problems than big 15's in big boxes. And there are more examples like that...
Thanks wax, Chris. Yes, a couple of smaller subs is probably the sensible path forward. As an interesting distraction... I’ve been looking through the VBSS thread on the AVS forum... A simple option but not sure how musical. Not small either but a bit smaller than the BR (Qtc =0.707) I’ve been sizing using simple online calculators. Using DSP to flatten the response from a smaller box seems to be part of the solution too.
Yes, total volume displacement.
Unfortunately there is no standard for measuring and specifying the xmax so it is very hard to compare drivers across brands.
dave
Distributed subs are good (1 sub counteracting room peaks & dips in the response, dialed in with placement, better is if those are push-push loaded (greatly (90%?) reduces energy loaded into the cabinet). 3 x 12 or 4 x 10 should perform better. I like the CSS SDX10. 44-56 litre sealed. Sealed works better for EQ. They can be vented but i prefer sealed, one can more easily match room gain (2nd order rolloff instead of 4th order) and the box does not unload below the tuning frequency.
dave
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