In a month I'm moving into a new house and I'm working on designing a music-focused sound system to go in the basement for a DJ/dance party setup. I've put together a two-way top/main that I'm really happy with thus far (passive-crossed PRV 8MR-500NDYv2 with a B&C DE250 on the ME20 horn), but I'm struggling with what to do for the bass/sub area.
Specs: Room is approx. 14 x 24, maybe 8-9' ceilings. Drywall + carpet.
Planning for two mains and two subs in opposite corners - mains mounted on ceiling, subs on the floor. All enclosures must be DIY. Crazy SPL not required but should have plenty of headroom as the space will (hopefully) be full of bodies from time to time. Pro amps & EQ will be used - subs will probably run parallel off a single channel. Music will primarily be house, disco, techno, funk & soul. Hoping to build at least one sub in advance.
Now questions:
1) What size subwoofer/bass cabinet(s) is recommended for this space? I had initially planned on 2x18's but after testing one main in a similarly-sized basement room with a single low-power 8" sub driver, I'm wondering if 18's are overkill. Certainly a smaller driver would save some floor space. I don't need ridiculous low bass (my neighbors foundation is merely 4' away) but would like plenty of 'kick' to the drums; I suppose that means transient response is as or more important than depth?
2) Would a simple reflex cabinet suffice? Simplicity of construction is a must, and smaller is better (4-6 cu.ft. is doable, as long as it's tall and shallow). I understand the trade-off from sealed to vented, but I don't know if that will matter for my application?
3) I'd prefer to stay under $100 per driver. I had initially pegged the Dayton Audio PA 18" as I won't need crazy power or XMAX, but maybe I've overlooked something? Or, if going with smaller diameters, what would you recommend?
Thanks all.
Specs: Room is approx. 14 x 24, maybe 8-9' ceilings. Drywall + carpet.
Planning for two mains and two subs in opposite corners - mains mounted on ceiling, subs on the floor. All enclosures must be DIY. Crazy SPL not required but should have plenty of headroom as the space will (hopefully) be full of bodies from time to time. Pro amps & EQ will be used - subs will probably run parallel off a single channel. Music will primarily be house, disco, techno, funk & soul. Hoping to build at least one sub in advance.
Now questions:
1) What size subwoofer/bass cabinet(s) is recommended for this space? I had initially planned on 2x18's but after testing one main in a similarly-sized basement room with a single low-power 8" sub driver, I'm wondering if 18's are overkill. Certainly a smaller driver would save some floor space. I don't need ridiculous low bass (my neighbors foundation is merely 4' away) but would like plenty of 'kick' to the drums; I suppose that means transient response is as or more important than depth?
2) Would a simple reflex cabinet suffice? Simplicity of construction is a must, and smaller is better (4-6 cu.ft. is doable, as long as it's tall and shallow). I understand the trade-off from sealed to vented, but I don't know if that will matter for my application?
3) I'd prefer to stay under $100 per driver. I had initially pegged the Dayton Audio PA 18" as I won't need crazy power or XMAX, but maybe I've overlooked something? Or, if going with smaller diameters, what would you recommend?
Thanks all.
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Multiple subs would be a good choice, especially for the environment used here. A few smaller subs could be used.
http://gedlee.azurewebsites.net/Papers/multiple subs.pdfhttp://gedlee.azurewebsites.net/Papers/Setting up subwoofers.pdf
http://gedlee.azurewebsites.net/Papers/multiple subs.pdfhttp://gedlee.azurewebsites.net/Papers/Setting up subwoofers.pdf
Reflex tuned to around 25hz (for good response down to 30hz). I think your incorrect on not needing high levels as 'party' level is far more than normal listening level. I would use 2*18" reflex at least. 18" sub drivers are generally the most cost effective in terms of the output per unit money. The more subs you use the more even the bass will be through the room, 4 subs one in each corner usually works very well.
The PA18 looks ok the main practical difference between using that and a more expensive driver will be that the cab will be larger and that the maximum output per box will be about 8dB lower. But you can always upgrade the driver later if you need more output. I would prioritise having more subs over having one high end sub in an install situation.
The PA18 looks ok the main practical difference between using that and a more expensive driver will be that the cab will be larger and that the maximum output per box will be about 8dB lower. But you can always upgrade the driver later if you need more output. I would prioritise having more subs over having one high end sub in an install situation.
Bass Speakers - Guitar / Bass | Eminence Speaker
Just as a quick example; many choices. "bass guitar" speakers can take a lot of power and are usually fairly high sensitivity. If you want really loud and deep bass BOTH; maybe a pro sub woofer should be your first choice.
Just as a quick example; many choices. "bass guitar" speakers can take a lot of power and are usually fairly high sensitivity. If you want really loud and deep bass BOTH; maybe a pro sub woofer should be your first choice.
If you want accurate bass, and not at ear-bleeding levels then four, possibly even two sealed 18" subs would be adequate, and give you the tight and accurate drum sound you are looking for. (My small PA manages 120db at 30Hz in-room using 4 x 700W 50l 18" sealed subs). They will take a lot more power to drive (which is cheap these days) for the same output as ported subs, but are much more compact and with considerably less stored energy which would otherwise blur the sound. Very easy, quick, and cheap to build too!
My mantra is: "MOVE A LOT OF AIR, gently...".
Yes, you could easily achieve the same output from a pair of ported 12" drivers, but the precision and rate of decay of individual drum beats will always be better using a sealed enclosure and low excursion. It is very revealing to look at the step response of different loadings on the DataBass website. The step response of a typical sealed enclosure is practically over in 20ms, whilst some ported, horn loaded, and tapped horns can still be ringing a quarter of a second after the signal is removed. (Stored energy; mass on a spring, if you get my meaning!).
Even if you don't like Metallica, the double pedal kick drum is extremely revealing of unwanted energy storage in subs; many reproduce it as a ppphhhttttttt sound with little detail instead of the individual machine gun-like impacts when reproduced on subs with a fast decay time. It is this characteristic, I think, which is partly responsible for the sound you describe as 'kick', not transient response. With the processed signal fed to a sub there is no sharp-edged transient whatsover - it has been filtered out. As long as the sub can produce the highest frequency it is fed without rolling off, it is 'fast' enough, to use a term I hate but which seems to have become the norm! It is the HF driver which is responsible for the sharp rise time of a transient event, and the DE250 is a reliable, good-sounding choice.
Cross the sub over at about 120Hz, add Linkwitz Transform to taste (very simply with digital processing), and you will have a really cracking little system which sounds more like an overpowered hifi than a PA system!
My mantra is: "MOVE A LOT OF AIR, gently...".
Yes, you could easily achieve the same output from a pair of ported 12" drivers, but the precision and rate of decay of individual drum beats will always be better using a sealed enclosure and low excursion. It is very revealing to look at the step response of different loadings on the DataBass website. The step response of a typical sealed enclosure is practically over in 20ms, whilst some ported, horn loaded, and tapped horns can still be ringing a quarter of a second after the signal is removed. (Stored energy; mass on a spring, if you get my meaning!).
Even if you don't like Metallica, the double pedal kick drum is extremely revealing of unwanted energy storage in subs; many reproduce it as a ppphhhttttttt sound with little detail instead of the individual machine gun-like impacts when reproduced on subs with a fast decay time. It is this characteristic, I think, which is partly responsible for the sound you describe as 'kick', not transient response. With the processed signal fed to a sub there is no sharp-edged transient whatsover - it has been filtered out. As long as the sub can produce the highest frequency it is fed without rolling off, it is 'fast' enough, to use a term I hate but which seems to have become the norm! It is the HF driver which is responsible for the sharp rise time of a transient event, and the DE250 is a reliable, good-sounding choice.
Cross the sub over at about 120Hz, add Linkwitz Transform to taste (very simply with digital processing), and you will have a really cracking little system which sounds more like an overpowered hifi than a PA system!
... In contrast, a single 15" in a compact ported box will put out 121dB sine tones at 40Hz, groundplane, using less than half the power of those 18"s.
FWIW, the time-domain response of a ported box is down to its frequency response. They're minimum-phase devices, where the phase is directly related to the frequency response, and nothing else.
ie, if you EQ'd a sealed box to match the response curve of a ported box, you'd get an identical phase curve, impulse response and step response.
I stand by my recommendation of a couple of good 12"s in ported boxes.
Chris
FWIW, the time-domain response of a ported box is down to its frequency response. They're minimum-phase devices, where the phase is directly related to the frequency response, and nothing else.
ie, if you EQ'd a sealed box to match the response curve of a ported box, you'd get an identical phase curve, impulse response and step response.
I stand by my recommendation of a couple of good 12"s in ported boxes.
Chris
My 2c...
Since you said DJ/dance party setup....imo it gets hard to have too much sub.
Definitely a couple of 18"s...you might find you want more. (Sorry Chris, but two 18"s will be far from vision blurring silly
)
Smaller drivers can make alot of sine wave SPL, but displacement (area x excursion) makes big transients come alive, so if in any doubt go bigger.
It's also better to get displacement with less excursion, like MrKlinky said....
so another reason to go bigger.
As was stated by Chris661, sealed vs ported should sound the same if frequency response is the same for both (including rate of bottom end rolloff below f-3).
Placement shouldn't matter either, or at least never has for me using the same driver in both sealed and ported boxes (tuned to same response).
Since you said DJ/dance party setup....imo it gets hard to have too much sub.
Definitely a couple of 18"s...you might find you want more. (Sorry Chris, but two 18"s will be far from vision blurring silly
)Smaller drivers can make alot of sine wave SPL, but displacement (area x excursion) makes big transients come alive, so if in any doubt go bigger.
It's also better to get displacement with less excursion, like MrKlinky said....
so another reason to go bigger.
As was stated by Chris661, sealed vs ported should sound the same if frequency response is the same for both (including rate of bottom end rolloff below f-3).
Placement shouldn't matter either, or at least never has for me using the same driver in both sealed and ported boxes (tuned to same response).
Perhaps we have different tastes but blurry vision is 140dB+ peaks, to do that it has to be a very very large system or quite a small well sealed space or your head has to be inside a horn or similar. Even 14 FLH in a lossy warehouse space driven by 4*MA5002VZ is at its limit before hitting that kind of SPL on the dance floor. I have only experienced bass this loud a few times; Hidden in Salford next to the ground floor sub stack (void double 18"/21" stack to ceiling height), a ~50 person dance floor with 12*18" reflex subs and the original ministry of sound bass horns (6 Bertha horns with extensions in a well sealed room).
I personally only have 4*15" isobaric reflex subs but will hit their limits sometimes in larger rooms, they would be fine in your room but Its not a headroom for days situation at party levels, even if the mid/treble is at a sane level the bass can be very elevated in electronic music or afrobeat. If you have the space for larger subs I don't see a disadvantage, they will be more efficient, lower THD and capable of higher SPL.
On the floor space point thats also key for me so I build my cabs to have minimum footprint as you can see.
I personally only have 4*15" isobaric reflex subs but will hit their limits sometimes in larger rooms, they would be fine in your room but Its not a headroom for days situation at party levels, even if the mid/treble is at a sane level the bass can be very elevated in electronic music or afrobeat. If you have the space for larger subs I don't see a disadvantage, they will be more efficient, lower THD and capable of higher SPL.
On the floor space point thats also key for me so I build my cabs to have minimum footprint as you can see.
Attachments
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My 2c...
Since you said DJ/dance party setup....imo it gets hard to have too much sub.
Definitely a couple of 18"s...you might find you want more. (Sorry Chris, but two 18"s will be far from vision blurring silly
Smaller drivers can make alot of sine wave SPL, but displacement (area x excursion) makes big transients come alive, so if in any doubt go bigger.
It's also better to get displacement with less excursion, like MrKlinky said....
so another reason to go bigger.
As was stated by Chris661, sealed vs ported should sound the same if frequency response is the same for both (including rate of bottom end rolloff below f-3).
Placement shouldn't matter either, or at least never has for me using the same driver in both sealed and ported boxes (tuned to same response).
Ah, I'd missed the "drywall" bit of the first post.
My (brick) living room of similar size adds around +15dB at 40Hz, so it's pretty easy to get very silly SPLs.
Oh, and I was thinking about the latest high-end 18"s. The Dayton 18" mentioned on the first page would have 6dB less displacement.
Chris
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All great stuff, thanks for the input so far. Sounds like smaller drivers could work, but two 18's will definitely work.
Maximum top-end SPL is not a priority, although efficiency is a big plus - in terms of cash spent, floor space and power requirements. Upgrading drivers down the line is a definite possibility - at some point I will likely take this system out to the backyard. So, I'll accept the trade-off and go with the reflex design.
More on space - four corners is not going to work, at least not with full sized 18's. One corner will be taken up by a desk, PC, and most of the electronic components of this system (my 'office'), and opposite that corner is the foot of the stairs. The GedLee paper is interesting, I could conceivably fit a smaller sub under my desk (or somewhere else) to achieve the same effect.
Let's assume we go with two of the Dayton PA18 - some follow up questions:
1. Box size and tuning - I'll admit that fiddling with WinISD hasn't been very illuminating for me. What would you all recommend in terms of size, tuning, and vent configuration? @Kipman, I get an odd-looking curve when I tune in the 20's, is that normal?
2. Box size again - can someone explain why this driver would require a larger enclosure than a higher end driver? Or perhaps more directly, is there any disadvantage to making the larger enclosure now if I wanted to upgrade drivers down the road?
3. Box shape - would much prefer a tall and shallow enclosure. Any disadvantage to this, assuming I compensate for a high center of mass?
Maximum top-end SPL is not a priority, although efficiency is a big plus - in terms of cash spent, floor space and power requirements. Upgrading drivers down the line is a definite possibility - at some point I will likely take this system out to the backyard. So, I'll accept the trade-off and go with the reflex design.
More on space - four corners is not going to work, at least not with full sized 18's. One corner will be taken up by a desk, PC, and most of the electronic components of this system (my 'office'), and opposite that corner is the foot of the stairs. The GedLee paper is interesting, I could conceivably fit a smaller sub under my desk (or somewhere else) to achieve the same effect.
Let's assume we go with two of the Dayton PA18 - some follow up questions:
1. Box size and tuning - I'll admit that fiddling with WinISD hasn't been very illuminating for me. What would you all recommend in terms of size, tuning, and vent configuration? @Kipman, I get an odd-looking curve when I tune in the 20's, is that normal?
2. Box size again - can someone explain why this driver would require a larger enclosure than a higher end driver? Or perhaps more directly, is there any disadvantage to making the larger enclosure now if I wanted to upgrade drivers down the road?
3. Box shape - would much prefer a tall and shallow enclosure. Any disadvantage to this, assuming I compensate for a high center of mass?
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HiFi Loudspeaker Design
These bass reflex (vented) calculators may help; you can see what different alignments require different tunings and box sizes, etc.
These bass reflex (vented) calculators may help; you can see what different alignments require different tunings and box sizes, etc.
HiFi Loudspeaker Design
Another calculator; put in a custom box size and see what results compared to a "standard" alignment.
Another calculator; put in a custom box size and see what results compared to a "standard" alignment.
1)
In the past few decades with the availability of digital processing prospeakers are no longer designed for flat response but instead maximum output when equalized. This is especially pertinent for subs as they require EQ in room anyway due to room modes and as Chris has pointed out they are minimum phase.
I would recommend Hornresp for designing subs as it has the tools to quickly maximize output. In the attached example I have made a sub of 200L with a 25cm long port of area 200 cm^2 and used EQ to flatten the response and apply a protective high pass. The sub is limited by the xmax specification of the driver to 116dB/1m in an open field environment and has a -3dB of 28Hz. As this box is excursion limited if it was tuned higher you would get more output from it, however you would then start missing the low notes. If you import the hornresp record .txt in hornresp you can tweak it to taste.
2)
The PA460-8 has a relatively weak motor with a BL^2/Re of 88 while a top end sub like the B&C 18DS115 has a BL^2/Re of 304. This means that the B&C can work in a much smaller box as it can push harder against the pressure of the box. It will also be more efficient when you take into account the real power dissipated in the subwoofer voice coil, however the response of such a subwoofer will not be flat and as such to apply the EQ needed a high output voltage may be required from the amp. If you want to learn more about this these videos may be useful:
Power Handling Deep Dive - YouTube
T-S Parameters in the 21st Century - YouTube
3)
any crazy shape can work just keep port ends unobstructed. I quite like using solid wood grills as well, a significant proportion of the drivers radiating area can be blocked without major issues and metal grills are expensive and prone to buzzes and rattles. I also like to make the ports out of wood. Check out the design I posted earlier in the thread for some reverse mounted cavity loaded port fun.
In the past few decades with the availability of digital processing prospeakers are no longer designed for flat response but instead maximum output when equalized. This is especially pertinent for subs as they require EQ in room anyway due to room modes and as Chris has pointed out they are minimum phase.
I would recommend Hornresp for designing subs as it has the tools to quickly maximize output. In the attached example I have made a sub of 200L with a 25cm long port of area 200 cm^2 and used EQ to flatten the response and apply a protective high pass. The sub is limited by the xmax specification of the driver to 116dB/1m in an open field environment and has a -3dB of 28Hz. As this box is excursion limited if it was tuned higher you would get more output from it, however you would then start missing the low notes. If you import the hornresp record .txt in hornresp you can tweak it to taste.
2)
The PA460-8 has a relatively weak motor with a BL^2/Re of 88 while a top end sub like the B&C 18DS115 has a BL^2/Re of 304. This means that the B&C can work in a much smaller box as it can push harder against the pressure of the box. It will also be more efficient when you take into account the real power dissipated in the subwoofer voice coil, however the response of such a subwoofer will not be flat and as such to apply the EQ needed a high output voltage may be required from the amp. If you want to learn more about this these videos may be useful:
Power Handling Deep Dive - YouTube
T-S Parameters in the 21st Century - YouTube
3)
any crazy shape can work just keep port ends unobstructed. I quite like using solid wood grills as well, a significant proportion of the drivers radiating area can be blocked without major issues and metal grills are expensive and prone to buzzes and rattles. I also like to make the ports out of wood. Check out the design I posted earlier in the thread for some reverse mounted cavity loaded port fun.
Hi Kipman, excellent post.
Does it make sense to you if I alter your point 1)
from..."In the past few decades with the availability of digital processing prospeakers are no longer designed for flat response but instead maximum output when equalized."
to.. designed for flat response from low level all the way to 'maximum output' .
Where 'maximum output' equals when flat response falls apart.
Does it make sense to you if I alter your point 1)
from..."In the past few decades with the availability of digital processing prospeakers are no longer designed for flat response but instead maximum output when equalized."
to.. designed for flat response from low level all the way to 'maximum output' .
Where 'maximum output' equals when flat response falls apart.
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