Hey, I'm very new to speaker design so please understand that I might ask really basic questions or talking about things in the wrong way (please correct me if I do!) I am hoping to build a subwoofer to accompany my Cambridge Audio SX-50's in house partys and possible small outdoor events (garden) this summer. The music I tend to play is techno and drum and bass heavy as well as dub and reggea therefore I am less worried about getting the perfect audio quality and more hoping to pack some punch in the low end.
I have seen online on subwoofer design ported subwoofers which to my understanding is just an enclosed subwoofer with a hole on the enclosure. However when I go see my local soundsystems play I think they use hog horns or superscoops. Do these go louder than normal posted designs and how come these aren't as common in home/car audio sytems? Finally, which would be the best for my application?
Edit: I've also seen "isobaric subs" which can apparently pack the same bass for a smaller enclosure. Could these be incorperated in horn or ported subs to make them take a smaller footprint?
I have seen online on subwoofer design ported subwoofers which to my understanding is just an enclosed subwoofer with a hole on the enclosure. However when I go see my local soundsystems play I think they use hog horns or superscoops. Do these go louder than normal posted designs and how come these aren't as common in home/car audio sytems? Finally, which would be the best for my application?
Edit: I've also seen "isobaric subs" which can apparently pack the same bass for a smaller enclosure. Could these be incorperated in horn or ported subs to make them take a smaller footprint?
For a horn to go really low it needs a very large mouth. Like the back of the horn extends into the garden outside and the mouth tales up the entre wall.
The PA stuff you see is unlikely to actually be subwoofers. unless there is a large array of woofersdesigned to work together.
Most common for your use would be a reflex or a tapped horn (really a version of a TL with limited bandpass).
You have to decide how big you can live with. And you should check what range the bass in your source actually goes. A lot of the impact desired is often more like 40-120 hz. Woofer territory, not subwoofer really.
Note that 2 woofers is better than 1, and if each woofer has 2 drivers push-push it can be a lighter cabinet and more easily moved about. A single 8” will not do much outside.
dave
The PA stuff you see is unlikely to actually be subwoofers. unless there is a large array of woofersdesigned to work together.
Most common for your use would be a reflex or a tapped horn (really a version of a TL with limited bandpass).
You have to decide how big you can live with. And you should check what range the bass in your source actually goes. A lot of the impact desired is often more like 40-120 hz. Woofer territory, not subwoofer really.
Note that 2 woofers is better than 1, and if each woofer has 2 drivers push-push it can be a lighter cabinet and more easily moved about. A single 8” will not do much outside.
dave
With that sort of design target, I'd suggest that an 8-inch subwoofer is not the way to go. You need some reasonable bass extension down to at least 35 Hz or so. And also the ability to generate some decent low-frequency SPLs. I think a 10-inch driver is the minimum that can be realistically considered as being able to fulfil the design requirement. A high-excursion 12-inch driver would prove to be even better. A vented subwoofer will give you a bit more bass extension, as many subwoofers are designed with that application in mind, and have the appropriate Thiele–Small parameters.
My only concern with using a 10" woofer is that I will need a bigger PSU which get quite expensive and all i can find is LED PSUs which are apparently not good. Can I use a server PSU which I mod myself as I assume I will need over 500W to drive it?
Class D amps are particularily good at bass, and often cheap.
A 10” will actually need less power than than the 8” (given 2 simialr designs), but there is a HUGE range of drivers that cam be looked at.
Ignoring sound quality, a woofer is a trade off between size, efficiency, and extention.
dave
A 10” will actually need less power than than the 8” (given 2 simialr designs), but there is a HUGE range of drivers that cam be looked at.
Ignoring sound quality, a woofer is a trade off between size, efficiency, and extention.
dave
The larger the woofer and enclosure, the more output it can create with a given amount of power.
A large subwoofer can get loud with a few watts.
Your Cambridge Audio SX-50's sensitivity is 87dB one watt/one meter, so at 100 watts (+20dB) one can put out ~107dB SPL, the pair at most +6dB, 113dB using 200 watts peak.
The average power used at 200watts peak might be ~20watts.
A tapped horn enclosure like the SS15 has ~105dB 1w/1m sensitivity in the upper bass range, with 100watts it could hit around 125dB.
https://www.diyaudio.com/community/threads/single-sheet-th-challenge.170771/page-113
It's made from a single 4x8 sheet of plywood:
TH enclosures can be around +6dB more efficient (use 1/4 the power) than a bass reflex that has the same low frequency response.
Isobaric loading can reduce size of an enclosure by at most 50% for a given low frequency response, but use double the power and drivers for the same output as the single driver.
Isobaric loading only made sense when drivers with the same parameters as the isobaric pair were not readily available.
Art
For some reason I can't quote the most recent post. Nevertheless are there alternatives to the SS15 for 10" drivers as I don't want it took big or too expensive. Also is a "TH enclosure" the same as "SS15"?
The previous post is not quotable… far, far too many were abusing that and the janitors had to remove the extraneous quotes.You can stillselect a snippet of the post and quote that.
dave
diyAudio moderation team
dave
diyAudio moderation team
SS15 is the name of a popular TH (Tapped Horn) enclosure design. The loudspeaker "taps" two sides of the same horn.
Tom Danley originated "TH" as a descriptive name for his DSL (Danley Sound Labs) commercial subwoofers which range from 8" to 21" driver size.
Others have designed TH enclosure designs for nearly any speaker frame size, and their enclosure sizes range from under 28L to thousands of liters.
Here is a TH designed for a 10":
https://www.diyaudio.com/community/threads/tham10-a-10-compact-th-proposal.182209/
Martinsson has THAM (TH Anders Martinsson) from 6" to 18".
https://www.martinsson.cc/blog/static.php?page=static140228-173656
It is a clever quarterwave design. Double tapped TL is just as accuarte a description.
dave
So I have been doing my research and educating myself more in the world of speaker design and have been messing around with hornrep with the THAM10 and it seems good for frequencys from 55hz to 130ish however lots of the music I listen to goes lower than that therefore I have been digging and found the TPAM 10HT which goes to the mid 20s but isnt as loud and has a rather large notch in it... would be be worth having 2 TPAM 10HTs, 2 THAM 10s or 1 of each?
Is the design with the big ‘notch’ in the freq response shapes more like a ‘pipe’ without a flare, like the Tham(Tapped horn)
(I’m just nerding out/curious on the affect of these shapes in qw resonators where the front and rear outputs are forced to interact ’inside’ the design )
(I’m just nerding out/curious on the affect of these shapes in qw resonators where the front and rear outputs are forced to interact ’inside’ the design )
Two of the same will give you +3dB sensitivity, half the power for the same output.
Given the same power (voltage) each, a pair will have +6dB output, and sound ~ twice as loud.
Probably better to have a pair with the response you would prefer, as mixing may not result in similar gains.
Now my next issue is power..The B&C 10NW64 is "600W continuous" and "300W Nominal power handling" whatever that means. And at 8 ohms too. Does that mean that if I have 2, my amp should be rated for 1200W and if so, peak or rms? Also as this is DIYAudio after all, will I be able to DIY my amp and powersupply or will I be best of buying one. If so, any recommendations?