Superlow frequency subwoofer

soiset

You know, the Marchand unit is about as much as the SMS-1. The SMS-1 flattens the response to 15 Hz (it's listed freq response), and the subsonic filter can be set as low as 5 Hz with the new firmware update (low enough for me!). Since the SMS-1 is a digital unit, do you think that it would have a similar effect of providing boost below the 15 Hz limit, but obviously to a level less than flat?

I mean, if it takes a 10 dB boost at 15 Hz to bring the response to flat, then at an octave lower, which I think is 7.5 Hz, would the boost have disappeared (assuming 12 dB/octave falloff)? Or would the unit somehow fail to provide any boost at all under 15 Hz, brick wall style?

Systems

soiset wrote:

You know, the Marchand unit is about as much as the SMS-1. The SMS-1 flattens the response to 15 Hz (it's listed freq response), and the subsonic filter can be set as low as 5 Hz with the new firmware update (low enough for me!). Since the SMS-1 is a digital unit, do you think that it would have a similar effect of providing boost below the 15 Hz limit, but obviously to a level less than flat?

I mean, if it takes a 10 dB boost at 15 Hz to bring the response to flat, then at an octave lower, which I think is 7.5 Hz, would the boost have disappeared (assuming 12 dB/octave falloff)? Or would the unit somehow fail to provide any boost at all under 15 Hz, brick wall style?

I know very little about the SMS-1 but I will see if I can find some details on its operation.

soiset

Outlaw has a really good user's manual for it:
http://pdf.outlawaudio.com/outlaw/docs/sms1guide.pdf

Systems

Cool i'll check that out.

soiset

I think I have the solution: Crank up the gain on the super-sub amp, use the SMS-1 to flatten the response down to 15 Hz, and whatever happens below 15 Hz just happens. I think a giant, well braced, sealed box for two of the 18" drivers, probably the Soundsplinter models that come in at $702 per pair, would be just fine. No fancy calculations or measurements for me to do, just build the super-sub cabinet well, and let the SMS-1 take care of the rest. I can use it to cross at 28 Hz. From 28 to, say, 100 Hz, I'll let the two PSW-1200's, which will be set just beside each of the two front mains, do their thing.

The SMS-1 has outputs for 3 subwoofers. I don't know if these subs can be managed as handling separate freq ranges, but if they can, oh, how sweet and easy it will be.

Systems

The sms-1 certainly has a lot of useful features with built in crossover and phase adjustment etc but its EQ section is primarily meant to smooth out the in room response of a sub not boost the very low end.It will not do the same thing as a BASSIS but you may get satisfactory results with it ,and there is a lot of potential for tweaking.

Also I remembered another unit that can be made to work like the BASSIS and has some features similar to the SMS-1.Not sure of the US pricing but check it out.http://www.behringer.com/DEQ2496/index.cfm?lang=ENG

Systems

Sure amouse,Do you have info on those drivers namely the TS parameters ?What is the maximum size the enclosure can be.I assume you want to keep the enclosures fairly compact.Also can you build simple opamp circuits?

Systems

Ok with those drivers the NAD amp and an EAS circuit you can have yourself a very nice pair of subs that can reach into the <20hz range in compact sealed boxes.
Designs built using the EAS controller have excellent transient response and tight controlled bass which is what you want for music reproduction.
The circuit is very simple,I built mine up on a small protoboard.Here is a link describing the controller, click on project 48. http://sound.westhost.com/projects-3.htm

Systems

Here is a pic of my controller.I'm using two relatively inexpensive but good performing 12"car woofers because they suited the design.

Systems

oops here is the pic of the controller.

Systems

I meant #48 thats what I used and it is much simpler to implement and the enclosure can be more compact.For it you would just use the values stated in the article.#71 is an option as well and there is a spread sheet that will calculate the component values but you need to know the Fc and Qtc of the driver box combo.This info is easy to obtain from a modeling program.

Sherardp

tcsounds or soundsplinter subs look insane, check those out

Sherardp

tcsounds or soundsplinter subs look insane, check those out

Systems

Sherardp wrote:

tcsounds or soundsplinter subs look insane, check those out

check the links in post #6 of this thread..

soiset

Gott in himmel:

http://www.tcsounds.com/lms5400.htm

Which do you think would deliver better super-subsonic response, one tcsounds lms5400, or two of the soundsplinter rl-p18's : http://www.hometheatershack.com/forums/soundsplinter/3810-new-premium-series-18-driver-soundsplinter-unleashes-beast.html

in a huge, minimum 8 cubic feet, but possible 40-50 cubic feet box? Most likely driven by this: http://www.gbaudio.co.uk/data/ma1200.htm

Systems

soiset wrote:

Which do you think would deliver better super-subsonic response, one tcsounds lms5400, or two of the soundsplinter rl-p18's :

Both will give you very deep bass but the dual SS's will have more maximum output capability.
Here is another player in the big woofer game. the Fi Q18:) https://ssl.perfora.net/www.ficaraudio.com/sess/utn;jsessionid=1545f87a8c4b377/shopdata/0020_Q/product_overview.shopscript

If you have that much space to use I would consider building large ported box.It would not need any electrical assistance(EQ) to reach into the low teens.

soiset

GV#27 wrote:

Both will give you very deep bass but the dual SS's will have more maximum output capability.
Here is another player in the big woofer game. the Fi Q18:) https://ssl.perfora.net/www.ficaraudio.com/sess/utn;jsessionid=1545f87a8c4b377/shopdata/0020_Q/product_overview.shopscript

If you have that much space to use I would consider building large ported box.It would not need any electrical assistance and will reach into the low teens.

The Q18 has an Fs of 24.5 Hz, and the others I listed are at 18 and 20. Wouldn't that indicate that the Q18 would deliver less pressure in the sub-20 Hz region at the same wattage? Well, that and the sensitivity. If I were to use a spreadsheet to determine the optimum configuration, which parameters would be entered? I assume, for starters, given a sealed box, I would enter volume, wattage, sensitivity, and Fs. What else?

For a ported box, I think I'd need to farm out that design, bc I understand that is a bit more advanced. Is that advisable?

Systems

Better yet why not try a box modeling program like Win ISD.It will allow you desgn sealed and ported boxes.You can download a free version here.https://ssl.perfora.net/www.ficaraudio.com/sess/utn;jsessionid=1545f87a8c4b377/shopdata/0020_Q/product_overview.shopscript
Their are many examples of a large ported designs around you could duplicate one of them.for example check out this one. http://www.hometheatershack.com/forums/soundsplinter/3519-dual-rl-p15-d2-llt-sub-project.html

soiset

sweet, thanks

soiset

Guess what is being sold within 5 miles (that's as close as ebay will tell me):
http://cgi.ebay.com/Velodyne-SMS1-SMS-1-Subwoofer-Control-Unit_W0QQitemZ180096559714QQcategoryZ3275QQrdZ1QQcmdZViewItem

If anyone wants to bid on one, let me know, and we can collectively bid on more than one, maybe saving some dough. I have sent a question regarding shipping, and maybe they will let me pick up.

soiset

GV#27 wrote:

Better yet why not try a box modeling program like Win ISD.It will allow you desgn sealed and ported boxes.You can download a free version here.https://ssl.perfora.net/www.ficaraudio.com/sess/utn;jsessionid=1545f87a8c4b377/shopdata/0020_Q/product_overview.shopscript
Their are many examples of a large ported designs around you could duplicate one of them.for example check out this one. http://www.hometheatershack.com/forums/soundsplinter/3519-dual-rl-p15-d2-llt-sub-project.html

That forum is great. There are folks there doing almost exactly what I want to do, and getting the results I'm after. I really appreciate the tip.

Systems

Your welcome.
Yes there are some interesting designs over there for sure.I really like that monster that I provided the link for.It was very well done.

VR3

I dont have any real advice. Ive never even thought about making a subwoofer that hits to 10hz. Haha.

What I will say is this...

Making a subwoofer isnt rocket science.

You need a massive enclosure, a low tuning point, multiple drivers capable of handling alot of power, low frequencies.

Things to remember though, the drivers ability to move does not nessicarilly mean low frequency response. You could take 16, 18" Pro Audio drivers with the -3db of 30hz and tune them to 10hz in an enclosure and you will get effortless 10hz. Just based on the fact its in a MASSIVE enclosure, you have 16 drivers - so you are moving TONS of air and you will have a massive amp.

The hardest job a sub does is below 30hz. If you crossover it over at 30hz and let it dedicate its job to that point.... your bounds are endless to what you can do. You are not looking for fidelity at this point. You can use whatever you want because it does not matter.

Its all about moving air, as long as its done one way or another - it dosnt really matter.

Im hardly the guru on this though. Just what I have gathered from reading and such.

Really though, if you could put these subs in the ceiling and work from there - itd be better

soiset

Well, I was thinking more like two 18's, not sixteen! When you say "tuned," do you refer only to ported enclosures, where the port diameter and length are coordinated with the box volume and speaker parameters? That is, are only ported enclosures "tuned?"

Also, what does it mean to the performance of a system over a range of frequencies to say that it is "tuned" to a specific freq? Does that mean it will peak at that point, or that it will fall off below that point? Or does it mean something else?

Thanks for your help.

VR3

In a ported enclosure - you tune it to a specific point.

Below that point the ported enclosure loses ALOT of output.

Port = Fall drastically
Sealed = Fall gradually

But, you will most likely need a port - and a massive one at that.

TennesseeOutlaw

Even though the box we be quite a bit larger, why not consider a 4th order ( or possibly 5th or 6th order) bandpass enclosure that can be tuned to a specific point, and puts out substantially higher output than your conviental sealed or ported enclosers. If you have a cetain frequency range that youre trying to achieve with this sub with the highest SPL possible, go with bandpass.. You will just have to be very careful to not blow the speaker.. Distortion is a bit harder to hear in a bandpass enclosure, as you only hear/feel the air coming out of the ports/vents and not the movement of the speaker itself.

Josh

VR3

Yeah but who wants a one note 10hz woofer...

Your goal would be 10-30hz Id think.

soiset

I think I'm sold on the LLT idea. Two 18's, giant box, giant port, big amp, bone-crunching fun.

madmax

Most bass is 50 to 90 hz anyway. What is below 50 (which is almost nothing) is pretty much lost through the recording process anyway. Speaking of the recording process the AudioControl Epicenter (car version) or the home version utilizes a cool idea to synthesize what should be there. The way it works is through some sonic traits of the notes lost. Lets say there was a real low bass note present but it was very low and pretty much lost in the recording process. Even though it is not there the multiples of it (higher frequencies) are still there. Sometimes listening to the multiples allows your brain to know it was there even though the actual frequency was lost, like listening to a song on AM radio. Anyway the Epicenter looks for the multiples, synthesizes what it thinks should have been there and adds it to the output. Might be something worth looking into for your sub-subwoofer. If you get to the point of wanting to try one let me know.
madmax

Systems

Madmax is correct you would not need deep bass response for music (other than pipe organ)but there are some movie soundtracks like War of the Worlds that contain <20hz material.If your subwoofers are capable of cleanly reproducing it it will add some serious impact to the those scenes.