Recommendation for driver for REAL LOW bass output - 18",15"?

Zeus the thunderer · « **on:** 15 Dec 2008, 07:16 pm »

Hi
I am looking for the driver recommendations for the really low bass output.I am thinking either 15" or 18".I am still not sure whether to use ported or sealed box.
I plan to use 2 of these drivers in 2 boxes,each sub for one channel.Powered by B&O ICE modules.
The thing is - i really like both fast and low bass.Is sealed box better for this?
My speakers have 2 of 12" bass drivers each.But i think it will not satisfy me ultimately.
Which driver would you recommend for this?I am a little more for the 18",i must admit.If any of you have experience with this, i'd like to hear from you.
Any help would be much appreciated.

mcgsxr · « **Reply #1 on:** 15 Dec 2008, 07:21 pm »

I suspect that sealed will be the way to go for both music and HT.

Can you tell us a little more about your room (specs) and the size of boxes you are willing to put up with?

HT or music or both?

woodsyi · « **Reply #2 on:** 15 Dec 2008, 07:41 pm »

Kevin at DIY Cable is selling Maelstrom woofers although they are out of stock at the moment I believe.

These 18" woofers go low.

TRADERXFAN · « **Reply #3 on:** 15 Dec 2008, 09:22 pm »

15 " Sealed servo controlled subs sound like what you really want...
http://www.rythmikaudio.com/D15SE.html

tight and low bass (that is if your room can handle it)

They offer to sell individual drivers with amps for DIY too.

Why ice power amps? Is that what you already have?

-Tony

Zeus the thunderer · « **Reply #4 on:** 15 Dec 2008, 09:50 pm »

Yes,i already have ICE modules.200 ASC,and i will build (with a help of my friend) monoblocks for this purpose.
My room is 29 m2 big.Don't know how much in sq feet.It is a big room,tall also.The speakers are Silverline Sinfonia.They have one 7" mid-bass driver (in sealed enclosure) and two 12",in vented boxes.These are big and heavy (250 lbs) speakers.
Most people would not ask for anything more in bass,but i want that deep,deep sub-20Hz bass...
Music only is my thing.
These subs will probably play only below 50-70 Hz.

Tyson · « **Reply #5 on:** 15 Dec 2008, 10:08 pm »

I'd also recommend getting a Behringer Feedback Destroyer - it will allow you to tame your major room modes. Room modes are the thing most responsible for the sense of "bloated" or "slow" bass.

Zeus the thunderer · « **Reply #6 on:** 15 Dec 2008, 10:33 pm »

I like Maelstrom-X woofer,as well as rythmikaudio solution.They both seem very interesting.The only problem with finished subwoofer is the shipping fee.I live in croatia (Europe),so getting the drivers and then finishing the subs here seems like a better idea.
I plan to heavily treat the room,and have no experience with active solutions of bass problems.

*Scotty* · « **Reply #7 on:** 15 Dec 2008, 10:34 pm »

Zeus, you might try passively bi-amping your Silverlines with your monoblocks and seeing what results you get before investing in subs. Your Silverlines are rated to 18Hz on the bottom and may do better than that depending on where they are placed in the room. If you currently have a shortage of deep bass this may be due to your listening position being in a standing wave null which would result in depressed low frequency output. A lot of bass is mono in nature and as a result both left and right channel contribute to its reproduction. When this is the case you have the equivalent of a single 18in. driver producing the lowest frequencies,(ie. four twelve inch woofers roughly equal one 18in. in cone area). I have a 37 m2 room with a similar amount cone area,a total four 12inchers operating below from 150Hz to below 20Hz. I also have the same efficiency as you do,96db. This is enough to blow me out of the room with movie soundtracks and music with low base content.
Scotty

Zeus the thunderer · « **Reply #8 on:** 15 Dec 2008, 10:51 pm »

Yes Scotty,
You could easiliy be right.Basically,my Silverlines will be powered by 18 W/ch 320 B XLS SET amps.These yet have to be built for me.
Rear 12" woofer will be powered with those ICE modules,limited by resistor attenuiator for adjusted bass output.
It is not the question of amount of bass.I just have the idea the system will be better with two 15" subs.I am not sure if Sinfonias can play 15 Hz.I am not sure about this yet,and first all the other things will be done.Including finishing amps and bi-amping the Silverlines.
BTW-What do you mean by "Passivelly bi-amping"?
Which speakers do you own?96 dB?What amplification do you use?
Thanks

*Scotty* · « **Reply #9 on:** 16 Dec 2008, 01:41 am »

Hi Zeus, I am using Reimer Teton GS speakers. Here is a link to the 6 Moons Road tour article on them. http://tinyurl.com/ypzqj8 Mine are the Home Theater version with 12in. woofers.
My amp is a Stan Warren 60 watt/ch GainClone. See links to my system in my signature. Depending on your speakers crossover design you can feed the same signal from your preamp to two separate amps and let the speakers crossover divide signal. You have then powered the bass with the ice amps and the mid and highs with the SET and not used an external active crossover. Finding 15Hz. in your listening room is kind of like hunting for sea monsters, they are seldom seen and hard to capture. If you reproduced 15Hz. in your room you might not recognize that it happened. it is kind like having a ghost in the room,you know there something is in the room with you but you can't see it and you are not sure what it is. You don't actually hear it so much as feel it, and this is at high volumes. Extreme low frequency capability is useful in reproducing the sense of space that is occasionally captured in a recording done in a large acoustical space or venue. I seldom encounter a 16Hz tone on anything but a few recordings of organ music.
Have fun with your system it sounds like an interesting setup.
Scotty

Zeus the thunderer · « **Reply #10 on:** 16 Dec 2008, 06:59 pm »

Yes,Tetons seem great.

I never heard them,but have considered them before.

One thing i don't get about 18" woofer - everywhere specifications say freq. range starts from either 30 or 35 Hz (rarely 25 Hz).
I think every 18" driver can give 20 Hz easily,with that size.I have 8" driver in my speakers (second system) and it plays 30 Hz audible with no problems.
How do they mean that the low end is at 30 Hz?Maybe these specs refer to just the driver,with no box

*Scotty* · « **Reply #11 on:** 16 Dec 2008, 09:54 pm »

Zeus,What you get out of a bass driver in a sytem with an enclosure depends on the system design. The woofer has a narrow range of enclosure volumes where it will perform at its optimum with the lowest distortion,best transient response and lowest anechoic 3dB down point. It would be nice if the subwoofer mfgs would give a peak spl at a given 3dB point with a distortion figure so that you would have some idea of what a subwoofer was actually doing down there. Almost no one will give these kind specs however. I view every single subwoofer without this information available as a potential BOOMBOX until proven otherwise.
Scotty

Kevin Haskins · « **Reply #12 on:** 16 Dec 2008, 10:11 pm »

Quote from: *Scotty* on 16 Dec 2008, 09:54 pm

Zeus,What you get out of a bass driver in a sytem with an enclosure depends on the system design. The woofer has a narrow range of enclosure volumes where it will perform at its optimum with the lowest distortion,best transient response and lowest anechoic 3dB down point. It would be nice if the subwoofer mfgs would give a peak spl at a given 3dB point with a distortion figure so that you would have some idea of what a subwoofer was actually doing down there. Almost no one will give these kind specs however. I view every single subwoofer without this information available as a potential BOOMBOX until proven otherwise.
Scotty

I don't know how valuable it would be. Every driver is different and if it's optimized for ported alignments it would have a decided advantage over a driver optimized for a sealed alignment at a given 3dB down point. I also generally don't think it is all that smart to design for a anechoic 3dB down point anywhere south of about 30-35 hz. Why? Well.... you have to account for room gain otherwise you end up with a bloated first octave. Room measurement equipment and some PEQ ability will help you tame those sort of problems but that is another issue.

The best method for manufactures to report data on subs in my opinion would be a complete Klippel analysis and possibly some distortion testing on the raw driver in a small sealed enclosure (in a chamber). That would at least allow you to look at driver non-linearities separated out from the room, port contribution, etc... The problem is that most people wouldn't understand the data and you would need to get everyone to agree to a standard and publish their data accordingly. It just isn't going to happen. There is no incentive for people to publish that data and if companies started to, they would get "marketing" numbers just like they do with their published spec's now. Everyone knows it is a lie and nobody believes the published spec's for loudspeakers anyway. What good is creating another standard to lie about?

Maybe I'm being a pessimist.

TRADERXFAN · « **Reply #13 on:** 17 Dec 2008, 12:10 am »

Quote from: Zeus the thunderer on 16 Dec 2008, 06:59 pm

Yes,Tetons seem great.
I never heard them,but have considered them before.

One thing i don't get about 18" woofer - everywhere specifications say freq. range starts from either 30 or 35 Hz (rarely 25 Hz).
I think every 18" driver can give 20 Hz easily,with that size.I have 8" driver in my speakers (second system) and it plays 30 Hz audible with no problems.
How do they mean that the low end is at 30 Hz?Maybe these specs refer to just the driver,with no box

As others have commented, there is more to it than the size of the driver...
You could read up on some parameters here
http://www.eminence.com/resources/data.asp

And you can see how the different boxes change the freq response of the same driver, as well. For example a couple of boxes with an 18" pro audio driver...
http://www.eminence.com/pdf/cab-sigmapro-18-2.pdf

Would you build your icepower amps into the enclosure, to keep speaker wire length as short as possible and maximize your damping factor?
-Tony

*Scotty* · « **Reply #14 on:** 17 Dec 2008, 12:25 am »

In my previous post I should have said every (subwoofer system) is a potential BOOMBOX which is what I meant to imply not the bass driver per se. A good driver can always be used in the wrong enclosure and yield poor results.
Scotty

2gumby2 · « **Reply #15 on:** 17 Dec 2008, 11:10 am »

I ordered a couple of Maelstrom-X drivers and Maelstrom passive radiators, but as I was shopping around, I also considered Acoupower. Those Acoupower drivers look pretty serious as well.
www.acoupower.com

mcgsxr · « **Reply #16 on:** 17 Dec 2008, 12:24 pm »

I asked earlier what size boxes you can accomodate in your room.

http://mach5audio.com/projects/viewtopic.php?f=7&t=3&sid=0cea32d807a54173c9717575649e387a

Built with these 18's - http://www.mach5audio.com/zen/index.php?main_page=product_info&cPath=65&products_id=181

Good for infinite baffle too, if you have a spare room (literally!).

There are cheaper 18's too - http://www.mach5audio.com/zen/index.php?main_page=product_info&cPath=66&products_id=182 - 3.3 foot sealed boxes, or 5 foot ported boxes, or 10 foot EBS boxes, tuned to 18Hz - likely with bad transients for music though.

I would stick with sealed, with EQ, to hit the low lows you seek...

Zeus the thunderer · « **Reply #17 on:** 17 Dec 2008, 10:11 pm »

first of all,thanks for all the answers.

Tony,i am planning to use as short wire as possible.I am not sure about placing the amp in the box though.I would like to avoid vibrations.Maybe placing the amp on the back of the box?Not sure yet.How would amp-in-the-box improve damping factor?

Quote from: mcgsxr on 17 Dec 2008, 12:24 pm

I asked earlier what size boxes you can accomodate in your room.

http://mach5audio.com/projects/viewtopic.php?f=7&t=3&sid=0cea32d807a54173c9717575649e387a

I would stick with sealed, with EQ, to hit the low lows you seek...

I think sealed will be the answer.I can spare about 60 x 60 x 60 cm = 216 Litres.
That should be enough.I think Maelstrom is capable of serious low bass.But is it fast enough?In sealed box,that is..
I wish Maelstroms had more sensitivity and 8 Ohm impendance.It seems like a great woofer.

woodsyi · « **Reply #18 on:** 18 Dec 2008, 01:38 pm »

Quote from: Zeus the thunderer on 17 Dec 2008, 10:11 pm

I think sealed will be the answer.I can spare about 60 x 60 x 60 cm = 216 Litres.
That should be enough.I think Maelstrom is capable of serious low bass.But is it fast enough?In sealed box,that is..
I wish Maelstroms had more sensitivity and 8 Ohm impendance.It seems like a great woofer.

They are fast enough driven by Parts Express 1000 W Sub amp each in sealed boxes. Kevin built me 2.

Zeus the thunderer · « **Reply #19 on:** 18 Dec 2008, 03:32 pm »

woodsyi,

How big are the sealed boxes with maelstroms Kevin has built for you?
4 cubic feet or more?And how much do these amps cost?I think with Maelstroms power and damping factor of the amp is very significant