I need a sub (Hows that for a title...)

[Nick M]

Andrew recommended I post here, so here it is
For background of my home theater progress...

https://www.htguide.com/forum/showthread.php?t=10691&page=4

I currently have a SVS PB10-ISD I'm trying out. Potential budget for this project if I return the SVS will be around $800, $1000 Max.

I live in an apartment, so 15A is the one and only power option. I'm a single guy, so dimensions can be like 3'x3'x8' with no WAF to worry about.

I'm experienced with mechanics and the use of most tools, but my last wood project was in 8th grade. I can weld if this gets serious... :rofl:

I want solid inaudible infrasonic response that I can feel mixing my spleen and small intestines around when listening to pipe organs on SACD. I have five bookshelf monitors and due to my pre/pro the crossover during analog bypass is 80Hz, so this thing will need to blend well with them. I am pretty picky about the bass getting at all congested or even warm, so I'm looking for lightning fast response and good decay. My room is roughly 1500ft^3. Here is a layout (sometimes the link won't work, but if you click it 3 or 4 times it will).

Image not available

I know this is alot to ask for the money, but I'm hoping someone has a solution. For HT I normally listen at the 75dB calibration point, but need something that can issue that quick slam such as when Saurons finger hits the ground in LOTR: FOTR, or give a very clean response of Frodos heartbeat in LOTR: ROTK. Response in scenes such as the Pod Race in SW: E1 needs to be clean and deep without rumble.

Ok, I think thats the jist of it...

[Bent]

:rofl: :rofl: :rofl: :rofl: :rofl:

Nicholas, you may want to revisit LOTR;FOTR, LOL. (I'd sugest use the semi-colin as I did...)

:W

(Having the " : F " part makes an unwanted smiley show up. :ROTFLOL )

[Nick M]

LOL! I just fixed it as you posted.... :rofl:

[Bent]

It's too late, I already pee'd my pants laughing.

[Nick M]

:rofl: ... ops: ops: ops:

[Andrew Pratt]

Given that I'd take a serious look at a Tumult or Ascendant Audio Driver both are 15" and put them in a sealed 3-4 cubic foot box and add a pro amp or plate amp to power it. You likely won't be able to afford the Tumult but the Ascendant drivers are exceptional as well and use the same XBL technology. If you went with a pro amp you'd likely be able to get the BFD as well which would really help tailor the sound. You should be able to make something along the lines of this Kilimanjaro around that budget providing you use a pro amp not a plate amp. there's some details on the Tumult based sub on my webpage under the DIY link as well as this response plot. As you can see it has no problem going down very deep when called upon to do so.

[Nick M]

A few questions Andrew.

According to the text on your link, the Kilimanjaro design uses the $500 Tumult driver along with a 1000W amp and is capable of only mid-20Hz extension. The SVS PB10 will belt out a respectable 20Hz (albeit with unacceptable rumbling during intense scenes). I'm looking for solid response down to around 16Hz. Are there any designs capable of this in my price range?

[Chris D]

Okay, I just had to post to see what : F does. (re-edited)

[ThomasW]

No big deal, just takes a really big box.

Buy a Avalanche 18", buy a Behringer EP-2500 amp and a Behringer DSP1124P.

It's late and it's been a long day I'll post the specifics tomorrow.

[Nick M]

ThomasW you have me interested...

That 18" Driver looks menacing!
"Yeah, it's gotta Hemi, whats it to you?"



Questions...
Will I be able to move this thing with my 15A outlet?
Will it be responsive and not muddy or rumbly?
Will it blend well at 80Hz with my monitors?

[taz13]

I just spent some time playing around with various items in my house to see how many amps they're were each pulling and it was very educational. My toaster and coffee maker each were pulling out between 5 and 7 amps each while the microwave and hair dryier were up near 12! On the HT side both power amps (Rotel RMB 1075 and RM1080 were typically around 1 amp with peaks to 2 amps with heavy continous bass). The sub amp which I thought would be higher typically was fairly low unless I turned up its volume way beyond its calibrated levels. For giggles I also plugged in both power stips that the rest of the AV gear is plugged into and they were both under half an amp. I guess my dual 20 amp lines are likely not in any real danger

As you can see our equipment doesn't draw as much as we think. Here is the link this came from https://www.htguide.com/forum/showthread.php?t=12538
Depending on what else you have on that 15a circuit( remember they are rated at 80% continuous or 12a)
And I definitely have to remember that smiley :rofl:

[junior77blue]

Well, I can't comment on adire's home audio subs. But I did use one of their car audio subs, 12" bramha. It was a beast of a sub. However, there were 2 issues with it. Tinsel lead slap (actually pulled one off the post) & dust cap noise. This was in a sealed enclosure in a trunk and I could still hear the dust cap. Off to ebay it went...

[Andrew Pratt]

I'll let Thomas comment more on the design specifics but the 15A line won't be a problem and if you can spring for the BFD ($100) you won't have any problems getting it to blend properly. As for playing below 20 Hz I'd think long and hard about why you feel you need to go that low. To get their isn't easy nor cheap and it often requires going with a ported sub that's tuned really low...which means you give up SPL higher up where you actually need it. Regardless as you'll see from the SPL plot of my small sealed tumult I've still get decent extension below 20 and yet group delay is kept in check and I never have to worry about the sub unloading below the tuning point like you do with ported designs.

[cjd]

A few questions Andrew.

According to the text on your link, the Kilimanjaro design uses the $500 Tumult driver along with a 1000W amp and is capable of only mid-20Hz extension. The SVS PB10 will belt out a respectable 20Hz (albeit with unacceptable rumbling during intense scenes). I'm looking for solid response down to around 16Hz. Are there any designs capable of this in my price range?

Make sure you're not comparing sealed to ported designs as well. (I didn't check the links at all to see, but the Tumult *can* go below 20 quite easily. Or any of the Avalanche drivers).

I recently built a sealed Tumult in ~85L. Preliminary testing suggests that with minimal EQ it's playing below 20Hz.

Bigger box and more bottom end extension. Or port. Or IB if you can swing that.

C

[Andrew Pratt]

My Tumult is in about the same sized box as well...nice aren't they :yesnod:

[ThomasW]

Questions...
Will I be able to move this thing with my 15A outlet?

This is audio not arc welding

Will it be responsive and not muddy or rumbly?

Yea like I'm well known for designing crappy sounding subs. Your room will be the biggest influence on the sound of the sub

Will it blend well at 80Hz with my monitors?

Depends on your monitors. It will certainly blend as well as any other sub.

Now read this thread and look at the pictures in the link Pete posted. The project isn't complete since there have been problems with the supplier where Pete buys his lacquer.

https://www.htguide.com/forum/showthread.php?t=11980

[Nick M]

As you can see our equipment doesn't draw as much as we think.

Cool. Its just that I see some amplifiers require a 20A outlet, and didn't know if the amp needed to drive this beast would require one too.

As for playing below 20 Hz I'd think long and hard about why you feel you need to go that low.

I love the presence it gives pipe organs and impact it lends certain scenes in movies. The realism it gives to cannonfire is awesome. This little PB10 I'm using now kinda flirts and teases me with it, but as I said, it doesn't dish it out with authority and lacks in other areas.

Yea like I'm well known for designing crappy sounding subs.

Sorry man. I know what I like in sound, but I don't know squat about what I need to do to make it. :B No offense intended! :T

Depends on your monitors. It will certainly blend as well as any other sub.

Probably a stupid question, but does a driver that large struggle to play clean and fast around say 80Hz compared to a 12" driver? I'm just curious what you gain and lose as you increase/decrease your driver size. In addition, how does a sealed sub benefit over a ported sub. What are the benefits/shortfalls of building say 2 12" or 15" subs vs one 18".

I read through that whole thread and also looked at "Adam's Avalanche" website. Looks fairly complex with the internal bracing. What tools do you need for this, and do you have any blueprints? Also, everything will be going in one room, so will one of those pro-amps generate alot of fan noise? I'm probably not reading your graphs correctly, but it looks like the sub is down -8dB at 20Hz, and -13dB at 15Hz. I can see that its still over 100dB SPL, but when I'm playing it at around 75dB will this response drop in a linear fashion? I know these are probably all newb questions, but please bear with me... ;x(

[Dennis H]

That graph doesn't include room gain which will boost the bottom end. With a sealed sub, you can make the response whatever you want with an equalizer. That's what the Behringer DSP1124P is for. You'll need it anyway to correct for room problems so it can do double duty and boost the lowest freqs if it's needed.

[ThomasW]

Probably a stupid question, but does a driver that large struggle to play clean and fast around say 80Hz compared to a 12" driver?

Fast bass is called treble. :wink:

The urban myth about small drivers = fast bass is just marketing BS. It takes the movement of large amounts of air to reproduce low, loud bass. Properly designed large drivers are just a good if not better than smaller drivers.

Yep big high output subs need to be heavy and they need to be stiff. Bracing makes the cabinets stiff. If you have a hand jigsaw you can make the cutouts for the braces. Neatness scores don't count when the woodworking is hidden inside the closed cabinet.

As Dennis noted the lowest frequencies are boosted by the box loading into the room. Room gain is the same thing as so called 'cabin-gain' in cars.

Also you're going to be boosting the very low frequencies with the Behringer. This device must be purchased, it's not an option. There are other ways to boost the bottom end, ports, PR's, LT circuits, etc. These are more complicated, and more work to build and use. And in the end you'll still benefit from having a DSP1124P. So buy it up front and build a simple sealed box.

[Nick M]

Fast bass is called treble.

:rofl: Ok smarty... :P
What I meant by "Fast" is (and I believe I'm using the correct word here) Decay. The ability to for the driver to start/stop fast enough so that trailing edges of notes sound realistic and not drawn out/warm. This also leads me to think that a "fast" sub would also be better able to give you clean seperation of notes during heavy bass scores. Help me out here... ops:

And where do I find a step by step box guide, tool list, measurements, etc.

Thanks Thomas! :T

[cadman]

new Peerless SUBWOOFER 830844

these are very musical and just out,
very fast.
Subs with very high watts are not fast, they can go very low but not musical they are to stiff to be fast.
I made 2 subs with these new Peerless SUBWOOFER 830844 they are very small boxes are really good IMO for the price you can get them at Solen.ca

my box size is 16x16x16 outside with 1inch walls and 2 passives each boxes
and I have 2 boxes they go down to 21hz I rate them high but (it's my oppinion and mine only)

TO EACH HIS OWN OPINNION

just helping (i do not appreciate been flammed) for helping

[Dennis H]

Subs with very high watts are not fast, they can go very low but not musical they are to stiff to be fast.

Yikes, the F word, the M word, the stiff myth and the watts myth, all in one sentence! Thomas, you're up.

[GrahamT]

Yikes, the F word, the M word, the stiff myth and the watts myth, all in one sentence! Thomas, you're up.

:lol: Yep, nothing to do with woofer speed or fast bass.

Cadman, and others, read this:

http://www.adireaudio.com/Files/TechPapers/WooferSpeed.pdf

I find that people usually associate fast bass with high Q sealed subs. 60 Hz is 60 Hz. Either a sub can play the frequency, or it cant.

Thomas wont steer you wrong. It isn't so complicated to build a great sub, there's no magic. Just get a big well designed driver (no replacement for displacement), build proper big box ( IB ) and get a big amp. You'll be well on your way to low distortion bass.

[ThomasW]

Cadman,

Subs with very high watts are not fast, they can go very low but not musical they are to stiff to be fast.

I'm sure you can find forums accepting of a post like this. Unfortunately for you this forum deals in science fact, not science fiction. So I know you'll restrain yourself from posting further flights of fantasy.

Nicholas,

The term you're searching for is 'transient response'. And yes this sub will have good transient response. Your room will do more to muddy the bass, than using a big driver will.

And where do I find a step by step box guide, tool list, measurements, etc.

You don't. The outside box measurements are in the thread. And they are...

23.5 x 23.5 x 30, doubled 3/4" cabinet walls. The 30" dimension is the front to back depth. The driver is mounted in the 23.5"X23.5" front baffle

But you won't find a piece by piece cut list. That you can create one knowing the outside dimensions of the box and the fact that the box is made using doubled 3/4" walls. So the inside dimensions are 3" shorter than the outside dimensions so, 20.5"X20.5"X27"

What tools do you think you need to cut the pieces of wood, glue them together, and make the necessary cutouts?

[Dennis H]

As Thomas mentioned, the room is often the culprit in "slow" bass. It can cause frequency response swings of 20dB or more. Those are fixed with careful placement of the sub and chairs along with bass traps and equalization. Below is a pic showing what happens when a room/sub combo has a big 80Hz peak. The top curve is the input signal and the bottom one is what the mic picks up. Muddy, slow, bloated, whatever subjective term you use for it, it sounds really bad. Flattening out the frequency response, whatever it takes to do that, will also fix the curve in the pic.

[Nick M]

Did some measurements with my PB10-ISD

Here is my hand drawn FR graph. Its not exponentially compressed either. All of my readings were adjusted using the RS SPL meter table SVS provided. Plenty of Peaks/Nulls.

I wasn't feeling that inaudible bone marrow/soul moving sensation at the sub 20Hz infrasonics. You could feel it a tiny bit, but it wasn't anything powerful and dropped off quickly with each step down in frequency.

http://mysite.verizon.net/nicholasmosher/fr.JPG

You might need glasses for this one

EDIT: The link works off and on. My ISP sucks (verizon). :M

[awm]

Graham T -- thanks a bunch for that Adire link. I've known the bottom line re the "fast" bass myth for awhile now, but not all of the physics behind it. While it does make sense to me that a Lamborghini can and will be a LOT quicker off the line than a Miata (heavier car plus powerful motor = better acceleration), that analogy is still inadequate. The white paper explained it perfectly and makes complete sense, as well as providing some cool basic test data.

Cadman, no offense but I hope you checked out the link. It's pretty compelling.

Andy

[GrahamT]

I wasn't feeling that inaudible bone marrow/soul moving sensation at the sub 20Hz infrasonics. You could feel it a tiny bit, but it wasn't anything powerful and dropped off quickly with each step down in frequency.
:M

That is because even though 20 Hz measures flat, it may not feel or sound flat. Check out the Fletcher Munson curves:http://www.webervst.com/fm.htm I and many others EQ the response to get a house curve.

The SVS wont pressurize a big room at 20 Hz. It cant move enough air. You need lots of displacement for that.

A good 15" or 18" driver in an EBS box will get you the pants shaking bass you're looking for. Try a 18" Avalanche in 20 cubes in an EBS. That should do it. :twisted:

Graham T -- thanks a bunch for that Adire link. I've known the bottom line re the "fast" bass myth for awhile now, but not all of the physics behind it. While it does make sense to me that a Lamborghini can and will be a LOT quicker off the line than a Miata (heavier car plus powerful motor = better acceleration), that analogy is still inadequate. The white paper explained it perfectly and makes complete sense, as well as providing some cool basic test data.

You're welcome. I think that explains things pretty well also.

[ThomasW]

Nickolas,

One reason your current sub sounds so wimpy is the huge null at 35Hz. You might move it a couple feet one way or the other and see if the null changes or goes away.

BTW if you download Sonnie Parkers Excel workbook it will generate plots with the Radio Shack corrections built-in

Here's a link

http://www.snapbug.ws/bfd.htm

[Dennis H]

That room response doesn't look too bad compared to some I've seen. The Behringer, along with moving the sub a bit as Thomas said, can help that a lot. I just looked up the PB10; I hadn't seen that one. It uses what SVS calls an entry level 10" driver. They source their drivers from TC Sounds so that probably means it's similar to the 10" TC2 which can move about 1 liter of air peak-peak. The Avalanche 18 can move over 6 liters so, in a ported box, it would be like having 6 of the PB10s. That should get your pants flapping, your plaster cracking and your neighbors calling the cops.

[Nick M]

I have close to zero carpentry skills, but can learn quickly with experimentation. What type of saw do I use to cut out the hole where the driver goes? Do I need some type of clamp when glueing things? Do you cut notches into the boards to join them? I definetly will have to find some box blueprints so that I can make something properly and not have it blow apart... :B

I'm also nervous about using a pro-amp with the sound of the fan. Do you stuff the box with polyfill? How dense do you pack it? I see there are plate amps that will push 500-1000W into 4 Ohms. Are these things any good?

Are there any websites you guys would recommend that have detailed walk throughs?

I read that article about transient response. Does this mean fewer windings and more power = higher transient response? It still makes me wonder though... holding a 3" diameter wiffleball in one hand, and a 3" diameter lead ball in the other, I can sure extend and retract my arm faster with the wiffleball. If F=ma, a=F/m. As you increase m doesn't a decrease? I'm a retard engineering drop-out, so dont mind me :B (I did get good grades though :W) Inertia must play a role in here somewhere...

[Andrew Pratt]

Nick you'll need a router to cut the driver holes.

[Bent]

Nicholas, the mass does come into play, but in this league, it's more the voice coil inductance that is what is determining how quickly the driver can change pace.

I'm a technician and I'm supposed to know who made this law, but it kinda sounds like
"a voltage applied across an inductor will induce another voltage in such a way as to oppose the volatge that caused it. This is called "Back EMF" and is what is doing all the magic in most motor assemblys.

[ThomasW]

Perhaps you have a friend, relative, neighbor with some carpentry skills? Tackling a project like this maybe a bit much for a first time builder.

If there are woodworking stores near you they sometimes have a shop and instructors you can rent.

[BobD207s]

Nick
since the svs is so close - why not get a BFD for $100 and try that - when Kevin P got his svs it wasn't exactly what he wanted but once he installed the BFD he tamed that SVS so it was perfect
Hope this helps,
Bob & Kevin P

[Kevin P]

Like what my friend Bob D207 above said, a BFD is likely to help tame that SVS (or a DIY sub if you do go that route). The issue is not with the sub itself most likely, but the acoustics of your room. Have you tried moving the SVS out of the corner or try another location in the room? Corner loading a sub tends to make it boomy. Adding bass traps, carpeting (if your room isn't carpeted already) or even some overstuffed furniture to the room to absorb some of those reflections will likely help as well.

I think you'll be quite happy with a properly tweaked SVS. And even if you go the DIY route, you'll still want to tweak your room and use a BFD to get the best performance out of any sub you end up with.

[Dennis H]

Plan B, requiring less carpentry, would be a tube sub, similar in concept to the original SVS subs. The only tools you'll need are a jigsaw and a drill. Google tube sub and you'll find lots of articles. I think Thomas has one somewhere. The tube is thick cardboard used for forming concrete columns. The cylindrical shape gives it its strength so it doesn't need to be heavy. Cut wood caps for each end, put it on some short legs, cover with upholstery fabric and you're done.

Edit, okay I didn't get many google hits with tube sub but sonotube subwoofer worked. Here's a step by step by Ron Stimpson, one of the co-founders of SVS, before he and Tom turned their DIY hobby into a business.

http://www.hometheaterhifi.com/volume_6_3/diy-11-sonotube-subwoofer-september-99.html

[Bent]

Also, before turfing the 10" SVS, please try "the put the sub in the chair and crawl about the room" trick - I would have, but my DIY subwoofer is 260 pounds - and since it is working, I haven't made any progress with doing the veneer and legs yet.

[ThomasW]

A router and a circle cutting jig are really mandatory for building a tube sub. Trying to cut airtight endcaps with a jigsaw is very difficult.

But Dennis is correct a tube sub is 1/3rd the work of a box sub. And they need NO internal braces ...... :B

Patrick Sun has pages and pages and pages of info on building tube subs.

http://www.io.com/~patman/diy.html

I have 2 tube subs detailed on my website

http://home.comcast.net/~audio-worx/page93PetesTube.html

http://home.comcast.net/~audio-worx/page88Tube-Zilla1.html

[Nick M]

Ron suggested I move the PB10-ISD next to my couch.
Gain was increased to 75%. Recalibrated to +/- 1dB at 70dB with Avia.
Here are the results...
***All readings were modified using SVS' RS SPL meter table***

http://mysite.verizon.net/nicholasmosher/room.jpg

http://mysite.verizon.net/nicholasmosher/fr.JPG

(Same deal... open/close/open/close to get them to work)

An SPL increase of 9dB at 15Hz, my first null moved forward in the FR, and response between 60-85Hz flattened out. I have a Huge 97.5dB peak at 20Hz...

The infrasonics are definetly better. I'm still getting some rumbling during intense bass sections on SACD, and the PB10 is sticking out during some intense passages. Running it -3dB down helps a bit, but then I lose impact.

Last time I looked at the clock it was 2pm... now it's 9pm?!

That box looks like some serious woodwork, and given that all my tools are for working on engines and metal, I would have to dedicate moo-lah from the driver/amp/enclosure to getting the router and what not. I do appreciate the help though. Man is this a pain! :M :B

[Saurav]

Here's another recommendation for a BFD. This is a before/after picture from when I first got the BFD. This was with the sub in the corner. Moving it a few feet reduced the 45 Hz null a good deal, and my current measurements are pretty decent.

Image not available

[Andrew Pratt]

Nick if you can't make a box there's still the option of building the sealed titanic in the box from Parts Express. There's other vendors selling pre built or flat kits as well that you could investigate.

For your reference heres the info I posted about that option in the other thread

That unit did very well in a review on HTF a few months ago against some similar priced contenders (no HSU though) and it does go deep :T

As an alternative solution consider this...

Box

Amp

Driver

Total cost is about $350 so you've got some room for shipping and maybe to buy a router or jig saw to cut the driver hole.

If you wanted to make it even easier just get the Titanic cabinate instead that has the holes already cut out. Add the Titanic 12" driver and use the same plate amp above and you'd really have a nice sub that would walk all over most of the one's anywhere near this price point. The Titanic route is slighly above your SVS budget but it would be more inline with their Ultra models. The 15" DVC driver would be around the same SPL output as well given its larger diameter....either way you wouldn't be left wanting for bass If you can't swing the Titanic but wanted the Titanic box the 12" DVC driver would work in that box as well. It wouldn't be as good as the Titanic but it would still compare fairly well with the SVS ISD driver I think. Both of these would obviously be sealed sub's but they'll still reach down very deep and won't bottom out with that plate amp...plus you can be proud of something you've built :T If this is something you would actually consider start a thread in the DIY area and have the guru's there comment on the various options. There are other drivers around that you could use as well from Adire and Ascendant that may or may not be cheaper.