| shaunly |
| I'm just wondering, how do companies like Bob carver or sunfire get there subs very low like around 18-25hz in such a small enclosure. I see some subs that is only about 12in. square sealed box that get's crazy lows. I ask this because I am looking to built a home sub for my house and I want it small but still be able to get nice lows. |
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| richie00boy |
| Massive excursion and huge power. Also slight twisting of the response figures, e.g. not using -3dB point but -6dB or even -10dB, and taking room gain into account. |
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| paulspencer |
They claim 59mm p-p excursion. I'm not sure if that is xmax or xsus, but it's a lot for a 10" driver!
They use passive radiators which allow the smallest box with 20 Hz extension.
The distortion is probably quite high.
If you want to do better for less money and don't expect it to be quite so small:
* get a high excursion driver like the Stryke/AE AV12
* get a pair of 15" passives
* put it in a reasonably sized box
* 500w plate amp
* BFD for eq
When you realise the price you pay when you make it very small, you will probably want to make it bigger. |
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| shaunly |
| I have 1.25cuft to work with. Which sub would be the best for the space I have. I'm just trying to get it under 30hz. |
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| Dave Jones |
| quote: | Originally posted by shaunly
I have 1.25cuft to work with. Which sub would be the best for the space I have. I'm just trying to get it under 30hz. |
A Peerless XLS with a passive radiator a small box will get down. I have a 10" version that measures flat deep into the 20's in my office. Search for XLS and you will find a ton of hits. There's a new version called XXLS too.
The 12" needs a box that's about 1.25 ft^3 (35 liter). The 10" can go in a box as small as 20 liters nominal. When ordering the passives, be aware of how much moving mass they have; There are two versions of each PR. Of course, if you get the lighter one, you can add mass by attaching washers or whatever.
http://www.d-s-t.com/main/tech/appxls2.htm
http://www.d-s-t.com/main/tech/appxls12b.htm |
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| paulspencer |
| Music or HT or both? |
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| shaunly |
| that's a very nice sub, but it's kinda over my budget. |
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| shaunly |
| quote: | Originally posted by paulspencer
Music or HT or both? |
both |
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| paulspencer |
| Sounds like a job for a 12" with a pair of passives. XLS or AV12 are both good candidates which work well in small boxes. The latter with more excursion (double) will have more output, probably as much as two XLS subs. |
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| shaunly |
| quote: | Originally posted by paulspencer
Sounds like a job for a 12" with a pair of passives. XLS or AV12 are both good candidates which work well in small boxes. The latter with more excursion (double) will have more output, probably as much as two XLS subs. |
those are both very nice drivers, but im on a tight budget, so I can't really get those. Probably later on when I start building more speakers and have more experience, but more now, it's got to be something cheap :D |
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| paulspencer |
What is your budget?
Forget passive radiators then. Either go with a small sealed box with a Linkwitz transform or a larger vented box.
The AV12 is on pre-order at the moment for $140 USD. That will match an XLS passive radiator sub in output but with a sealed box. It is also cheaper at the moment than just the XLS on its own.
The Shiva isn't much cheaper. If $140 is too much then I'd say start hunting around for some special deals. You might find some on clearance.
You could also look at Dayton DVC for $105 or Quattro for $75 at Parts Express |
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| paulspencer |
Check this out Stryke Audio Clearance items
eg. 1 SAE1201. Basically identical to a shiva but with a single 4ohm VC. $60 for that one. 15mm xmax
If you can pick that up it would be a great deal ;)
Not sure if it's still there |
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| shaunly |
This is going to be my first time building a home sub, so I dont want to spend a lot of money. Once I get more experience I'm going to get better equipment and built better subs. I already bought those Dayton and an Audiosource amp. I've read from a guy that it is rated 50W @ 8ohms, I'm going to be running @ 4ohms, hopefully Ill be gettin a little more power. So basically I just need to figure out what's the best enclosure to go with.
amp: http://www.newark.com/product-detai...ml/58-9681.html |
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| paulspencer |
| Now it's time to plug in some numbers into Win ISD (pro is best). You probably have 80-100w into 4 ohms. You might consider making it a vented sub and see how small you can make it, since you don't have a lot of power on tap. If you have a go and post some sim results we can give feedback ;) |
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| shaunly |
| quote: | Originally posted by paulspencer
Now it's time to plug in some numbers into Win ISD (pro is best). You probably have 80-100w into 4 ohms. You might consider making it a vented sub and see how small you can make it, since you don't have a lot of power on tap. If you have a go and post some sim results we can give feedback ;) |
this is what I got. It is in a 1.3 cu.ft tune to 30hz |
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| paulspencer |
| That's max spl ... we need to see SPL. Plug in 80w and then show SPL chart as max SPL shows what you can get based on xmax ... ie it's misleading and doesn't show if it's tuned correctly. |
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| shaunly |
| did I do something wrong, because there's a big dip there. Here's another graph |
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| shaunly |
| ops sorry, heres the SPL graph |
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| Stocker |
That is not such a big dip.
Rod Elliott on his ESP pages has the circuit to turn your a tiny sub into a low-frequency champ by lots of equalization, power and excursion. Plus the amplifier that could do it. Add a box and sub and you're almost there. |
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| BillFitzmaurice |
| Get the MCM 55-2421 8" long throw sub driver from MCM. Measured specs are Fs 30 Hz, Qts .25, Vas 22l, cost less than $35. From the size box you want to use you can get f3 at 36 Hz, so with room lift it will do the job. Definetely the bang for the buck driver. |
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| shaunly |
| quote: | Originally posted by BillFitzmaurice
Get the MCM 55-2421 8" long throw sub driver from MCM. Measured specs are Fs 30 Hz, Qts .25, Vas 22l, cost less than $35. From the size box you want to use you can get f3 at 36 Hz, so with room lift it will do the job. Definetely the bang for the buck driver. |
that sounds like a nice driver. I'll look into it. Thanks |
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| paulspencer |
I can't find specs on that MCM woofer. It looks like a good candidate for a budget sub but you can't really design it without specs. Parts express have some cheap subs or different sizes. There is also a TB sub that looks similar to that MCM woofer.
Also have a look at
APEX , they have two cheap 8" subs, one for $20, one for $40. The latter is better.
Two options:
* cheap 8" driver in a vented box
* larger 10" or 12" driver in a sealed box with LT
Re: your sims
Looks like you could tune the box lower, and also I suggest this:
1. look at max power and find the lowest point within your intended bandwidth - probably a bit above tuning
2. enter in that amount of power into signal
3. check cone excursion over bandwidth
4. look at SPL - now you have the max SPL you can get without overdriving |
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| Dave Jones |
| quote: | Originally posted by shaunly
This is going to be my first time building a home sub, so I dont want to spend a lot of money. Once I get more experience I'm going to get better equipment and built better subs. I already bought those Dayton and an Audiosource amp. I've read from a guy that it is rated 50W @ 8ohms, I'm going to be running @ 4ohms, hopefully Ill be gettin a little more power. So basically I just need to figure out what's the best enclosure to go with.
amp: http://www.newark.com/product-detai...ml/58-9681.html |
How did you do that? I've tried several times to browse that web site and the MCM one. It's slow and clumsy. I see empty boxes where the pictures should be. The links to technical descriptions don't work. Neither do the links to the manufacturer's web pages. Do you have to have a login to make it work? (That would be so stooopid.) |
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| Dave Jones |
| quote: | Originally posted by shaunly
This is going to be my first time building a home sub, so I dont want to spend a lot of money. Once I get more experience I'm going to get better equipment and built better subs. I already bought those Dayton and an Audiosource amp. I've read from a guy that it is rated 50W @ 8ohms, I'm going to be running @ 4ohms, hopefully Ill be gettin a little more power. So basically I just need to figure out what's the best enclosure to go with.
amp: http://www.newark.com/product-detai...ml/58-9681.html |
What are "those Dayton"? Does the Audiosource amp have "boost", and if so how much at what frequency? |
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| shaunly |
| quote: | Originally posted by paulspencer
I can't find specs on that MCM woofer. It looks like a good candidate for a budget sub but you can't really design it without specs. Parts express have some cheap subs or different sizes. There is also a TB sub that looks similar to that MCM woofer.
Also have a look at
APEX , they have two cheap 8" subs, one for $20, one for $40. The latter is better.
Two options:
* cheap 8" driver in a vented box
* larger 10" or 12" driver in a sealed box with LT
Re: your sims
Looks like you could tune the box lower, and also I suggest this:
1. look at max power and find the lowest point within your intended bandwidth - probably a bit above tuning
2. enter in that amount of power into signal
3. check cone excursion over bandwidth
4. look at SPL - now you have the max SPL you can get without overdriving |
Those 8in. on looks pretty nice, I'm going to have to play with them on Winisd to see how they perform. That website also sell some plate amps for good price too.
| quote: | Originally posted by Dave Jones
What are "those Dayton"? Does the Audiosource amp have "boost", and if so how much at what frequency? |
Dayton: http://www.partsexpress.com/pe/show...tnumber=295-480
I don't believe that Audiosource amp has a bass boost.
Here's the link to the amp: http://mcm.newark.com/NewarkWebComm...SKU=58-9681&N=4 |
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| m4dm4n |
MCM 55 2421 is similar to Tangband w8-740c except it got lower qts, fs and have 16mm xmax instead of tb's 12mm.
MCM 55-2421
fs 24.7hz
qts 0.18
qms 3,420
qes 0.19
Le 2.49 mH
Re 3.4 ohm
vas 39,4 L
BL 13.35 Tm
Sd 207,2
MAX power 240w (120w rms) |
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| shaunly |
| quote: | Originally posted by m4dm4n
MCM 55 2421 is similar to Tangband w8-740c except it got lower qts, fs and have 16mm xmax instead of tb's 12mm.
MCM 55-2421
fs 24.7hz
qts 0.18
qms 3,420
qes 0.19
Le 2.49 mH
Re 3.4 ohm
vas 39,4 L
BL 13.35 Tm
Sd 207,2
MAX power 240w (120w rms) |
:bigeyes: very low qts, fs and 16mm of xmax. This looks like the perfect driver for me. Where did you get these ts parameters. I couldn't find it anywhere on MCM website. |
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| jjdche |
If that Xmax is really +/-16mm I'd be very impressed. How could they produce a woofer with that much linear excursion for $30?
Honestly, what is the cheapest driver available with more than 15mm Xmax? $125?
Heck, it would still be a great deal if it was 16mm p-p. |
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| BAM |
Build the Stryke Audio AV12 subwoofer. Do it right, right now, or do it again later. Building a sealed box is easy. Check out the box this guy did: http://www.mattder.com/archives/200...as-it-worth-it/
The Stryke Audio AV12 is a great driver. I have one from a previous production run and it is really, really great. I have yet to bottom it out, though I hope to avoid that all together. That's not to say it's inefficient, just that it has a really huge mechanical excursion limit, like 2" p-p, and an electrical excursion that's just slightly less by a few mm. Really a first-rate design, and one of the finest, cleanest bass drivers out there. A 350w amp will work well, and the Parts Express 500w amp will work spectacularly, though it would of course be more expensive. I got the 500w amplifier as a Christmas present, and it really gets the AV12 hopping. |
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| shaunly |
| quote: | Originally posted by Jim York
True, but isn't the title of this thread low bass in a small box? 15 inches cubed isn't huge, but it isn't small either. If you really want to do it right build an AutoTuba (www.billfitzmaurice.com) and be prepared to be blown away, for less than a hundred bucks. |
What size driver does the AutoTuba take? Do you have any experience with it? Sounds like a well design bass horn. I might just give it a try for my car. 14x14 is good, but 32in. long is too big for my living room. |
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| BAM |
But I thought that the title of this thread was LOW bass in a small box. I have always known horn designs, especially small ones, to have very poor bass extension, like only down to 40 Hz or so. But even getting to 40 Hz means a very large box. Horns do have very high output, so if your intention was to get Lots Of Bass instead of Low Bass, then a horn design would be worth looking into. I know that the Tuba 18 will be a corner-loaded style horn, so only operating in 1/8th Pi Space, but even that can only make so much difference. I imagine the Tuba 18 will be acting mainly as a bandpass box. In your house, for home theater, I don't think you'd find many who would tell you that an AV12 in a sealed box is a poor solution.
I suppose that at the lower frequencies, the Tuba 18 will be acting mainly as a bandpass enclosure, because its 18"x18" mouth won't get you that much really low bass. Corner loading, as I said before, probably won't affect it too much, in that if you get flat response to 35 Hz I would be surprised.
I appreciate what Bill Fitzmaurice is trying to do, which is to bring good horn design more into the mainstream of audio, but I think that he finds himself designing bass horns for applications where a bass horn really isn't the best solution. |
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| BAM |
| That sort of sensitivity suggests to me that Bill has found a way to make the Tuba 18 operate mostly like a bandpass box. Perhaps I might build one just to see how well it works. I'm working on a pro sound basshorn design for the HL10 woofer, so I'm more used to working in 2 pi space. |
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| idex |
Well I am that guy and I actually had to turn it the sub down because it was shaking my house too much. I highly reccomend building one if you are thinking of a DIY sub.
Matt |
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| paulspencer |
I'm a bit surprised that this discussion has gone from one extreme to the other! Small 8" subs to big bass horns!
IIRC the Tuba still has quite decent output down as low as 20 Hz ~ 90dB-1w1m. With some eq you can get a flat in room response down as low as a sealed AV12 and still get high output. Done this way, your horn will be much more limited in output BUT this will mean very low distortion for music. The performance won't be as good down low, but down in that range it's not as critical due to the ear's insensitivity. When you want to crank the music and get plenty of ooommpph in the midbass, you can get it. The price you pay is size, they are quite big.
Still, a pair of AV12 sealed subs either side of your couch as small coffee tables will have plenty of output, and if you do it right, they can do the disappearing act, both visually and sonically. This is what I'm doing with my subs. :D |
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| philip |
On the subject of low bass in a small box - isn't that the dream? - I think the new adire audio koda 8" is a contender. If you look at the adire website they have 6 different plans for putting in in sealed and vented boxes of .25 - 1cuft. Plus, its not that expensive. Unfortunately (or not depending on your plans) its a 4ohm driver.
It's true there aren't too many drivers that model low in a small box - although there are notable exceptions like that mcm driver and the tang band w8. On the subject, parts express only lists the w6, which is an insane 6" long-throw subwoofer that can get an f3 of 35Hz in a ported box. Where can one find the w8 subwoofer?
Philip |
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