speakers/subwoofer

[Viperoni]

Mookow, I was rethinking your situation, and frankly, most subs will just bottom wayyyyyyy too much with that kinda power + super low frequency

What would I do?
Get a much more massive driver. Namely the BluePrint 1803, toss it into a 10cf box, use several ports that can be closed to change the tuning frequency, from ~25hz for music to ~10hz for your bass tones. You will never be able to bottom that driver, or go past it's linear excursion limit with a 250watt amp...either out of box or in box. NEVER.

The Okara's look pretty cool.

Remember that;

<< the Okara II has been designed specifically to perform at its best when placed either on a bookshelf or stand within two feet of the rear wall >>

so it won't sound to good out in the room.

 

[pdo]

is this going to be for hometheater or music? Lately the trend seem to be passive radiator subwoofer with pro audio amplifier with massive amount of wattage.

 

[Mookow]

<< Mookow, I was rethinking your situation, and frankly, most subs will just bottom wayyyyyyy too much with that kinda power + super low frequency

What would I do?
Get a much more massive driver. Namely the BluePrint 1803, toss it into a 10cf box, use several ports that can be closed to change the tuning frequency, from ~25hz for music to ~10hz for your bass tones. You will never be able to bottom that driver, or go past it's linear excursion limit with a 250watt amp...either out of box or in box. NEVER. >>



HOLY F*CK!!! I looked at the specs on that thing. 51mm Xmax is almost 2 full inches. Its about double what I was planning to spend on the subwoofer driver, but its really tempting me to work a little more over the summer.



<< The Okara's look pretty cool.

Remember that;

<< the Okara II has been designed specifically to perform at its best when placed either on a bookshelf or stand within two feet of the rear wall >>

so it won't sound to good out in the room. >>



Thats a good thing. I think I'd just put them on the stands, near the corners of my room, pointed at the middle (which is pretty close to the couch and my chair... in other words, my most likely listening positions). However, to repeat... will I need a reciever?

 

[ArmenK]

If you are going to build the sub yourself, it will be MUCH easier if you build a tube based sub. You can find detailed instructions on making one on Patrick Sun's webpage. He has built 3 different tube based subs and documented the construction of each one. If you have any questions regarding this type of stuff, go over to Home Theater Forum and ask questions under the DIY section. Good luck!

 

[Mookow]

Oh, I forgot to ask... Viperoni, could I mount either the 15" Dayton DVC or the 18" blueprint driver as down firing? In particular, I'm thinking putting my enclousure on legs and turning it into a (sturdy as hell, obviously) end table, and having the cone down firing.

 

[glen]

Measuring and building boxes is a pain in the ass and not needed - Unless you can't afford the room.
Measure the closet in your living room.
Pay someone to make a nice baffle for it with a CnC router.
For under $600, you can throw four 15" tempests in there.

 

[Viperoni]

<< is this going to be for hometheater or music? Lately the trend seem to be passive radiator subwoofer with pro audio amplifier with massive amount of wattage. >>



Only problem is you're gonna need massive amounts of PR area.....and massive PR's to begin with. I wouldn't even consider a 15inch DVC with a single PR, a pair are a must, and even then I'd be worried with the 6hz test :Q

Jack's sub is nicely done, and I like massive ports (or PR's, same difference), because they give a LOT of SQ ("punchiness" improves because the drivers have to work less to "push" the air out through the port. Basically the bigger the better).



<< HOLY F*CK!!! I looked at the specs on that thing. 51mm Xmax is almost 2 full inches. Its about double what I was planning to spend on the subwoofer driver, but its really tempting me to work a little more over the summer. >>



Indeed it's nuts. You shouldn't be able to bottom it in free air with 250watts....even at super low frequencies, not even 5hz should be able to bottom it I dont think. Needless to say, in a box, it'll be moving very very little.

The area where this driver excels at is a LT (Linkwitz transform), where the woofer plays from the boxes f3 point and down. You will need an EQ to accomplish this, but look at the sunfire cube, it uses the same kinda design.

BTW: a 1803 in 4cf sealed box with 1kw wouldn't exceed Xmax @ 10hz.....but you should be able to pull off 105db in room..if not more.



<< Thats a good thing. I think I'd just put them on the stands, near the corners of my room, pointed at the middle (which is pretty close to the couch and my chair... in other words, my most likely listening positions). However, to repeat... will I need a reciever? >>



sounds decent.
what do you have right now to drive speakers? You could use your Klipsch amp to drive the Okara's, but you could also get a low buck Nad or Parasound amp for ~$100 on eBay. Say around 20-40watts a channel. Add a nice preamp, again, Nad, Parasound, Carver maybe? Maybe even a nice bottlehead.com Foreplay tube amp kit ($150).
You could go with a receiver, but IMO, unless you want to go HT in the future, a good amp+preamp would be a much better choice.




<< If you are going to build the sub yourself, it will be MUCH easier if you build a tube based sub. You can find detailed instructions on making one on Patrick Sun's webpage. He has built 3 different tube based subs and documented the construction of each one. If you have any questions regarding this type of stuff, go over to Home Theater Forum and ask questions under the DIY section. Good luck! >>



I've seen Pat Sun's sonotube a long time ago, the only part that's hard to do is to cut out the end caps. You likely need a circle cutting jig + plunge router to do it...$$$$$$$ unless you know someone that can do it for you



<< Oh, I forgot to ask... Viperoni, could I mount either the 15" Dayton DVC or the 18" blueprint driver as down firing? In particular, I'm thinking putting my enclousure on legs and turning it into a (sturdy as hell, obviously) end table, and having the cone down firing. >>



No problem with either. My own 15inch DVC will be downfiring, now it's facing up because I dont have any legs to hold the box up
You want to build one HELL of a strong, 4cf, sealed box?
Scroll down a tad to see the "North Leviathan box", in PDF format



<< Measuring and building boxes is a pain in the ass and not needed - Unless you can't afford the room.
Measure the closet in your living room.
Pay someone to make a nice baffle for it with a CnC router.
For under $600, you can throw four 15" tempests in there. >>



Problem is he'll be moving
IB's obviously bottom easier than boxes, but they have awesome SQ potential. And give off more super-low end bass...at the expense of powerhandling/overexcursion risks.

 

[Mookow]

Viperoni,
I decided to do something I dont think you were expecting... I decided to show some initiative, so I downloaded WinISDbeta .44 and have been playing around with it a little. Since I didnt see the Blueprint 1803 driver in the database, I loaded what I saw on the 1803's spec page into the program. It didnt have ALL the specs that WinISD wanted, but it had all but 4 of them, so unless you can show me a better tool or tell me the missing specs, I think I have a decent view of what this speaker will be able to do. I figure I can, using your closing and opening different ports idea to tune it, set this up:

Music/Movies/general usage:
20 cu foot box
tuned to 16 Hz
produces 91.08dB @ 100Hz (all dB given at 1Watt level unless otherwise specified)
produces 86.79dB @ 20Hz
produces 86.74dB @ 16Hz
lowest dB between 20Hz and 100Hz: 86.68dB @ 22.5Hz
port length: 20.08"
port width: 8"
W x H x D: 34.52" x 54.33" x 21.31"

Tone usage (I cant set the graph to lower than 10Hz to view the dB levels, so since you recommended tuning to 10Hz, I did):
20 cu foot box
tuned to 10Hz
produces 90.94dB @ 100Hz
produces 82.52dB @ 20Hz
produces 79.69dB @ 10Hz
port length: 60.55"
port width: 8"
W x H x D: 34.52" x 54.33" x 21.31"

Note: the WxHxD measurements do not take into account internal bracing, etc. That will be adjusted once you tell how I should do it. Currently, the measurements are including .75" thick board for the sides. Currently, I figure with the legs to bring it off the ground and the added height to balance out the internal bracing, this subwoofer should be 5'1" or 5'2" high .
Now, for my questions:
For closing/opening the different ports, how would i set up the ports to do that? I assume duct tape wont work too well
Instead of having a 8" port, could I put in two 6" ports (which together have a higher cross-sectional area) at the shorter length that is specified for a single 6" port? As you can see, unless I do something, the 10 Hz tuned port will be longer than the subwoofer is high.
Is there a program that can simulate a subwoofer's output lower than 10Hz? I would like to see the 6Hz level.
The webpage for the 250W amp says it will filter out <20Hz noise. Any way to prevent that?
Assuming I purchase that 250W amp, I can use it to power my other speakers too, right? Or should I get one of each, one to power the sub, one to power the satellites?


If I remember any other questions, I'll post them.

 

[glen]

Like I always say, use an Infinate baffle and an EQ.
I use a 5 band parametric, the Symetrix 551.

 

[pdo]

If you have excel you can download Unibox to model. I hope you know that 20cf is the size of the refrigerator. If you can afford those kind of sizes then might as well try 2 15" Tempest like these . It's Geocities so you might have to copy and paste.

 

[Mookow]

<< If you have excel you can download Unibox to model. I hope you know that 20cf is the size of the refrigerator. >>



I know exactly how big it will be. I already posted the dimensions, and whipped out my measuring tape to see how big that would be in the room. The corner that it will go in has been selected. Thanks for the program, btw

One small problem with that sub... it weighs 475 lbs

 

[AmigaMan]

I was going to suggest Bose, cuz they rock!!!

Darn you guys are smart. I thought I knew a little something about audio when I was into car stereo in my youth, but this stuff is WAY over my head.
And 20cf is HUGE! If (and note, that this is a BIG if) Bose did sound good, that's what I would be aiming at. Small==not visible==ok to wife. She would kill me if I tried to get a 20cf box into the house just for some bass.

 

[Mookow]

<< I was going to suggest Bose, cuz they rock!!!

Darn you guys are smart. I thought I knew a little something about audio when I was into car stereo in my youth, but this stuff is WAY over my head.
And 20cf is HUGE! If (and note, that this is a BIG if) Bose did sound good, that's what I would be aiming at. Small==not visible==ok to wife. She would kill me if I tried to get a 20cf box into the house just for some bass. >>



This isnt going to be for just "some" bass... 250W amp, 18" driver, 20cu ft box with an 8" wide port...you could take 20 bose "bass modules" and they wont be able to crack this, esp the <20Hz stuff.

 

[AmigaMan]

LOL! I find it pretty funny that Bose has a Bass Module when you can't even hear the bass. Much less the midrange, and then there's the missing highs...
But I digress, I don't want to change this to a Bose bashing thread. At 6hz, you aren't gonna hear anything but you'll definitely feel it. Do you have the music to play that low? I think a lot of the audio reviewers out there use that 18hz blast from the Overture of 1812 to test subs. You just gonna play some test tone to get that 6hz?

 

[Mookow]

<< LOL! I find it pretty funny that Bose has a Bass Module when you can't even hear the bass. Much less the midrange, and then there's the missing highs...
But I digress, I don't want to change this to a Bose bashing thread. At 6hz, you aren't gonna hear anything but you'll definitely feel it. Do you have the music to play that low? I think a lot of the audio reviewers out there use that 18hz blast from the Overture of 1812 to test subs. You just gonna play some test tone to get that 6hz? >>



The plan for doing the 6Hz prank is to use a 6Hz tone.

BTW, for you getting a sub, you could hide it in your living room, right out in the open. Make a table, fit a down-firing sub (say 8" or maybe 10"), run the wires through the leg, and its a totally "stealth" sub. The box doesnt have to be big... 3-4cf range. It'll kick the crap out of a bose bass module.

BTW, wish me luck, I'm off to my econ midterm

 

[Viperoni]

Mookow,

Nope, I wasn't quite expecting you to, but know what you can see what you'll get

Don't even think about going that big for music. It'll sound pretty bad.....but it will belt out those low frequencies VERY loudly. VERY.
For music, I'd seriously recommend the 4cf sealed box.....like the one from North Creek Music.

There is an option in one of the view or option menus to change the DB scale, colours, and the low frequency limit too I beleive.
I use UniBox, a more accurate, plus more advanced and harder to use freeware modeling program, but it ends @ 10hz and 130db

The single 8inch port should be enough.
BTW: imagine a nice 3x3x3 foot coffee table....27cf for bass


Yup the amp does have a subsonic filter, but it starts lower than 20hz I believe, somewhere around 15hz.
*I think*
Yup, you can remove the bass boost, and like I did, you can turn it into a 24db/octave lowpass filter (I have mine @ 45hz, but I dont like it that low and will move it up to ~65hz).

The amp is a mono design, made for powering subs, it can be modded to give full range output, but I wouldn't use it for full range. On the inside, it has a pair of wires, + and -, that you connect to the sub driver to give it power. The speaker leads on the outside are not powered, they just filter out bass from the connected sats, if you feed the signal like that.

 

[Viperoni]

^

 

[Mookow]

<< Don't even think about going that big for music. It'll sound pretty bad.....but it will belt out those low frequencies VERY loudly. VERY.
For music, I'd seriously recommend the 4cf sealed box.....like the one from North Creek Music.
>>


What happened to the

<< a 10cf box, use several ports that can be closed to change the tuning frequency, from ~25hz for music to ~10hz for your bass tones. >>

? I liked that idea. Though, shouldn't I tune it closer to 18-20Hz for music? Tuning to 25Hz keeps it pretty flat to 30Hz, but then it rolls off pretty fast.



<< The single 8inch port should be enough. >>


I was asking about using 2 6" ports because they would be shorter, not for the increased area (which is pretty much minimal). Can it be done? Or, rather, will it work like that?



<< BTW: imagine a nice 3x3x3 foot coffee table....27cf for bass >>


I'm now leaning against the "2 seperate enclosures" idea, unless its really easy to switch between the 2. Otherwise, I think I'd rather go for a box that does music as its first priority, but can also handle the 6Hz tone fairly well.



<< Yup the amp does have a subsonic filter, but it starts lower than 20hz I believe, somewhere around 15hz.
*I think*
Yup, you can remove the bass boost, and like I did, you can turn it into a 24db/octave lowpass filter (I have mine @ 45hz, but I dont like it that low and will move it up to ~65hz). >>


Is there any way for me to find out where it filters at? How hard is it to remove the bass boost and change it into a low pass filter?



<< The amp is a mono design, made for powering subs, it can be modded to give full range output, but I wouldn't use it for full range. On the inside, it has a pair of wires, + and -, that you connect to the sub driver to give it power. The speaker leads on the outside are not powered, they just filter out bass from the connected sats, if you feed the signal like that. >>


Thanks for clearing that up.

 

[Viperoni]

<< ? I liked that idea. Though, shouldn't I tune it closer to 18-20Hz for music? Tuning to 25Hz keeps it pretty flat to 30Hz, but then it rolls off pretty fast. >>



Generally the larger the vented box, the worse it sounds for music. But at the same time, the more SPL or low end extension you get from it. It defientely is a trade off.

If you wanna go with it though, yup, it is flat to 30hz, which is all you need for most music, and even then the F3 is 22hz.
But if you wanna go a bit deeper, 20hz would be fine to tune to.

The dual 6's would have slightly more port area, but they would require a slightly longer port length, plus the problem that they have more surface area inside the port, that actually creates a bit more friction. I'd go with 1 8incher because of the above, and it'll be damm huge




<< Is there any way for me to find out where it filters at? How hard is it to remove the bass boost and change it into a low pass filter? >>



Take a look at the Spec and Bass Boost Circuit PDF's, but if you wanna do the lowpass filter mod like be, there's a little more modding involved (changing 4 parts instead of 2 )

John K's 300-794 amp mod page

Unfortunately all his pics are down....inc. the bottom one where the lowpass filter mod is

 

[Viperoni]

^

 

[tops2]

finally, i'm learning something about speakers...
when i try to look at it online, theres ssssoooo much info that it gets overwhelming sometimes...

 

[Viperoni]

<< finally, i'm learning something about speakers...
when i try to look at it online, theres ssssoooo much info that it gets overwhelming sometimes... >>



Hehe, that's the cool part about DIY, so many difference choices.
Like if I want to build a pair of $100 speakers, I have a decent amount of drivers to choose from, but if you go to a store to buy $100 speakers, you have very few choices.
I love DIY