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DIY similar to a Velo SPL1500/DD15, Revel B15 or Fathom F113 (sealed)???

17K views 90 replies 10 participants last post by  Owen Bartley 
#1 ·
OK, so I have been looking for a new subwoofer and was looking at some of the sealed designs from JL Audio, Velodyne and Revel. I really really like the sound of some of these subs and I think I want to go with a sealed design.

I am going to purchase the Velodyne SC1250 amp with active EQ to make the EQ part of it easy. I guess with that amp, It can EQ up to 2 seperate drivers, so if I make one with an 8 ohm imp, I could add another later. I was just planning on getting the Velodyne SC15 subwoofer (passive), but I figured I could build something just as good for less (they retail for $1000).

I was looking for a simple set up, like just purchasing a SEALED enclosure from PE or someone else and dropping a really nice 15" driver. Since I will already have the AMP, this gives me about $300 or so I can spend on a driver, which figure I could end up with something similar or even better than the stock drivers in the JL, Velo, etc...

Like I mentioned, I would like a sealed design, a smaller enclosure for a room that is about 4000 cu feet.

THANKS FOR YOUR HELP, I am new to DIY home audio, so any advice is appreciated!!
 
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#66 ·
OK,

Lets take a closer looks at the graphs that were posted here earlier (again, thanks for doing them).

Lets compare and someone tell me if I am looking at them wrong. FIRST, lets get a few things out of the way. I am NOT a HUGE bass head, I prefer "Music" over HT and pure SPL output. The sub is corner loaded and a velodyne SC1250 amplifier (1250w into 8 ohms RMS, and 3000w into 8 ohms peak......at 4 ohms, of course it is more). This sc1250 also has parametric EQ abilities, so I will be flatening out the FR curve using it for room and driver. Also the sub will ONLY be used to freq below 80 hz

so if you compare the graphs, also consider that there is actually 1250w RMS, and 3000w peak (if we are talking 8ohms). Also consider I will be using a PEQ, corner loading, and if heavy fill helps, I will do that too.

So here are the graphs before any of that is considered:

Torrent/TC 12" (x2)=106 dB @ 20 Hz, 118 dB @ 60-70 Hz (12 dB rolloff?)

Dayton Titantic 12" (x2)=106 dB @ 20 Hz, 118 dB @ 60-100 Hz (12 dB rolloff?)

Titantic 15" (X1)=106.5 dB @ 20 Hz, 118.5 dB @ 60-100 Hz (12 dB rolloff?)

Shiva X (x2)=106.5 dB @ 20 Hz, 118 dB @ 60-100 Hz (11.5 dB rolloff?)

Tempest X (x1)=106.5 dB @ 20 Hz, 118 dB @ 50-100 Hz (11.5 dB rolloff?)

IXL 18" (x1)=107.5 dB @ 20 Hz, 117 dB @ 60-100 Hz (9.5-10 dB rolloff?)


I guess I am supposed to look at

1. how flat the curve is

2. How many dB at 20 Hz

3. How many dB at peak

4. Where the Peak is

5. Where the low is

6. How fast it rolls off

If this is true, the graphs don't look that much different to me.

Pure output at 20 Hz, the 18" IXL looks the best, by 1.5 dB (is this really that big of a deal?).....The IXL also looks the flatest with the least roll off, but only by a couple dB, is this really a big deal as well?). It seems like they are all pretty close and I would notice subtle difference in my PEQ, room placement, acoustics and power than I am going to notice at the actual driver.

Please tell me if I am looking at these numbers wrong.

Thanks.
 
#69 ·
Pure output at 20 Hz, the 18" IXL looks the best, by 1.5 dB (is this really that big of a deal?).....The IXL also looks the flatest with the least roll off, but only by a couple dB, is this really a big deal as well?).
The IXL18 only looks the flattest because they didn't publish the Le of their driver. The voice coil inductance of the motor will act like a lowpass. The bigger the Le, the lower this effect will happen. I think I put a note about that below the graph.
 
#75 ·
OK, after doing some extensive research last night, I figured that the Torrent Mistral/TC sub will be the best way to go for the money, plus they are running low so I had to jump ASAP. I will probably but 2 of them in a 3 cu ft PE enclosure and reinforce the enclosure a bit. I will run them in series, as I understand that the are dual 4 ohm (DVC) speakers, so I will get the total to be 8 ohms.

As discussed before, I am running these with a velodyne SC1250 amp/PEQ (1250w at 8 ohms RMS, 3000 w peak.....this is the same amp section they use in the DD18, with the PEQ unit they use in the SPLR line).

Another thing that got thrown in the mix. I was able to get a velodyne SC12. Is is the exact same set up as the SPL1200R, but without the power.

http://www.velodyne.com/products/product.aspx?ID=22&sid=145w407w

http://www.velodyne.com/products/specs/sc-12.html

The reason I got this one is because I was originally debating whether I should get (2) of these (they are in very small boxes) or do a DIY project. NOW it looks like I am going to do a bit of both. I got the thing for $350 NIB DELIVERED ($799 retail) so I had to jump on it. I have been a bit frustrated that I can located my SVS sub-direction, so I might put this velodyne in the cabinet just underneth my electronics FACING the listener, and corner load the (2) Torrent drivers right next to the couch. Both units will be 8 ohms, which is what the SC1250 is built for. the SC1250 has a build in PEQ, so I will have to see how it integrates. Hopefully running 2 different brands of WOOFERS doesn't cause any problems.

Here are some questions for you guys.

1. Should I build the (2) torrents in an opposed figuration, or is there a better way to run them like one facing forward and one facing down, etc....?

2. Will the 2 different brands of subwoofers have a negative effect, or should it be pretty easy to tune with the 7 band or auto PEQ on the SC1250?

3. Any recommendations or thoughts on my ideas above, as far as placement, etc...?
 
#76 ·
1. Should I build the (2) torrents in an opposed figuration, or is there a better way to run them like one facing forward and one facing down, etc....?
I would either put them in one cabinet opposed OR make two cabinets. The advantage of the former is that they will cancel out vibration and having the drivers co-located will maximize the room gain boost. That being said I personally (opinion!) prefer spreading multiple subs out. You don't get as much boost as they don't couple as well but I find that you can minimize room modes more and get a flatter response.

2. Will the 2 different brands of subwoofers have a negative effect, or should it be pretty easy to tune with the 7 band or auto PEQ on the SC1250?
People have used different brands of subs together but it usually does not work well. Basically you are limiting your extention to the worst of the pair. Say for example one goes down to 25Hz and the other 20Hz between 20Hz and 25Hz you suddenly drop from two subs to one. The fact that even in the usable range the responses will be different tends to make this a bad idea.

If you haven't already bought different stuff I'd heavily suggest gettiing matched subs.

3. Any recommendations or thoughts on my ideas above, as far as placement, etc...?
There are many threads here and articles online about how to set up subs. I'd do some searches first. The very short story is to start with the subs in corners and move them around until you get the gain boost and/or flat response you want.
 
#77 ·
I age with Boomie. I think this mix and match is a bad idea, but if you're gonna do it anyway, put the two torrents in separate boxes and put them equally in the room - maybe two end tables flanking the listening position. I have read that some folks who use different subs in the same space, had the best results going nearfield. YMMV
 
#78 ·
Hmmmm, the way my room is set up, this wont be possible. I really have to put the 2 torrents in the same place. I am leaning towards doing them in an opposed configuration in the corner next to the couch, Sc12 facing the listener.

I understand that there could be some mismatch concerns, but the more I think about it, the more I wonder if we are over analyzing it???? (I am the beginner here, so I might totally be wrong). It isn't uncommon for people to run larger main speakers with built in subs (some even being active subs) and some as large as 12" or 15" subs, and there never seems to be an issue of "mismatch", in fact a lot of times people will even run ported subs in the mains and run a sealed active subwoofer seperately. I guess it is good to know that there "may" be a problem, but I am not so sure it IS going to be a problem. At least I have some options for sure. I jumped on the SC12 because it was such a great deal, knowing in the back of my mind, if it didn't infact work properly, I could always sell it and not lose money on it (or at least use it as a sub in another room, if I ever do one).
 
#83 ·
I'm a little confused now... are you going to be running a total of 3 subs now? (the new DIY, your old SVS, and your new SC12) Have you tried just the SVS and SC12 together to see if that will be enough for you? I'm not familiar with the Torrent subs, but usually a good DIY design really knocks the socks off most small/entry level commercial subs.

Had you considered a downfiring sub that you could disguise as furniture? That way the cone appearance wouldn't matter and you could go on performance alone.
 
#86 ·
Just an update. I got the Torrent/TC Sounds DB500 drivers and should be getting 2 drivers that are supposed to be TC1000 (I am trying to get the TSPs, but it isn't as easy as I imagined) tomarrow, so I need to figure out which set of drivers will do the best.

I have been reading some reviews of the DD18, F113 and the SVS PB13/ultra, after reading these, I am not sure if I can come close to those guys without using an LMS level driver.
 
#87 ·
Rodney, I think you can come close, but what will be limiting your project with the drivers you are using is the enclosure size. If you absolutely have to keep things small, there's only so much you can do. If you can build a bigger box, you can rival or even beat those subs I think, but if you have to stay small, the only real way to match them is to put in a ridiculous driver (LMS5400) and feed it tons of power and EQ; basically you have to throw a lot of money at it.
 
#88 ·
Good point, I am leaning towards doing an enclosure now in the 4.5 cu ft range, which isn't a HUGE jump, but a bit. I also have to remember that I probably never listen to my stuff as loud as those other systems go. In other words, if the PB13 will be flat to 20 Hz all the way up to almost 120 db, If I can get a similar result but to around 105 db or something, that should be enough for what I use it for).
 
#89 ·
You probably hit the nail right on the head there, with listening volume. I mean really when it comes down to it, the overhead is great to have, and comparing graphs is good, but all that really matters is that it has enough for YOU at your usual volume. My poor old Tempest wouldn't hold a candle to most of the projects we've seen lately, but it still satisfies me. I bet you can make it play pretty low and flat, just not at brain melting levels, which you'd hardly ever use.
 
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