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Want To buy 2 SI 18" subs. D2 or D4? Will this be enough from my place? PICS!

post #1 of 21
2/12/13 at 9:44pm
Thread Starter 
Hi, I want to buy 2 18" SI subs. I'm on a budget. I currently have an ep4000 and want to use it for these two subs.I dont know what would work best the D2 or D4s. I plan on purchasing some of flat packs from DIY Soundgroup. I am thinking two separate cabs to disperse the sound more evenly throughout the room. I don't listen to extremely loud levels. Usually -9 to -15 on my avr. I am not looking for bass no knock stuff off the wall,I just want my family and I to have the theater experience that will keep us at the edge of our seats if you know what I mean.

Room is 15x20x10 and leads into another small living room and open frames doors (if thats what you call them) to the kitchen area.

The issue- I currently have 2 Dayton HFs with 2 o audio 500w amps. I do not use the sub woofers because I cant get any sound from them LITERALLY!, THE 8'' SUBS ON THE Av123 Onix rs1000 sound louder than my 2 sealed 15s. I also get this very nasty and high pitched "POP" sound from them.Using Denon 4311 and tried audyssey but nothing worked mad.gif . I even moved the subwoofers to 3 different rooms in the house to see if it was that so called "house curved" or room issues but nothing worked.

Setup- Denon 4311 avr. Running a 14TB dedicated movie server using XBMC. Sony vw85 projector. Av123-rs1000 towers and RSC-200 (Big Foot) center channel, no surrounds yet eek.gif




Finished product w/o subwoofers


BTW, selling the 1 Oaudio 500w plate amp basically never been used if any one wants to get one on their hands now that the company has gone out of business.
Edited by deathinc - 2/13/13 at 9:47am
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post #2 of 21
2/13/13 at 4:58am
I would do the D2, IIRC, that would give you your 4ohms VC in series, then each side of the EP would be seeing 4ohms. If you run the VC in parallel, that would be 1ohm which would not be good.... Hope this helps
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post #3 of 21
2/13/13 at 9:20am
Quote:
The issue- I currently have 2 Dayton HFs with 2 o audio 500w amps. I do not use the sub woofers because I cant get any sound from them LITERALLY!, THE 8'' SUBS ON THE Av123 Onix rs1000 sound louder than my 2 sealed 15s.

wait a minute.........you really need to figure out why these don't work before you go onto bigger subs.

Is your o audio 500w plate amps really working?

You have a EP4000, have you tried powering the subs off that to check?

Fix what is not working before you move onto other subs.
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post #4 of 21
2/13/13 at 9:45am
Thread Starter 
The amps are working, they bottom the sub woofer. Also tried the ep4000 on them and nothing ...

I think its the cabinets, I have never done wood working. I made them 24 x24x2, no bracing. I did not use clamps to hold the box together. I don't know how to check for leaks other than putting my hand (wet) around the edges to see if I can feel any air . I am just pulling the trigger in 2 18s and go with DIY Soundgroup flat packs to make things easier for me.
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post #5 of 21
2/13/13 at 9:52am
I suggest you try those Dayton HF's on the ep4000. It almost sounds like there is either a wiring issue with the plate amp to the driver, or the amps themselves have issues. Those drivers should be slamming before you ever hear them bottoming out hard.

Can you buy 15" flatpacks and run them off of the ep4000?
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post #6 of 21
2/13/13 at 12:24pm
Thread Starter 
I will buy the flatpacks when they are available at erich's website. Even if the daytons work with the new box I still rather sell them and get the 18" SI speakers smile.gif
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post #7 of 21
2/13/13 at 4:58pm
Are the subs wired correctly so that they are both in phase? You'll get no bass from two subs playing out of phase.
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post #8 of 21
2/13/13 at 5:29pm
Thread Starter 
i tried running 1 subwoofer and no success. the negative in the subwoofer is connected to the negative in the amp, + to the +. Should I try something else?
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post #9 of 21
2/14/13 at 5:35am
Either the driver is dead, or the amps are dead. The later is probably more unlikely, I suggest you order some flat packs for your 12's first and get them into a better cabinet and hooked up properly, then you might think that the bass is perfectly fine and thus, save like $500 bucks!
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post #10 of 21
2/14/13 at 6:43am
Thread Starter 
Quote:
Originally Posted by Martycool007 View Post

Either the driver is dead, or the amps are dead. The later is probably more unlikely, I suggest you order some flat packs for your 12's first and get them into a better cabinet and hooked up properly, then you might think that the bass is perfectly fine and thus, save like $500 bucks!

I think it might be the driver. Ihighly doubt my ep4000 and two oaudio 500 are all dead. When I hook up the subwoofer in free air at very low volume it starts popping. Been like that since the day I purchased it.
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post #11 of 21
2/14/13 at 7:49am
in theory....the ep4000 can handle 2 ohms per channel.

following that, the drivers that maximize the power would be the d4 drivers wired in parallel so that each driver has a net of 2 ohms.

hook up one driver per channel and you should get about 1000 watts ino each driver.

in reality, the ep4000 will not deliver a full 1000 watts per channel at 2 ohms at 20hz for any period of time, so if you get dual 2 ohm drivers, wire them in series for a net 4 ohms per driver and hook one per channel, you will get 650 watts per channel. it can probably do that power at 20hz at least for a little while.

bottom line is it probaby doesn't matter which ones you get because the amp is going to be a limiting factor.

...

a simple test for the potentially bad driver is to measure its dc resistance with an ohm meter.

another test is to hook a 9v battery up to it and see if the cone moves.

'popping' is not what a driver should be doing when hooked up. it sounds like the driver is bad.
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post #12 of 21
2/14/13 at 7:57am
Thread Starter 
Ok so I hooked up the subwoofer to my denon 4311. Only left the center channel on the Avr connected.. I pluged in the subwoofer to the Front right speaker and tested the sub woofer. It played very good. I then changed the wires on the amp - to + and + to -, this seemed to improve the performance of the subs. I think that the cabinets are way too big no bracing which causes the subwoofer to bottom out and sound very boomy when I want to use it to watch movies.Heres some pictures of how big and how crappy my work is . Subwoofers are 21.5 x 24.5 x 24 with NO BRACING. Did the math and its about 7 cubic ft internal yeah......its too big!


Edited by deathinc - 2/14/13 at 8:08am
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post #13 of 21
2/14/13 at 8:01am
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

in theory....the ep4000 can handle 2 ohms per channel.

following that, the drivers that maximize the power would be the d4 drivers wired in parallel so that each driver has a net of 2 ohms.

hook up one driver per channel and you should get about 1000 watts ino each driver.

in reality, the ep4000 will not deliver a full 1000 watts per channel at 2 ohms at 20hz for any period of time, so if you get dual 2 ohm drivers, wire them in series for a net 4 ohms per driver and hook one per channel, you will get 650 watts per channel. it can probably do that power at 20hz at least for a little while.

bottom line is it probaby doesn't matter which ones you get because the amp is going to be a limiting factor.

...

a simple test for the potentially bad driver is to measure its dc resistance with an ohm meter.

another test is to hook a 9v battery up to it and see if the cone moves.

'popping' is not what a driver should be doing when hooked up. it sounds like the driver is bad.

just test them out they are good and the amps are good. Its the huge boxes and me not being able to move my gain above 1/4 on moves without getting the popping sound. With music its another story, they don,t bottom out. I will probobly keep them and have them as outdoor subwoofers with new cabinets. I still want the SI subwoofers. I assume 2 of the SI would give me the performance of 3 15" hf or maybe even 4?
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post #14 of 21
2/14/13 at 8:15am
Having cabinets too big doesn't make them quiet. It actually makes them louder at low volumes. Not being braced also won't cause this problem, although it is a problem perhaps in other ways.

If your current subs are HF, they are probably the Dayton RSS390HF-4 15" reference subwoofer, correct? They like pretty darn big boxes.
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post #15 of 21
2/14/13 at 8:19am
I your using one ep4k with two 18's you want the D4's so you can wire them as 2 ohms each channel
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post #16 of 21
2/14/13 at 8:20am
With those sized boxes you really could just make a bigger cutout to fit the SI 18", use silicon to seal up all inside edges/gaps, add some bracing, and add some polyfill. And you would be set. The box doesn't look that bad honestly. You could easily finish it and it would look perfectly fine and professional.
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post #17 of 21
2/14/13 at 8:22am
IMO;
a) Keep them for multiple subwoofer approach as 3rd/4th subwoofer for flat response across multiple seats
read here
http://mehlau.net/audio/multisub_geddes/

b) add bracing, using dowel rods/other round, see this, you should be able to do that thru your existing 15" dia hole
If they model slightly "big", you can make a "box", put inside to eat up some small cu ft volume, are they 4.5 cu ft or so internal volume? Seems 3 - 3.5 cu ft may be better sized for them.

http://www.avsforum.com/t/1450889/official-scorpion-si-build-thread/30#post_22841697
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post #18 of 21
2/15/13 at 8:32am
Thread Starter 
Just orderd two SI 18 D4s. Now I just need the cabinets. How much performance would 2 of the D4s give me vs the 2 15s?
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post #19 of 21
2/15/13 at 8:51am
Quote:
Originally Posted by deathinc View Post

Just orderd two SI 18 D4s. Now I just need the cabinets. How much performance would 2 of the D4s give me vs the 2 15s?

Look at this site, has exact answer to your question, hopefully you can read and grasp the data table
http://www.data-bass.com/data?page=systems&col=drivers&type=0&sort=desc&mfr=-1
data-bass%2520websiteImage.JPG
Edited by mtbdudex - 2/15/13 at 8:59am
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post #20 of 21
2/15/13 at 10:04am
Quote:
Originally Posted by deathinc View Post

Subwoofers are 21.5 x 24.5 x 24 with NO BRACING. Did the math and its about 7 cubic ft internal yeah......its too big!

I come up with 5.79 internal volume after driver displacement. You have to take into account material thickness. The SI drivers actual model pretty well in larger enclosures. You just have to be a little more careful with power.
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post #21 of 21
2/15/13 at 7:30pm
Thread Starter 
Quote:
Originally Posted by mtbdudex View Post

Look at this site, has exact answer to your question, hopefully you can read and grasp the data table
http://www.data-bass.com/data?page=systems&col=drivers&type=0&sort=desc&mfr=-1
data-bass%2520websiteImage.JPG


I don't see the 15" dayton HFs,Sorry I'm not very good at this......
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