Home Theater Forum and Systems banner

Wanna Build a New Sub for HT

3037 Views 23 Replies 7 Participants Last post by  funky_waves
Hi All,

Really like all the great info on here. I started looking at this site since I just had to send my 12" Sunfire Signature True EQ sub out for repair yesterday. I was actually over driving it all the time just because it couldn't really keep up with the rest of my system. It had decent sound but in my opinion I expect more for $2,000 than what I got. Anyway I have an Adcom GTP870HD receiver, Adcom 7805 (300 x5) amp, B&W CDM 9NT, CDM CNT, CDM 1NT speakers, and use a nice HTPC setup with a Xonar D2 Audio Card. This system is in my family room and is used for Music, Movies, and general TV watching. I've really been lacking in the bass dept. and never really could get the bass at my listening position very well. I've looked up a bunch of info so far. Doesn't look like the LMS-5400 is available any more, but there's the Acoupower 15 and 18 as well as some other good ones out there. When I was into Car Audio I was really in to JL Audio Stuff. Their HT stuff is just a lot more than I want to spend on the sub ($3500-$11,000!, yikes). I build cabinets and do a lot of other woodworking so building an enclosure would be ok. I'm looking for something I think close to the 4-3 cu. ft. range. I want something great for overall use and I like to be able to feel the bass when I'm on the couch. I'd love to hear what a good combination Woofer/Amp would be that I could build my sub around. I don't really have a preference of Plate Amp or Separate Component. btw I also have an AudioContol Series III Phase Coupled Activator that I haven't used in a couple of years that I'd like to dig out and use.

Here's some Idea's
1 Acoupower 15 with an E.D. LT-1300
1 Acoupower 18 with an E.D. LT-1300
2 JL Audio 12W6v2's with an E.D. LT-1300

Thanks for your help.

See less See more
1 - 20 of 24 Posts
I think the 4-3 cubic foot range is a bit small for the acoupowers... I also think you should look at a ported design instead of sealed because that sunfire is claimed to go as low as 16Hz so you will need lots of output to match it. You should look at a pr design because you want a small box and don't seem to concerned on the price.
You've got some great gear there, so a quality sub is in order. What are your room dimensions. This will help to determine just how much 'Sub'
you'll need.
Just as a head's up, there's a guy selling his 18" LMS and a passive brand new in the classified area on this site.
It's a great room setup. The family room is 19 x 15.3 with an 11' ceiling, the entry off to the right is 12' x 10' with a 12' ceiling, The Kitchen/Dining Nook behind is 23.5' x 13.3' with a 9' ceiling. I know all these odd shapes make stuff difficult. Thanks for the help.

I wouldn't use the LT1300 with an acoupower while 1300 watts would be enough the drivers are 8ohm so the LT1300 will be putting out quite a bit less power. I would reccomend a seperate pro amp, such as the QSC plx3602 or Crown Xti 4000, or any amp rated for 1500-2500watt at 8ohms,

While the 18" would work in 4 cubic feet sealed(that is the absolute minimum) I would go with the 15" in 4 cubic feet with two 18" passive radiators, and feed it ~2000watts. It would give you solid output just below 20hz, if you can possibly go a bit bigger you would get even lower, 5-6 cubic feet gets you down around 15hz, and requires only ~1500 watts to use its full potential.
Nathan, What 15" sub would you recommend? How would output be on this vs my Sunfire?

The 18" and 15" i was refering to are the Acoupower, one 15" acoupower with 2 18" passive radiators in 4 cubic feet with 2000watts would have ~12db over the sunfire from 16hz-25hz,(the "feely" bass) That would be like having four of the sunfire's, for the low bass, above 50 hz four sunfire's would likely go louder. But below 50hz the Acoupower would have significantly more output, more and more as the frequency goes down.

The CSS SDX 15 would be good as well but not as good as the acoupower and would need a larger enclosure.

An Audiopulse revo 15 or axis 15 would be somewhere inbetween. working in the same size enclosure as the Acoupower, all would have simmilar output.
Accoupowers are good subs and can handle the power. As Funky points out, don't skimp and get the LT1300, go for something with around a 4kw rating.

A solid and proven amp that can be found used (and sometimes new) is the Crown CE4000.
ok, that kinda output sounds really good to me. Is there any special type of radiators that I have to use. Should I dl some software so that I can get enclosure dimensions? I'm about ready to get started!

The only 18" high excursion passive radiators avialable that I know or are these I would use the 2100 gram ones, unibox is a good program to download, just plug in the driver parameters and radiator parameters and the box volume you would like and it will show you the predicted response curve. For box dimentions whatever shape gets you the desired volume and physicly fits the componants, which can be difficult when doing such a small enclosure with large parts, I think it would work in an enclosure 20"wide x20" tall x 26" deep with 1" think front for the driver, if flushmounted(.75" if not), and 1.5" thick sides if flushmounted(.75" if not), for the passives, .75" top bottom and back. You would have to keep the passives as far back as possible to clear the driver, 26" should be deep enough, and give you 4cubic feet net with bracing ect. But you should wait untill you have the componants and hold them together and measure to be sure.

Be sure to brace the box well especialy if you dont flushmount the parts and only have .75" think all around.
See less See more
Looks good with dual 18" passives in 5cuft with 1kw. But seems to need allmost the same size box as ported so i don't see the advantages to PRs in this case. Personally, i'd do two Maelstrom 18's sealed 3.5cuft for a space that big. With eQ and enough power, should be devastating.
Looks good with dual 18" passives in 5cuft with 1kw. But seems to need allmost the same size box as ported so i don't see the advantages to PRs in this case. Personally, i'd do two Maelstrom 18's sealed 3.5cuft for a space that big. With eQ and enough power, should be devastating.
Well the bigger the better and if he can go big enough ported would be great, but he said he was looking at 3-4 cubic foot range, and the best way to get low extention in that small of enlosure is with PR's. In a 4-5cubic foot enclosure to tune to the same frequency as the PR's, you would need a 7" port 55" long. Then the enclosure would have to be not only 60+inches in one direction but would have to be 1.3cubic feet larger due to the space the port takes up. That would work fine if he wants to do that, but then you also have to consider the first port resonance is 126hz and would have to be dealt with.
What driver would you choose Nate for a PR system, the Maelstrom or the Acoupower? I tried both and the Maelstrom looks much better at less than half the price ???
I've email exchanged with Carlos a few times at Acoupower. Seems they are now Crown dealers and I can get a good deal on a sub and amp. They can even do something with the DSP on the amp? I don't know anything about those amps but the xti4000 is supposed to put out some serious power. He is wanting me to go more like 6 cu. ft though and not four.

For a PR system I would go for the Acoupower. The malestrom needs over 8 cubic feet for a PR system which is big enough a ported enclosure would work fine, the malestrom would work in a sealed enclosure of 4 cubic feet, but the 15" with PR's would have 3-4db more output from 18-25hz than the Malestrom. Not a lot but noticable. As for sound quality I cannot say, The acoupower drivers I have used and they are very low distortion linear drivers, I have not heard the Malestrom yet so I am not sure how it would compare.

If you don't want to spend that much for the Acoupower and PR's the CSS SDX15, or Audiopulse Revo, with PR's would still have ~3db more than the Malestrom on the low end. Personly if you can afford it I would go with the Acoupower. Second choice would be the SDX15, or Revo.

As for the enclosure size I would also recomend 6 cubic feet, 24" cube like our FW15.3, but if space is tight 4 cubic feet would still work well, but is the absolute minimum I would go.
See less See more
Yeah but the Accupower looks to roll off heavily around 18.5 hz in 150L-maybe due to the kinda high Fs for 15" ? I guess i'm just having a hard time justifying the price of the driver-don't mind me-sorry.
How about an Acoupower 18" in a 6 cu. ft. sealed enclosure with the Crown XTI4000??

If funds aren't a huge deal - I wouldn't skimp if you want a beast of a sub. Go with a couple Maelstroms with a huge amp. More output than one Acoupower 18". Don't think I'm discrediting the acoupower because apparently it keeps up with the LMS - but "there's no replacement for displacement" right?

I wouldn't even think of getting anything by JL unless space is REALLY REALLY a concern - and certainly wouldn't think of getting the W6's. WAAAAY less throw than the W7's, even though they look almost the same.
How about an Acoupower 18" in a 6 cu. ft. sealed enclosure with the Crown XTI4000??


That would be better for music but a 15" with dual 18" passives you would get more down low so that would be better for home theater, either would be very nice or music and home theater, and would obliterate your old sub.

FYI we will be testing an 18" acoupower in ~130L 4.5cubic feet sealed enclosure with a QSC PLX3602. I can do some comparisons to the FW15.3 I will post the results in our forum section.
1 - 20 of 24 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.