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Discussion Starter · #1 ·
I want to do a budget build based on the Shiva-X driver. I also would like to use a 300w BASH plate amp to further cut costs. Both components would be about $300 total right now.


I don't have a need for massive output, I just can't turn things up overly loud where I live. However, I can play my movies and music at a very respectable level. I want to get the most bang for my buck basically. I really see no need for more than the 300w amp. I just need some solid designs to base my box on to get the most out of it.


If I go sealed I save having to buy ports or PR's so it makes it even more of a budget sub. Would the 300w BASH amp be suitable for this build or would I need something with a PeQ? If so, I'll just build a ported version possibly....looking for some designs. I really wanted to get started building this box this week but I need something on paper. If anyone has some suggestions and/or actual designs I would appreciate it. TIA.


Also, I don't have size restraints or a preference to sealed/ported. I just want to keep the budget down...materials are already covered.
 

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Quote:
Originally Posted by Danielson99 /forum/post/17024354


I want to do a budget build based on the Shiva-X driver. I also would like to use a 300w BASH plate amp to further cut costs. Both components would be about $300 total right now.


I don't have a need for massive output, I just can't turn things up overly loud where I live. However, I can play my movies and music at a very respectable level. I want to get the most bang for my buck basically. I really see no need for more than the 300w amp. I just need some solid designs to base my box on to get the most out of it.


If I go sealed I save having to buy ports or PR's so it makes it even more of a budget sub. Would the 300w BASH amp be suitable for this build or would I need something with a PeQ? If so, I'll just build a ported version possibly....looking for some designs. I really wanted to get started building this box this week but I need something on paper. If anyone has some suggestions and/or actual designs I would appreciate it. TIA.


Also, I don't have size restraints or a preference to sealed/ported. I just want to keep the budget down...materials are already covered.

i would increase your budget.


get a behringer ep2500 amp.


get a behringer mic220.


get two shivas. plop them in sealed enclosures. move them around your room until you get a good frequency response, then kill the modes with the mic220.


done!


mo money? yep. but don't screw around. just do it right man.
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by LTD02 /forum/post/17024433


i would increase your budget.


get a behringer ep2500 amp.


get a behringer mic220.


get two shivas. plop them in sealed enclosures. move them around your room until you get a good frequency response, then kill the modes with the mic220.


done!


mo money? yep. but don't screw around. just do it right man.

Where's a good place to get the ep2500 and mic220?
 

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Seems a bit presumptuous to instantly tell the OP to up his budget and build without knowing his room size and design goals. A single Shiva-X w/ Bash 300w is an extremely capable sub that can go sub-20hz at reference levels in most small to medium sized rooms.


For the OP, take a look at the 4.3 ft^3 and 6 ft^3 reference Shiva-X designs. The reference plans call for round ports, but it's very easy to adapt those designs for slotted ports if you want to. The 4.3 ft^3 version is designed with the 300w amp in mind and keeps costs down by using a single port that is sized big enough to not cause noise with the 300w amp.


One caveat is the PE BASH 300w amp will require a resistor modification to lower the subsonic filter to take full advantage of the low-end capabilities of the Shiva-X in a low-ish tune vented enclosure.
 

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Quote:
Originally Posted by Stephen Hopkins /forum/post/17025656


Seems a bit presumptuous to instantly tell the OP to up his budget and build without knowing his room size and design goals. A single Shiva-X w/ Bash 300w is an extremely capable sub that can go sub-20hz at reference levels in most small to medium sized rooms.

how much secondary power capacitance on that amp?


how many parametric eq's does it have?
 

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Couldn't tell you... but my modded 300w Bash drives my Ascendant Avalanche 12" (fairly similar to the Shiva-X) to around 110db in-room down to 18hz. Enclosure is 6 ft^3 tuned to 18hz w/ dual 4" flared ports (fairly similar to the reference 6 ft^3 Shiva-X). Room is roughly 15' x 25' with the listening area roughly 15' x15', rear enclave (not ideal) placement. MulitEQ XT helps tremendously (much more than expected) in overcoming my poor placement.
 

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Quote:
Originally Posted by Stephen Hopkins /forum/post/17025886


Couldn't tell you... but my modded 300w Bash drives my Ascendant Avalanche 12" (fairly similar to the Shiva-X) to around 110db in-room down to 18hz. Enclosure is 6 ft^3 tuned to 18hz w/ dual 4" flared ports (fairly similar to the reference 6 ft^3 Shiva-X). Room is roughly 15' x 25' with the listening area roughly 15' x15', rear enclave (not ideal) placement. MulitEQ XT helps tremendously (much more than expected) in overcoming my poor placement.

hi stephen,


if you are happy with your system, then i am happy for you (darn, that sounds like such an ahole comment, but i mean it honestly). every system doesn't have to be the ultimate. it just has to be "good enough" for the owner. once you hit "good enough" for you, then you are done! no need to go any further.


115db is reference and most folks around here run their lfe hot. are you measuring modal peaks or average spl? how frequently does your amp clip?


i'm just betting on probabilities in my suggestion.


see welti's/harman's paper on multi-subs for the many benefits of multiple subs. for music, if you listen relatively loud, 90-95db midrange from time to time, and listen to well recorded, uncompressed recordings, you need upwards of 120db+ from your subs. without that kind of headroom, you will be compressing/clipping. does it matter? that's up to each person to decide.


a 300w/12" ava offers bass far beyond what most "box store" subs will provide. that's not a shabby system by any means. sorry if somehow my comments came off that way.


the system that i suggested offers much greater power, much greater capability to minimize/remedy modal ringing, and much greater performance, for not much more money. this is why i suggested it.


over and out.
 

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I've never had the amp shut-down or go into protect from clipping, but I'm honestly not sure what its clipping protection method is. 110db is what I get in-room at 18hz (I wasn't clear about that) which tracks fairly accurately as the F3 point... because of a decent size peak (~ 3db still, after MultiEQ XT, more like 6db before) centered around 55hz I was afraid an average would be skewed. Given all this (I don't have the data in front of me, it's at home) I'm guessing my overall response is probably closer to 112 - 113db and the 55hz-centered peak is up around 115db - 116db.


If I were to upgrade something, it would be the amp, but probably just up to the O-Audio 500w BASH amp so as to tame my one bad peak a little further with the PEQ and come in right-around that 115db reference on average. That might also be a worthwhile upgrade for the OP without killing his budget.


The benefits of dual subs, as well as sealed subs with tons of EQ are definitely apparent. More than anything else, I wanted to make the point that A LOT of people in this sub-forum take the "go big or go home" approach and push it hard on others. I just like to let people know that they really can do a lot with modest budgets, and in many cases that the more all-out reccomendations could end up being overkill for them. Great thing about a single Shiva-X (or most DIY subs) is you can always add another if you do need more.
 

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Discussion Starter · #10 ·
I do appreciate the responses. Perhaps asking me to up my budget would be overkill but it's also good to get different ideas and take it all into consideration.


I guess the bottom line is that my requirements aren't much right now. My viewing area is about 14'x14'. It's not an enclosed room as it opens a bit behind and to the side. The walls are cement on all sides. I'm running a PA-120 right now and it's fairly satisfactory for HT but not for music...and I'm looking for something more. Since I have a CNC, Saws, Sanding bench, Spray booth and all/any other tools necessary to build a box I thought I'd build something 'appropriate' for my home. Yes I'd like to be running dual subs but I'll add a second down the road. I really don't require alot of SPL, what I want is quality. I think that a 300w bash amp in either a sealed or ported design would truly be more than enough for my needs. Having a wife, kid and 13 pets keeps the volume to 'sane' levels. I do get the odd chance to turn the music up to pretty loud levels and I listen to my movies at a decently loud volume...but I really will never require what many people need for output. There's alot of room gain too.


Considering I'll add a second identical sub down the road and trying to keep my budget down...I'd like to try a 300w bash amp with the Shiva-X driver. Can I buy the modified amp for this already? They sell for around $150 so if it's gonna cost more to have it modded then I might consider getting the O-audio 500w amp that has a PeQ built in already. I think they sell for only $79 more than the 300w bash amp. However, I'd prefer to just stick with the modified 300w bash because it does help keep the budget down. I've gone over this in my head time and again...and I say...'ok, lets just bump it up to $229 for the O-Audio' and then I think...'why not just bump it again to $279 for the ep2500 and have an amp to run 2 subs?'


I decided to just keep it to a minimum...after I slap myself...I realize that I just don't need to spend that much money to have a slammin' subwoofer.


Stephen...I have seen the drawings for the Passive Radiator Shiva build from the DIY website. I can't seem to find the ported design, does anyone have the drawings for that build or know where to get it?
 

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The mod for the PE 300w BASH is simply desoldering 2 resistors and replacing them with 2 resistors of different values.


The Shiva-X ported reference designs are described in a white-paper on the DIY Cable website in the Shiva-X product page. Enclosure dimensions and cut-list aren't provided, but volume, port-length, and fill amounts are. If you search around some older posts you can probably find a rendering and cut list someone else put together... probably for a round-port AND slot port version you can chose from.
 

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Quote:
Originally Posted by LTD02 /forum/post/17032202


what do mean by cut sheets?

Pretty sure he's looking for a dimensional layout of the individual panels of an enclosure on 4' x 8' sheet of 3/4" MDF, or at least the dimensions of the individual panels. There were a lot of these floating around back when the "Easy-Button" threads were still going strong. I think it was NeoDan who was pretty quick to generate them for folks on request (could be wrong).
 

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Discussion Starter · #15 ·
Assuming the plate amp and driver cutout were adjusted, do you think that THIS (page 6 and 7) enclosure would be a good design for the Shiva-X and Bash 300w amp? If so, would the 300w bash on PartsExpress do the job with this ported design?


Personally, I'd rather do a slot-ported design for the sake of making the build a bit easier, not to mention cheaper. I just can't find a good diagram with a cut-sheet...or just a good design with all the measurements.
 

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Reading through your posts, you've got a fairly realistic view of things; not everyone can slap themselves to their benefit. The only issue I see with the thread is lack of participation - only 2 respondents so only two points of view. I'll add a third, but it's just my opinion, nothing special.


I have about a year on a Tempest X and Oaudio BASH 500 amp, basically big brothers to what you're looking at since the Oaudio and PE 300W BASH amps are nearly identical down to the screw placement. Why'd I go this route? I got free boxes, pure and simple. kgveteran had upgraded to 4x15" subs, offered a pair of boxes free, and lived not too far away. Here's what I learned.


I knew a 12" would be plenty, but these 3 cu ft boxes were cut for 15s so I spent the extra on the 15". I was right; this is far more power than I need, especially since I then built a nice pair of mains with a very respectible low end. I only use the sub for DVDs, since that's my only true 5.1 signal source (yes, I need an receiver upgrade, but my kids are in college and priorities are priorities). DIY Cable's subs were recommended for their low distortion and the current Shiva X sale makes it a great deal; I'd go for one but for that priority thing.


Regarding enclosures, I understand you've got great fabrication facilities, but don't undersell small sealed boxes as a starting point. Room gain is a huge factor at low frequencies, 5-15dB if Kevin Haskins' simulations are accurate. I measure a fairly flat response to almost 10Hz in my 16'x22' stick-and-sheetrock room, and you'll see even more room gain in a smaller room with concrete walls. My bottom line for you; MDF is cheap and you can always go bigger and ported later, or add a second sub if you feel the need.


Regarding amps, I shyed away from the PE amps because of their requirement to change PWB components. I've no qualms about soldering, but rather had a desire to optimize. Unique among cheap plate sub amps, the Oaudio 500W has lots of external controls. It's more than variable low-pass frequency (XO to mains) and phase; I really liked that the high-pass/sub-sonic filter was also a rotary switch and that it has parameteric EQ to kill any big peaks. It's $60-70 more, but the added power also gives me head room. I figured with 90W/channel in my receiver, I'd want at least 4x more power in the sub to cover as much as a 6dB boost to acheive flat response. 300W is close, but 500W with the added optimization flexibility was the kicker.


Regarding cut sheets, if you have anything like MS Office, use the drawing tools. I use Excel to calculate dimensions, then the drawing tools to create rectangles the size of the pieces I need, then fit them into a rectangle the size of the lumber I want to use. It requires a bit of time, but it also lets me identify some basic cuts to be done at the lumber store to bring things down to manageable size. I really like to fit into MDF handi-panels, but you may not need to.


Finally, in a concrete room, you're going to get room modes like nothing I've seen, so plan on doing some degree of accoustic treatment and sub placement optimization. That's another advantage of a small sealed box - it fits in more places. The simplest trick is to put the sub in your sitting position then find where the bass sounds best, and put the sub there. If you want a larger "sweet spot" it's not that easy, and I'll point you at Floyd Toole's book, Sound Reproduction, which devotes 50 pages to the topic.


Have fun,

Frank
 
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