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post #1 of 41 Old 07-18-2016, 04:57 PM - Thread Starter
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Built-in Subs for Large Room

I am in the process of building a HT in my basement (non-dedicated), and have just completed my LCR and surround purchase and installation (NHT M7's and C1's). I have been spending a lot of time in the (purchased) Subwoofer forum learning about subs and trying to figure out which subs to purchase.

Background & Expectations:
- My basement is 8400 cuft as shown in this attachment.
- I am currently thinking about purchasing (2) subs (either high-power 15" or 18" like the Rythmik FV15HP, JTR Cap118HT or PSA V1800) in the locations shown on the layout
- Purchasing the subs above would constitute a budget of about $2600
- I have HTiB sub now (110w 10") that I got as a gift until I can complete my HT; so I don't have a solid baseline that I'm trying to exceed (although I'm hoping to avoid upgradeitis!)
- We enjoy movies (80%) and Music (20%) as a family
- Because the room is not dedicated (or sealed from the rest of the house), most of the listening will be at lower listening volumes (-20 to -10)
- Every once in awhile we will want to 'crank it for fun' (video or top 40/dance). I plan to add Motion Actuators to supplement and allow "fun at lower volumes".
- Sound Quality is a higher priority than SPL.
- I'm pretty sure I want ported subs due to room size


My qualifications (limitations) for DIY:
- I do not have the skill (or desire) to design my own system, but I can follow directions/plans that are known and proven (simpler is better! )
- I am mechanical by nature, and can perform simple electrical work
- I have a brother in-law that can help me with some woodworking, as I am limited in the tools I have (and little interest to fill my garage for one project)
- The DIY plan needs to include enough design detail that I can implement


I have posted a few questions/comments in the subwoofer forum, and a few people have suggested that I consider DIY as I will get similar performance with higher value/lower cost.

I have a couple of ideas of how I would DIY if it made sense for me.

Option #1: I think that a pair of these subs (Rythmik FV15HP, JTR Cap118HT or PSA V1800) would meet my needs.
Q1: Is there a DIY plan that is similar to the subs that I am considering now, with a similar size and SQ?

Option #2: My wife would (eventually) like me to add a built-in bench along the backwall of our HT area (see second attached image). This could be a great hiding place for (up to) four ported subs. I love the great execution that @16hz lover built here
Q2: Is there a ported sub DIY plan that would allow me to put (4) boxes together, and still hide it with a sitting bench over top? (<18" tall, <23" deep, up to 10' wide total). I can wrap/hide the subs, but need help with picking the DIY subs
Q3: Would my bass be very localized if I put all subs about 12' behind the MLP? (Do I need at least one sub in another location to eliminate localizing)?

Thanks in advance for your response(s)!
Kamper
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post #2 of 41 Old 07-18-2016, 06:33 PM
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there is a sub that will fit in just about every space or one can be designed. bass interacts with the wall in the room creating constructive and destructive interferences which can cause big peaks and dips depending on the placement of the subs. your room is a non-standard shape so it would be very difficult to predict how placement will impact the experience at your seating location. before building a big project that might only fit in one location, testing that location for its response might be a good idea.

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post #3 of 41 Old 07-18-2016, 06:42 PM - Thread Starter
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Quote:
Originally Posted by LTD02 View Post
there is a sub that will fit in just about every space or one can be designed. bass interacts with the wall in the room creating constructive and destructive interferences which can cause big peaks and dips depending on the placement of the subs. your room is a non-standard shape so it would be very difficult to predict how placement will impact the experience at your seating location. before building a big project that might only fit in one location, testing that location for its response might be a good idea.
Makes sense... how would you tackle this project?
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post #4 of 41 Old 07-18-2016, 08:13 PM
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Google sub crawl and welcome to wonderland😀

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post #5 of 41 Old 07-18-2016, 08:29 PM
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Quote:
Originally Posted by Kamper View Post
Makes sense... how would you tackle this project?

if you have a sub that you can move around the room and measure the response at the various listening positions with some test tones, that will provide some idea of what you can expect. playing some test tones (which you can find on the internet) and measuring with a simple spl meter will provide quite a bit of information. if you are more adventurous, check out room eq wizard (REW). lots of info and its is a free tool.

otherwise, I'd shoot for a build that can work in many locations as experimenting may end up being the only way to know.


also, in many cases, it isn't really just "tweaking" the bass. it can be the difference between "booming", "missing", or all kinds of other descriptors that people often think is the sub's fault itself.
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post #6 of 41 Old 07-19-2016, 06:00 AM - Thread Starter
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[quote=manuetdeo;45441249]Google sub crawl and welcome to wonderland😀

FWIW, I did do that with my HTiB sub, but not sure how to apply it to choosing a sub. The positions indicated on my layout did sound good (fortunately the "bad" sounding areas are in the front corners where I have doors).

Quote:
Originally Posted by LTD02 View Post
if you have a sub that you can move around the room and measure the response at the various listening positions with some test tones, that will provide some idea of what you can expect. playing some test tones (which you can find on the internet) and measuring with a simple spl meter will provide quite a bit of information. if you are more adventurous, check out room eq wizard (REW). lots of info and its is a free tool.

otherwise, I'd shoot for a build that can work in many locations as experimenting may end up being the only way to know.


also, in many cases, it isn't really just "tweaking" the bass. it can be the difference between "booming", "missing", or all kinds of other descriptors that people often think is the sub's fault itself.
I'm still following, and I can do that. What sub do you recommend me starting with for DIY? I want something with high SQ, ported, and low extension; as I'm thinking if/when it works that I could build multiples and hide them under a built-in bench (or place them in the proper location(s) ). I tried following the Johnny subs, but it appears that there are many variants.

Q1: Is the Johnny box the best application for me? What sub/amp would you recommend?
Q2: Can I change the box size (move 3" from width to height)?

I don't mind doing homework, if pointed in the right direction... but to be honest, I'm overwhelmed by what appears to be many variants of a base design; and I'm not smart enough to know which is best for me.

Thanks,
Kamper
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post #7 of 41 Old 07-19-2016, 06:51 AM
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A relatively easy way to get your feet wet is the DIYSG ported 18 flat pack, SI DS4 driver, and iNuke 6000Dsp.


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post #8 of 41 Old 07-19-2016, 07:47 AM
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Yes you can change dimensions as long as volume is constant

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post #9 of 41 Old 07-19-2016, 09:11 AM
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This looks like the perfect room for stuffing a bunch of IB subwoofers and AV electronics into. Unless that is your stairwell... ?


Retail subwoofers are a waste of time. Too expensive and often poor performing.
The only thing they have going for them is looks and a no hassle warranty.

With DIY you still get a warranty, but it's on individual parts. There are really only two main parts: the amp, and the cone. The rest is wood and speakerwire which doesn't need one.

Many people look at doing veneered end-table subwoofers, or IB subwoofers when they want them hidden.

IB subwoofers act like really large sealed subwoofers but without the inefficiencies of small box syndrome.
A single inuke nu6000dsp can push 8 18's in an IB without problem.

The SI-18's are a popular driver: http://stereointegrity.com/product/ds4-18-subwoofer/
The UM-18 is another: http://www.parts-express.com/dayton-...-coil--295-518
A lot of people do two of these and a nu6000DSP for earthquake style bass: 1-40hz sealed or 15hz ported.

and then two of these and another nu6000DSP for night-club style chest-thump mid-bass: 30-300hz sealed or 35-40hz ported:
http://www.parts-express.com/dayton-...oofer--295-036

You have the budget to do both, which will create some kick-a$$ bass in your room.

I always recommend that people focus on the 30-300hz bass first, it is cheaper and easier to do.

Getting 1-30hz requires an infinite amount of subwoofers and amps. There is no upper limit. One AVS'er did 16 HST-18's and 60kW, and another did 16 SI-18's and 28kW... and they still wanted MORE!!! Not because it wasn't good equipment, but rather, because infrasonics have no upper limit...
110db @ 10hz = 1db @ 1khz LOL!
80db @ 20hz = 1db @ 1khz LOL!
It takes a LOT of SPL to get anywhere below 30hz, that is just how human hearing works.
It takes 160-180db between 1-20hz to actually make ear drums experience discomfort or hurt them at those frequencies.

Alternatively, some people just add D-box for those with a budget of $5-10k per chair, or Crowson's for $500-1000 per chair, or Buttkickers for those with even tighter budgets... That way they can still get the sensation of an earthquake without needing 16 18's in the room.
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post #10 of 41 Old 07-19-2016, 09:32 AM
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Quote:
Originally Posted by Kamper View Post
Q3: Would my bass be very localized if I put all subs about 12' behind the MLP? (Do I need at least one sub in another location to eliminate localizing)?
That will cause a phase-issue with your mains. Unless... you run your mains as "small" and set them to handle down to ~50hz or so; then it won't be localizable and the phase-issue will be minimized/masked.

For those that like to run large mains down to 15-30hz, I recommend getting a miniDSP or DSP'ed inuke and applying 10-30ft of delay to the nearfield subwoofers. That way they will be in-phase with the mains/center. Then you can get away with running the subs up to ~80hz or so.

Nearfield subwoofers are a great way to avoid room nulls and minimize the inverse-distance law effect. Which means it will sound smooth and loud for the least amount of subwoofers and least hassle, more often than not...

The only downside is needing that DSP to make it "optmized".

They say that 4 subwoofers (i.e. subwoofer point-source locations) is pretty much "optimal" for smooth bass in a room.
With nearfield subwoofers, that can often be reduced down to only needing 2 locations to achieve "similar" smoothness-results. Nearfield and front-wall is a common configuration. (or front-corners stacked.)

Last edited by BassThatHz; 07-19-2016 at 09:46 AM.
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post #11 of 41 Old 07-19-2016, 10:02 AM - Thread Starter
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Originally Posted by FriscoDTM View Post
A relatively easy way to get your feet wet is the DIYSG ported 18 flat pack, SI DS4 driver, and iNuke 6000Dsp.


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Thanks for the feedback. It appears that DIYSG only creates a cube (the hardest shape to eventually/hopefully cover with bench). Do you know of any rectangular knock-down kits? If not, what designs already exist that I could duplicate?

How would your proposal perform relative to the subs I'm considering buying; in terms of SQ and SPL?
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post #12 of 41 Old 07-19-2016, 10:30 AM
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If you have available space to implement an IB arrangement, you can do no better! The key word is available space though.

If you have enough space to put together an IB arrangement, you will have the absolute best subwoofer from a SQ perspective. Then from there, you just add more drivers/power to suit your bass needs.

I knew from the start that I wanted an IB sub for my HT. I listento music equally as much as watching movies. I designed it such that bass is smooth without requiring excessive EQ. As a matter of fact, the only EQ is that from Audyssey. The location of my drivers was the trick to achieving that smooth bass response. It's all about planning before the build.

This part of my build thread explains the installation hurtles I met and overcame to build the IB subs into the walls. Pics would be in the main post....


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post #13 of 41 Old 07-19-2016, 10:31 AM
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Quote:
Originally Posted by Kamper View Post
...
I'm still following, and I can do that. What sub do you recommend me starting with for DIY? I want something with high SQ, ported, and low extension; as I'm thinking if/when it works that I could build multiples and hide them under a built-in bench (or place them in the proper location(s) ). I tried following the Johnny subs, but it appears that there are many variants.

Q1: Is the Johnny box the best application for me? What sub/amp would you recommend?
Q2: Can I change the box size (move 3" from width to height)?
...

Dayton 460ho is a good sound quality driver that gives up a little bit on the very bottom end.
Dayton UM18 is a little stronger on the very bottom end.


for an enclosure, how about something like this? three subs end to end make 10 feet. recessed driver for protection. tuning point around 17hz. suggested driver is the 460HO.


bang for the buck amp is the inuke 6000dsp. fan noise may be an issue but there are some solutions for that.


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post #14 of 41 Old 07-19-2016, 10:53 AM - Thread Starter
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Quote:
Originally Posted by BassThatHz View Post
They say that 4 subwoofers (i.e. subwoofer point-source locations) is pretty much "optimal" for smooth bass in a room.
With nearfield subwoofers, that can often be reduced down to only needing 2 locations to achieve "similar" smoothness-results. Nearfield and front-wall is a common configuration. (or front-corners stacked.)
My front is full (no room for subs), as shown in this attachment. I can put subs on left side, or rear of HT area (gotta love non-dedicated rooms! ).

Quote:
Originally Posted by BassThatHz View Post
This looks like the perfect room for stuffing a bunch of IB subwoofers and AV electronics into. Unless that is your stairwell... ?
The SI-18's are a popular driver: http://stereointegrity.com/product/ds4-18-subwoofer/
The UM-18 is another: http://www.parts-express.com/dayton-...-coil--295-518
A lot of people do two of these and a nu6000DSP for earthquake style bass: 1-40hz sealed or 15hz ported.
and then two of these and another nu6000DSP for night-club style chest-thump mid-bass: 30-300hz sealed or 35-40hz ported:
http://www.parts-express.com/dayton-...oofer--295-036

Alternatively, some people just add D-box for those with a budget of $5-10k per chair, or Crowson's for $500-1000 per chair, or Buttkickers for those with even tighter budgets... That way they can still get the sensation of an earthquake without needing 16 18's in the room.
Thanks for the recommendation on the subs!
That is not a stairwell, but it is cold storage and does not have power to it; and the surrounding walls are finished...so difficult to hook up a sub in that room.

Q1: Do you have a recommended ported box design for the SI-I8's or PA460's?
Q2: Can I put all four subs together on the back wall (ie - (2) SI-18's + (2) PA460's) and then run them off a single nu6000? (It would give me a chance to hide them all - if possible - under a built in bench). Does the DSP allow you separate controls for two different speaker types?

I do plan on adding the Crowson's after I get my subs in place.
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post #15 of 41 Old 07-19-2016, 01:49 PM - Thread Starter
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Quote:
Originally Posted by LTD02 View Post
Dayton 460ho is a good sound quality driver that gives up a little bit on the very bottom end.
Dayton UM18 is a little stronger on the very bottom end.

for an enclosure, how about something like this? three subs end to end make 10 feet. recessed driver for protection. tuning point around 17hz. suggested driver is the 460HO.

bang for the buck amp is the inuke 6000dsp. fan noise may be an issue but there are some solutions for that.
Wow! Great input, and thank you for the image. It helps immensely!

To summarize, I can throw in either the 460HO or the UM18, and I trade off SQ (460) for bottom end (UM18), correct?
The SI-18 was also mentioned earlier in this thread. Would it work well in this enclosure, and what trade-off does it offer?

I'm thinking SQ is more important than bottom end, as ULF will be difficult (expensive) due to my room size; so right now I'm leaning toward the 460HO.

Do you think that I will be able to hear the location of (3) subs in the back of the room? (assuming I properly EQ/Phase per BTH's recommendations)
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post #16 of 41 Old 07-19-2016, 02:13 PM
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Quote:
Originally Posted by Kamper View Post
Wow! Great input, and thank you for the image. It helps immensely!

To summarize, I can throw in either the 460HO or the UM18, and I trade off SQ (460) for bottom end (UM18), correct?
The SI-18 was also mentioned earlier in this thread. Would it work well in this enclosure, and what trade-off does it offer?

I'm thinking SQ is more important than bottom end, as ULF will be difficult (expensive) due to my room size; so right now I'm leaning toward the 460HO.

Do you think that I will be able to hear the location of (3) subs in the back of the room? (assuming I properly EQ/Phase per BTH's recommendations)

either the 460ho or the um18 will be fine. it isn't going to be night and day either way. both work well.


the si-18 would probably be best in a largish sealed cab.


the concern about the location has nothing to do with localization of bass frequencies. the concern is how that location interacts with your walls and how the reflected waves sum/cancel at your listening positions. with three subs, there will be some smoothing, so that will help, but there have been builds where folks put multiple subs in one area and then were disappointed because the room effects and seating position put them in a big null (bass gets cancelled out).

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I mentioned the flat pack as a convenient option that wouldn't require much effort up front and would probably be easy to resell. If you are open to cut your own wood then you have many many options. Perhaps the b&c 21 is another driver worth considering or alternatively waiting a bit to see how the Mach5 24 looks.


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post #18 of 41 Old 07-20-2016, 06:57 AM - Thread Starter
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Originally Posted by LTD02 View Post
either the 460ho or the um18 will be fine. it isn't going to be night and day either way. both work well.


the si-18 would probably be best in a largish sealed cab.


the concern about the location has nothing to do with localization of bass frequencies. the concern is how that location interacts with your walls and how the reflected waves sum/cancel at your listening positions. with three subs, there will be some smoothing, so that will help, but there have been builds where folks put multiple subs in one area and then were disappointed because the room effects and seating position put them in a big null (bass gets cancelled out).
Thanks LTD02, good explanation of the room impact, and not just placement.

I'm trying to solve the potential null and have thought of two approaches: 1) Build two subs and place them either on back wall or separate locations (side and back) and then use REW & ears to determine what works best (add a 3rd sub if needed). 2) Build three subs, and be prepared to move one to the side if all three in back isn't acceptable.

Which do you think is a better strategy (or is there another/better plan)?

Thanks again for the modeling of the sub boxes; it's extremely helpful. The model you created (20"x24"x40") is great for my potential bench.
Question: Am I trading off any SQ with this design (Did the shape create/limit the performance of the driver and sub system)? Also, is it easy to show the predicted frequency response graph and is there a cut sheet for the box? (I'm not sure what software you are using, or how easy it is to get those outputs). Thanks again for the support!

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post #19 of 41 Old 07-20-2016, 09:50 AM
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Quote:
Originally Posted by Kamper View Post
Thanks LTD02, good explanation of the room impact, and not just placement.

I'm trying to solve the potential null and have thought of two approaches: 1) Build two subs and place them either on back wall or separate locations (side and back) and then use REW & ears to determine what works best (add a 3rd sub if needed). 2) Build three subs, and be prepared to move one to the side if all three in back isn't acceptable.

Which do you think is a better strategy (or is there another/better plan)?

Thanks again for the modeling of the sub boxes; it's extremely helpful. The model you created (20"x24"x40") is great for my potential bench.
Question: Am I trading off any SQ with this design (Did the shape create/limit the performance of the driver and sub system)? Also, is it easy to show the predicted frequency response graph and is there a cut sheet for the box? (I'm not sure what software you are using, or how easy it is to get those outputs). Thanks again for the support!
in your room, it isn't really possible to know. generally, the more subs the better.


sound quality doesn't really depend on enclosure design for this type of thing. that depends more on the driver itself.


winisd is the program that i use. if using windows 7, http://www.linearteam.org/temp/winisd-07x.exe


i haven't worked out the cutsheet. if you need some help with that, let me know...

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post #20 of 41 Old 07-20-2016, 09:53 AM
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not a whole lot to look at. here is the graph for 3 co-located subs with 1100 watts each.


in room, the response will look very different.


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post #21 of 41 Old 07-20-2016, 11:55 AM
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Sound Quality for a subwoofer is somewhat of a red herring. The box design doesn't have much to do with it. One thing you can do from a SQ perspective is to not run the amps and drivers to their absolute limits, where distortion goes through the roof. Other than that, the room is the next biggest thing to deal with. EQ can do a lot, but can't fix everything. Would you consider rearranging the room, i.e., putting the TV on a different wall, or swapping roles of the game room and great room?
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post #22 of 41 Old 07-20-2016, 01:18 PM - Thread Starter
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Originally Posted by rhodesj View Post
Sound Quality for a subwoofer is somewhat of a red herring. The box design doesn't have much to do with it. One thing you can do from a SQ perspective is to not run the amps and drivers to their absolute limits, where distortion goes through the roof. Other than that, the room is the next biggest thing to deal with. EQ can do a lot, but can't fix everything. Would you consider rearranging the room, i.e., putting the TV on a different wall, or swapping roles of the game room and great room?
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in your room, it isn't really possible to know. generally, the more subs the better.

sound quality doesn't really depend on enclosure design for this type of thing. that depends more on the driver itself.

winisd is the program that i use. if using windows 7, http://www.linearteam.org/temp/winisd-07x.exe

i haven't worked up a cut sheet for those enclosures
LTD02 - Thanks for the link to WINISD... more learning! I thought the rabbit hole was shallow, but am enjoying the tumble so far!

I asked the enclosure question because I have been following the ID sub companies, and when they come out with a new sub there appears to be a lot of time spent in the development; hence my speculation that the enclosure was key. Makes sense that they are working more on the subwoofer design and DSP program to optimize the product.

In my situation, it appears that I can make (3) subs for about the price of (2) equivalent ID subs. If SQ issues come from high output, then I should be able to overcome it with 33% more output (ie -their designs may 10-20% more efficient, but my additional sub will overcome that efficiency), correct?

Do you guys agree that the UM18 and 460HO are the correct subs for my room size and SQ expectations? Which sub would be "next step up"? (I'm wondering if I need to spend $30-50/sub or $300-$500/sub to improve SQ... I'm interested if $50/sub, not if $150+/sub)
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post #23 of 41 Old 07-20-2016, 02:58 PM
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...
In my situation, it appears that I can make (3) subs for about the price of (2) equivalent ID subs. If SQ issues come from high output, then I should be able to overcome it with 33% more output (ie -their designs may 10-20% more efficient, but my additional sub will overcome that efficiency), correct?

Do you guys agree that the UM18 and 460HO are the correct subs for my room size and SQ expectations? Which sub would be "next step up"? (I'm wondering if I need to spend $30-50/sub or $300-$500/sub to improve SQ... I'm interested if $50/sub, not if $150+/sub)

i'm not sure what numbers you are using for your comparos, seems like there may be some confusion on the use of terms. anyway, internet direct cabs are usually compromised because they have to be a form factor that an average person will accept and they have to be shipped. diy allows for building custom cabs that are as large as possible, but still fit within the space. typically diy will provide greater than twice the value and more flexibility. if there was a much better sub for $50 more than everybody would be using that one.

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post #24 of 41 Old 07-20-2016, 07:09 PM - Thread Starter
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Originally Posted by LTD02 View Post
in your room, it isn't really possible to know. generally, the more subs the better.

winisd is the program that i use. if using windows 7, http://www.linearteam.org/temp/winisd-07x.exe


i haven't worked out the cutsheet. if you need some help with that, let me know...
I just pulled down the winisd, but couldn't find either the Dayton or SI driver information. Are those separate add ons, or do I need to look under a different name than Dayton and Stereo Integrity?
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post #25 of 41 Old 07-20-2016, 07:12 PM
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Quote:
Originally Posted by Kamper View Post
Do you guys agree that the UM18 and 460HO are the correct subs for my room size and SQ expectations? Which sub would be "next step up"? (I'm wondering if I need to spend $30-50/sub or $300-$500/sub to improve SQ... I'm interested if $50/sub, not if $150+/sub)
The only driver I'd consider from that perspective would be an AE TD18H+ or IB18HT (for Infinite Baffle.) They use a motor designed for low distortion and linear performance as their primary goal. Most other premium drivers are designed for maximum displacement and power handling, not low distortion. But any driver will play cleanly if you don't push it and the amp too hard. And again, the room, placement, setup, EQ, and such factors will probably have more impact than the driver you select.
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post #26 of 41 Old 07-20-2016, 11:50 PM
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Originally Posted by Kamper View Post
I just pulled down the winisd, but couldn't find either the Dayton or SI driver information. Are those separate add ons, or do I need to look under a different name than Dayton and Stereo Integrity?

i'm not sure if there is a data base of additional drivers. i always just enter the thiele small specs myself.


the process is:


make sure all fields are clear, then
enter qes then hit tab, enter qms
hit tab a couple times and let it calculate qts
hit tab a few times to move to mms
enter mms, re, bl, le, sd, xmax, and pe
by using tab after entering each data, it will calculate what it needs to
sometimes the specs calculated don't match exactly the manufacturer specs, but its only rounding type errors, so it is not material
keep an eye on the units. if they don't match, click on the units to scroll through the options. entering a driver sd as 1130 sq cm will give one set of results. entering it as 1130 sq m will give another!
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post #27 of 41 Old 07-22-2016, 12:18 PM - Thread Starter
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Thanks LTD02, I plugged in a few drivers and its working! (or I'm not smart enough to know it's not working properly! ) I can now "see" how each driver plays in a given enclosure, and where one performs better than another.

Dog gone you guys (@LTD02, @iz7j, @blah450 , @BassThatHz , @rhodesj , others...)! I was mentally down the path of purchasing solid subs from an ID company, only to have you guys encourage/ask/inform me on the benefits of DIY. I've gone from skeptic (too hard for me), to intrigued (what if it is a better value) to almost convinced (big DIY koolaid stain on the upper lip! ) that this is the right thing to do because of the value and DSP flexibility it provides me.

I now am seriously considering the building (4) enclosures. If they play well behind me (my MLP) (according to REW and ear) then I'm done. If not, I can move one or two of them to another part of my room to improve performance.

I'm now ready for "Step 2" in the process, but would like support on what's next. Being data driven, I have the natural gift of over analyzing; and want to avoid that in this process. I also recognize the value of setting up what is best for my situation. So here are few questions (note: Assumption is I'll use an iNuke6000DSP) :

1) LTD02 provided a great starting point for an enclosure in post #13 above. Do I need to further optimize it? If so, can you point me to a resource? If not, is there software for generating a cut sheet; or do you wing it? (or send it to a local to fabricate)?

2) Driver proposals so far include DS4 (just saw limited offer), UM18-22, and AE TD18H+. Is there a resource that summarizes that pros/cons (comparison chart?) of these - and other similar - drivers so I can choose what works best for my large room and desire for great SQ? Are there other drivers I should consider?

3) I can (will) read up on the experiences of other builds to glean lessons learned from other DIY's. Is there anything else to study prior to pulling the trigger and getting my enclosures built and drivers ordered? (Is there another key component to good SQ that I need to study/decide upon?)

I appreciate everyone's input and support so far. I've been fearful that I would build subs and be frustrated with the muddy/boomy sound, but now think that I can get better performance for the same cost as I would if I had purchased good ID subs.
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post #28 of 41 Old 07-25-2016, 07:51 PM
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This site has about 800 pages of subwoofer comparison reading material:
http://www.data-bass.com/systems

You don't have to worry about SQ or boominess. But you might have to worry about pro amp fan noise. They aren't silent like plate amps are.
You'll only hear it during quiet passages.
When you are bassing it you won't hear a thing!

For sealed subs I wing it, for ported and horned I use Google Sketchup for modelling and cut-sheets.

All I have is an entry-level Ryobi Table Saw/router/power driver, a drywall T-square and some wood clamps.
About $700 total in wood-working tools. You could easily spend $1000 on just a table saw.

A Ryobi will cut your head off, but a SawStop won't even cut your finger.
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post #29 of 41 Old 07-26-2016, 07:26 AM
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We use those SawStop tables at work, man are they cool....
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post #30 of 41 Old 07-26-2016, 08:53 AM
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Built-in Subs for Large Room

I run SI 18 subs with the iNUKE 6000dsp. I replaced the fans in my iNUKE - it's easy to do if you are so inclined - it only requires splicing a couple of wires and using a screwdriver.

The SI subs are on clearance, but later on, possible weeks or months later, they will be introducing a lower-cost sub similar to the HT18D2, which is what I run.

Once you get winiSD setup correctly and pick the cabinet design and specifications, other than proper assembly with the right bracing, sound quality will come by having large drivers and a large cabinet. The ID and retail designs actually do require a lot more engineering and design because there are many tradeoffs to getting good bass in a smaller cabinet. But stuffing a large woofer into a large cabinet is half the battle. The DSP that's out there today - the INUKE DSP, or the miniDSP, or the built-in DSP in many AVRs for example, are now basically able to achieve anything you want.

If you do end up wanting custom flat-packs or any other custom cabinet design, my boxes were designed and cut by @squire s007 here on AVS. I ended up doing trapezoidal boxes to fit into a bay window cutout. He shipped them, and A buddy and I assembled them.

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Last edited by murphy2112; 07-26-2016 at 08:56 AM.
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