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Overkill?

post #1 of 55
2/6/07 at 5:22am
Thread Starter 
Hey guys, a few of you have helped me out recently in lots of questions about subs that I've had.

I'm leaning towards building something using the DB500 drivers from TC sounds since they seem to be a good deal and it looks like their specs are good (20mm xmax, etc).

However, in talking with a couple of members, it seems that I may be dissappointed with going this route and shouldn't "cheap out" and should build something more powerful. However, I tend to think that even if I was to build a sub with one of these drivers, it would still probably be a much better sub than 75% of what's out there in the stores. Am I wrong to think this?

Sometimes I feel that because the people on this forum are probably the pickiest (I mean that as a compliment) when it comes to subwoofers, that perhaps I could build something that's not quite as powerful as some of the suggestions and it would still be a great sub.

Don't get me wrong, I appreciate all that I have learned from several experts in this forum! I just think many of the people here are buildings subs to satisfy the extreme of demands, not the norm.

I'd love to have the ability to put a 15 cubic foot sub in my family room, but ther'es no way that's going to happen, so I'll have to deal with making something much smaller.

Anyways, I guess what I'm asking is, even if I was to build a basic DIY sub with a driver like that mentioned above, and a basic 300/500 watt amp, would I be disappointed, or do you think something like that will beat most of the commercial subs available in BM stores (assuming it's build correctly)?

Thanks!
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post #2 of 55
2/6/07 at 5:29am
My motto...

You can't make anyone in this lifetime happy but yourself so do what makes YOU happy!

It's a learning process and the only real suggestion I might give is leave yourself open to upgrade options in the build whether its a better driver, amp, or box.
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post #3 of 55
2/6/07 at 6:04am
The truth is you will probably be happy with such a sub, but at the same time we like headroom around here. But we aren't building your sub, you are. So if you want to get your feet wet, make a very very decent lesser priced sub, go for it. I all but guarantee you it will be a success in your eyes, and that is what matters.



PS. How big is your family room and do you usually listen at high volumes?
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post #4 of 55
2/6/07 at 6:23am
Thread Starter 
Hi Willd,

The room is 20 x 16 x (8 height on one side, 18 on the other), so 4000 cubic ft. I am leaning towards a design of 2 TC500s with a sampson amp (thanks to one of many advices of thylantyr!).

I would love to build the best and largest sub possible, but really the max I'd be willing to do for size in my family room is around 28 x 20 x 20 external. I don't think my wife would be too crazy about anything larger than that!

BTW - Thylantyr suggested something like 1 TC-2000 instead of 2 TC-500s (12"). So that one driver would give me more bass than the other 2? Granted, I'd still be paying alot more for it!

Thanks!
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post #5 of 55
2/6/07 at 7:46am
I think the sampson SX1200 running to 2 DB-500's would make an awesome setup. I like two seperate enclosures around 3.5 cubes with a 20hz tune. You will hit excursion at about 17hz so a high pass somewhere around there may be in order. I believe this would give you plenty of this forum's precious "headroom".

Later
Seth
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post #6 of 55
2/6/07 at 7:51am
Thread Starter 
Hi Seth,

Thanks for the response. Any reason why you'd go 2 seperate enclosures vs just one, other than being able to place them on different sides of the room, etc?

Thanks!
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post #7 of 55
2/6/07 at 8:32am
Thread Starter 
So I am now a little more familiar with WinISD. I plotted out 2 of the DB500s and WinISD gave me a suggested box of 201 liters at 21.77hz. 201 is unfortunately too big for what I want in my room.

So I changed it down to 125 liters at 21.77 and the response shows it down 1db at 30hz and down 3 db at about 24.5 hz. Is that not good?

If I left it at 201 liters, the graph shows it down 1 db around 22.5 and down 3 db at exactly 20 hz. While this is preferred, I just can't justify having a box that big in my family room.

If I have to, I could go up to 175 liters, but i'd prefer not to. 150 looks promising down 1 db around 27hz and down 3 db around 23hz.

Do these look okay? I'm sure it's not as good as what many here would like, but I would imagine better than many other subs available out there.

Am I looking at the right things?

thanks!
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post #8 of 55
2/6/07 at 8:46am
Would you prefer one enclosure or two? If you could go with two, I'd really try something like 100liters each, tuned to 17Hz. That and the Samson amp would be a great combo, I think.

It would probably match fairly well with your room gain (not that we know exactly what to expect).



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post #9 of 55
2/6/07 at 9:02am
Thread Starter 
Wow, I don't think I really have the room/asthetics for 2 100 liter boxes in my room. Would the designs I mentioned above be totally off? Just trying to see if I'm heading in the correct direction or not.

What exactly is the tuning frequency? I don't quite understand that part. Thanks!
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post #10 of 55
2/6/07 at 9:32am
Midfi,

I think 2 enclosures is a good idea for two reasons.

1. They would be lighter and easier to move around.

2. As I understand it, having two subwoofers in a room can help to even out bass response throughout the room. There are will certain dips and peaks based on location.


If you are really concerned with eclosure size you could go with 2 db-500's in a sealed box that is around 3.5 cubes with that same sampson amp.


Later
Seth
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post #11 of 55
2/6/07 at 9:39am
Thread Starter 
Hey Seth, thanks,

Wouldn't going with the 3.5 enclosure for the 2 DB500s reduce the SPL output greatly as compared to a ported design?

I only as because with my room being as large as it is (4000 cubes), I want to make sure I still hit a decent SPL across most frequencies.

Thanks again!
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post #12 of 55
2/6/07 at 9:41am
Quote:


However, I tend to think that even if I was to build a sub with one of these drivers, it would still probably be a much better sub than 75% of what's out there in the stores. Am I wrong to think this?

Sometimes I feel that because the people on this forum are probably the pickiest (I mean that as a compliment) when it comes to subwoofers, that perhaps I could build something that's not quite as powerful as some of the suggestions and it would still be a great sub.

Don't get me wrong, I appreciate all that I have learned from several experts in this forum! I just think many of the people here are buildings subs to satisfy the extreme of demands, not the norm.

By all means you are correct. A high quality 12" driver with decent power is probably enough for most people. Many of us do go to the extremes, and we will spend time argueing over small differences in infrasonic capability or this alignment vs that

The thing I will warn you of though is that if you are anything like us, once you get a taste of good bass, you will become addicted. It probably won't happen in the first month or two, but if you were to build this smaller sub you are suggesting, maybe 6 months down the line we'd see you back here again starting a thread, "I like my bass, I just want it to go a lot lower and louder!" - I've seen it happen time and again

By the way, I wouldn't even attempt to get into infrasonics with such a sub and a room that large. I'd set a goal of only worrying about 20hz+, that way you can use small enclosures, have plenty of output, and still have port overkill.
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post #13 of 55
2/6/07 at 9:54am
If you must go with a single enclosure, I'd go for 150 liters, tuned around 19Hz with a 6" port.
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post #14 of 55
2/6/07 at 10:09am
Thread Starter 
Quote:
Originally Posted by Willd View Post

If you must go with a single enclosure, I'd go for 150 liters, tuned around 19Hz with a 6" port.

This is in reference to using 2 DB500s 12" ?

Thanks!
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post #15 of 55
2/6/07 at 10:10am
Thread Starter 
Quote:
Originally Posted by SteveCallas View Post

By all means you are correct. A high quality 12" driver with decent power is probably enough for most people. Many of us do go to the extremes, and we will spend time argueing over small differences in infrasonic capability or this alignment vs that

The thing I will warn you of though is that if you are anything like us, once you get a taste of good bass, you will become addicted. It probably won't happen in the first month or two, but if you were to build this smaller sub you are suggesting, maybe 6 months down the line we'd see you back here again starting a thread, "I like my bass, I just want it to go a lot lower and louder!" - I've seen it happen time and again

By the way, I wouldn't even attempt to get into infrasonics with such a sub and a room that large. I'd set a goal of only worrying about 20hz+, that way you can use small enclosures, have plenty of output, and still have port overkill.

Thanks Steve,

I'm definately not looking to hit any infrasonic frequencies at the moment, but like you said, I'm sure that will change.

You response makes we wonder if I should just get one DB500, mate it to a PE 500 watt amp and create a single ported enclosure. If I want more bass, I could always add a second!
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post #16 of 55
2/6/07 at 10:20am
The 100 liter, 17hz looks fine for each DB500. But you need approx 4" x 30" port. Will it fit
in a square design? heh

Making the box bigger solves the port length problem. I was suggesting two DB500
in a bigger box to *maybe* squeeze in a 6" port or at least dual 4" ports.

The samson sugggestion wasn't mine

I was suggesting the buttkicker @ 2ohm operation for 900w of headroom per
woofer for $250.

Bash 500w plate amp cost $225. 250w per woofer.
EP2500 proamp cost $329. 750w per woofer. {more like 400w per woofer, lol}
Samson SX1200 cost $300 and is rated for less than EP2500, my guess is that
you'll get 300w per woofer.
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post #17 of 55
2/6/07 at 10:23am
Quote:
Originally Posted by midfiman View Post

Thanks Steve,

I'm definately not looking to hit any infrasonic frequencies at the moment, but like you said, I'm sure that will change.

You response makes we wonder if I should just get one DB500, mate it to a PE 500 watt amp and create a single ported enclosure. If I want more bass, I could always add a second!

I'm sure if you made one DB500 subwoofer with 500w plate amp that
it will beat your current subwoofer you use in home. But you wanted
SVS performance so the dual DB500 to mimick SVS plus buttkicker
would kill the SVS design, IMO. {or single TC2000}.

FYI, did you see the SVS specs? They use three 3" ports, higher tuning.
They suggest plugging one or two port holes to lower the tuning.
Why would I want dual 12" woofers with a 3" port ? LOL What is SVS trying
to sell to consumers .. eye candy ..
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post #18 of 55
2/6/07 at 11:06am
Thread Starter 
Cool, I'm leaning more and more towards a single ported box with dual DB500s in the smallest enclosure possible and using the buttkicker or Samson amp.

If I was to make 2 seperate boxes, can I put them on top of each other, or will the vibrations vibrate the top one off little by little? Thx!
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post #19 of 55
2/6/07 at 11:13am
Yeah, I forgot about the Buttkicker, and of course it gets my vote for various reasons.

Like thy said...

Quote:


Making the box bigger solves the port length problem. I was suggesting two DB500
in a bigger box to *maybe* squeeze in a 6" port or at least dual 4" ports.

Yeah, go with as big a box as you can have, then use either a 6 or two 4" ports, and go with the buttkicker. That would serve you well I think.
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post #20 of 55
2/6/07 at 11:26am
Just make a slot port. That should solve the problem of fitting the port in the enclosure.
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post #21 of 55
2/6/07 at 11:37am
Thread Starter 
How do you calculate for a slot port vs one that is made from "tubes"? I'm assuming by slot you mean just having the MDF have a slot opening on one side, yes?
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post #22 of 55
2/6/07 at 11:46am
In playing around a bit with simulation, you really aren't gonna get too good of results with two drivers in a ported enclosure unless you are willing to go 200 liters at least. So with that said, I'd just go with a single more optimized one for now, and when the addiction kicks in down the road, you can go big time then.

I'm looking at 140 effective liters, 5" port that is 20.5" long, and a 500 watt plate amp with 18hz highpass filter. You might be able to find a 5" diameter piece on Sonotube at a hardware store - where 6" is typically the size, some have reported that you will find variations. Looks like 110db+ capability from 21hz up.
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post #23 of 55
2/6/07 at 12:03pm
Quote:
Originally Posted by thylantyr View Post

I'm sure if you made one DB500 subwoofer with 500w plate amp that
it will beat your current subwoofer you use in home. But you wanted
SVS performance so the dual DB500 to mimick SVS plus buttkicker
would kill the SVS design, IMO. {or single TC2000}.

FYI, did you see the SVS specs? They use three 3" ports, higher tuning.
They suggest plugging one or two port holes to lower the tuning.
Why would I want dual 12" woofers with a 3" port ? LOL What is SVS trying
to sell to consumers .. eye candy ..

The dual driver SVS subs use 4" ports. The single driver models use 3" ports. Many run their Ultras in 16Hz tune, with two 3" ports open.
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post #24 of 55
2/6/07 at 12:04pm
Thread Starter 
If such is the case, maybe I should just invest in a better driver than the DB500 for a single vented box enclosure and move up to something like a 15" DB 2000 or perhaps a Adire Audio Brahma 12" or something like that (putting maybe $300 max for the driver)?

How is SVS able to put 2 12" drivers in the smaller enclosure with the 600 watt amp? It's 19 x 26.5 x 28 on the outside, so i'm assuming it's internal volume must be something like 6.5 to 7 cubic feet, no?

Oiy, this is SOOO hard to decide!
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post #25 of 55
2/6/07 at 12:17pm
You can calc slot ports in WinISD. Just go to vent and click on the circle. It will change to a square an viola... slot port calculations
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post #26 of 55
2/6/07 at 12:35pm
You could go 2 drivers in 180 liters with a 23hz tune, 6" port, and 1000 watts with 18hz highpass if you are willing to give up some linearity.
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post #27 of 55
2/6/07 at 12:38pm
Thread Starter 
Just spoke to Thilo who's an engineer at TCSounds, and here's what he had to say:

1. 2 DB500s (12") will produce more SPL than one TC2000 (both in vented box) but will also produce more distortion

2. 2 DB500s in a 5 cubic foot box tuned to about 22hz will work very nice, or 6 cubic foot box tuned to 20hz

3. 1 DB500 in about 2.75 to 3.00 cubic foot box tuned to 20 hz

4. Buttkicker amp will work nicely with the 2 DB500s in a vented box


Thought this was interesting because if I can use a 5 cubic foot box for 2 of these, that would be VERY appealing!

Any thoughts? I have no idea at this point because some of the experts here have said I would need to go at least 7 cubic feet who definately know their stuff, but i'm assuming a engineer at TCSounds who was using thier own modelling software also knows a thing or two, so who knows!
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post #28 of 55
2/6/07 at 1:24pm
Midfi,

Most of the guys here love thier huge boxes and low tuning frequencies. By going smaller you might give up a few hz down int the teens but I think a box that is significantly smaller is worth it! I would go with 5 cubes at 22hz. I doubt you will notice the diff. between a 22hz and 20hz tune anyway.


Later
Seth
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post #29 of 55
2/6/07 at 1:30pm
Quote:
Originally Posted by Pradeep View Post

The dual driver SVS subs use 4" ports. The single driver models use 3" ports. Many run their Ultras in 16Hz tune, with two 3" ports open.

I was looking at this model.
http://www.svsound.com/products-sub-box-isd2.cfm

Dual woofers + three 3" flared ports.
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post #30 of 55
2/6/07 at 1:36pm
Quote:
Originally Posted by midfiman View Post

Just spoke to Thilo who's an engineer at TCSounds, and here's what he had to say:

1. 2 DB500s (12") will produce more SPL than one TC2000 (both in vented box) but will also produce more distortion

2. 2 DB500s in a 5 cubic foot box tuned to about 22hz will work very nice, or 6 cubic foot box tuned to 20hz

3. 1 DB500 in about 2.75 to 3.00 cubic foot box tuned to 20 hz

4. Buttkicker amp will work nicely with the 2 DB500s in a vented box


Thought this was interesting because if I can use a 5 cubic foot box for 2 of these, that would be VERY appealing!

Any thoughts? I have no idea at this point because some of the experts here have said I would need to go at least 7 cubic feet who definately know their stuff, but i'm assuming a engineer at TCSounds who was using thier own modelling software also knows a thing or two, so who knows!

This is consistent with what has been said.

Two 12" woofers can beat a single 15" woofer of similar quality.

The box size recommendations are in the ballpark for one or two woofers.

Buttkicker is a nice option.

Steve: where does one get a high pass filter?

How is SVS able to put 2 12" drivers in the smaller enclosure with the 600 watt amp? It's 19 x 26.5 x 28 on the outside, so i'm assuming it's internal volume must be something like 6.5 to 7 cubic feet, no?

Anyone can put 2 12" drivers in a box, the question is performance. Don't copy
a commercial design, try to make a better one.
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