Help finding a sub.

[mgboy]

I'm looking for a 8Ohm VC 500 Watt Sub. Go. I can't find anything like that, even though there must be one somewhere. Thanks for the help. Don't ask why, as you might find out in a few weeks if you see another build thread of mine.

[aceinc]

Would you prefer 5 1/4" or 18"?

I think a few more specs might elicit a more reasonable answer. Without giving away too many secrets, how about whether you're looking for a sub suitable for ported, IB, or sealed enclosures?

This http://www.partsexpress.com/pe/showd...number=295-455 will handle 350 watts at 8 Ohms.

Paul

[Jerm357]

Heres a few nice 15's. Just make sure you get the dual 4ohm ones and you can wire it for a 8ohm load.

http://www.soundsplinter.com/rlp15_s...formation.html

http://www.tcsounds.com/tc2000.htm

[brent_s]

The alignment... ported/sealed, cabinet volume, tuning frequency all effect the power handling. The thermal rating listed in the T/S parameters for a driver is almost meaningless for designing the actual sub.

For example, a TC Sounds db500-12 (not an 8 ohm driver...but 2 in series would be) in a sealed box with Q of .703 exceeds rated Xmax with 500 watts below 26 hz. In 4 ft^3 tuned to 20 hz, 500 watts won't reach Xmax until 17hz. Increase the ported box size to 6 ft^3 and 500 watts will now exceed rated Xmax in the mid 20s.

In other words, you're going to have to supply more details before anyone can give you a solid recommendation. Box size limits, frequency response and SPL goals, that sort of thing.

-Brent

[mgboy]

What about this driver used as a subwoofer (LLT tuned to ? )

http://www.partsexpress.com/pe/pshow...43&rak=295-085

Or is the Xmax way to low to be any good?

I'm just always searching for new cool things.

[BoomieMCT]

mgboy wrote:

What about this driver used as a subwoofer (LLT tuned to ? )

http://www.partsexpress.com/pe/pshow...43&rak=295-085

Or is the Xmax way to low to be any good?

I'm just always searching for new cool things.

You *could* use it but there are other things I'd spend $160 on. This would probably be okay in a HUGE horn loaded box assuming you had a very big room to fill.

[brent_s]

mgboy wrote:

What about this driver used as a subwoofer (LLT tuned to ? )

http://www.partsexpress.com/pe/pshow...43&rak=295-085

Or is the Xmax way to low to be any good?

I'm just always searching for new cool things.

If you're building a PA rig, it's probably decent. As a hometheater sub, would you be happy with an -3db point of 30hz and -18db @ 20hz? Did you look at PE's suggested design document?

This driver's a perfect example of my comments about power handling specs. The voice coil on this thing can probably easily dissipate the spec'd 500-700 watts all day long. However, put it in the 7.5 ft^3 box tuned to 33hz recommended by PE and you exceed Xmax with 300 watts around 50hz. A bigger box and lower tuning get you a slightly better looking response curve (for HT), but excursion limited power drops below 200 watts in the upper 30/low 40hz area. Since performance is really about output and not how much power you have to feed it...above 30hz this thing is actually quite substantial, as you'd want/expect from a PA/sound reinforcement driver.

It's not just Xmax that's the problem, all of theT/S parameters work together to shape the frequency response and output...as they said in college, the proof is left as an exercise for the reader.

As several of us have already asked...what are you objectives and constraints for this project. An 8 ohms driver that handles 500 watts by itself is a meaningless requirement.

-Brent

[mgboy]

brent_s wrote:

If you're building a PA rig, it's probably decent. As a hometheater sub, would you be happy with an -3db point of 30hz and -18db @ 20hz? Did you look at PE's suggested design document?

This driver's a perfect example of my comments about power handling specs. The voice coil on this thing can probably easily dissipate the spec'd 500-700 watts all day long. However, put it in the 7.5 ft^3 box tuned to 33hz recommended by PE and you exceed Xmax with 300 watts around 50hz. A bigger box and lower tuning get you a slightly better looking response curve (for HT), but excursion limited power drops below 200 watts in the upper 30/low 40hz area. Since performance is really about output and not how much power you have to feed it...above 30hz this thing is actually quite substantial, as you'd want/expect from a PA/sound reinforcement driver.

It's not just Xmax that's the problem, all of theT/S parameters work together to shape the frequency response and output...as they said in college, the proof is left as an exercise for the reader.

As several of us have already asked...what are you objectives and constraints for this project. An 8 ohms driver that handles 500 watts by itself is a meaningless requirement.

-Brent

I see.


Well I was just wondering if there were any drivers out there that would handle that amount of power (not saying it's a lot) because after upgrading my current subs, this A500 will need a work out, so rather than having two 200/250 watt subs, why not have 1 larger 500 watt sub.

It would be used as a HT/music sub, either sealed, or LLT anywhere from 14-19.

[aceinc]

If all it took to make a great subwoofer for all applications was to find a driver that handled a specific amount of power, then there would only be 1 driver on the market. If we ignore corporate greed for the moment, the reason there are so many drivers is that they all have their own pros and cons.

To stretch an analogy; You can marry a supermodel, or the girl next door, and you will acheive different lifestyles based on their individual features. Some may prefer the supermodel, some, the girl next door.

The same is true with drivers, do you want loud, but not too deep and works well in large crowded spaces choose the driver you posted, or the supermodel. If you want deep, stay at home, and works well in a small room, choose a home theater driver or the girl next door.

As with spouses, there are many to choose from, but before you go on the hunt, decide what's important to you, and what features are required to help you acheive those goals.

Paul

[brent_s]

Ok, we sort of have one design requirement...max of 19 ft^3...is that internal gross or net or external volume?

For the A500, while you can limit yourself to 8 ohm drivers for bridged operation, you're probably better off looking for a dual 4 ohm coil or using dual 4 ohm drivers. Same power delivered from the amp, more driver selection, and the amp will probably be happier not running bridged.

How about budget? Using an SPL meter, how loud do you listen? What are your main speakers, rest of system? How far will you be seated from the sub? How big is the room?

Right now this is just a modelling exercise which you should be able to easily do yourself. Download WinISD Pro or Unibox and have at it. Be sure to read WinISD's help files on how to enter driver parameters.

Some recommended reading:
http://ldsg.snippets.org/idx.php
WinISD help/technical articles contained in the applications help section
http://www.diysubwoofers.org/

Limited to the A500...for the money, you're probably not going to beat PE's DVC15. On sale for $99/each with free shipping right now. Dual 8 ohm coils, wire in parallel for 4 ohm/driver. Get two, build a box of 12-14 ft^3 net internal tuned to 15-20 hz. Duals also gives you the option of building 2 boxes to help even out room response.

Another relatively inexpensive option, two TC Sounds db500-12s in 10ish ft^3 tuned 17-20hz. Probably very close to being an underpowered SVS Plus/2, but you're offsetting the lack of power somewhat by using a larger box. Not as much output as the dual DVC15s, but a flatter curve.

-Brent