Peerless XLS10 project on the tightest of budgets

[StillWonderingWhy]

Hi all,

After seeing the amazing builds on this site, I knew it was the forum to join for an aspiring DIYer like myself. Anyway, after poking around on the internet for literally days, trying to absorb all that is "speaker building", I feel mostly settled on this nice 10" sub design I found on the website hardwareanalysis. (New users can't post external links, so a little Google search for: 10" subwoofer how-to will get you there.)

The plans call for a Peerless XLS 10" subwoofer and passive radiator. The PR design sounds pretty interesting to me, so I'd like to give it a shot. Unfortunately it seems impossible to find the called for peerless PR online. (Fast-forward 8 hours of my life browsing the web and learning about WinISD...) I think the CSS APR10 with about 600g of added mass should be a nice replacement for the Peerless passive radiator. Ideally someone could check my WinISD work, as I'm still new to it.

The main requirement for this project is price, honestly. It's not that I don't have a discerning ear, it's just that I can't drop a bunch of money on a subwoofer at the moment. A friend who has woodworking experience will be helping me out (more like, I will supervise him) for the enclosure. He is donating some good grade plywood for this, and from what I've read plywood is a decent alternative to the common MDF. Unless there's an incredibly important reason NOT to use this material, I'd like to stick with it. Power is coming from a 250w plate amp that I've had sitting around for a while. The only adjustments it has are volume, phase and low-pass cutoff. My previous subwoofer was actually the amp in its own box + a car subwoofer I had left over. I ended up selling the subwoofer, and thus the project at hand

Use will be 40% movies, 20% games, 40% TV. Room size is 15x15x8, although the room is openly connected to a second room of equal size. I realize this might make a 10" woofer too small for my needs and am open to suggestions. However, I don't listen to material particularly loud, so take that into consideration. My first subwoofer was a 8" Yamaha sub with 100w that was inadequate. At one point I had a 12" sealed adire shiva hooked up to the 250w amp which was probably more than I needed. Somewhere between those two would be great.

As my planning stands right now I'm looking at about $140 for the XLS10 plus $70 for the CSS APR10 = $210 over and done. If anyone knows how to get better bass for the same price... you have my full attention . A big thanks goes out to anyone who cares to give me a hand in the planning of this. If not I'll still post updates and pictures as I go.

[StereoClarity]

Have you thought about not using a PR and just using a sub in a ported alignment? You didn't mention enclosure size being a requirement so I think that would work better for you. If you went ported you could use the money saved from the PR to put into a better driver (possibly a 12").

I have a pair of Peerless XXLS12's that I love to death. The SD12 woofer from CSS could be an option as well.

Was there any particular reason you wanted to use a PR?

[StillWonderingWhy]

I suppose the benefits of a small enclosure and a favorable bass response sounded good. Of course when someone writes a how-to article on PR they must like it. My previous subs have been sealed, so I wanted to try something different. Ported meets that requirement as well. I guess I had heard that porting is sensitive to tuning, and this was before I found out about WinISD. Any comment on margin of error for a ported box?

One other question I've had is that my amp isn't sealed, so I guess it should be in its own compartment. When running the wires from the amp to the driver, how does one go about doing that? I assume it should be relatively air-tight, or else it defeats the purpose of walling it off.

[Mike P.]

PR's are an advantage to subs that require a small net volume. Porting a 30 liter enclosure to 20 hz would require a 4" diameter port to be 76" long.

Most plate amps that are "open back" have sealed controls and are relatively air tight.

What make and model of plate amp do you have? The info is needed to determine where the Hi-Pass filter is and if the amp has any boost applied. Both the HPF and boost or no boost will affect the perfomance of your sub build.

[StillWonderingWhy]

It's the basic 250w amp that used to be sold on parts-express. I believe it's #300-794. If it has bass boost, it's not the model with a dial to adjust it after assembly.

[Mike P.]

Here is some modeling. Orange is the XLS10 in 30 liters with a APR10 with 315 grams of mass added to create a tuning of 21.5 hz. Power input is 240 watts with a HPF at 18 hz assuming your amp is the #300-794. $140 for the XLS10 plus $70 for the CSS APR10 = $210.

Pink is the new TRIO12 sub that will be released shortly from CSS. Shown in 92 liters with 2 APR12's with 450 grams added to each PR to create a tuning frequency of 21.8 hz. Power input is 240 watts with a HPF at 18 hz, same as the XLS10. The new 12" sub and a pair of APR12's will cost less then $200. Superior performance for slightly less money then the XL10 APR10 combo, it would be worth the wait.

[StillWonderingWhy]

Wow, as expected amazing insights Mike, thank you. Definitely an option I'll think about. There's not a real rush on this project (ideally it would be ready in 4-8 weeks, but not necessary) so I'll wait and check out the TRIO12s. Is CSS planning a kit that would make the price so low? ~$200 is a great deal for that much hardware!

[Mike P.]

Yes, the initial offering will be a special with the sub and 2 PR's. It should be within 2 weeks, as far as I know.

[StillWonderingWhy]

Excellent. I'll be first in line to buy a set then. I'm pretty excited I'll be able to keep a moderate sized box, get even more SPL and keep within budget. Any chance you have the mounting specs as well so I could get started on a box design and possibly fabrication?

[Mike P.]

The box design for the TRIO12 is the same as the SD12 subwoofer which the TRIO12 will replace. The mounting specs for the TRIO12 are preliminary and won't be released until they are in hand and can be verified. The 92 liter box design can be found here:

http://creativesound.ca/pdf/Quartet12_Subwoofer_Kit.pdf

[StereoClarity]

Bob and I have emailed back and fourth about the Trio12. It's going to be a very excellent woofer indeed. I'm excited for that to become available!

[StillWonderingWhy]

I did some modeling today with the SD12 and 2 PRs, and if it's anything like that it should be an excellent setup. I'm seriously excited!

Now to figure out the finish for the box. I have some silver wood grain style speakers this should ideally match. I'll have to do some research into how to make that finish.

[StillWonderingWhy]

A few updates. First, I checked my purchase history on PE, my amp is actually the 300-796, not the 300-794 as I had remembered. Not sure if that matters, they seem almost identical. Second, the APR12s came in yesterday!

I'm sure most of the CSS devotees here have seen them, but I'll throw in my pictures all the same:




The units are lighter than I was expecting, and the weights are heavier than I was expecting. It's incredible the maximum mass they're spec'ed to handle. Even though they're not particularly heavy, they do seem well made and the screw-off cap to change mass is very slick.

I also modeled the TRIO12 in WinISD. It seems like the PR excursion is an issue, even at 250w. Am I missing something here? (I loaded up the same project twice to show PR and EQ settings)

[Mike P.]

What net volume is the modeling?

[StillWonderingWhy]

3.2 cu ft, as per the kit specifications. The T/S params of the APR weren't labeled quite normally, so I kind of had to guess, but I think they should be correct.

[Mike P.]

The PR parameters are correct. I'll model it as soon as I get a chance.

[Mike P.]

The high pass filter should be Butterworth, 2nd order at 19 hz. Leave the Q blank.

[StillWonderingWhy]

Thanks Mike! Looks lovely now