Building subwoofer using 18LW1400 driver in vented box

nice looking box...but the length of that port has me concerned...how did you arrive at such a short port with no bends in it?

It is a bad idea to add boost below the tuning frequency because the driver becomes unloaded and you run the risk of bottoming the driver even with small amounts of power. In fact, most people will run a high pass filter for ported subs.

Any pics of the driver?

I recently did something similar with an Eminence Kappalite and a Bash300 and I really liked the results. I used a Behringer crossover at around 50Hz to split up the bandwidth between the Kappalite and my HSU STF3.

I bet you got it from Neil Smith. Nice driver.

Great Job for a first attempt! Hell, great job on a 20th attempt.
Enjoy.

The sub and FR looks great.

Excellent. The FR at the low end will be increased by room gain.

What did you finish it with?

Glad you went this route. So how does the 21LW1400 compare with the PB13U in terms of SQ above 30Hz? (if you would kindly do a comparison).

However I gather from your original post that you would operate both at different passbands, the pro driver for above 30 and SVS below 30?

How did you measure that? What distance from sub, placement of sub, was it in room, etc?

I wish more people understood the benefits of a more efficient design. That sub will achieve volume levels which will cause immediate and permanent hearing damage with power that other drivers would need just to reach things like thx reference levels. WHich means it's not even breaking a sweat when asked to produce only reference levels.

That looks great! I got to tell you the truth...at one point I was itching to buy those 21s as well.

What tuning frequency did you go with? I am curious what a close mic sweep of the 21 would look like.

DL86, the PB13U distortion plots/SPL levels are clearly documented in HTS and AVTalk sites. When you do hear audible distortion in the bass, it should be pretty high in % already. I guess the 21LW1400 should be pretty low distortion. I think I recommended you the 18LW1400 based on value, instead of the 2242H.

I would love to see what Audiopulse may come out.

What you really ought to try is some acoustic rock, trance or R&B, sit just 15 cm in front of the 18sound sub, and turn up the volume when you are not in a critical listening mode. It will just punch you silly.


The 2242 is a very good driver, moreover looking at it as a whole you can easily sell the 2242 for a good resale price and have good demand for it, nobody will mistake it for 3pcs of Peavey Lo-riders which will be of even better initial value.
I was interested in using good pro components for "hifi purpose", initially as an "audiophile" I was still pretty skeptical about pro stuff as they can whack and go loud but are more like lo-fi - ya know the typical kinda thinking? I was listening to one of the local DIYers sys and we were playing with Lowthers, Azura horns/JBL lenses, vintage JBL LE-85, Altec and stuff like that (audiophilia). The dual 2242s kinda caught my attention. I know stuff like Emerald Physics CS2, WLM loudspeakers and some higer-end hifi dabble in such a way too but at an exotic price. The EP CS2 got the best sound of the show, better than quite a lot of silly priced audiophilia stuff (all at high SPL). WTF? Its just Eminence 15 Alphas OB and Sel D220 Titanium with cheap opamps DCX2496, every single audiophile rule is broken. That goes to show how a good and very optimised engineered drivers + implementation can perform in a certain situation. After hearing the 2242s I never looked back.

PS. You are EQing the 18sound right?

But I was "bitten" too, the Beyma AMT-150 did not meet my expectations - though it is one of the best in the mids/uppermids, lower treble (it sounds better than horn loaded and still maintains that dynamic/punch presentation of horn loading). EQ / tweaking does not fix anything.
Check out the price too.
http://www.usspeaker.com/beyma%20tpl150-1.htm

impressive non-EQed measurements!

SVS pb-13U can really dig low down to 6 hz

You have incredible room gain actually!

I'm thinking of scraping this whole audiophile thing altogether and going pro audio all the way with my system.

Pro audio is the "dark horse" in the game

DL86, you would have to understand as you dig farther down into infrasonics, even with very accurate compensation values for your mic in REW, the computer/notebook input electronics would probably be inaccurate. But seriously I don't think anyone needs much accuracy over there that low down, as long as you know you are getting output.... LOL!

You have to be careful with the pro stuff. I have a pair of Beyma 10MW/Nd vented, whenever I exceed 100dB/1m for 1 cab and 105dB/1m for the other (approx) I'd get some funny rattling distortion kinda sound suddenly, its as if the magnets inside are loose and rattling with some midrange kinda noise. I'm not sure what is happening, but I will try to put some superglue on the individual neodymium magnets and see (i can't close the vents between the magnets as they serve as cooling holes). Can't be both drivers are faulty at the same time, I believe its a design flaw. As you can see its not a 100% hit all the time even with EXPENSIVE drivers.

I'm not letting that bother me, since I am enjoying the Lambda 15s so much that the Beymas don't get any play time at all. But one fine day when I am free I shall fix it, so that at least the $$$ is not wasted (can't sell DIY for nuts over here in SG). Trying to earn as much money as possible while the chance/opportunity is still available!

The Beyma CP380/M is a very good driver, you can try that.
Or use the Neo version the 385Nd, but seriously i believe they are around the same. Do it active with EQ, no issue with the funky impedance peaks and whatever different horn compensation needed for whatever horn flare you choose. You should try the Lambda TD drivers from aespeakers, they are very very good and most importantly don't cost much. Do a search, they are used all over the place in many designs over here and DIYA.

I have been using pro drivers for several years and I doubt I will ever go back to typical audiophile drivers. However, some are a lot better than others for this application and there isn't as much info out there so research and choose carefully.

As an AE driver owner like 2100, I would highly recommend them.

first, awesome build!

second, awesome build!

third, have a look at the 12nmb420. it has a lot going for it (ruler flat frequency response, low (and most likely ruler flat) inductance, high efficiency, good magnetic damping, i can't find distortion plots (but given the design, my guess is that distortion is very low), curvilinear cone, sufficient power handling capability)...i really can't find anything wrong with it. flawless?

that sub is CRAZY !

DL86,

Do you have any updates?

How are you liking your sub?