Bass Shaker?

[Mike P.]

Ok just got it XMAX is 6mm

Bad news. There is no way these can be used for HT. They are impossible to model ported, and in 3 cu.ft sealed they would take 30 watts to reach Xmax and output drops fast below 50 hz. These are only for car audio and not even good in that application. Sell them, get what you can for them and put the money towards a better sub.

[SAY IT LOUD]

thats ok Mike thanks anyway i only paid $60 for them inc shipping. I like the Mach 5 Audio IXL 18" subwoofer or 12" subwoofer what will give me the best bass for movies? and what size sonotube would you recomend for both applications. Cheers Troy

[Mike P.]

How big is the room and is it open to other areas? Would a 13 cu.ft. sonotube be acceptable if you go with a IXL-18?

[SAY IT LOUD]

I have a dedicated home theatre room with one door 6 metres long and 5 mertres wide. I am going to put home theatre velvet curtains around the room with no shine or lustre im leaning towards matt black and the ceiling will be painted dark grey.

13 cu.ft is too big. the ED subs look very solid with great TPS and xmax now i dont know so can you please advise me of the better sub i will stay with 12" or 15" if i can get away with it.

[Mike P.]

What's the biggest size that would be acceptable?
Are you willing to build a box or do you want to use sonotubes?
What's your budget for subs and amp?

[SAY IT LOUD]

I want 2 sono subs no more than 300L each max i want big bass as i watch alot of action and sci fi movies budget $2K in total

[Mike P.]

A couple of points. The first is the issue of shipping overseas. If there is any problem with a ED sub and you need warranty, you have to pay the shipping back to them. I would advise using a sub that is available to you in Australia. Since you want big bass for of action and sci fi movies, the IXL-18's in 255 liters would impress you. Powered by an EP-2500 would be well within your budget. They would need to be in 500 mm or less diameter tubes to get enough height for there to be enough room between the back of the sub and the end of the port.

[SAY IT LOUD]

thanks Mike good point. I will order the IXL 18 and the EP 2500 and sono tube Next week and keep you posted

[Mike P.]

Will you be building one or two of these? Be aware the port needs to be 8 inches in diameter and 40 inches long. You may also need a HPF.

[SAY IT LOUD]

i will be building two. Can you tell me the length and the width of the sonotube i need? What is a HPF? So a 20" tube L? W? using an 8" port 40" long gives me what Hz? What is the best Hz for movies how low can i go with the IXL 18? I really need all the information to build it. thanks for all your help Mike. Cheers Troy

[Mike P.]

Since it's a 18 inch diameter sub the sonotube would need to be 22 inches diameter to allow for the legs. To get enough height for the port, the net volume would be 270 liters tuned to 18.5 hz. Here are all the dimensions of the build, look it over and see if it's acceptable for you.

[SAY IT LOUD]

Looks good so the formula is 22" sono tube 52.76" L, what thickness will the end caps be? and the ports 8" D and 35.98L results in 18.5Hz is this correct?

[Mike P.]

52.76" is the overall height including the end caps, not including the legs and base plate. The end caps are two .75" pieces glued together, one inside the tube and one outside the tube as shown in the pic. Legs should be 4" long, and you are correct about the port.

A HPF is a high pass filter, it protects the sub from over excursion at the lower frequencies. This design would need one at 14 hz, depending on how hard you push the subs. If you want to get the maximum from the subs, consider the Reckhorn B1 HPF unit. It also has the ability to boost the input voltage from the receiver to the EP2500 if the receiver doesn't have enough output voltage to drive the Ep2500 to its maximum.

You can expect 114.5 db at 20 hz plus room gain from one sub powered by one channel of the EP2500. Two of these in your room would be a real treat.

[SAY IT LOUD]

Thanks for the info i couldnt do this without your help. I can't wait to start building them i don't have the tools to cut the MDF but i can get it all cut for $20 including the recess for the driver. i post pics of the build when i start to finish cheers Troy

[Mike P.]

Sounds good. Start a build thread when you're ready.

[Blueeyedfrog]

Mike, that looks like an excellent design based exactly on Troy's specified requirements.

However, Troy you might like to consider tuning to 15hz (365ltr effective volume). It would only increase the length of the tubes by about 7" or so and of course, would not increase the size of the subs' footprints at all. It would really allow the IXL-18s to dig in deep - perfect for HT. It would also allow you to use the one piece ColloPorts ports (one 6" port for each sub, 22.83" long) which would increase the performance of the overall design (due to the ports having radius flares) by dramatically reducing the chances of chuffing. This would also allow more flexability for the placement of the subs because it reduces the chance of being able to located the sound coming form the subs (due to chuffing). You may find that you won't need a high pass filter either with this design (can someone confirm this?). I have run mine very hard and they don't seem to need one.

Remember, once you get the subs covered with a dark material you won't really notice the size of them with the lights out in your theatre (especially if they are at the rear of the room!). Eg. http://www.hometheatershack.com/foru...ld-thread.html. And being the same size footprint they won't take up any more floor space.

Still, Mike's design will still definitely rock the house if you are really stuck on max size. Just my 2 cents worth.

[Mike P.]

I'll agree. Going bigger and tuning to 15 hz would reduce the chance of needing a high pass filter.

[SAY IT LOUD]

thanks for that sam ok it's worth it to go to 15Hz. yes i can go up i will get 2 IXL 18" off you next week. Cheers Troy

[SAY IT LOUD]

Hey Mike is it really necessary to have BEHRINGER DSP1124P FEEDBACK DESTROYER for HT? Cheers Troy

[Mike P.]

No, it's not necessary. The majority of people don't use one. I will suggest you go with a 8 inch diameter port. The air speed is high with a 6 inch port, well beyond the point of port compression.

[SAY IT LOUD]

ok so ill stay with the original plan 52.76" L and ports 8" D and 35.98L for 18.5Hz or are you saying change the port to 6"?

[Blueeyedfrog]

If you stay with the 8" ports you'll need a slightly different length than Mike's original recommendation. A change in (8") port length, combined with change in enclosure size, is what you need to change your tuning from 18.5 to 15hz.

Mike, you're right re the 6" port airspeed and compression but that is only for ports without flares. According to Collo's flare-it software, radiused 6" ports should be chuff free: http://www.subwoofer-builder.com/flare-it.htm

Can't say I've experienced hearing any chuffing but I stand to be corrected.

Added benefit with going with the flared 6" and 365 litres at 15hz is that you can get 2 sonosubs out of one length of 3 metre sonotube, thus save a bit of cash. However, if you can get the tube length down under 1.5 metres using the 8" ports then either solution (8" unflared or 6" flared) should be acceptable (i.e. equally economical).

Sam

[Mike P.]

No, I'm saying 365 liters tuned to 15 hz with a 8 inch diameter port. Going with the bigger volume will give you much more low end output and it's the reason I originally asked if 13 cu. ft. was acceptable. You'll be glad you changed your mind. Here's a comparison between the two models. The 365 liter model has a 7 db advantage at 15 hz, which is substantial.

[robbo266317]

Hi Mike, The link doesn't open for me?

[Mike P.]

Which link?