[Navydoc]

I have finally gathered all materials (sans MAL-X driver) to build a 24" cube (based on NEOdan's cutsheet). After reading tons of threads I am torn between sealed (my original plan) versus adding 2 of the EX-PR18 PRs to the box. Since I am ready to glue (all parts cut) I must decide. The deal that Kevin has posted on the driver + PRs looks pretty good when the MAL-X is back in stock.

Room is rather large (24 x 35 x 8) so output is important. I primarily listen to music (60%) and watch movies (30%) / concert DVDs/Bluray (10%). Musical taste is varied but I listen to a lot of 70s hard rock and traditional jazz (probably a weird combination). Volume is usually - 10 dB from reference, but occasionally will play at reference if no one else is home. For amplification I am leaning towards a Crest Audio CC2800.

Any advice would be great, I tried to model on WinISD but couldn't figure out how to model PRs.

Thanks

 

[Navydoc]

Thanks for the simple explanation.

How do I calculate the required mass for each PR? I know the mass effects the tuning but do not know/understand the math required to calculate. Would like the have good bass extension - but don't want to have extreme power requirements due the the sub producing the deep bass.

What tuning would you suggest and how much mass is required on the PRs to get to that tuning? With the extra funds required for the PRs will need an inexpensive subsonic filter - any suggestions?

Thanks again for the advice. I want to build the PR-version, just need some clarifications.

 

[Navydoc]

I'd push the size up a little if you go PR. You want about 7-9 cubic feet. You are going to load it up with mass based upon the size of the enclosure but your tune will be around 17-18Hz.

This would be difficult as I already have started construction using NeoDan's 24" sealed cube cutsheet. All materials are cut, ready for assembly.

With this driver, you need power. Basically, if you have a lot of stroke, running in realistic sized enclosures and designed for 1st/2nd octave, you need the power to utilize it. There is no way around it.

As you indicated power is relatively inexpensive, I could spend less on an amplifier (go w/ EP2500 vice Crest Audio) to free funds for other expenses of PR compared to a sealed design (low pass filter, PRs, etc).

In terms of inexpensive, I'd advise the following. I'd either build it with the right parts or build something else that requires less power. Personally, I'd not build a sub without EQ & room measurement tools. It can make a significant improvement in sound quality. The SMS-1 is my standard recommendation because of flexibility and ease of use and it has a variable subsonic filter for a resonant build. The EP-2500 is less than $300 street price. Between the two of them you have < $700 invested in power, room measurement, and all the signal processing you need. If that is out of your budget, I'd aim for a less expensive sub that doesn't require the power of the Maelstrom.

Kevin Haskins
Exodus Audio

Seems to me that to stay close to my original budget, I should stick with my original sealed plan and add an EQ/room measurement tool. Lots of people are happy with the sealed sub. I am replacing a 10-yr old Paradigm sub, so no matter how I proceed it will be a vast improvement.

Thanks again for your assistance!

 

[Navydoc]

Congrats on the start, the Mal-X's in a 24" sealed cube are fantastic and will really put out tons of excellent clean powerful bass.... providing that they are powered properly.

If I may make a suggestion, I have 3 of these in a very very large room, 1/3 larger then yours or better. If I were you, I would shoot for an amp larger then the ep2500, I tried using them and they kept clipping everytime I would get close to the output I wanted from them. It was impressed upon me that I would not benefit from larger amps, stating I would only get a touch more output from them before I smacked them to bits. Regardless I knew I was amp limited. I went out on a limb and bought 3 - Crest 8002 (4000w bridged) - overkill to be sure.... every and all problems I had were long gone, and I could be happier with this combination. The amps aren't set even close to full output but they provide me with tons more headroom and aren't struggling to power my subs....

The Mal's can handle much more power sealed - almost beg for it... You will get much more output with a bigger amp then EP2500's

Depending on how much output you are looking for, you may want to add a second Mal-X for that size room.

Thanks for the advice. I have been looking at the Crest line (CC-4000 (4000 watts bridged into 4 Ohm) or the CC-2800 (2800 w bridged)). Decided to go sealed w/ either the Reckhorn B-1 or the Elemental Design eQ.2 (I am leaning towards the ED). Started gluing the box this weekend - lesson learned is that you can NEVER have enough clamps! I am taking photos and may start a build thread when completed.

 

[Navydoc]

Did you check out the BFD? If so, what didn't you like about it? On the two units you mentioned, I would enjoy the ability of reaching up and twising a good old fashoined knob. On the other hand, the BFD has so many more channels, plus you can save settings...

Sorry it has taken so long to get back on the board, extensive travel for my job and honey-do lists.:dizzy:

The BFD looks to have a steep learning curve, I am looking for simple solutions. The two-band ED looks quite capable but I am concerned about the turn-on thump warned against in the manual. I don't think I need the gain of the Reckhorn, I have not seen that people have had troubles with Onkyo HT receivers friving pro amps.

I did settle on going sealed (my original plan) and completed the enclosure over the 4-day weekend.