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Discussion Starter · #1 ·
About four months ago I built a test box(23.5" cubed-sealed) for my new Tempest-X and EP2500.

Then I broke my wrist and was casted. Just after getting my cast off I was jumped and robbed and broke two ribs.


I am finally in good enough shape to build my ported enclosure.



Want to use .75" MDF. I will reuse any panels I can from my sealed box as well.

I tried, when new, to calibrate my sound card and then take readings, but never figured it out after spending time and money.

I'm afraid I still wouldn't be able to do it successfully without a step by step walk through which is a pain in the ass for anyone.


So....anyone want to step in front of the bus to help?
(have tons of room to work with, but a salways the smaller the better unless it robs performance)
 

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I used removeable panels for my test box. It enables me to go from sealed to ported very easily and it gives me a range of tunings from 33hz down to 12hz or so.


I used bolts, washers and wingnuts to secure the panels and I used three 4" pvc elbows for the ports.


Oh sorry to hear about your bad luck.
 

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Discussion Starter · #3 ·
My test box is already built and has been for months. It will have to be deconstructed.


But that is a good idea for future projects, thanks!(are you the one with handles on the one test box?)
 

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What a run of bad luck - I'd wondered where you'd gone!! Welcom back


As I recall, we each got our Tempest Xs and Radio Shack SPL meters at roughly the same time. I had no problem getting REW set up and running with the SPL meter, to the extent that Santa brought me an EMC8000 and mixer for Christmas. That they remain unused is more a result of my focusing on completing a pair of NatP's towers (1 down this weekend, one more by the Super Bowl, then we measure).


If you're using Room EQ Wizard (a real wizard, not the kind Microsoft foists on us), everything you need to know is here:
http://www.hometheatershack.com/room...tml/index.html


The hardest part for me was figuring out which of the 10 sound card connections was L and R, input and output. Once I had the sources/sinks identified, and got the right signals going in the right directions, it was quite straight forward. One reason I haven't dived back in with the EMC8000 is that I want to finish the second tower and compare the full LCR set to just a center with 35 year old Advent mains.


By the way, I found that the sealed box sub did fine in my room at my main listening position with just a little EQ from the Oaudio plate amp PEQ. I would assume with an EP2500 you'd also use a more advanced EQ, and REW has the ability to model EQ and communicate the settings to the DSP.


While EQ isn't a panacea, you've got plenty of power to drive the Tempest X and overcome the small-box limitations. I recommend exploring what you've got before cutting up the old box. You already spent that money, work the investment a bit before spending more.


If the link isn't helpful, PM me and we can talk specifics off-line. I can take you as far as frequency response, and helping you may teach me more than I know now - yes, this is a blind-leading-the-blind offer!


Have fun,

Frank
 

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Discussion Starter · #6 ·
Thanks Frank!

I actually have read all that info roughly four times.(I do have Room EQ downloaded)

I went and bought the needed equipment in order to use my now aging tower to calibrate, but could not get it right.

That is when I broke my wrist.

In the meantime I still couldn't figure out what I was doing wrong....this is why I said I basically need a walk through in simple terms or I'll stay stuck like the dummy I am.



While the sealed does sound superb throught the whole frequency range I use it for, it is just a little lacking from 40Hz-70Hz. I'm hoping I can make up some dB's there and not lose much lower.

My room is bigger than I thought....it is ~3700 sq. ft. to fill.

I would get a second driver, but I decided to wait until I move in the not too distant future.


I forgot that I will need to buy an EQ for this since going ported.(I had a cheap one before eQ.2 but ditcched it after finding I didn't need it with my sealed set-up after some test listening)
 

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Quote:
Originally Posted by evilbeaver /forum/post/15532190


I think thats Ricci but mine has handles too.

Yep. Gonna do another better one come spring. Do you have pics or a build thread on yours? I'd like to see what you've got going on. Maybe I can co-opt a few ideas for the next one
.
 

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Discussion Starter · #9 ·
I had a 16 day period(two weeks off) where I watched I believe 19 movies and even played a couple video games from BB on my PS3.

It was fun for awhile, but then I got super bored not working....and ribs are a real pain in the butt.


By the way, thanks guys for the words! The wrist happened while playing human jungle gym with my young neices at a family picnic, but the ribs were from getting beat the heck down by five young guys who robbed me....so that stunk much worse as it hurt the ego too.
 

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Ricci - I'll need to take a few pics when I get home. I have a few things I would do differently if I build another one.

My box uses an upfiring configuration and clamps to secure the driver which allows me to remove and swap drivers easily. The big problem is that I built a tall box. Trying to pry a Stroker Pro out of it was a major pain in the a$$.


I'd also like to incorporate a system inside the box that allows me to modify box volume easily. Probably more panels to cover up bracing.
 

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Quote:
Originally Posted by E-A-G-L-E-S /forum/post/15532292


Thanks Frank!

I actually have read all that info roughly four times.(I do have Room EQ downloaded)

I went and bought the needed equipment in order to use my now aging tower to calibrate, but could not get it right.

That is when I broke my wrist.

...

I was using a brand new PC, but 7.1 capability just made it harder. The only calibration I recall doing is a loop back so REW could calibrate the sound card, and that was a small effect. Uploading a mic/meter cal file was straightforward (I can't comment on cal file accuracy). Setting average sound levels was as well. It was easy to do, but then I had limited objectives - make sure my new sub was doing what it should, and fix whatever I could with the amp's PEQ.


What do you mean by "get it right?"


Are you referring to REW results or your room integration for the sub? What makes you think you're wrong? (Or did I get somethign wrong and not notice?)


Have fun,

Frank
 

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Discussion Starter · #12 ·
Well, kind of like the movie character "can't get right" in "Life".....I just couldn't get it to work.

I tried the loop but then couldn't even begin in the program for some reason.

Asked for some help and then almost immediately got hurt and forgot about this until now.

Went back to the program and I'm stumped from the start as to what to do.



I was under the impression that figuring out my room response was vital to building a proper enclosure?

Otherwise I'll just use one of the posted builds of ~13cuft and go.
 

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I've been thinking of building a modular subwoofer. A sealed subwoofer of proper size, but with a removable panel where you could add on another box with a port and have the total volume be correct. I'm interested in ideas to join the 2 boxes together and have them seal. I have a few ideas, but nothing I'm completely satisfied with. I'd love to see pics of these test boxes with removable panels.


Dr V
 

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Discussion Starter · #14 ·
So I'm thinking that I'd like a higher tune than the typical 16Hz....perhaps more like 18Hz/19Hz.


I would prefer it to be a standing up design, almost sonotube like but rectangular....with the port above the driver and both front facing.


Maybe ~11-14cuft with 18/19Hz....with what a 8" x 32" port??


**I want to make sure I accomplish my goal: More output from 40Hz-80Hz, while trying not to lose too much below 20Hz as I love the rumble in BR's.
 

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I'm no expert, but given how easily my sound card calibration went, I'd wonder if you're connecting to the right sound card ports. I recall that a) my sound card was very flat and b) you can usually skip the sound card calibration. You do need to use a mic/meter cal file, but that's not self-generated.


I see no real need to "know the room" before making a sub, beyond having enough capacity to fill the volume to the desired SPL.


Frank
 

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Dr. V,


Here are a few pics of mine. Note. This is very rough as it was kind of a proof of concept for me and I built it with very rudimentary tools (skilsaw, jigsaw) in my back yard in 2 afternoons. Plus I'll be dragging it in and out of doors and all over the place so fit n finish wasn't on the list at all. The removeable baffle (for trying different drivers and easy removal of 80lb behemoths) does work and seals fine. I hope to make a bunch of improvements with the second version though.


Sorry Eagles. I hope you don't mind the off topic discussion in your thread.
If you do just say so.







 
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