7.6 cu.ft Maelstrom- X 18" build

**sub_crazy** · **09-28-09, 02:30 PM**

Quote:

sub_junkie wrote:

I also found a small cracked piece of drywall in the corner of the sub.

Only a TRUE bass junkie would be happy about cracked drywall............Nice job

**sub_junkie** · **09-28-09, 03:11 PM**

I'm not necessarily happy about it, I just find it funny. I gotta get a SPL meter and see what the dB's are in my closet on the supposed 6hz and 11hz tone of Bass I Love You and the 16hz on The Bass Will Destroy You. It almost feels like your eardrums are going to explode. For some reason, the very low frequencies are magnified in there... It's awesome.

**sub_junkie** · **09-28-09, 09:44 PM**

What would it change if I turned off the Clip Limiter on the Dip switches on the EP2500?

**NEO Dan** · **09-29-09, 12:03 AM**

Did you disconnect the RCA to XLR cable from the MIC2200 or the AVR?
I'd recommend disconnecting the XLR end of the cable from the MIC2200, if the noise goes away that means the RCA to XLR cable is shorting pins 1 & 3 as I warned you above.

**sub_junkie** · **09-29-09, 12:47 AM**

I had disonnected the Sub out RCA cable from the RCA to XLR cable going to the MIC2200, but I haven't disconnected the RCA to XLR cable from the 2200.

I just disconnected the Sub out RCA from the one going to the 2200, and the noise changed. I disconnected the input cable from the 2200, and the noise was gone. That means I have a bad RCA to XLR cable, right?

Thanks for solving my problem

**sub_junkie** · **09-29-09, 10:07 PM**

I just called B&H Photo, and they are sending me a new cable for no charge. It's the same one, so hopefully that will solve the problem, and that the problem doesn't lie in the way the cord is made itself.
My 150w plate amp would put out less watts is 4ohm rather than 8ohm, correct?

**NEO Dan** · **09-29-09, 11:02 PM**

I'd be surprised if the new cable were any different than the one you already have. But hey, at least they were nice enough to ship you out one for free. Brownie points for good customer service. You can re-terminate the cable and fix the problem if you can solder. If you can't solder I can make you a cable, but that's not free

Out of curiosity what AVR are you using in your setup?

**sub_junkie** · **09-29-09, 11:26 PM**

I can solder if needed

Sometimes it's not the neatest job, but it definitely works. Thanks for the offer too

I'm using a cheap Insignia 500w 5.1 channel receiver. I'm looking to upgrade it down the line, but it migh be a while. My dad thinks that now that I upgraded the sub I don't need to do anything else.

But, I have to do what he says, so it might be the end of upgrading for a while. But, there is always birthday's and Christmas'... haha

So you think that the problem lies in the cable not having the correct grounding (I guess, if you want to call it that...cause I don't know)

**sub_junkie** · **10-01-09, 01:54 AM**

Could the bad cable somehow be the cause of the sub reaching its Xmax while listening to a few rap songs? The surround looks like the Anarchy woofer when near its peak.

**Ryan Anderson** · **10-01-09, 08:14 AM**

Quote:

sub_junkie wrote:

Could the bad cable somehow be the cause of the sub reaching its Xmax while listening to a few rap songs? The surround looks like the Anarchy woofer when near its peak.

I think it would be a good idea for you to sit and watch while playing various things for a while so you get a good idea of how much output you get and where your excursion is at doing so. maybe some sweeps too to get an idea on frequency:excursion. Once you get a good image in your head, you'll have an idea just from output and sound to know when you might be nearing limits.

**sub_junkie** · **10-01-09, 11:28 AM**

That's what I have been doing. Whenever I hook up a new amp to something like my old subs, I would watch it, see wha it was doing at whatever volume, and try to remember that that is all I could get out of it. Either way, the Mal-X should be able to overpower my front speakers when they are set a -7 to -10dB and the volume on the receiver is at 70dB, right? Could it just be near its Xmax due to the MIC2200 boosting the pre-out voltage so much? My receiver's sub channel is set at 0-+5dB, and the 2200 is usually set at the same, and the gain is all of the way up on the EP2500.

Either way, I'm extremely happy with my new sub

**Ryan Anderson** · **10-01-09, 09:28 PM**

what I have learned from experience is ignore settings. it is all about what is actually happening. wattage. clipping. frequency.

"so and so had his deck only 1/4 the way up and his gains only 1/2 and it was so loud! I can't wait till he turns the gain all the way up and turns his deck all the way up! It will be so amazing it will blow his windows out and you will hear it 2 miles away!"

settings don't mean much. the RMS your sub is getting is what matters, and at what frequencies. I'll bet you could give it full power from 60Hz on up in bursts with no worries. Try playing full power 20-30Hz above tuning or, I don't remember what you got going on for SSF, but 10Hz below tuning.... all of that stuff means much more. (EDIT don't actually do that! lol. I guess if you're careful, you can try it while watching it but start the volume low and see how high you can turn it before it really starts moving along... will learn a lot)

My first big mistake once I started properly porting, was I didn't realize that when I tuned below 20Hz, excursion becomes a problem in the 30s.... I didn't realize the port stopped helping with excursion above tuning. That was a long time ago. I've learned from my mistakes, and I still am. Hmmm... I wonder what I'm gonna break next.... hahahaha

**sub_junkie** · **10-04-09, 12:17 AM**

Quote:

Ryan Anderson wrote:

what I have learned from experience is ignore settings. it is all about what is actually happening. wattage. clipping. frequency.

"so and so had his deck only 1/4 the way up and his gains only 1/2 and it was so loud! I can't wait till he turns the gain all the way up and turns his deck all the way up! It will be so amazing it will blow his windows out and you will hear it 2 miles away!"
settings don't mean much. the RMS your sub is getting is what matters, and at what frequencies. I'll bet you could give it full power from 60Hz on up in bursts with no worries. Try playing full power 20-30Hz above tuning or, I don't remember what you got going on for SSF, but 10Hz below tuning.... all of that stuff means much more. (EDIT don't actually do that! lol. I guess if you're careful, you can try it while watching it but start the volume low and see how high you can turn it before it really starts moving along... will learn a lot)

My first big mistake once I started properly porting, was I didn't realize that when I tuned below 20Hz, excursion becomes a problem in the 30s.... I didn't realize the port stopped helping with excursion above tuning. That was a long time ago. I've learned from my mistakes, and I still am. Hmmm... I wonder what I'm gonna break next.... hahahaha

That almost sounds like what my dad said when I told him I wanted to order an 18"

Well, what is kinda weird is while listening to Bass I Love You by BassoTronics, the sub is nearing its Xmax (or what is looks like to me) on the most of the other higher tones besided the 6hz and the 11hz tones. It looks like that on the 30-40hz tones. I will try to take a video of it playing Bass I Love You, Throw It Up Chopped And Screwed, and see if you guys can tell me if it is nearing its Xmax or if its just distortion from other things, etc... But, I know it's hard to tell what stuff is doing when its not in person, but maybe someone can give me a guideline or something, possibly.

Thanks again for the help everyone.

**Ryan Anderson** · **10-05-09, 09:37 AM**

Quote:

sub_junkie wrote:

Well, what is kinda weird is while listening to Bass I Love You by BassoTronics, the sub is nearing its Xmax (or what is looks like to me) on the most of the other higher tones besided the 6hz and the 11hz tones. It looks like that on the 30-40hz tones.

Thanks again for the help everyone.

well let me elaborate on my story. The first time I actually designed a ported box using software ( for years and years up until then I dropped ports in boxes and called it good, cut them shorter, made them longer...just played) I tuned to 19Hz and used it in-home off my PC before trying it in the car. At that time, I thought I could set my power (volume) by playing at the tuning frequency and bringing it to the highest excursion I felt was safe, set my sub sonic filter just below that, and I wouldn't have to worry above that. I bottomed the driver playing with test tones because I didn't realize the port doesnt help with excursion very much as you get further away from tuning... I thought since excursion gets so much smaller from playing 20Hz to 40Hz in a sealed enclosure, that I would be safe from 20Hz on up.

Not true! The port helped from say 17Hz to 25Hz, then not so much... so when I got up to 33-36 I am guessing, excursion was back up.

I now know.

So, in your case, you're tuned even lower... so you get even less port help up "high" in the 30-40Hz range. Have you messed with plotting software yet to help visualize everything?

**sub_junkie** · **10-05-09, 06:38 PM**

Yes, I modeled quite a few things in WinISD. I found out that I would need to run a minumum of 3100w to make it reach its Xmax at 24.40hz. To reach it at 30hz, I would need 3600w. 40hz would need 6500w. All of these are asuming at 10hz HPF. Now, I know that the EP2500 can't put out anythig near those numbers, unless the EQ is jacking it up. I checked that in WinISD, and with running 1950w, the Xmax was at 37mm at 21hz. Anything above 27.48hz is in check with the Xmax. That is atill running at 10hz HPF.

There's no way that this problem can't be associated with my bad cable, right?

Thanks again for the help everyone. I really appreciate it.

**NEO Dan** · **10-05-09, 06:45 PM**

Time to engage the common sense button and back off a bit throttle jockey

**sub_junkie** · **10-05-09, 06:59 PM**

That's what I did as soon as I heard the distortion as far as I could tell. I am NOT going to hurt my sub haha

**Ryan Anderson** · **10-05-09, 07:36 PM**

Quote:

sub_junkie wrote:

Yes, I modeled quite a few things in WinISD. I found out that I would need to run a minumum of 3100w to make it reach its Xmax at 24.40hz. To reach it at 30hz, I would need 3600w. 40hz would need 6500w. All of these are asuming at 10hz HPF. Now, I know that the EP2500 can't put out anythig near those numbers, unless the EQ is jacking it up. I checked that in WinISD, and with running 1950w, the Xmax was at 37mm at 21hz. Anything above 27.48hz is in check with the Xmax. That is atill running at 10hz HPF.

There's no way that this problem can't be associated with my bad cable, right?

Thanks again for the help everyone. I really appreciate it.

hrmm... if your modeling is correct, then it sounds like youre getting more power than you think... your amp is rated RMS, so driven into clipping ( I think you said it's indicators are saying it's not though?) it can put out considerably more.... but yeah, volume check!

**sub_junkie** · **10-05-09, 07:39 PM**

You are correct. When the sub looks like its at Xmax, the EP's clip lights are not on.

**sub_junkie** · **10-05-09, 09:11 PM**

I forgot to put in my post about the 1950w being at 37mm Xmax at 21hz. That was also with a Parametric EQ at 15hz, with a Q or 1.2, and a dB gain of 5dB. That was incorrect. I had thought that that was what it was set on, but the fc was supposed to be set at 10hz. When its set at 10hz, the Xmax is in check until 12.93hz.

Just wanted to clarify that.

**Ricci** · **10-06-09, 12:20 PM**

I modeled things and you should be fine with most content even with 2000w. However here's the deal, things are not as simple as they are made out to be in a modeling program.

In your alignment there will be 2 spikes in impedance one above and one below the port tune because it's a resonant alignment. A sealed system will only have one. Higher order systems like BP 6th, BP 8th, TH, etc will have 3 peaks or more. The upper impedance high point will occur at about 29hz in your system and should be above 20ohms from 28-31hz, which is a very bass rich region. What this means is that your sub is very efficient right there and the high impedance above 20ohms means that very little actual power is needed to get the subs cone moving like crazy. Only a few hundred watts. Model your sub in WINisd and then look at the impedance tab and the amplifier apparent voltage tab to see what I mean. Then there is also the fact that heating in the vc's and impedance rise can change things as well. Under the driver tab add 140deg to the vc's and watch what happens. If the EP2500 can supply 200w or so into the drivers impedance around 30hz then yes it could cause over excursion.

Also what are you using for a HPF? You'd be safer with it moved up a little to 12 or 13hz. You could get a high level 10-12hz transient that could cause problems if you've got it cranked. It's probably not likely but hey....I'm throwing it out there. Also notice that the second impedance maximum is well below your tuning at about 8.6hz. It requires virtually no actual power applied to the driver there to make it go crazy. 55w applied to the driver at 8.6hz gives 45mm excursion. This is another part of the reason it is ill advised to run a resonant system much below tune.

**sub_junkie** · **10-06-09, 02:53 PM**

Can I fix any of those issues?? And, even though the HPF is set at 10hz, the bottoms out on the higher fc's in Bass I Love You. It looks well within its limits on the 6hz and 11hz tones even with EQ set at 10hz with a Q of 1.2, and a dB gain of 6.

**Mike P.** · **10-06-09, 04:24 PM**

Quote:

EQ set at 10hz with a Q of 1.2, and a dB gain of 6.

You're boosting 10 hz with 6 db?

**sub_junkie** · **10-06-09, 04:53 PM**

A 10hz HPF setting

http://i111.photobucket.com/albums/n.../MIC2200/1.jpg

**Ryan Anderson** · **10-06-09, 06:22 PM**

Quote:

Ricci wrote:

I modeled things and you should be fine with most content even with 2000w. However here's the deal, things are not as simple as they are made out to be in a modeling program.

In your alignment there will be 2 spikes in impedance one above and one below the port tune because it's a resonant alignment. A sealed system will only have one. Higher order systems like BP 6th, BP 8th, TH, etc will have 3 peaks or more. The upper impedance high point will occur at about 29hz in your system and should be above 20ohms from 28-31hz, which is a very bass rich region. What this means is that your sub is very efficient right there and the high impedance above 20ohms means that very little actual power is needed to get the subs cone moving like crazy. Only a few hundred watts. Model your sub in WINisd and then look at the impedance tab and the amplifier apparent voltage tab to see what I mean. Then there is also the fact that heating in the vc's and impedance rise can change things as well. Under the driver tab add 140deg to the vc's and watch what happens. If the EP2500 can supply 200w or so into the drivers impedance around 30hz then yes it could cause over excursion.

Also what are you using for a HPF? You'd be safer with it moved up a little to 12 or 13hz. You could get a high level 10-12hz transient that could cause problems if you've got it cranked. It's probably not likely but hey....I'm throwing it out there. Also notice that the second impedance maximum is well below your tuning at about 8.6hz. It requires virtually no actual power applied to the driver there to make it go crazy. 55w applied to the driver at 8.6hz gives 45mm excursion. This is another part of the reason it is ill advised to run a resonant system much below tune.

It seems no matter how much research you do, the game just keeps getting deeper. Going from experimental days of "drop a PVC pipe in there and see what it does. Cut it shorter, try again. How about a 2nd port?" to playing with WinISD... but now it seems WinISD's main transfer function, excursion, and SPL tab don't tell the whole story either? 55 watts from 8-9Hz? A couple hundred from 28-31hz?

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