So today I finally got my custom ordered eD sub, an A2-300 without an amp. It's also got an upgraded O-series driver which is rated at 400w. After happily dragging it in from my front porch I hooked it up to my Crown 402d (300w per channel) and started setting it up through my receiver with a sound level meter. (The Audyssey setup kept telling me there was too much ambient noise so I had to do it manually.) I started to turn the trim up, but when I got to +10.0 dB (which did not sound loud at all) the sub stopped rumbling and started making a sound very similar to a light wind. What the heck happened??:eek:

Did I get a bad sub, did I break it or what? It's definitely not working. I tried the "emergence" scene in War of the Worlds and got nothing. I tried reversing the polarity on the sub but that didn't fix the problem. Could the problem be the gain control on my amp (I had it on 100%)? I was under the impression that I could give it a heck of a lot more power than 300w.

This really stinks.

How do you know something didn't happen to your amp? Try hooking up the sub to one of the main channel outputs of your receivers amp. Make sure the receiver is set to play that channel as "large" in the bass management. See if the sub plays. If it does, it means your Crown is at fault.

So today I finally got my custom ordered eD sub, an A2-300 without an amp. It's also got an upgraded O-series driver which is rated at 400w. After happily dragging it in from my front porch I hooked it up to my Crown 402d (300w per channel) and started setting it up through my receiver with a sound level meter. (The Audyssey setup kept telling me there was too much ambient noise so I had to do it manually.) I started to turn the trim up, but when I got to +10.0 dB (which did not sound loud at all) the sub stopped rumbling and started making a sound very similar to a light wind. What the heck happened??:eek:

Did I get a bad sub, did I break it or what? It's definitely not working. I tried the "emergence" scene in War of the Worlds and got nothing. I tried reversing the polarity on the sub but that didn't fix the problem. Could the problem be the gain control on my amp (I had it on 100%)? I was under the impression that I could give it a heck of a lot more power than 300w.

This really stinks.

er... kinda sounds likes you had the voice coils hooked up out of phase or something.... might have blown it, or it might've been defective to begin with, or it could've been your amp. Gotta try the driver with a different power source to be sure.

and what were you doing at +10db? :)

are you saying that the sub stopped working playing test tones from the receiver?

and what were you doing at +10db? :)

are you saying that the sub stopped working playing test tones from the receiver?
Yes, it was during the test tones. The sub wasn't playing loud enough to be heard so I figured I'd have to turn it up a bit. Really, it wasn't playing very loud.

The amp appears to be working as normal, but I'll try connecting to to another source.

Yes, it was during the test tones. The sub wasn't playing loud enough to be heard so I figured I'd have to turn it up a bit. Really, it wasn't playing very loud.

The amp appears to be working as normal, but I'll try connecting to to another source.

Just make sure the voice coils aren't wired out of phase or this can happen, heh:

http://blog.edesignaudio.com/?p=265#more-265

I just tried another amp for the sub and now it's working just fine. So it looks like there's something wrong with the first amp I used. Can speakers do something to an amp? Before I tried using a different amp I re-wired everything to determine if I was out of phase but that didn't do anything. WTF??

it's possible you fried the input on the 1st amp by sending a +10db signal?

it's possible you fried the input on the 1st amp by sending a +10db signal?

Since it is a pro amp I doubt it, after all he was just sending the test noise to the amp -30dBFS, but could be I guess...

I think it is just a bad amp, exchange and you should be just fine, warranty on the amp is 3 year no fault.

Keep sending +10db signals and the gain at Max and I will bet my house you blow either the driver or your amp or both.....these subs are designed for high output NOT abuse.

Yeah, 100% gain on the sub and +10 db is a recipe for disaster. You should stick to no more than 2'oclock on the sub gain and definitely less than +10db on the receiver setting.

Just make sure the voice coils aren't wired out of phase or this can happen, heh:

http://blog.edesignaudio.com/?p=265#more-265

Love that video!

Yeah, 100% gain on the sub and +10 db is a recipe for disaster. You should stick to no more than 2'oclock on the sub gain and definitely less than +10db on the receiver setting.

Actually, for a pro amp you may need to use the +10db on the receiver for it to pick up the signal but definitely less then 100% gain on the amp.

Yeah, 100% gain on the sub and +10 db is a recipe for disaster. You should stick to no more than 2'oclock on the sub gain and definitely less than +10db on the receiver setting.

Well obviously I'm ignorant on the subject. I've always set the gain to 100% on all channels of my amps, which also power the left, center and right speakers. Should I set the gain down on those too? What the heck does gain do anyway? I figured it just determined how much power the amp was using, so 100% gain seemed like it was just outputting 100% of the power, which is what I assumed it was built for.

I didn't think I was stressing the system because the sub just didn't sound that loud. Live and learn, I guess.

Well obviously I'm ignorant on the subject. I've always set the gain to 100% on all channels of my amps, which also power the left, center and right speakers. Should I set the gain down on those too? What the heck does gain do anyway? I figured it just determined how much power the amp was using, so 100% gain seemed like it was just outputting 100% of the power, which is what I assumed it was built for.

I didn't think I was stressing the system because the sub just didn't sound that loud. Live and learn, I guess.

Out of curiosity what kind of readings were you seeing on your SPL meter?

I wasn't trying to diss you with the settings you had. The A2-300 getting fed 300 watts at +10 db with 100% gain on the sub would shake everything so hard and would put alot of wear and tear on your driver and amp.

Is your Crown amp fried or have you gotten it working again? Also, what did you have your sub cross-over set to? I'd recommend 80 Hz if you can set it to that to avoid sending your sub signals above that threshold.

lennon, The SPL meter showed much less than <0dB. I think it was set to 70, or whatever the correct setting is for the rest of the speakers..

Maytime, I didn't take your comment as dissing at all. Shoot, I'll own up to my stupidity here. I should've researched the gain thing more thoroughly. But it was never shaking the house very hard. I'll try the amp again tonight, perhaps with another speaker. Who knows, maybe the phase was wrong on the speaker wire.

Can anyone tell me what gain level I should set the other speakers to?

Contact Crown.

For the non-proamp users, the "gains" on pro amps are actually attenuators starting at -0db and going down from there. Because home audio and pro audio voltage levels differ, it's not unusual for home users to have the gains all the way up.

Secondly, just because the "trim" was at +10db, does not mean the master volume was at -0db, nor does it mean he was playing a -0db sine wave. Had either the MV or the source signal been -11db or less, he'd still be outputing less than a reference signal to the amp. For example, -30db signal, -0db MV, +10db sub trim = -20db output to the amp. Does that make sense?

Can anyone tell me what gain level I should set the other speakers to?

-Play multiple -0db signals or sweeps from your DVD or any other source of equal output.
-Make sure that signal is not clipped.
-Then turn up your receiver/preamp and note at what volume it makes your outputs clip.
-Turn your preamp down .5db-1db, which ever it lets you do.
-Double check to make sure it's not clipping.
-Turn up the gains on your amps till they either clip, or you think you're going to blow your speakers.
-Now, level match all your speakers and sub(s), using the one that will clip/blow first as a reference. In other words, if you have to set the center at +3db, instead, turn everything else down -3db and keep the center at -0db.

Now when you play anything, you can crank up your system and know that if anything is recorded at reference, you can turn your receiver/preamp up to -0db max! Anything past that will put your system at jeopardy. Otherwise, if anything is set to +2db for example, then you will only be able to turn your receiver up to -2db. Make sense?

Phew!

I turned the gain way down on the first amp (that I thought was damaged) and reconnected the sub. I then went back into the receiver's test tones and the sub/amp works again! If I were to guess, the amp automatically shut off when I got to +10 dB and would not reset itself until I turned the gain down. I'm now at 2 o'clock and everything (thank God!) is working again. I'll try to run Audyssey although it's been giving me a lot of "Too Much Ambient Noise" messages so I don't know how far I'll get with that.

It's actually a good thing this happened now while I was only feeding the sub 300w instead of tonight when I planned to bridge the amp and give it 900w!

I'm glad it worked out and nothing was damaged. The sub thanks you for not sending it 900W I'm sure ;)