Axiom Home Page Forums General Discussion Stereo EP175 vs. EP350

M60s, EP350, QS8s, VP150, Denon 2802. Thought about a 100 watt Sony ES receiver that would only go up to 5.1 - was available at a great price - but just didn't sound as good.

i have basically the same system as you, except for a vp100, and yammi rxv1300. i think this system sounds great, and can surely play loud.
dan

As some of you may remember, chesserroo has been complaining about the port chuff noise from his EP350 during certain very loud, bass-heavy passages.

The other day, I finally "succeeded" in inducing an audible port chuff on my Hsu VTF-3, an allegedly more powerful (and pricier) sub than the EP350. It was with a recording of Saint-Saens Symphony #3 the "Organ" Symphony, 2nd Movement, included in the Boston Audio Society test CD #1.

The organist uses the 16Hz low-C pedal tone quite generously in this recording, and that tone induced a subtle but audible port chuff on my VTF-3. I think it was audible because those passages were otherwise very quiet. I don't know the peak velocity of the air coming in and out of the port during that passage, but when I put my hand at about one foot from the port, it felt like a large blower shooting out the air flow. It WAS powerful!

So... I guess that some port chuffs are a more or less inevitable accompaniment of ported subwoofers. Given that it cannot be completely prevented even in the VTF-3 (arguably one of the "kings" of under-$1000 subs), I guess if you want to completely avoid port chuffs, you probably have to go with a sealed sub -- and of course, high-performance sealed subs are quite expensive.

chess, do you feel better now?

That is interesting sushi.
I don't doubt that many ported subs when pushed loud enough should produce some amount of port chuff, unless of course the port is 18" in diameter for a 12" woofer.

You are certainly the first person i've heard from that has mentioned this issue with a Hsu sub.
I don't know why the EP350 seems to hit the low notes for me with chuff and yet has not done so for others using similar settings.

You are right in that the best way to determine whether your sub will produce any amount of chuff is to use a quiet but low note passage from music or dvd (LOTR- Mines of Moria --goblin drums works well for my example).
Keep cranking up the gain on the sub until you hear it and you will get an idea of how much it takes to produce the chuff.
Using the LOTR piece, i can produce chuff using a volume settings as low as 25% on the EP350.

So you both have to try real hard (Sushi a little harder) to create that port chuff. Seems like you're picking nits. My only prior surround experience was a cheap Sony receiver we bought Dad in the early 90s, playing Pro Logic through the Jensen surrounds that Circuit City threw in for free. You can imagine the honeymoon period I'm going through now with this Denon/Axiom set-up.

BigWill, yes, we are (at least I am ) definitely picking nits. I have absolutely no complaints on the performance of my VTF-3. It was more of a curiosity-filling moment for me.

chess, the LOTR passages do NOT produce chuffs on the VTF-3, at up to the reference level. I guess in order to produce port chuffs, the bass signal has to carry a lot of amplitude at near-Fo (port resonance) frequencies, which is 16-20Hz in the case of the VTF-3, operating in the max-extension mode.

Bigwill,
There is no nit picking here.
I think you misunderstand just how easily my EP350 creates the noise.
A 25% gain setting is not large. In fact, i reported in my original post that i had tested the gain at 10-15% (8 oclock mark on the dial) and still heard the chuff but to a lesser extent, although still audible.
The port chuff is created with my onkyo set at a typical listening level for me, around 65 on the 0-100 scale which for an Onkyo 797, is not that loud.
That EP350 should be able to handle the LOTR passage i mentioned as easily as the Hsu subwoofer, but it doesn't even come close.
Some people have mentioned they have had no problems whatsoever with the EP350 and a handful of others have also described the occurrence of the noise and therefore managed to create the port chuff with very little effort.

I've done everything i can think of short of drilling a new, third port hole in it.

For near a thousand dollars Canadian, i'm a bit disappointed. BUT that is not to say the sub doesn't pump out some solid bass otherwise. It rattles my upstairs, 2 floors up, almost as if you were in the basement.
During loud playback or 'busy' movie scenes, you cannot really notice the chuff since it is drowned out by other noise.
Quiet passages that use rumble (starting of a volcano/earthquake in the background, TRex foot coming down during Jurassic Park when the kids are in the car, goblin drums in LOTR in the mines when all is quiet listening after the armour suit fell down the hole, etc.) make the chuff EXTREMELY audible and this takes away from an otherwise quiet scene.

If i turn down the gain, i lose the rumble. If i turn up the gain i get the port chuff. The sub needs to handle it better in my opinion.

I heard something ugly out of my EP350 last night during Blade II, but the wife gets annoyed when I start fiddling with things during the movie, so I just turned its volume down a little. It didn't sound like wind, but I'm guessing that noise is the same thing that comes out of yours.
By the way, I have appreciated your insight and patience with my prior questions - you should be on the Axiom payroll.