Ever have a Dayton RS driver leak around phase plug?

[looneybomber]

I have 3 of the 4 drivers in my Dynamic 4T with an air leak around the phase plug. These have been used very little and have leaked since I installed them. Is this a common problem?

http://www.youtube.com/watch?v=gsC2FH-GQvU

[5th element]

Oh indeed they do. My RS225s leak quite badly around the phase plug. Of course the smaller the sealed box that you put a reference driver in the greater the pressure will be. Mine are in a tiny ~10 litre box, I'd imagine that the chuffing around the phaseplug would be far less of a problem if they were in a more conventional box of say around 40 litres. Is the dynamic 4T sealed?

[looneybomber]

Is the dynamic 4T sealed?

Nope, but they leak regardless if it's sealed or ported. In the vid I sealed the port since 30hz (the sine wave used) is below tuning.

[Jed]

Out of the 12 RS180s you own, how many are making mechanical noise?

Personally, I wouldn't except audible distortion, and I'd have them replaced under warranty. Although I'm not sure how loudly you're playing the 30hz tone or whether it's exceeding xmax of the driver.

As I mentioned on my forum, if you need me to help just shoot me an email. I'm also curious what PE's response will be to your inquiry for warranty coverage.

Jed

[cjd]

There is no seal there, just a long difficult path for the air.

I've never ever heard one make noise as a result of air movement, and I've pushed the HECK out of the drivers I have (way past xmax - I did finally find xmech on the RS270 and still no chuffing that I remember, but it was scary how hard I had to push things.

[looneybomber]

Well, so far 5th Element says leaks are normal and CJD says no way. I guess I expect them to be whisper quiet like my TD15h's. I should have made this a poll to see what the consensus is.

Out of the 12 RS180s you own, how many are making mechanical noise?

Not tested the other 8 yet. Been home for an hour and now it's bed time for both me and the kids. I don't know if I will have time tomorrow after work to get any more tested.

Personally, I wouldn't except audible distortion, and I'd have them replaced under warranty. Although I'm not sure how loudly you're playing the 30hz tone or whether it's exceeding xmax of the driver.

Only using a 30hz test tone at near maximum vol on my receiver (~20-25w/driver) to bring out the noise. Although the chuff is audible in some songs, which is how I heard it in the first place...and I too find it annoying.

As I mentioned on my forum, if you need me to help just shoot me an email. I'm also curious what PE's response will be to your inquiry for warranty coverage.

Jed

I just dropped them an email. I will keep you posted. Thanks.

[cjd]

I say leaks are normal, just shouldn't be making noise.

30Hz at 20W on the RS180 may bring out *suspension* noise. Maybe. Have to run excursion numbers.

[5th element]

Here's my RS225s chuffing in their 10 litre cabinet. Both the left and the right channel do the same thing although the right channel is slightly worse then the left.

http://www.mediafire.com/?j7ue88aq9ru6649

[---k---]

Of course they leak. It is a gap.

30 hz tone at near maximum volume? Sounds like an insane test designed to blow a driver up. I wouldn't be shocked by slight noises at those levels.

Are you really comparing a $50 mass produced driver to a $300 hand built driver?


But, you shouldn't hear anything at normal volumes listening to music. The only time I've heard noise around the phase plug was after being stupid and having the driver in the garage while building the speaker and I got saw dust in the gap. Gentle compress air fixed the problem.

[5th element]

Xmax was not exceeded in that file I posted, the chuffing begins at around what looks like about 5mm p-p. I chose 30hz because it requires less power for a given excursion. Maybe in a 40 litre box you'd get chuffing at around 20mm p-p which does exceed xmax. In my application the chuffing occurs way before any limits are reached, granted I'd never hear it with music playing but still, it's there.

The SEAS W15CY001s I've got do the same thing too, chuffing around the phaseplug when put in a small sealed enclosure. The chuffing occurs way before you reach Xmax.

[looneybomber]

The SEAS W15CY001s I've got do the same thing too, chuffing around the phaseplug when put in a small sealed enclosure. The chuffing occurs way before you reach Xmax.

Yeah, mine too. In a slightly oversized 4T enclosure (not a small box) even at a point 8-9db down from my recording (which puts it around 3W/driver) I get faint chuffing sounds. Granted, at that volume I can't hear it with music, but I can with sine waves.

Side note. They're silent in free-air, which makes me think the gap is clean of debris.

[looneybomber]

Of course they leak. It is a gap.

No one ever talks about them leaking, yet there's hundreds of people that have built Dayton RS based designs. That makes me think this isn't very common, otherwise a lot more folks would ask about it.

30 hz tone at near maximum volume? Sounds like an insane test designed to blow a driver up.

100wpc reciever divided by 4 drivers is within the driver's thermal and mechanical limits. Nothing maximal about it...other than my volume knob being close to it.

I wouldn't be shocked by slight noises at those levels.

It happens at levels nearly 10db lower, but it's much harder to pick up with the mic at that level.

Are you really comparing a $50 mass produced driver to a $300 hand built driver?

It sounds like what you're saying is at this price point we should accept mediocrity? I figured that would be reserved for the drivers 1/10 the price of these.

[cjd]

I suspect most people understand that it's going to leak due to the gap so they don't ask. I always assumed so, anyhow.

100wpc into 4 RS180-8's series-parallel wired at 30Hz is beyond xmax. Sealed.

Only way it wouldn't be exceeding excursion limits ported is if it's tuned to 30Hz.

C

[evilskillit]

I'm no expert but that sounds more like mechanical noise to me. Which I'd expect if you're making the speakers move a fair amount but not making any real audible sound. Could be completely wrong tho. Also I'm guessing with almost any program material what so ever that you wouldn't be able to hear that.

Have you tried generating a similar amount of excursion at the same frequency with the speaker not in a box to see what they sound like?

[looneybomber]

Have you tried generating a similar amount of excursion at the same frequency with the speaker not in a box to see what they sound like?

I did before I installed them. Free-air, they're silent.

[Jed]

What did PE say about the noise? If one of the drivers isn't making the same noise, I'd think that's reason enough to get an exchange for the ones that are making noise.

[baniels]

Well now I'm curious. I haven't noticed anything during normal listening. I will check my 8 this evening.

[looneybomber]

100wpc into 4 RS180-8's series-parallel wired at 30Hz is beyond xmax. Sealed.

I'll have to hook up my DMM and measure my voltage and ohms to figure out wattage. I assume it's less than 100w.
*edit* I will have to do this another day. It got misplaced.

What did PE say about the noise? If one of the drivers isn't making the same noise, I'd think that's reason enough to get an exchange for the ones that are making noise.

Tech support emailed me back about an hour ago. He said he has not heard of this problem before and will contact Dayton to see what they have to say.

The wife and kids are gone right now so I'm gonna get to swapping drivers while I finally have time.

*edit* They got home sooner than expected, so I was only able to take the old drivers out and test four new ones.

Of the four new ones (two still sealed NIB), one makes quite a bit noise. It's noticeable from 1ft away at -18db down from the volume level in the video. At -12db it develops the high pitched whistley chuff sound which gets horribly loud as I approach the volume level in the video.

Free air that woofer still produces some noise, but it's of a much lower frequency (arbitrarily throwing out numbers, but think 3rd harmonic (90hz) vs 30th harmonic (900hz) and you get the idea) and to much a lesser degree. Man I wish I had a sound card that would work with REW to get accurate measurements.