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Official Rythmik Audio Subwoofer thread - Page 252

post #7531 of 15139
Quote:
Originally Posted by Kruppy View Post

Watch out for dimmer switches or torchiere type lights with a dimmer on the same electrical circuit. I had some very audible buzz until I shut off my light.

Well the only thing plugged into the same circuit with anything like that is a three way light and as far as I know there are no dimmer switches on it.

Tomorrow with an extension cord I am going to try a different outlet and see if it keeps happening.
post #7532 of 15139
You mentioned your house wiring is from the 40's. There could be trouble with the ground as using water pipes for grounding can cause a loop also.
post #7533 of 15139
Quote:
Originally Posted by BeeMan458 View Post

You mentioned your house wiring is from the 40's. There could be trouble with the ground as using water pipes for grounding can cause a loop also.

Yeah and what sucks is the third floor is still old wiring but the first floor and basement have been redone. Hopefully we will be done refinishing the basement soon from hurricane water damage so at some point I will be back down there.
post #7534 of 15139
Smigro,
Do you have cable tv hooked up to any part of your system? If so, unhook the cable and check for the hum. I have also had ground loop issues with cable. If that's the culprit a simple $10 isolation transformer should take care of it.

Parts Express:
http://www.parts-express.com/pe/showdetl.cfm?partnumber=180-075
post #7535 of 15139
Mine is getting plugged directly into a Furman Elite15 power conditioner. Is there anything I should be concerned about ?
post #7536 of 15139
Quote:
Originally Posted by Kruppy View Post

Smigro,
Do you have cable tv hooked up to any part of your system? If so, unhook the cable and check for the hum. I have also had ground loop issues with cable. If that's the culprit a simple $10 isolation transformer should take care of it.
Parts Express:
http://www.parts-express.com/pe/showdetl.cfm?partnumber=180-075

Yes I do have a FIOS cable hooked up to my TV. I have the box running HDMI to my Onkyo and out to my TV. I will have to check that out tomorrow. Thanks for the suggestion.
post #7537 of 15139
Quote:
Originally Posted by K5/SS View Post

Mine is getting plugged directly into a Furman Elite15 power conditioner. Is there anything I should be concerned about ?

I have been looking into getting something from the Surge X line, but they are pretty expensive. I think that will be the next thing I add though.
post #7538 of 15139
Rythmik F12 or F12G or F15?

My listening area is about 3300 cubic feet. I have mains that extend nicely down to nearly 40 Hz. I am exclusively two channel and have no constraints on size or placement and intend to purchase two subs.

All the subs mentioned are within my budget, but I am wondering if any one of them shines especially bright for two channel use?

Would the 12" be better? Tighter? Faster? Is paper or aluminum best?

Thanks so much for the help,
Chip
post #7539 of 15139
My understanding is that it is not necessarily the size of the woofer that dictates whether it performs 'tight and fast' but how controlled and precise the whole driver handles.

Personally I would opt for the F15, or even duals, for two channel playback and if you like to play it loud then go for a HP variant.

Others will be better able to answer the possible qualitative differences between paper and aluminum. My perspective it wont significantly matter.

Best Regards
KvE
post #7540 of 15139
Hey guys, I just picked up an F12 on a whim and am very pleased so far. My F12 has an A300 amp and I am wondering what it would take to replace it with an A370. Is it just a matter of of plug and play? Any idea what the A370 amp will cost? I looked around on the Rythmik site but couldn't find the info I was looking for. I am running it downstream of a Velo SMS and have it dialed in pretty well except the upper end, say after 60Hz. I read on the Rythmik site that the A370 amps have a bit more extension up on top... I have only played with room position and the SMS an hour or two...so still a work in progress. Thanks in advance.
post #7541 of 15139
Quote:
Originally Posted by ravingndrooling View Post

Hey guys, I just picked up an F12 on a whim and am very pleased so far. My F12 has an A300 amp and I am wondering what it would take to replace it with an A370. Is it just a matter of of plug and play? Any idea what the A370 amp will cost? I looked around on the Rythmik site but couldn't find the info I was looking for. I am running it downstream of a Velo SMS and have it dialed in pretty well except the upper end, say after 60Hz. I read on the Rythmik site that the A370 amps have a bit more extension up on top... I have only played with room position and the SMS an hour or two...so still a work in progress. Thanks in advance.

I would imagine you woud have to send it into Rythmik to have them do it. Otherwise you might void the warranty on it.
post #7542 of 15139
Quote:
Originally Posted by Chipbyrd View Post

Rythmik F12 or F12G or F15?

My listening area is about 3300 cubic feet. I have mains that extend nicely down to nearly 40 Hz. I am exclusively two channel and have no constraints on size or placement and intend to purchase two subs.

All the subs mentioned are within my budget, but I am wondering if any one of them shines especially bright for two channel use?

Would the 12" be better? Tighter? Faster? Is paper or aluminum best?

Thanks so much for the help,
Chip

Since you plan on getting two, I would go for two F12's in that size room. It is about 50% larger than mine in volume and my two F12s pretty much idle along. If space and cost is not a consideration the F15's would give you a little more headroom but I doubt you need it.

I prefer the aluminum cone but Brian said once paper might be a hair better. I doubt I could tell and prefer aluminum. The servo and sealed design means no difference in sound quality between 12" and 15".
post #7543 of 15139
chipbyrd---What Brian at Rythmik and Danny at GR both say is that at medium and lower SPL levels, the paper GR drivers have a little bit more resolution (finer details are heard more readily). That is because the paper driver and foam surround of the GR have less mass than the aluminum and rubber surround of the Rythmik. At higher listening levels, the aluminum cones of the Rythmik drivers have a little less cone breakup (the cone not moving as a single piece). If you go with the aluminum, the 15 is only $100 more than the 12, so what the hell!
Edited by BDP24 - 12/15/12 at 9:46pm
post #7544 of 15139
Man its been over a year (1.5 years) since I bought my FV15HP, crazy how time flies. Unfortunately I haven't had much use of the sub for a variety of reasons, mostly due to an inner ear problem that I hope to rectify via surgery soon. It has really sidelined this hobby of mine. I've actually had this condition for 3-4 years now, almost right after I started getting active in audio. Bad luck or what!

Anyway, just dropping in to check out whats new in the Rythmik world and to say the rare moments that I got to use the sub to its potential were really great. Hopefully after surgery I'll be back and prominent in the community. I miss it. (Wish me luck, there is a ~10% chance I lose my hearing in my left ear!)
Edited by 1080pee - 12/16/12 at 12:43pm
post #7545 of 15139
I have had ear issues my entire life. I ordered a FV15HP to help eliminate some of the issues:)

Good luck with the surgery.
post #7546 of 15139
Quote:
Originally Posted by K5/SS View Post

I have had ear issues my entire life. I ordered a FV15HP to help eliminate some of the issues:)
Good luck with the surgery.

biggrin.gif I like that logic.
post #7547 of 15139
OK guys, I really need some suggestions here as I am getting ready to pull my hair out over this sub.

So I have taken all of the suggestions you guys have given me and I cannot get this humming noise emanating from the amp to go away. Now this is not a hum that is coming from the sub as far as I can tell, it is definitely coming from the amp and at normal listening volumes can be heard in my chair which is about 7-8 feet away.

So here is the run down.

On Friday I got the sub into its home, plugged it into my Raxxess PD-800 surge protector and started doing the initial setup. After about 10 minutes while I was fiddling with the sub settings I starting hearing a humming noise coming from the back of the enclosure where the amp is. After talking with a few people on here they thought it may be a ground loop issue and I was advised to get a cheater plug. After going to HD to get said plug I got home plugged it in the sub plug and then into the surge protector and everything seemed fine. The next morning when I woke up the humming noise was back. Back to square one.

So after exchanging a few PM's with people on here Saturday and one with Brian, it was suggested that I take the surge protector out of the equation and see what happens. So last night when I got back from a day long event at my brothers house I decided to give this a go. Unplugged the sub from the surge protector and right into the wall and the hum went away, what was weird here is that I did not use the cheater plug for this and everything seemed good. Well wouldn't you know I wake this morning for work and what do I hear...yup you guessed it humming noise coming from the amp again. So real quick before work I put the cheater plug back in to see if it would do anything and it did not make the noise go away.

I still have yet to try and run an extension cord from another outlet on a different circuit which I will be doing tonight, but at this point I really don't have faith that is going to help at all...considering the hum is not there when first plugged in but after being plugged in for say 10 hours it comes back.

Does anyone have any other suggestions for why this may be happening. At this point I am thinking that I may have a faulty amp, but I am no expert so I cannot and do not have any way on confirming this. Hopefully Brian will be around at some point today to chime in on this. I am not going to be happy if I have to lug this beast back to work to have it shipped out to be looked at (it was hard enough getting it in). Does anyone know if it is an amp problem if that is something that they will just ship out and I can install myself and return the old one (I am guessing not) or if I will have to send the whole sub back to Rythmik to have them look at it.
post #7548 of 15139
For those with dual subwoofers placed at the same distance to your couch, do you set the phase for both of them at zero?

Here's a guide from Brian (Rythmik):
Quote:
How to set up multiple subs?
One cool feature of phase/delay control on the plate amp is it allows you to compensate the phase difference arise from difference in physical distance. To use this feature, one needs to use line in, instead of LFE in. The purpose is to make sure that direct sound multiple subs arrive at the listening seat at the same time so there is no cancellation in sound. To do that, use the farthest sub as the reference. Then measure the physical distance difference in ft. Note the sound speed is about 1 ft per milli-second. As an example, say the difference is 5ft, then set the phase/delay knob on the closer sub at 5ms. Then one can use room EQ program to calibrate both subs at the same time.

Here's a feedback from forumer neutro:
Quote:
I finally put my subs in a symmetric position each side of the TV, so equidistant from the main listening location. Strangely I found that using 180 deg. phase difference between the subs both sounded the best and managed to get rid of a nasty null in the crossover region. So phase sometimes have unexpected consequences. The best is to try phase difference from 0 to 180 degs to see what sounds better, simply. In theory, with equidistant subs, setting one at 0 degrees and the other at 180 will create a dipole, and the listener will be exactly on the dipole's null boundary (perfect cancellation). In practice it's not necessarily the case. First, woofers can be wired in opposite polarity in the two subs -- which would require setting the phase to 180 degrees immediately (or changing the woofer's polarity). Second, this is only true in an anechoic setting. Inside a room, interactions with the room will create standing waves and room modes will be dominating the frequency response. What reaches the listener is a combination of sound directly emitted from the subs and sound reflected by the room boundaries. With subs the first component is generally not the strongest unless you sit beside the sub.

Here's Brian's reply regarding setting different phase controls (such as sub1 at 0 degree and sub2 at 180 degree) for subs located equidistant:
Quote:
Don't listen to those. Advise like that can work in a particular room and sub placement combination. It will cause cancellation of direct wave at your listening position. So what is left is the room reverberation (or in other words, echos in your room). The sound stage can completely collapse. That is not what we want.

You can try with your front speakers, if you connect them in phase, the sound stage is between your speakers. If you connect them out of phase, the sound stage becomes blurry. If your front speakers have excellent phase response, you will again hear very clear sound stage, but this time, the sound stage appears to be on your left and right sides with very little between the speakers. Now the sub is out of phase, but the front speakers are not, so what do we get? It is something in between. I for one think correct phase reponse is above everything. I have heard people wiring woofers out of phase with tweeters in order to fix an out of phase problem. This even happened to well known speaker designers. But those "fixes" have never become standard practices. In another words, you will never hear some speakers become outstanding because they wire the tweeter out of phase with woofers. They are....merely fixes.

Here's forumer LarryU's comment:
Quote:
If the subs are equal distances from the listening position both subs need the phase set to Zero.

Considering this diagram as an example of a non-symmetry room:

... sub1 is next to a large window but sub2 is next to a brick wall. Both phase controls at zero? ...or may be different?
post #7549 of 15139
Quote:
Originally Posted by Smigro View Post

Does anyone have any other suggestions for why this may be happening. At this point I am thinking that I may have a faulty amp, but I am no expert so I cannot and do not have any way on confirming this.

Based on this additional information Doctor, I'm inclined to agree with your opinion.

........................tongue.gif
post #7550 of 15139
Smigro,

I had the same issue that you had with my Rythmik. I went through the checklist just like you did including buying an Tripp Lite Isolation Transformer and adding ferrite cores to various power cables. What finally worked for me: I ran an extension cord from the sub and plugged the power cord into the same outlet as the rest of my equipment. Since that time, I have had no hum from the SW at all. You should give that a shot before you return the sub.

Good Luck!

Nick
post #7551 of 15139
Quote:
Originally Posted by nsiret View Post

Smigro,
I had the same issue that you had with my Rythmik. I went through the checklist just like you did including buying an Tripp Lite Isolation Transformer and adding ferrite cores to various power cables. What finally worked for me: I ran an extension cord from the sub and plugged the power cord into the same outlet as the rest of my equipment. Since that time, I have had no hum from the SW at all. You should give that a shot before you return the sub.
Good Luck!
Nick

Well that is my issue, right now I do have it plugged into the same outlet as the rest of my equipment and I still get the humming noise. When I get home I am actually going to try and run an extension cord on the opposite end of my room which is on a separate circuit to see if it fixes the problem.

I have been talking with Brian through PM's and he thinks it is something in my house electrical inducing the noise, but my issues with this is that neither of the two subs I had before this had this problem. Granted they were not as beefy as the one I have now, but I would think they would have still had this same issue if indeed it is something in my house electrical causing this.
post #7552 of 15139
Quote:
Originally Posted by Smigro View Post

Well that is my issue, right now I do have it plugged into the same outlet as the rest of my equipment and I still get the humming noise. When I get home I am actually going to try and run an extension cord on the opposite end of my room which is on a separate circuit to see if it fixes the problem.
I have been talking with Brian through PM's and he thinks it is something in my house electrical inducing the noise, but my issues with this is that neither of the two subs I had before this had this problem. Granted they were not as beefy as the one I have now, but I would think they would have still had this same issue if indeed it is something in my house electrical causing this.

A ground loop is a ground loop is a ground loop and you're not going get a hum from the back of your unit that's a ground loop if the unit is turned off and there's no speaker for the hum to play through.

Unplug unit, hum goes away. Plug unit in, no hum. Walk away and come back, hum is there......in the back of the unit where there is no speaker. My opinion, not a ground loop.

Based on your newly provided information, in my opinion, this problem does not look, walk or sound like a duck.

...................tongue.gif


What happens when you take the unit to a plug that qualifies as a known commodity; properly grounded and you plug in there? You said your downstairs wiring was newly, up to code wiring. Run an extension cord from a known outlet, make sure nothing is attached to the subwoofer and the subwoofer isn't touching anything (no connections and separated from any metal other than the power cord), turn it on and see what happens.

My understanding, if the unit is electrically isolated, there can't be a ground loop as there's nothing it can loop to.

The McCoys: "Hang on Sloopy."
-
Edited by BeeMan458 - 12/17/12 at 8:05am
post #7553 of 15139
Quote:
Originally Posted by Smigro View Post

Now this is not a hum that is coming from the sub as far as I can tell, it is definitely coming from the amp and at normal listening volumes can be heard in my chair which is about 7-8 feet away.
If the hum is heard as coming from the amp and not the speaker it's probably a 'singing' power transformer. If you want to be sure remove the amp from the cabinet; if it is from the speaker it can be very hard to tell the actual source, as low frequencies radiate omni-directionally.
Quote:
When I get home I am actually going to try and run an extension cord on the opposite end of my room which is on a separate circuit to see if it fixes the problem.
If it's a ground loop that will make it worse.
post #7554 of 15139
Well I just received another PM from Brian and he is going to send me out a new amp for me to put in, hopefully this will rectify this problem. I really like the sub and for the short amount of time I got to listen to it at loud levels (using Master and Commander cannon fire scene) the feeling was awesome...I have never felt chest pumping bass like that before in my HT.

So far I really have to say I am happy that I went with Rythmik. Brian has been more than helpful and the fact that he is just sending me the amp to change out on my own is just awesome. I really do hope that it is just something stupid with the amp and the change out fixes it. Guess I will find out in a couple weeks.
post #7555 of 15139
Quote:
Originally Posted by Bill Fitzmaurice View Post

If the hum is heard as coming from the amp and not the speaker it's probably a 'singing' power transformer. If you want to be sure remove the amp from the cabinet; if it is from the speaker it can be very hard to tell the actual source, as low frequencies radiate omni-directionally.
If it's a ground loop that will make it worse.

Thank you Bill. I am guessing a "singing transformer" is something that would be internal to the amp. If so Brian is sending me out a new amp so hopefully that will fix my issue.
post #7556 of 15139
Quote:
Originally Posted by Smigro View Post

OK guys, I really need some suggestions here as I am getting ready to pull my hair out over this sub.
So I have taken all of the suggestions you guys have given me and I cannot get this humming noise emanating from the amp to go away. Now this is not a hum that is coming from the sub as far as I can tell, it is definitely coming from the amp and at normal listening volumes can be heard in my chair which is about 7-8 feet away.

If you are hearing the hum, and disconnect the signal cable, does the hum go away? If yes, then it's probably a ground loop, if no then it's definitely not a ground loop. From what you've described, I'm guessing it's not a ground loop, but the amp itself humming.

From what I've read amp hum is most likely due to unclean power. I had a similar problem that turned out to be a dimmer in a lamp that is probably using an inline diode, which causes an uneven load and therefore a DC bias in the AC power in the whole rest of the house. Note that this was even on a completely different circuit at the other end of the house. I've read other stories of folks having such conditions come in from outside the house, caused by a neighbor or the faulty power company equipment.

Since your problem is intermittent, I'd guess the cause is some piece of equipment which is not constantly on. In your position what I'd try to do is (at a time when you hear the hum) is turn off or unplug everything else in the house. If necessary (or just easier) you can flip all the other breakers in the electric panel. If that makes the hum go away, then it's something in your house, and you can track it down methodically. If the hum stays then it's either from outside your house or a faulty amp.
If the problem is DC bias and you can't fix at the source for whatever reason, then an Emotiva CMX2 might be something to consider.

Good luck!
-- Dave
post #7557 of 15139
Quote:
Originally Posted by Smigro View Post

I have been talking with Brian through PM's and he thinks it is something in my house electrical inducing the noise, but my issues with this is that neither of the two subs I had before this had this problem. Granted they were not as beefy as the one I have now, but I would think they would have still had this same issue if indeed it is something in my house electrical causing this.

IIRC, Brian explained elsewhere (I think in this thread) that the specific design of the power supply in these amps makes them more susceptible to transformer hum due to DC bias in the incoming power than some alternative designs. Apparently Emotiva had the same issue in some of their products, hence the introduction of the CMX devices.
post #7558 of 15139
Quote:
Originally Posted by David_R View Post

If you are hearing the hum, and disconnect the signal cable, does the hum go away? If yes, then it's probably a ground loop, if no then it's definitely not a ground loop. From what you've described, I'm guessing it's not a ground loop, but the amp itself humming.
From what I've read amp hum is most likely due to unclean power. I had a similar problem that turned out to be a dimmer in a lamp that is probably using an inline diode, which causes an uneven load and therefore a DC bias in the AC power in the whole rest of the house. Note that this was even on a completely different circuit at the other end of the house. I've read other stories of folks having such conditions come in from outside the house, caused by a neighbor or the faulty power company equipment.
Since your problem is intermittent, I'd guess the cause is some piece of equipment which is not constantly on. In your position what I'd try to do is (at a time when you hear the hum) is turn off or unplug everything else in the house. If necessary (or just easier) you can flip all the other breakers in the electric panel. If that makes the hum go away, then it's something in your house, and you can track it down methodically. If the hum stays then it's either from outside your house or a faulty amp.
If the problem is DC bias and you can't fix at the source for whatever reason, then an Emotiva CMX2 might be something to consider.
Good luck!
-- Dave

Thanks Dave, I may have to look into that if the replacement amp Brian send out does fix the problem.
post #7559 of 15139
Quote:
Originally Posted by Smigro View Post

Thanks Dave, I may have to look into that if the replacement amp Brian send out does fix the problem.

Smigro, Sorry to hear about the issues. Although I can't help with what is wrong I'm confident you'll get it resolved and know you will love the results once you get it happy. Hang in there bud
post #7560 of 15139
Quote:
Originally Posted by Smigro View Post

Well I just received another PM from Brian and he is going to send me out a new amp for me to put in, hopefully this will rectify this problem. I really like the sub and for the short amount of time I got to listen to it at loud levels (using Master and Commander cannon fire scene) the feeling was awesome...I have never felt chest pumping bass like that before in my HT.
So far I really have to say I am happy that I went with Rythmik. Brian has been more than helpful and the fact that he is just sending me the amp to change out on my own is just awesome. I really do hope that it is just something stupid with the amp and the change out fixes it. Guess I will find out in a couple weeks.

Smigro,

Sorry I am late, I had a hum coming from both my amps on my FV15HP's, it turned out it was a kitchen light on a different circuit in the house causing the issue. I narrowed it down to dc offset and bought an Emotiva CMX-2 and it removed the dc offset from the line.
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