Official Rythmik Audio Subwoofer thread - Page 196

Im curious to hear your feedback as im guessing in theory the limiter should only kick in to prevent the amp from clipping which would sound horrible on its own and potentially damage the sub. The limiter should not affect sound quality one war or another imho.

This is exactly what I was thinking as I was setting up the sub in late January.

However, the sub did sound quite strange until I disabled the limiter. Mostly what I was hearing with enabled limiter was slurred attack/decay transients from instruments such as stringed acoustic bass, bass drums, tympani etc. At the time I put it down to a combination of run-in and limiter issue (sub had been delivered the previous day).

As I told Brian and Enrico at the time in an email message, my plan was, and still is to re-evaluate limiter after a suitable run-in period, but I haven't had the time do do so yet.

I normally run system volume anywhere between -35 db and -15 db. Never even approach reference levels.

Did you try the setting on different types of music ? I tried simpler tracks and the low damping is not ideal but for dance, new wave and trance the added "boominess" is awesome

Yeah I tried with rock, country, house, and dubstep. Was particularly interested in the bass in house and dubstep and did not like the low damping.

On the limiter my guess is that natural dynamics are compressed a bit at high volume/power draw levels......one thing Iain didnt mention was how loud he listened to music and what size room. I personally dont notice on my(I run a pair of D15SE's)subs having a difference in SQ whether the plate amps are set to auto or on in a rather small room(18x14)but it doesnt take much gain from my subs to get significant bass output. The gains are way down, so whether the limiter is on or off, I dont notice any real difference at all. Things like how the damping and extension are set might also play a role too on if the limiter has any noticeable difference in SQ since lower frequencies tend to require more out of the amp as well.

First I have heard a complaint about the limiter in the several years I have owned rythmik and followed this thread. I wonder if it is set too low for some reason in your sub...

Iain: Just looked over alot of your past posts........some thoughts I have.

Your running basically an F12. Not sure what size room your in, but your already at a disadvantage compared to F/D15 users in that your amp basically needs to double up the output power to have the same output level as the 15" users. Again, I use a PAIR of D15's in a modest size room. Even though you state you don't listen to music at "reference levels"(Which I believe is in the 105-110db range technically), you most likely pushing that F12 pretty darn hard. I actually can believe that you do in fact notice a difference when it is on. IMO based off this, you probably should have opted for an F15 or greater even, especially if your room size is larger than where I have my pair of D15's situated. Im actually going to be picking up another pair of D15's when the new XLR 2/3 amp is available. THe lower the gains, the better. In your case you should probably think of picking up another 12" Rythmik, I think an extra 6db output and clean headroom will serve you well.
Im actually surprised you didnt go with a 15" model originally. The only time I actually recommend the 12" Rythmik to people, is if space, total cost and listening levels being LOW under normal use is the main factor. I have found regardless of the size and material of the Rythmik driver used(GR paper cone, or regular aluminum), all the Rythmik subs blend in equally well to small monitors well above 120hz as the xover point. Im a big audiophile myself and a long time bass player, and find the even the D15's with a downfiring 15" driver can blend in seamlessly well above 120hz with small monitors that feature a 4" or 5" midrange driver. That is how good these subs are. The reason I feel the Rythmiks are absolutely the best audiophile subs out there right now at a reasonable cost.
WIth that said, one thing most customers don't do or fail to realize though is to properly match up the subs true clean output capability with the equipment they already have along with the size of the room and their normal output volumes. Most people I find significantly overdrive their sub system beyond what its capable of doing in these terms. Just like your main speakers, subs for music and movies need to be able to and will produce dynamic swings that are greater than 10-20db. The F12 has about 27-28db of clean headroom based off 1 watt RMS. So even when your listening to music below "reference levels", your sub and mains still probably are put to the task for quick intervals. Your subs sensitivity db/watt naturally is probably in the low 80 range in your room at best and probably at LEAST 6 db down from your mains at 1 watt of power if not more. This means that when your main speakers have 1 watt rms going through them, your subs have at LEAST 4-8 watts RMS at the same time output. So there is without question the good possibility that your single F12 has less than 10-15db of clean headroom in your situation and is probably why you notice SQ differences with the limiter on. You are most likely hitting quick transients that require more output than what the plate amp can give. I bet if you add a second F12(Always a GOOD thing )and gain another 6db of headroom, you would notice the limiter to be less of a factor or a non factor period. And in the process put alot less wear and tear on the plate amp and voicecoil of the sub as well in the process. And since you listen to mainly music IMO you should have a pair of subs regardless and have one per monitor. Not only will you have less potential localization, but your soundstaging will improve and the rooms bass response will naturally smooth out as well. Rythmik subs run best in PAIRS.

To add, with one of my systems that feature a pair of small modded Kef XQ10's(with an in room sensitivity in the mid to high 80 range) and I need a PAIR of D15's per SIDE(Currently I have one D15SE per side) at 20-40hz to technically equal the sensitivity and clean headroom of ONE XQ10 at 1khz that has about 2-300 watts of clean RMS/dynamic power(And this would basically be with any 15" sub, not just Rythmik)going through it. People who hear my system cannot believe how effortless the sound is on my system with such small bookshelf monitors. Its due in part because the sub system is matched up near correctly in terms of power and dynamic headroom to the main monitors and amplification. And I actually feel that I need at least one more D15 in this setup to be 100% optimal in terms of gain/power matching if not 2.

ntrain96, great post. This feels like a reasonable way to choose one of these subs. I have 88-90 db sensitive monitors in my ht room. I currently am running a really solid 100 watts to each. Your post does beg the question then...What are the sensetivity numbers for the rythmik subs. I was just at Brians website, and could find no mention of them...This does however make me feel like I should just pick the FV15HP as it is clearly the most sensetive sub of the bunch, and would therefore give the best movie performance in my 2300cf space.

In that sized room, no question go with a FV15HP. Honestly I feel Brian's vented subs sound just as good as his sealed units when set up and driven CORRECTLY for a given application. Hell, if your budget allows for it, grab a pair of em, or plan on grabbing a second one down the road. I feel that any system should have a minimum of 2 subs anyways for the reasons given above.

Honestly Brian, I think his sub is without question being "overdriven" on occasion on dynamic peaks.........quite honestly if the limiter does kick in, it does compress the sound obviously, but it does so to keep the amp/sub from hard clipping. I mean if a dynamic peak requires output of the sub and power to hit well north of the plate amps output capability, then naturally sub passages will not be linear in output and naturally the SQ altered. Honestly at the levels I play at, and considering how low my gains are set, I cannot tell a difference between auto(limiter) and "on"(no limiter), but thats most likely because I never or very rarely approach the plate amps output threshold.

jono,

My space is roughly the same size as yours and I have the FV15HP. My room is not sealed or acoustically treated and also opens up to a smaller space on the other side of my basement so the combined space is over 3600 cubic feet. The FV15HP performs very well in my space even with the large 6 foot plus doorway into the other part of the basement.

I am still working out all of the details on tweaking the FV15HP and working on doing some acoustic panels for the room so it is a work in progress at the moment, but IMO I don't think you could miss or go wrong with the FV15HP. I am very happy with its performance in my space and it should only get better as I tweak the setup.

I am also learning that subs (at least in my room) are very location sensitive and that moving these bad boys around to different locations can make a HUGE difference in perceived bass. I found out that the original location I had planned for my sub created a huge null (I think that is what is is called) right at my listening position and moving the sub just a few feet eliminated the null at my prime spot. So don't forget that aspect of subs as well in your decision.

Good luck.

Regards,

RTROSE

Unfortunately, the only way that I am getting such a "huge", "humungous", "Monstrosity"... into my house is by building into a cabinet that I am currently working on. The subs position will be fixed, but the seating arrangements are flexible (Long sectional couch), and so I hope that at least some of the couch will be in a good spot.


Jono

Thanks, Brian. If I could ask your indulgence one more time, what is the stud length on the supplied cone feet for the F12?

If Enrico or anyone else has the answer, that would be OK, too.

Great post, mate.

To reiterate from my earlier posts, my decision to disable limiter at the time is a temporary solution and was based on configuration out of the box.

I wasn't sure what to expect from the sub, but I just wanted to remove that roadblock from the path. Proper configuration learning curve has been slow and gradual, but I believe it's the best way to obtain a long-term satisfactory conclusion. Reckon 2-3 months for proper run-in.

I estimate indication of -25 db indication of front panel of AVR to be equal to 75 db speaker output. To reiterate from earlier post, I generally listen at levels of between -35 db and -15 db as shown by front panel of AVR.


Reason I chose F12SE is size and appearance. Cost wasn't a factor.

My first sub-woofer was a Paradigm PW-2200, IIRC, which I had for a few months several years ago. The thing was a big, ugly beast, but I tolerated it's appearance for awhile before I sold it. Haven't had a sub since then.

That said, I believe my decision to purchase the Rythmic was a good one. Sub is a beauty in that it fits well into environment and sound quality is superb.



Running Denon 3310 AVR and KEF iQ10 speakers in a 4.1 configuration. Not interested in centre channel.

OK, so your basically running a reciever capable of about 100 watts of clean output per channel. And the iQ10's are basically identical to my XQ10's(same exact driver and cabinet volume and tuning, cheaper xover and cabinet). Do not go by what you think is 75db(A normal conversation 2-3 feet away is 65-70db), its probably alot louder than you think as to your normal playing volume. Get yourself a cheap 20 dollar Radioshack spl meter and a pink noise test cd. You would be surprised at the actual volume levels you listen at. At -35 to -15 on your "AVR", you could easily be playing at volume ranges in the 80-100db range and not even know it, and have dynamics go well beyond 100db without question. If you find you have to talk loud or shout to have a conversation, or need to turn the volume down to have a conversation, your without question in the 90db plus range. If you can have a normal conversation with a person in a room without having to turn the volume down, then the one sub you have is probably sufficient. But if your playing louder than this, then without question you should be picking up another F12. In fact, regardless, I really think you should grab another one, as I would be my life that your already "soft" clipping the subs output on many occasions at least during large dynamics in the music.

Ntrain!! Your back!!

When I ordered my FV15HP I told Mrs. RTROSE it was big, but she would just have work with me on it. When it arrived she still was shocked how big it was. The big thing with her was where it goes in the room. THAT's where the big issue was. She currently does not like where it is as you can see the back of the sub when you walk into the room. It's not going anywhere as it sounds the best right where it is. So I told her that I would come up with something to held "hide" the back of the sub.

I am glad that I set up the "ground rules" regarding the basement long before I actually started construction. She could decorate the rest of the entire house, I get the basement. Hey that's fair right?

Regards,

RTROSE

I never left, lol, just lost the old password to my other account and have been busy actually all winter on finishing up my new basement HT system.

I have the same deal with my wife. Every once in a while she'll forget and try to influence what I do in "that room" and I have to gently remind her she has the other 90% of the house. Don't give in when it comes to the man cave, you'll be letting all of us down.
Tim

I can appreciate the sentiments. A mans cave is his cave. I had to choose. We don't have a basement in our small house. My man space encompasses most of the garage, most of the time. My "theater" room is also one of my kids play spaces. Floor space in our house is at a premium, and to be quite honest...tv, speaker, subs, and the like are not worth fighting over. (This sounds a bit like I am defending myself.) We all pick our battles I guess.

I can appreciate the sentiments. A mans cave is his cave. I had to choose. We don't have a basement in our small house. My man space encompasses most of the garage, most of the time. My "theater" room is also one of my kids play spaces. Floor space in our house is at a premium, and to be quite honest...tv, speaker, subs, and the like are not worth fighting over. (This sounds a bit like I am defending myself.) We all pick our battles I guess.

Just wondering...What is the outer most diameter of the flared ports that come with the FV15HP design. I am trying to figure out what size front baffle I will need to fit this beast into my cabinet. Thanks

Since the subject of whether or not an F12 delivers sufficient output has been discussed in this thread, I thought it might be an appropriate place for me to ask if anyone happens to know if the output of an F12 matches (or exceeds) the output of my old Velodyne F-1500. I'm considering replacing it with an F12 (since the E15 and F15 are not in my budget at the moment) but would only do so if the F12 could match the overall output level of the F-1500. Anyone happen to know?

No need to defend yourself, we all have different things/battles in our day to day cohabitation with our spouses. I'm sure it would be a horse of a different color if I had to share a space with the wife and kids vs. my own space in the basement. No worries, I have a big enough man card for both of us!

As for the ports, I'll measure tomorrow morning and get back to you on that.

Regards,

RTROSE

I'm not sure people are drawing correct conclusions. E.g. adding another sub may decrease the total SPL into the room and the only way to guarantee the maximum increase (6dBSPL) is to colocate the subs in a coherent configuration (say side-by-side midwall). Or that your position relative to the sub has more effect on SPL than sub size or amp output.

A concrete example: per Brian the F15 is +2dB over the F12 at 20Hz. If you want to take a big step you have to go to the FV15HP or equivalent.

To the other part of your question you might be able to get in the ballpark by comparing similar models at Data-Bass or Audioholics.

Thanks, Brian. Unfortunately, your response has a typo which makes your meaning less than clear (to me, anyway). Are you saying that any replacement foot should have a total stud length sufficient to allow 10-15 mm of threads to penetrate the insert after passing through the locking washer? And is it a thin (1-2 mm) locking washer or a thicker (5 mm) locking nut?

Gotcha!

What sort of xQ10 modifications are they?


Thanks for the information.

I'm able to have a normal conversation when volume is set to -25 db at AVR front panel. This then should equate to the 65-70 db speaker output as you mention above.

I had considered xQ10 originally, but decided against them because only apparent differences between them seemed to be cabinetry. I may reconsider them for my front speakers if there are considerable SQ differences between iQ10 and xQ10. Then I could run them in a 6.1 configuration.

BTW, one thing that's not been discussed is crossover frequency. I use LFE sub input from AVR and crossover is set at 110 hz. What crossover frequency is your system set?