2 Rythmik subwoofers

[eagle]

Hi

I recently bought 2 Rythmik F12SE subwoofers for a combination of HT and 2 channel duties. The good news is that they sound fantastic with a very nice tight and tuneful bass.

Having said that and despite my best efforts to date, I am unable to get the right bass that suits my tastes for both applications. This is due to the placement of subs in my room. I find one position works really well for 2 channel (both symmetrical 1/3 distance out from front wall, close to side wall) but not so well for HT. I find for HT, having both subwoofers on my front wall (symmetrical 25% in from side wall, close to front wall) has deeper bass and has that mid bass thump but looses pitch definition for 2 channel and sounds too loose.

I have been taking some measurements with my Radio shack sound meter and plotting on an excel spreadsheet (crude I know compared to REW but I haven't got the tools or understanding yet on how to use that program) and am wondering if some sort of EQ would suit my needs? I do have access to EQ through my Anthem receiver (ARC) but not so for my 2 channel set up (running an integrated amplifier only). Been thinking about buying a Velodyne SMS 1 or Anti-Mode 8033S. The Rythmik does have a PEQ for one band and I am using this to correct the hump I have at 55hz.

Any feedback as to what I should do?

Cheers

Dave

[Peter_F]

Hi Dave

I have my 2 x Rythmiks setup just for HT, which was calibrated for the room via the Denon AVR4311, Audyssey. The Rythmiks are sublime and they really have taken my HT to a whole new level.

I haven't been game to play around with the Rythmiks for the 2 channel rig as I'm still enjoying the HT so much and I'm not game mess around the settings at the present time.

My room has a hump at 58hz, so our rooms are almost identical in that regard.

What you are presently experiencing with integrating the Rythmiks for HT and 2 channel is pretty much what I thought would happen. I am keen to see how this works out for you and if all goes well I will pick your brain.

[eagle]

Cheers Flemo.

It always is a challenge trying to get the bass right for both mediums.

I've measured 2 humps at 30 hz and 55hz with a massive dip at 40hz. No matter where I put the subs, the 40hz dip remains but does improve in severity if I move them further out into the room. Right now, I am using the subs for 2 channel with a loaner pair of B&W 805's and have the bass well integrated (something I never really achieved with my last sub) and am pretty happy. I put in a pair of super chunky bass traps last weekend and they have helped a bit with the bass evenness throughout the room.

I think the ARC program in the Anthem will help the HT side of things but need something for the 2 channel side. I am pretty keen to try out a Velodyne SMS-1 but can't seem to locate one for a decent price. I did own one of the older Anti-Mode models and was not that impressed to be honest.

[sfdoddsy]

You should definitely EQ the subs using the ARC in your Anthem. It allows you to have settings for Movie and Music so you can have slightly different EQ and crossovers for HT and 2 channel, although once everything is flat you don't necessarily need to.

[Paul Spencer]

MiniDSP is all you need to EQ the bass, with the right measurement tools. When you get the bass right, it will work well for both music and HT. However, in nearly every situation,. EQ and placement are only part of the solution.

I don't trust auto systems - you need to test them! I tested one JL audio Fathom sub with an auto EQ routine - it actually did virtually nothing.

[Peter_F]

MiniDSP is all you need to EQ the bass, with the right measurement tools. When you get the bass right, it will work well for both music and HT. However, in nearly every situation,. EQ and placement are only part of the solution.

Hi Paul

Happy new year mate!

I run the HT and 2 channel systems in the same room and the only shared component between the two systems are the main speakers.

Just so I'm clear, are you saying that I can set the subs up for 2 channel use through the preamp (and power amp), and for HT through the AVR, with the sub settings being suitable for both applications, or are we strictly speaking about sub placements (or both)?

Cheers

Pete

[Paul Spencer]

Hi Pete,

Happy new year to you also!

The bass management side can make things more complicated, but leaving that aside, you should be able to run the subs all the time whether for HT or 2 channel and get a good result. If it's all optimised then the subs should not only be for LFE use, but provide a benfit to music as well. If you feel the subs take away from music, rather than enhance it, then either the subs aren't up to the task, or the room has issues, or the integration needs work.

[Peter_F]

Hi Pete,

Happy new year to you also!

The bass management side can make things more complicated, but leaving that aside, you should be able to run the subs all the time whether for HT or 2 channel and get a good result. If it's all optimised then the subs should not only be for LFE use, but provide a benfit to music as well. If you feel the subs take away from music, rather than enhance it, then either the subs aren't up to the task, or the room has issues, or the integration needs work.

I ask a question and get more questions??

It sounds like a bit of work to get the Rythmiks integrated properly into both systems. The room still has not been treated and I'm not sure when that will happen. I may be better off leaving things as they are until I have built and installed the Helmholtz absorbers. I think that will give me more to consider about how to proceed from there. Maybe by then Dave will have sorted his system(s) and room out and I can learn from him too!!

Cheers

Pete

[eagle]

^{Been busy trying to find the best position for the subwoofers in 2 channel mode and still not quite there. I seem to be getting some massive dips in the 40hz and 70hz areas and still major spikes in the 30hz and 55hz regions. I have tried positioning the subs at the front room corners, 25% in from the front corners on the front wall, 25% from front wall on the side wall & 50% from front wall on the side wall. Still yet to hit the jackpot... I am also starting to wonder if I should have gone for dual 15" instead of the dual 12"???}

 

^{The bass that I am happy with is very nice indeed. Very tight and controlled with a wonderful pitch. First time I have had a subwoofer system that actually sounds like it is coming from the main speakers. This is all without an external EQ, just using the PEQ function on the Rythmik plate amp.}

 

^{I will use the Anthem for HT eq but can't use it for 2channel, as I only use an integrated 2 channel amplifier for music.}

 

^{I'll also check out the MiniDSP option, as that sounds interesting. Is it suitable for a layman??}

 

^{Pete - More then happy to help out mate. Your welcome to pop around for a listen if you want. Alternatively, I can bring my 2 x 12" subs to your place to shake things up a bit.}  

Edited January 2, 2013 by eagle

[Paul Spencer]

Pete,

 

It does take some work to really get the bass to work. When I get out to measure systems I take a pile of measurements for different sub positions. I don't just pick a few, but basically any position you could possibly consider. Sometimes I will even put the mic up high to test positions like a ceiling infinite baffle arrangement (with the sub in the listening position). You end up with a huge pile of data, but I can then sort through it all and pick the best spots. If you do it right the first time, you don't have to keep digging out the mic and doing it again. It's easy at this point to get lost in all the data, but if you know what you are looking for, you can skim through it all and say "ok the subs work best in these positions - which of these are most practical?"

 

Rythmik subs are great. I compared them in the past to some drivers that were made in the same factory, as the earlier Rythmik kits. They shared many of the same parts - the same magnet and basket! The cones were similar, but the Rythmik was different in small ways that made a very big difference. Quite surprising how such small changes can do so much. Even set up with obvious room resonances, you can still hear the dryness in the bass - it tends to make you want to turn them up a bit more because they are so clean and controlled.

 

One thing I did find with them - Eq is not enough. You can take the more obvious boom out of major room resonances but you don't get the same control. I was never totally happy with mine until I started getting serious about bass traps. For a long time I thought I needed woofers doing the bass rather than subs. It was a big surprise when I added big bass traps. Suddenly the bass was just so amazingly tight. I have used traps that were so big that the decay as seen in waterfall plots was near perfect. I've worked out a target. If you can get the bass to decay 20 dB in the first 150 ms (and you can easily see that in REW), then if you have good subs like Rythmik and a reasonably optimised result to avoid major peaks and dips remaining, you'll get a very good result. This kind of result is rarely achieved, but you nearly always need some serious bass traps to get it. A very inconvenient truth!

 

Helmholz traps are a handy tool because they can be made low profile, but they have to be tuned right, and tested. They need many different tuning points and in many rooms they make little sense. Very much a case by case kind of thing.

[Davey Willo]

Dave mate I'll be gobsmacked if you feel the need to add the subs for 2 channel once your big mofo speakers arrive, you are a bass ***** n no mistake

[eagle]

Pete,

 

It does take some work to really get the bass to work. When I get out to measure systems I take a pile of measurements for different sub positions. I don't just pick a few, but basically any position you could possibly consider. Sometimes I will even put the mic up high to test positions like a ceiling infinite baffle arrangement (with the sub in the listening position). You end up with a huge pile of data, but I can then sort through it all and pick the best spots. If you do it right the first time, you don't have to keep digging out the mic and doing it again. It's easy at this point to get lost in all the data, but if you know what you are looking for, you can skim through it all and say "ok the subs work best in these positions - which of these are most practical?"

 

Rythmik subs are great. I compared them in the past to some drivers that were made in the same factory, as the earlier Rythmik kits. They shared many of the same parts - the same magnet and basket! The cones were similar, but the Rythmik was different in small ways that made a very big difference. Quite surprising how such small changes can do so much. Even set up with obvious room resonances, you can still hear the dryness in the bass - it tends to make you want to turn them up a bit more because they are so clean and controlled.

 

One thing I did find with them - Eq is not enough. You can take the more obvious boom out of major room resonances but you don't get the same control. I was never totally happy with mine until I started getting serious about bass traps. For a long time I thought I needed woofers doing the bass rather than subs. It was a big surprise when I added big bass traps. Suddenly the bass was just so amazingly tight. I have used traps that were so big that the decay as seen in waterfall plots was near perfect. I've worked out a target. If you can get the bass to decay 20 dB in the first 150 ms (and you can easily see that in REW), then if you have good subs like Rythmik and a reasonably optimised result to avoid major peaks and dips remaining, you'll get a very good result. This kind of result is rarely achieved, but you nearly always need some serious bass traps to get it. A very inconvenient truth!

 

Helmholtz traps are a handy tool because they can be made low profile, but they have to be tuned right, and tested. They need many different tuning points and in many rooms they make little sense. Very much a case by case kind of thing.

Hi Paul

 

I am intrigued about the bass traps as I have just installed 2 bass traps (SuperChunky) in the rear corner with the help of a fellow SNA member (Davey Willo) and although is has helped somewhat, still not fixing some glaring issues. I'll read up about these Helmholtz traps, as they could be just what I need given they can be tuned for specific frequency's.

 

I hear you about measuring multiple locations. At the moment, I don't have the right measuring equipment to do this effectively. Of course, if you wanted to check out the wonderful sights on the west coast (hint..hint)....I'm sure a few of us SNA members would engage your services. (trust me...the wine here is superb!)

[eagle]

Dave mate I'll be gobsmacked if you feel the need to add the subs for 2 channel once your big mofo speakers arrive, you are a bass ***** n no mistake

Hehe...I hope so mate and don't doubt they will add significant bass over the current set up. I just think 2 well placed and tuned subwoofers will be the icing to the cake.

 

I'll be bringing the subs around to your place Davo for a listen, as they will give you the type of bass you are looking for. (Not that you need it at the moment with those wonderful Dianne speakers)

[zeus]

if you can get a sms 1 i think that may help i had problems with my subs and the sms 1 fixed up my Whise nicely

[Amar Dhall]

I use 2 x SVS SB 13" subs for both two channel and ht. For me integration has been made easy with the analogue bass management of the Emotiva XSP-1 pre. It allows for you set the cross over points for both the mains (HP) and the subs (LP) when used for two channel listening. The pre also allows you to set stereo stereo subs for music, but then runs them as the .1 for movies. Admittedly these SVSs have a 2 band parametric eq built into them, which helps tames the problem areas.

 

At this stage I am enjoying dealing with bass management in the analogue domain, rather than introducing another A-D-A conversion. That said, the Mini-DSPs are a pretty amazing piece of kit.

Edited January 8, 2013 by Vitruvian