AlexM
Rank: Duo
Posts: 30 
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Post by AlexM on Sept 28, 2014 15:34:10 GMT
Hi, I've decided that all my system really needs is to add another octave of bass  My current speakers have a specificed -6Db frequency of 37Hz, so I think a powered sub will help provide extension to around 20Hz. I have been looking at the Rythmik 12" sealed box range of active servo subwoofers (see www.rythmikaudio.com/products.html). I am looking at 12" rather than 15" as I am a bit tight on space, and can't really fit in a 15". www.rythmikaudio.com/F12SE.htmlI also don't really need that much power output. the 12" model also times a bit better than the 15", and may integrate better with 6.5" drivers, but there is also a 15" version in a more compact cabinet that might be worthy of consideraton www.rythmikaudio.com/E15.htmlReasons for looking at a sub? I don't want bigger speakers in my living room, and these subs have a number of options to help integrate with the main speakers and the room. I am interested in what others have experienced adding a good sub into their system, what connection methods you may have and any tuning tips and recommendations. Cheers, Alex |
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Post by John on Sept 28, 2014 16:15:11 GMT
I use active bass but very different to what you be doing with your bass set up
I did initially go down a more traditional route with sub plates (BK Electronics) but much prefer what DSP has made to the bass. Having more control of what happening in the bass is something I wholeheartedly recommend but unfortunately think you can no longer get one built this way
You can either connect via the speaker cable or RCA I certainly preferred the RCA route
I know a lot of the guys from the Hawthorne forum like the Rythmik plate amp so imagine this will perform very well. If you can afford I would use 2 but you can always add at a latter date
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Post by MikeMusic on Sept 28, 2014 16:45:58 GMT
I may be biased........ Isobariks are what you need ! I found the P10 mains regenerator, (serious dough but it serves all and can stay through all upgrades) plus MCRUs Ultimate mains cables did wonders for the bass. Any mains improvements will help I'm sure |
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Post by MartinT on Sept 28, 2014 17:04:13 GMT
The only subs I can recommend are REL, because I've used them in the past. Designed for music and not AV, they have the controls to integrate them in pretty well. Don't be tempted to turn the bass up just because you can, it'll ruin the sound.
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AlexM
Rank: Duo
Posts: 30
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Post by AlexM on Sept 29, 2014 8:22:28 GMT
Thanks John and everyone else.
What views about placement? I know corner placement gives the greatest room gain (+6db) but that it can strongly excite room modes. I guess these could be notched out with the parametric eq on the sub plate amp, or via something more adventurous such as the anti mode dsp. I have limited positioning options, so in a corner is almost dictated.
Also from what I have read, a high level connection seems to be the preference for many, but I'm not sure what the pros and cons are - any views?
Cheers,
Alex
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Post by MartinT on Sept 29, 2014 16:41:55 GMT
High level will better integrate the sub with the mains as it takes the feed from the same power amp outputs.
As for positioning, you can move around the room at floor level while playing, say, 40Hz centred pink noise. Listen for the places where the bass is at it lowest and use the sub there in normal mode, or where the bass is at max and use the sub there in anti-phase mode. Then adjust and take readings with a sound level meter. Your tendency will almost always be to overdo the bass, so be prepared to back it off until it feels like the sub is hardly doing anything. That'll be about right, check by plotting your measurements into Excel.
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Post by John on Sept 29, 2014 17:25:17 GMT
Agree just move about as each room is different
From my own experience using RCA (Low Level) rather than the speaker (high level) worked a lot better. Most people I know who have explored both prefer the low level route. I just use a Y splitter RCA connection coming out of the pre to pick up the signal and run the same length cable to my bass active set up and power (mid treble) set up
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AlexM
Rank: Duo
Posts: 30
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Post by AlexM on Sept 29, 2014 20:56:46 GMT
Thanks for the tips. I have read about the 'sub crawl' method, i.e. placing the sub in your listening position and then crawling around on the floor to find the place where the test tone is at a maximum, and then place the sub there -did I get that right?.
Martin - in terms of measurement, can you describe your tuning method using a mic and sweep tons or pink noise? I assume that pink noise should show equal energy across the band. I'll have a look at some set up and tuning guides.
john - Interestingly, I understand that the high level feed must be taken from the amp terminals rather than the speakers for optimum performance. Why is this? .
were there any ill effects from using the y splitter on the pre out? .
Cheers
Alex
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Post by MartinT on Sept 29, 2014 21:14:14 GMT
Martin - in terms of measurement, can you describe your tuning method using a mic and sweep tons or pink noise? I assume that pink noise should show equal energy across the band. I'll have a look at some set up and tuning guides. john - Interestingly, I understand that the high level feed must be taken from the amp terminals rather than the speakers for optimum performance. Why is this? Will do, Alex.
The high level feed should be taken from the amp outputs because you don't want the effects of back-emf from the speakers affecting the subwoofer signal. Going from the amp terminals, where output impedance is lowest, will give you the cleanest signal. I used to use the 'B' circuit in my amp so that I could easily turn off the sub signal if I wanted.
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Post by John on Sept 30, 2014 4:42:28 GMT
I used to pick from the amp side but preferred the low level feed. My current set up will only allow low level feed
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Post by pinkie on Oct 1, 2014 7:59:41 GMT
My 2 bobs worth, cos I keep faffing with this. I repeat Martins warning - it is easy (it seems) to get carried away and dial in too much bass Room matching is important in terms of response at the listening position - that needn't really affect where the sub is physically in the room - the wife determines that. It is more critical to get the crossover point and overall gain level right. But to repeat again and again - don't get a "HiFi" bass result just cos your mate from Holland wants to feel organ notes in the chest  |
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AlexM
Rank: Duo
Posts: 30
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Post by AlexM on Oct 1, 2014 10:02:50 GMT
Yes, I'm very happy with the sound of the system as it is - I don't really want to change the sound of the system, just add some bass extension, so moderation is the key. Corner placement gives +6db room gain, but not clear if this placement causes other problems such as excessive excitement of room resonances that can't be counteracted by gain adjustment and/or use of parametric eq to notch out any modes at the listening position. My listening room is 15 x 18 x 8 ft.
I suspect I will set up the cross over frequency at less than 50hz, and use the sub to get down to 20hz or below (this sub will give useful output down to 14Hz). Hopefully this is will give better scale and atmosphere without obvious 'bass in your face!' |
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Post by John on Oct 1, 2014 10:44:30 GMT
Sound like a good crossover point to start from but do have a play with it
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Post by tony on Oct 31, 2014 2:26:48 GMT
Tried my big sony av amp with my 63s running an active sub into the mix, just as an experiment!!! Sounded pure pish/my good lady said it was like the Jurassic park soundtrack-----youve got to at least try some things?
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Post by John on Oct 31, 2014 5:14:51 GMT
A lot of sub woofers are more geared up for movies. I love the control going active and using DSP in the bass gives, but for most people its not a set up that would suit their system
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Post by MartinT on Oct 31, 2014 6:28:16 GMT
The thing about having deep bass capability is that music without deep bass should not sound in the slightest bit bassy, yet will be enhanced just by being able to reproduce the shifting air and presence of a recording venue.
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Post by John on Oct 31, 2014 6:59:35 GMT
Yes sums it up well.
Having the ability to take out my bass I feel like I am missing a lot of the music. My system sounds better with the bass added (This is the key it should enhance the listening experience with all types of music)
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Post by John on Nov 2, 2014 15:54:52 GMT
I am now convinced the best way to integrate a sub is to use DSP as this gives you the control over cross over and slopes in real time that allows you to get the best out of your bass speakers with the rest of your system and room
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AlexM
Rank: Duo
Posts: 30
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Post by AlexM on Nov 25, 2014 18:21:15 GMT
HI,
I have plumped for the BK XXLS400 12" sealed subwoofer. This includes a Peerless XXLS 12" long-throw woofer and BK's own 400W class A/B linear plate amp. I decided that the Rythmik audio F12 cost almost double the BK when shipped, and if I liked it, I could add a second BK 12" Sub and a Antimode for about the same amount as the 15" model, which is probably preferable.
I have specified a different filter scheme for the BK to the default (one variable LP filter 24Db/Oct 40-120 Hz + fixed 12Db/Oct LP filter @ 120Hz) to a variable LP filter acting from 24Hz to 80Hz at 24Db/Oct). BK offer this modification FoC, which is cool.
I'm looking forward to it's arrival - I should be able to get to <20Hz at decent levels with room gain.... hello neighbours!
Regards,
Alex
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Post by John on Nov 25, 2014 18:25:47 GMT
Let us know how it goes Alex
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