Sub wiring for stereo

[machinehead]

Gents, just got a C1 sub to complement my ATC SCM 12's.

 

The system focus on audiophile quality music.

 

The sub accepts either line level or amplified inputs.

 

1. Which do prefer for listening to music and integrating the sub with the monitors?

 

2. Does the wire need to be the exact same as what I am using for my speaker wire or interconnects?

 

Thanks.

 

[vortecjr]

for music I would use the hi level input in paralel with the speakers and yes the cable matters. I would come off the amp and not the speakers. This is the best way!

 

I would then use the line level/LFE for movies with the sub output if you are set up for that. Im just not sure how you would connect one sub out to two inputs. It might be a single rca cable or a y-adapter. Check the instructions at that point.

 

Regards

 

Jesus R

www.sonore.us

 

[ciamara]

If you are after audiophile playback, I strongly recommend not using a subwoofer this way. Sub-bass, contrary to what many people say, IS directional. Subwoofers like the C1 sum two channels of information and route it to a mono subwoofer, which gives an acceptable result, but certainly not a high end audiophile result. If possible, you should use an active stereo crossover and match sub bass drivers and cabinets to go with the speakers. Make sure that crossover is well designed and matched to your speakers or your results will not be very good. You could cross over at, say 80 Hz, and have two sub-bass enclosures -- one under each of your front right/left speakers.

 

I don't want to make you feel like you've made a bad decision with the purchase of a C1. If you just want thump, you'll get it. If, however, you want imaging at all frequencies, you really need each speaker "stack" to be full range.

 

FYI, if you do surround sound this way, tell your surround sound processor that you do not have a sub so that nothing is routed to the ".1" channel. Also tell it that you have full-range front right/left speakers. This way, when watching movies, you'll get all the subwoofer information out of the front right/left with better imaging and directionality. Set up properly, this can sound very nice.

 

[machinehead]

@ciamara

 

You couldn't be farther from the truth. You really should not comment on things you know nothing about.

 

The C1 does not thump at all. It is a perfect balance with the SMC 12's as if there are a pair of full range speakers instead of a 2.1 set up. True you can't get a true left and right bass response, but there is not thump at all. You should listen to an ATC system if you get a chance they are true gentlemen.

 

 

 

[ciamara]

Easy .... I wasn't suggesting that YOUR sub only produces thump. What I am suggesting, based on experience, is that a .1 channel, in general, is not as good as full range left and right channels, each with their own sub-bass capabilities. To say I know nothing about ATCs is simply untrue. I have listened to their products, including the SCM100s, among several others. They are very nice, though I personally am not a fan of the 3-inch dome midrange driver -- but again that's PERSONAL taste.

 

 

 

[machinehead]

Sanay,

 

I am only referring to the ATC C1.

 

I was not implying that you don't have audio knowledge in general. I am sure you guys do quality work.

 

The ATC C1 sub is the must subdued sub I have heard. I was worried when I bought it because I hate thumping bass.

 

But you could not make this thing thump it you wanted to. I have it set at 85% volume and you don't even know it is there,

it blends perfectly.

 

The full range ATC's are woefully out of my price range so they were not an option, the C1 allowed me to get into the ATC

brand and stay in my budget.

 

No hard feelings, my previous words were a bit harsh, I should have thought a bit more before writing.

 

Enjoy your evening.

 

Jeff

 

[ciamara]

Thanks Jeff -- I appreciate that. Just as an FYI, "thump" is generally (though not always) produced by using a horn-based or ported enclosure. To take it to one extreme, look at some of the top-end dance clubs out there (e.g. Stereolab in Singapore; Lotus Sound Bar in Hawaii, etc.). At THESE venues "thump" is desired, and it is achieved by horn-loading the sub-bass and mid-bass drivers in massive trapezoidal or scooped cabinets. This increases efficiency and distorts the sound, but in a way that is pleasing to the ear and desirable for the dance floor. If done correctly with high quality components, even audiophiles will appreciate such systems for what they can do. But maybe not in their homes, unless they like to throw parties!

 

Back to the worlds of the professional studio and home audiophile, direct-fiiring subs (in which the driver fires directly forward, or at the very least is not asked to force air through a smaller opening) should simply fill out the lower octaves without an exaggerated thump. As does your C1. I guess I should have been more careful in my use of the word "thump" up above ... Live and learn. Have a nice day.

 

[machinehead]

Thanks Sanjay for your information and kind words. If I ever get to Singpore that sounds like a great place to experience, in my younger days I have visited many clubs in LA. and many car stereo competitions where thump was wanted, and is fun. I can still find it fun as long it is not in my home!

 

Thanks again,

 

Jeff

 

[Christopher]

I have experimented with sub wiring in a number of systems over the years. Each approach has pros and cons. Below are a few approaches that I have tried with comments from my personal experiences.

 

Hi Level Inputs (speaker wire connections)

 

15 years ago, I wanted volume and bass. I was a semi-pro drummer and thought the more dB the better. I was using an Adcom preamp (GFP-565), Adcom amp (GFA-545II), B&W bookshelf speakers (DM570s) and two Yamaha subs for left and right channel (YST SW 100). Each sub was placed on the floor next to the respective bookshelf speaker that was on a stand. I used steel Sanus stands that resulted in tweeters being at ear height when I was seated in the listening position.

 

I used generic 10 AWG speaker wire from the amp to hi level inputs with each sub. Then I used the same speaker wire from hi level outs on each sub to corresponding speakers. Active crossovers with each sub were usually set at 80 Hz. The volume with each sub could be easily adjusted and they were usually set at 50%.

 

This approach worked well. The system played louder with less distortion than direct wiring to each speaker. The DM570s tended to bottom-out when played at loud volume when wired directly. Wiring the speakers with subs and active crossovers in the chain took the stress off low end. However, the amp was still running full range until it reached the sub’s active crossover. Then I tried another approach.

 

Direct Wiring to speakers and subs

 

A few years later (still over 10 years ago), I upgraded to floor standing speakers (DM580s) and 300 watt per channel mono bocks for power (GFA-565). There was a significant difference. Full range speakers improved soundstage, and bass was more integrated, tighter and articulate. The power with 565s seemed endless. Compared to the hi level input approach, this was an improvement.

 

Low Level Inputs (RCA) in between preamp and amp

 

More recently, I purchased an SVS sub that has hi level, low level and balanced inputs. It was an upgrade/replacement for a Paradigm sub that I purchased about 5 years ago. In this system, I’m running iMac>Amarra Mini>Benchmark DAC1 Pre>Rotel 200 watts per channel amp (RB 1080)> B&W speakers (CM-7)>SVS sub (SB12-Plus).

 

I have tried various configurations with the SVS sub. SVS techs recommended a low level RCA connection: preamp>sub>amp>speakers. This was also accomplished with balanced cables instead of RCAs. I tried both (RCA & balanced) and it involved low level runs to the sub and then back to the amp. The sub performed well, and the amp was relieved of heavy lifting, but the overall sound seemed compromised. To my ears, it was missing something.

 

After many listening tests, I decided to wire speakers directly from the amp. This also reduced a lot of cabling to and from the sub. The amp is receiving balanced inputs from the Benchmark. The sub is receiving low level RCA inputs from the Benchmark. In my experience, this yields the best results without adding sub-related crossovers and extra cables in the mix. Both CM-7 speakers are running full range with no external crossovers. I should mention that CM-7 speakers have frequency responses that generally range from 62Hz to 22kHz. I don’t use the sub all the time; when I do, I usually have the sub’s crossover set between 70 and 80Hz. With this approach, music seems more accurate and musical. I’m considering adding another SB12-Plus sub so that each floor standing speaker will have a corresponding sub for left and right channel (via RCA). But, I’ll probably upgrade speakers before adding another sub.

 

Frankly, I think my preferences have changed over the years. Instead of wanting loud music with lots of bass, I am trying to get closer to the recording. The accurate reproduction of music is a humbling goal. As a former musician, I appreciate and welcome the challenges. Thanks to CA, computer-based audio is now my reference and I continue to experiment with other systems. Exploring new technology is a joy and I prefer to keep an open mind to new approaches. Learning along the way has been fun and incredibly rewarding.

 

In the end, I think that equipment, combined with placement and wiring all contribute to our listening experiences. I’m not here to say that one approach is better than another. Hopefully you will find the approach that works best for you….and, if your preferences change…so might your approach.

 

Wishing you happy listening,

Chris

 

p.s. @ Sanjay,

 

I purchased Amarra Mini from you in December 2009 and my experience was very positive. You were knowledgeable and your advice was helpful. In addition to your technical skills, I found you to be easy to work with, personable and very dedicated. I hope that you continue to share your opinions here at CA.

 

 

 

[Spacecowboy]

Dear All,

I have just ordered two Sub's to supplement my main speakers and for high level input they just offer a Speakon socket. They also supply a Speakon cable with "naked" ends to connect to the Amp. As my main speakers are wired with a high quality "audiophile grade" cable, I don't want the Sub to run on cheap wire. I would want to use a Hifi cable with is supplied with either spades or pins. How do I get this into the Speakon socket. I haven't found any adapter on the internet. How do other tackle this ?

 

Thanks for sharing some advice :-)

 

Cheers

Christian

 

[ciamara]

Hi Christian,

 

Speakon connectors are great for pros, but they may not accommodate all audiophile-grade wires (certainly not the ultra-thick stuff). That being said, there are good connectors available and you can use decent wire to get very good results. Also, keep in mind that a sub with Speakon terminals is designed to work with Speakon connectors, so the weak link may not necessarily be the cable. Match the quality of the cable to the quality of the sub and the rest of the system. I hope this a little helpful...

 

 

Sanjay

 

 

[Spacecowboy]

Dear Sanjay,

 

thanks for your advice! I appreciate your professional expertise! Do I get it right, that I would have to buy a decent hifi cable cut off the eg. spades on one end and solder a high quality Speakon connector to the cable ?

 

Is there no "easy" way out ?

 

Thanks for some clarification...

Cheers

Christian

 

[blueixus]

Russ Andrews who are the UK distributor for Kimber offer a Spade to Speakon Plug Kimber Cable.

 

That is if your into Kimber Cable....

 

 

 

 

 

[Audio_ELF]

I'm not commenting on the quality of the connector, but Speakon connectors will take cable rated for 30amp mains (i.e. about 5mm sq) - there's not many HiFi cables (I've come across) bigger than that...

 

[blueixus]

Up to a 4 way connector (3 way for the sub), which is pretty good all things considered.

 

Another example of the pro world vs the audiophile world

 

[Shadorne]

Frankly I would not worry about wiring. It would probably be best as Sanjay mentions to pass a filtered line level signal to your sub. (Active configuration).

 

Instead of using the basic low pass filters in the sub you could add a parametric EQ in front and then notch filter for room modes. Room modes are almost always huge between 30 and 120 Hz....by filtering what your sub receives you can achieve a more accurate bass response.

 

Billy Woodman does not like this approach but honestly how many of us can afford a bespoke studio built by Roger D'Arcy!!! IMHO, the most practical way for home audio users (non-professionals) is to use EQ to smooth the bass response for room modal issues. There are several software programs that help you measure in room response - Room Eq Wizard, Fuzzmeasure etc. (you'll need a microphone and stand and a sound card or box like an EMU 0202 - and once you have measurements you will know what you are up against)

 

[ciamara]

@Eloise,

 

Yes, you are correct that Speakon connectors can accommodate fairly thick wires. Where we've had issues in the past is in attempting to terminate a very thick, audiophile-grade power cable with a Neutrik NL4FX connector -- it simply would not fit. For this application, though, I suppose most cable should work.

 

@Christian,

 

I have conducted some research into your equipment. The Speakon cable the manufacturer provides is designed to work with 3 conductors that should be connected directly to the amplifier terminals powering your full range speakers. This is not an approach we see every day, but the manufacturer feels this will give you, and I quote from the manual, "exactly the same signal as being supplied to the main speakers." They further say "this means that the character and tonal balance of the bass from the main speakers is carried through to the sub bass."

 

If you want to use these sub-woofer cabinets, you can work with the cabling the manufacture provided, or build a custom cable using audiophile cabling of your choice and good quality Speakon connector. Some have screw down terminals, and others should be soldered. Just remember to use the correct wiring pattern. There are 4 terminals in a Speakon connector, and you need to use the same ones the manufacturer used, and then make sure you connect the other ends to the correct terminals of your amplifier. This all assumes that your amplifier has binding posts that will allow you to do this easily. FYI, I believe the reason they have elected to use a Speakon connector here is that you will be sending an amplified signal from two sets of terminals (unbalanced). The Speakon minimizes the possibility of wires touching each other ... which would be undesirable for a host of reasons!