Subwoofer Help [Archive] - Audioholics Home Theater Forums

maximus73

04-15-2003, 01:48 PM

I recently moved into a new home where the builders pre-wired the house for sound.  In my home theatre room there is a run that is labeled "subwoofer".  This cable is a thick yellow cable with two pairs of speaker wires inside(red&black, white&green).  The one end of the cable(receiver end) has a device on it that takes the two pair and turns them into a single rca input.  The other end has nothing but the 2 pair of speaker wires sticking out.  My questions are:  What is that converter on the receiver end called and what should I look for when going to buy a subwoofer?  Thanks

Clint DeBoer

04-15-2003, 04:07 PM

Strange.. usually, you'd just run a single cable and then split the end at the subwoofer with a Y-cable to feed into both inputs of your subwoofer... Your scheme seems to indicate that they ran two cable runs and joined the end at your receiver.

If the other end isn't terminated with RCAs, you'll need to do that, provided you are using line-level inputs to your subwoofer.

See this article (http://www.audioholics.com/techtips/setup/loudspeakers/subwoofer_2channel.php) for more info.

05-14-2003, 11:28 PM

uhh hi everyone... i am a complete noob when it come to AV so i probably sound like a idiot.

ok i just bought a reciever(pioneer vsx-d411) its cheap but o well. anyway i have 2 sony xplode subs and i was wondering how to connect them? cause the cable i have has 2 wires on both ends, and my reciever only has 1 jack for the sub. i was wondering if there is a adapter that i can get or something? any help is greatly appreciated...thx

Clint DeBoer

05-15-2003, 10:02 AM

So you want to connect two car audio subs to a home receiver?

05-15-2003, 11:45 AM

if its possible  <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

05-15-2003, 11:59 AM

or can i  just hook one up somehow?
can i like put a rca connecter on the end of the wires or something?

Yamahaluver

05-16-2003, 10:01 AM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>hawke : Strange.. usually, you'd just run a single cable and then split the end at the subwoofer with a Y-cable to feed into both inputs of your subwoofer... Your scheme seems to indicate that they ran two cable runs and joined the end at your receiver.

If the other end isn't terminated with RCAs, you'll need to do that, provided you are using line-level inputs to your subwoofer.

See this article (http://www.audioholics.com/techtips/setup/loudspeakers/subwoofer_2channel.php) for more info.
hawke,

Do we still need to use the Y cable for subs as most of them are set to bridge the signal when a mono RCA cable is attached to the L channel? I know Yamaha and M&K doesnt reccomend using Y cable for RCA in.

Clint DeBoer

05-16-2003, 10:19 AM

Depends on the sub. Velodyne CHT Series need the Y-adapter. I don't know what model sub maximus73 has.

05-17-2003, 02:15 AM

so is it possible guys? if so can u tell me how?

05-19-2003, 06:28 PM

does anyone even know if its possible?

Clint DeBoer

05-20-2003, 10:26 AM

You can connect either a speaker level input to a car sub that accepts AMPLIFIED audio signal (but it will require the sub to have an integrated crossover), OR you can connect the LINE LEVEL output of the receiver to a self-powered car  subwoofer.

I'm not familiar with the model you have - but there are the guidelines to follow. Connectors aren't a important as the presence of a crossover, or the sub being self-powered.

05-20-2003, 03:48 PM

uhh ok, can i get that in english??? jk  i am a noob though so could u explain a bit more?

by the way i have a pioneer vsx-d411 reciever and 2 10" sony explode subs

the receiver has a rca jack for the sub and the subs have the pressure-hold things for the wires.the subs arent self powered either.

would it be eaiser if i got somesort of powered box or something?

Clint DeBoer

05-20-2003, 05:18 PM

"You can't get there from here." <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

Hang loose and save up for a powered subwoofer.

05-20-2003, 10:21 PM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Guest : uhh ok, can i get that in english??? jk *i am a noob though so could u explain a bit more?

by the way i have a pioneer vsx-d411 reciever and 2 10" sony explode subs

the receiver has a rca jack for the sub and the subs have the pressure-hold things for the wires.the subs arent self powered either.

would it be eaiser if i got somesort of powered box or something?
If your subs have built in crossovers as I suspect most of them do, then all you have to do is connect your receiver's amp section to the sub and then take the connection from the sub to your main speakers.

Eventualy, a powered sub would be the best choice for you as it would tax your receiver less and enable you to get better performance out of it.

05-21-2003, 01:31 AM

k thx guys ill get a powered sub... sounds like it be the best option i appreciate the help

05-21-2003, 01:33 AM

do u guys have any recamendations for a mid-grade powered sub?

Clint DeBoer

05-21-2003, 09:15 AM

What do you mean by mid-grade? How much do you want to spend?

05-21-2003, 03:22 PM

under $300 US

Clint DeBoer

05-21-2003, 05:14 PM

Try looking at Velodyne subs on eBay (http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2 F&krd=1&from=R8&MfcISAPICommand=GetResult&ht=1&SortProperty=MetaEndSort&query=velodyne)
Axiom Audio's EP series starts at $380, but if you wait for a B-stock deal, you may find it cheaper.

05-21-2003, 11:58 PM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Guest : do u guys have any recamendations for a mid-grade powered sub?
The Yamaha SW-320 is avaialable at e-bay for $340 and the awesome YST-SW 800 with class D 800 watts amp and fantastic sound is for $500 at the same e-bay.

Check them out.

05-22-2003, 02:47 PM

is the velodyne cht-10 a good bargain at about $200

Clint DeBoer

05-22-2003, 03:03 PM

That's about fair. It's a good sub, though not very tight - once you compare it to more expensive models. If you want somehting to fill in the low end, the CHT-10 (which I have personally heard at length) will do fine.

Bottom line: for $200 it is a great choice.

05-22-2003, 03:26 PM

is it a good idea to get it or sould i get something nicer?

05-22-2003, 03:30 PM

i have like 40 min on that one... (its 2:30 eastern) what do u recomend for a 'tighter' sound and what exacty does that mean? more punch or somethin?

05-22-2003, 03:34 PM

is the VELODYNE CT-120 a better sub?
can get it for the same price

BTech

05-25-2003, 03:33 PM

Hi all, Quick and easy question ... If your not running speakers through your sub, then what exactly does the crossover do ?

05-27-2003, 11:48 AM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Quote </td></tr><tr><td id="QUOTE"> If your subs have built in crossovers as I suspect most of them do, then all you have to do is connect your receiver's amp section to the sub and then take the connection from the sub to your main speakers.
</td></tr></table>

This could be a recipe for disaster, especially if the sub is rated at 4 Ohms. *You can easily overdrive a receiver's amplifier into clipping and/or protective shutoff.

In the case of unpowered sub(s) I would recommend a separate power amplifier for the sub(s) instead of the receiver's amps, or as you indicated get powered sub(s).
__

BTech,
The sub's crossover is there as an alternative to using the internal crossover in the HT processor. *Many subs have a switch that turns off their internal crossover completely. *If they don't then you simply turn the sub's crossover up to it's highest setting when using the crossover in the HT processor.

For example, to use the sub's internal crossover you could feed the L&R *LINE-OUT from the HT processor to the sub first, and then use the L&R *LINE-OUT from the sub to the L&R *LINE-IN *of the amplifiers for the main speakers. *This could also work with receivers if they have L&R PRE-OUTs and L&R AMP-INS.

This means in the HT processor you must set sub=no, mains=large and set the sub's crossover frequency between sub and mains to blend them where they sound the best. *

A good crossover starting point is to set the sub's crossover an octave above the mains -3dB low frequency spec, but this does depend on what type of crossovers the sub uses.

An example of the octave above the mains -3dB;
mains -3dB = 30Hz
sub xover set to 60Hz