Subwoofer Connection...A newbie is in need of help!!

[Cyclop]

Hey people.

I recently bought a used set of "Fidek" brand 7-channel amp complete with sub, fronts, backs and center. I just have one problem...can't seem to figure out where to connect the sub. The only thing I can see in the back of the amp is an "Out 1" and "Out 2" RCA plugs, and when I use those the sub sounds like a regular speaker but it's not a good sound (i.e.: I hear too much high, not enough bass).

I talked to MArk Duncan here on the forums, and he was talking to me about "Filters" for the signal so that the sub receives the right bass signal (and not just a regular speaker one). Only "Filter" I could find was an "Input" plug on the back of the sub...I posted pics on a quick web page I did, along with the specs of my system. If any of you would be kind enough to give me a hand it would be greatly appreciated!

Here is the link: http://www.geocities.com/cyclopguy/

Thanks a lot!

 

[Unregistered]

The input on the back of the sub says filter 20-150Hz but it's not clear to me if it actually filters to that frequency range (which would imply that its crossover frequency is 150Hz) or simply that the sub is rated from 20Hz-150Hz and you should send it a signal that is already filtered to that range.

Either way using out1 or out2 on the amp is not going to do what you want. They look like any normal line output, which means when you connect that to the sub input you are sending it a full range line level signal. If you say it sounds like a normal speaker then that input on the sub is simply stating that the signal should be filtered to the range 20-150Hz and the sub itself will not do it.

You need either a receiver/pre-pro with bass management (to set the crossover frequency somewhere at or below 150Hz) and connect the pre-outs of the receiver to the amp OR you could buy an outboard device that allow bass management like the ICBM from outlaw.

 

[Cyclop]

Oh boy, thanks for your reply...lots of technical terms here for me. I'll try to keep up... You mentioned: "You need either a receiver/pre-pro with bass management (to set the crossover frequency somewhere at or below 150Hz) and connect the pre-outs of the receiver to the amp"

Ok, so does that mean I need to buy a new amp? Cause if it's the case I do not like this option If I understood wrong could you please detail?

"OR you could buy an outboard device that allow bass management like the ICBM from outlaw"

Ok this sounds more like the cheaper way to do this...do you have any more information on how this thing would function? Where do I plug it on the amp? In the "Out" plugs? And what about the sub...does it get plugged in both "Input" RCA connectors?

Sorry for my ignorance, and thanks a lot for your help!

[Edit] Yikes just did a search for that Outlaw ICBM...250$ US that's a lot just to plug the sub!! Anything cheaper that would do the job for a non-audiophile person like me? I just want the sub to receive a bass channel that's it.

Thanks again....

 

[markw]

First question you need to answer.

What does that knob on your unit that says 20 - 150 do? This could make or break you. This is an open book test. RTFM.

 

[Unregistered]

markw,
Where do you see a knob that says 0-150? There is simply a label below the input. Obviously the first thing I thought of was the sub has its own crossover and a knob to set it like nearly all subs I've seen. I don't see that, unless it is hidden from view.

Cyclop,
Sorry for the confusion. I see only inputs for cd, dvd, etc and a few line outs. So my info still holds. You will need an active cross-over between the out1 and the sub. The ICBM is such a device and I've seen them alot cheaper than $250. A cheaper alternative may be available at Radio Shack or other electronics stores.

...Unless your sub does have a crossover setting knob which is just not visible...as markw assumed it does.

 

[JohnA]

Problem Solved

Here is what you got. You have the 2 outs from your Reciever, these are full range, so by themselves you are sending full range audio to the sub. From the pics on your web site the sub has no adjustable X-over....so what are you to do?....go to Parts Express and get 2 passive in-line x-overs.

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=266-254

We have other x-over points:

Part # x-over point

266-250 50Hz
266-252 70Hz
266-256 150Hz

To save some money, get a Y spliter and combind the L/R from the amp to a mono input on the sub and then you only have to get 1 x-over.

Hope that helps any questions you can contact me @
johna@parts-express.com

 

[markw]

1) Yep. After upsizing the picture, I see the knob is only a level control. It didn't upsize when I did it last time. He's gonna need a filter.

2) Depending on where the sub signal is coming from, wouldn't combining the L/R signals result in a mono feed on what was the L/R signal as well as to the sub? I do know from past experience that when doing this between a preamp and a power amp, it resulted in three mono channels, not two stereo signals and one combined mono sub channel.

 

[Cyclop]

Wow at last the light at the end of the tunnel!!

Guys thanks a lot for your replies...you guys seem to know what the heck you are talking about.

Markw: No there is no knob for the crossover...only a volume knob.

JohnA: Looks good...so if i understand well, I buy a pair of those connectors, and plug them between my "Out1" and my sub's "Input" RCA connectors, and that will do the job? Am I missing something here cause it's a pretty cheap alternative and sounds simple enough, even for me If it is the case, you listed the part # for different Hz, which is better for me?

As far as the "combining with a Y splitter to save money" goes, I read that they are sold in pairs so I think that solves the issue.

Will be waiting for your input before I buy the connectors...thanks again!

 

[JohnA]

It is up to you

After looking at the pic again of the back of the sub it looks like there are two options (the White which says "Line" this "should" take a full range signal "a line out" and filter it. The Red says "20 - 150" this "should" be a Low Level input {if your amp had a sub out it wiuld go in there} Now I don't had the manual for the sub so I don't know I just guessing. If it doesn't work like that try this: First unplug the red and see what happens, if you still get sound your going in the right direction, then test the red the same way, if you get sound out of both (with no difference than you can use both or just one or the other) now if you get sound out of just the white then that is the one to use if you go with a mono signal. So here is what you have: Sound out of one- use a "Y" adapter and buy one filter, sound out of both - use both and gt two filters.

"you listed the part # for different Hz, which is better for me?"

that is where you are on your own What you will have to do is try and try again, buy one set of filters at "X Hz" and see if you like it...if not exchange them for a different one. Parts Express has a 45 day return policy...I can't give to a solid answer cus' each sub is different and so is each room. Or you can just buy a new Dayton Audio 10" sub for $124.88
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=300-632

I hope this helped and didn't confuse you more...if it did i'm sorry...If you need more help just ask.

 

[Cyclop]

Ok got ya...

Ok thanks JohnA, I think I understood. Just one last thing tho, I understand you can't tell which filter Hz will work better in with my equipment/environment, but can you explain me the difference between lower (20) and higher (150) HZ? I.e.: will the 20 Hz deliver more bass to the signal?

Thanks again!

 

[JohnA]

Here you go

here is the info the "X Hz" is the point where the the filter "allows" the signal to come through...if you get the 266-252 which is a 70Hz filter, filters out everything that is not 70Hz and below +/- 3db.

Does that help? Also the 20-150 on your sub is the Hz range that it can take. So it works well between 20 and 150...I would start out with a 100Hz filter and if you still get midrange in the sub then drop it to the 70Hz but I wouldn't go below that...you would miss some good bass whan playing movies.

 

[Cyclop]

Ah, I understand now. I will follow your advice and go with the 100Hz for now. Again, thanks a lot for your help, it was greatly appreciated!

 

[JohnA]

Any Time!