Subwoofer questions

[Cygnus]

Hi guys, I have some questions about subwoofers. I don't have one yet, but when I do, I would like to know some stuff about it, and how my receiver would work with a sub.

Subwoofer cable, isnt this just a standard RCA cable that goes from the receiver to the subwoofer. Or is there a difference between an RCA cable and a subwoofer cable? However, the sub would probably allready come with a cable anyways..But i'd still like to know about this.

Regarding the receiver (Denon AVR-1705).

Now, if I set the subwoofer to "YES" on the Denon, does the subwoofer work in all sound modes, not including Denon's DSP's? These are the modes which I'd like to know if the sub would work on:

Direct
Stereo
Dolby Prologic
Dolby Prologic II (Cinema, Music, Game)
Dolby Prologic IIx (Cinema, Music, Game)
Dolby Digital
DTS NEO:6 (Movie, Music)
DTS ES DSCRETE

Does the sub turn on and work in all of these modes? Even for the stereo mode, so it'd be like 2.1?

Now, obviously i'd have to play with the xover settings, to make the sub sound right.

And, what shuold I look for when buying a sub? What features etc.?

 

[Takeereasy]

Question #1 Sub cable and many rca cables are the exact same inside. You should stay away from compoaite stereo (red & white) rca cords because they aren't required to run at the same impedence as other rca cables. In other words digital coax, component, composite video, and sub cables are all supposed to be able to pass the same kind of signal at the same quality.

Question 2: I don't think your sub will work with the setting "direct". It will however work with every other setting including DSP modes.

Question 3: Features to look for are many. One main concern is how low a sub will play. The human hearing spectrum is ideally from 20 hz to 20,000 hz. Most times it will be less than that, but supposedly you would want an entire HT to be able to reproduce sound from 20 to 20k hz. That is considered "ideal". Buying a sub that can play to 20hz or lower with authority is not cheap, trust me, i'm looking for a sub right now myself. Not too much music will hit 20hz, I've heard somewhere that really powerfull pipe organs go down to 25hz or so. 20hz and below is more for HT purposes.

Another impotant feature is how high a sub can play. Subs need to be able to play pretty high in order to integrate into a speaker set up in most cases. My Marantz receiver has a cutoff at 80hz. That means my speakers are only fed sound down to 80hz. All other bass is sent to the sub. If the sub cant produce sufficient sound at 80hz then there will be a gap between the speakers and the sub that you will hear evertime there is supposed to be sound at that level.

Another thing to look for is opinions. Look on sites like this one for opinions on subs you have researched, as well as sites like audioreview. You already know to demo so I wont put that down.

This one is up for debate, but for myself, weight is a factor. I have a sub that weighs 30lbs and I hate it. My next sub will be at least 50lbs I've decided.

SPL's are important (sound pressure levels). The higher the SPL's the more you'll feel it. Anything from the high 90's and up is really good.

People will also tell you that the size of the driver is very important for different reasons. Bigger drivers, say 12" and up will move more air, while smaller drivers like 8" or 10" are supposed to be more musical. Not always the case but usually to change either of those principals involves $.

There's more but last night was poker night and I can't think too clear, out till 4 am and I didn't wina damn game, out 3rd in all 3.

Edit, should read 3rd to last in all 3 games.

 

[Cygnus]

Thanks for the tips Takeereasy! I appreciate it!

 

[bray]

Denon & sub

My sub works in "direct" and "pure direct" mode on a Denon 2805.

 

[Takeereasy]

I just read your manual and Bray is right. It looks like the only way to defeat your sub is to manually turn it off using either your receiver or the controlson the sub. Soory to point you in the wrond directio, it's just always been my experience that direct = no sub.

I also forgot to mention wattage wiht regards to subs. You need a lot of pwer to get really low in most cases. Look at the RMS powr rating more than the Dynamic rating. If a subs RMS is 300w for example it can have a dynamic power of 700w. Power isn't everything, but it's important.

Also holy crap! That Denon is feature loaded. I had no idea how loaded it was. While I'd never use several of those features they are still nice to have. That is a ton to get with an "entry level" receiver.

 

[mtrycrafts]

A sub will work with any RCA type cable, including the red and white audio cables, no problem. One thing to remember though is that a video cable will work in an audio setting as well then you only need one kind of cable for all RCA applications, digital, video and audio; an audio cable, red/white should be used for analog audio only.

 

[Takeereasy]

A sub cable is should be a decent quality 75 ohm cable. Often times red and white stereo cables are skimped on by manufacturers. I'm not saying that there will be noticible sonic differences, just that it's better off to go with the cable that is better constructed, that is usually a 75 ohm cable, and the one's I listed Composite video and the like are often times better quality cables than the red and white stereos, at least in my experience.

For my sub cable I am using a monster composite video cable that I got at a discount that was massive to say the least ($3.25 for a $90 CDN cable). It is one of those pretty braided jacket models, but it doesn't do a better job than my AR cable did before it. Cygnus, just go to an audio store, or even Futureshop, look at all the sub cables, and see what the impedence is on every single one of the cables.

 

[Cygnus]

Thanks for the tips, takeereasy...now...how would I hook up a subwoofer to my receiver that has these connections?

Where would all those go to on my receiver?

Thanks
Travis

 

[SilverMK3]

Can't say for sure, but I'd set the switch to "subwoofer direct" and plug the single coaxial subwoofer cable from the LFE out on the receiver to the bottom-right RCA jack labelled "LFE" on the subwoofer.

 

[Cygnus]

Yeah, that makes sense now...I don't have a subwoofer yet, but when I do if it has all of these connections I wanted to know how to hook it up.

Thanks

 

[jaxvon]

Just for reference, the lowest note on a big pipe organ is 16Hz. So if you listen to some mega big pipe organ music, you're gonna need a heavy-duty sub.