Incorporating a sub (or 2) with a 2 channel system

[lcolbur1]

Hi,

How might I go about incorporating subs in a system with 2 speakers (left and right) which are both wired to a 2 channel integrated amp?

Thanks!

[Kal Rubinson]

You need an external crossover or you need to get a sub with one built in. For stereo only, the RELs are pretty good.

[lcolbur1]

Would it be possible to build the crossover without having to design it around the existing speakers?

[Kal Rubinson]

Sure. First, we are not talking about passive networks as the sub should have its own amp. However, at these low frequencies and with 24dB slopes, you do not need to do much customizing but you will need some way to set levels and it might be a good idea to be able to tweak frequency.

Were you planning to build the sub? If not, there are subs with crossovers and amp ready to go. There are also plate amps with built in crossovers.

[lcolbur1]

I was hoping to build subs and like the idea of using a plate amp with built in crossovers. I suppose I could just buy the plate amp, but are there any better and/or cheaper options of powering the subs and controlling the frequencies without having to replace my 2 channel amp?

Thanks

[Kal Rubinson]

The plate amp powers the sub through an active LP filter but has a passive HP filter for the output of your 2 channel amp to feed the main speakers.

See: http://www.parts-express.com/wizards...TOKEN=72809229

[lcolbur1]

Ok, so would it be wired as such?:

speaker output to plate amp input, and low level output to amp input.

I'm not sure if it helps, but I have a NAD C 316BEE Stereo Integrated Amplifier shown here:

http://nadelectronics.com/products/hifi-amplifiers/C-316BEE-Stereo-Integrated-Amplifier

Thanks

[Kal Rubinson]

Ok, so would it be wired as such?:

speaker output to plate amp input, and low level output to amp input.

I'm not sure if it helps, but I have a NAD C 316BEE Stereo Integrated Amplifier shown here:

http://nadelectronics.com/products/hifi-amplifiers/C-316BEE-Stereo-Integrated-Amplifier

Thanks

No. Follow the links and read up. Speaker output to plate amp input terminals and plate amp output terminals to main speakers as well as, internally, to the amp/sub.

http://www.parts-express.com/pdf/300-805m.pdf

http://www.parts-express.com/pdf/300-784.pdf

[ruseriousclark]

I was hoping to build subs and like the idea of using a plate amp with built in crossovers. I suppose I could just buy the plate amp, but are there any better and/or cheaper options of powering the subs and controlling the frequencies without having to replace my 2 channel amp?

Thanks

Do you have any other processing equipment in your setup? If so disregard the following:

I don't want to complicate the issue here but what you are describing is bass bins, not subs necessarily. Really just depends on your intended use, but bass bins are better suited to musical applications and I guess can be dual purpose for some HT but they are really an extension of the mains for lower mid and low end.

I run bass bins in one set up but its because they are 1) Strictly for music, 2) specifically for the mains which are not adequate in the lower mid range, 3) a sub would be too much.

Why bass bins? They can be cheaper.(I've got about 150.00 in each of mine) Easy to customize. They look cool. One two channel can run everything. ( Not really ideal, but it can be done.)

Karl is right in every thing he has said. I would add that his original response with and external crossover is what I would do. Or build the crossover into the bass bin.

Plate amps as an option is much more simple, but if you are wanting to add mid to low end assigned to each speaker you may be wanting bass bins. If you just want multiple sub-woofers all playing simultaneously then a single plate amp is your best option. Just a thought.

[Kal Rubinson]

Do you have any other processing equipment in your setup? If so disregard the following:

I don't want to complicate the issue here but what you are describing is bass bins, not subs necessarily. Really just depends on your intended use, but bass bins are better suited to musical applications and I guess can be dual purpose for some HT but they are really an extension of the mains for lower mid and low end.

I run bass bins in one set up but its because they are 1) Strictly for music, 2) specifically for the mains which are not adequate in the lower mid range, 3) a sub would be too much.

Why bass bins?

Yes, why? How do you define "bass-bins" in such a way as to distinguish them from subs when applied similarly? Why would a sub be "too much?" See REL's configuration.

Kal (not Karl)

[ruseriousclark]

Sorry Kal. Spell correct thinks you are Karl. :W

Sub was just too much $$$ given the money I had in the speakers I was pairing it with. 200.00 speakers 500.00 sub didn't make sense. May not be the case here.

Bass-bins/sub-woofer...semantics really. My reasoning in assigning names given the similar duty whether it be to a single speaker or set of speakers is dependent upon application. Where the applied duty extends to a frequency range outside that of a traditional sub-woofer (i.e., 150hz and lower) and operates in relation specifically to another channel (not on LFE or mono) I like to refer to these as bass-bins. Just what I've been able to ascertain. That and I typically think of bass-bins as being more of an extension to each speaker. Creating a quasi-3way, 4-way, etc. Not withstanding that both bass-bins I've used were driven by the same channel as the loudspeaker nullifying the need for additional power. Which I believed to be his original question.

Last time I did one I think I spent about 300.00 for two, built the cabs myself and had two M8n wired in parallel, driven at around 125watts crossed over to the bookshelf speaker at 300 or 400hz. The drivers were pretty flat below 500hz so crossover work was minimal (tech at PE figured it up). Bookshelf would get a little angry playing in the 100's. These things worked beautiful and extended plenty low enough for music listening.

I could be WAY off. That's just my application and understanding. Hoped it would serve as a cost effective means to comply with what requirements lcolbur1 has levied.

Again...it really depends on what the application and intended use will be. Just throwing out an idea that hadn't been mentioned.

lcolbur1- Are you trying to have a dedicated sub for each each speaker playing in stereo? What do you feel your system lacks and what do you want to accomplish?

[lcolbur1]

Thanks for your comments guys.

ruseriousclark,

I think that your definition of 'bass bins' is what I had in mind. My current speakers are not putting out as much bass as I would like them. Essentially, I thought maybe I could just add two larger drivers (12 or 15 inch) in separate enclosures, one for the left speaker and one for the right.

I actually think my main concern is cost, as I find that building anything myself saves $. Keeping this in mind, I did not want to have to buy an amp to power them, but rather use my existing amp to do so.

Also, because my speakers are in stereo, I wanted the bass bins to be in stereo as well.

like you said,

an extension to each speaker. Creating a quasi-3way, 4-way, etc. Not withstanding that both bass-bins I've used were driven by the same channel as the loudspeaker nullifying the need for additional power

Are there any bass bin builds/plans out there?

[lcolbur1]

Also, these are just for music, and the drivers dont have to be 12 or 15 inches.

[ruseriousclark]

I'll hope that someone with better technical experience than myself will be able to nail down for you what I'm about to type but I believe I understand your quandary.

A few things you may need to know:

To start, the use of a 12-15" driver would indicate that you are looking for lift in frequency response and higher SPL in a sub-woofer range. What you need to know here is that these frequency levels are non-directional. Meaning it doesn't matter where the speaker is located or if they run stereo or not, the sound is basically the same given there is no boundary loading(boomy placement next to a wall or in a corner), etc. So I understand why you think two budget subs running in stereo is beneficial but it really doesn't accomplish anything more sonically than one well built sub can do, other than the symmetrical aesthetic appeal.

Kal suggestion will work in almost every option where bass bins are much more specific and unique, but fill an important gap. Lots of people including myself have a dedicated sub for music only systems. There is nothing wrong with that and depending on the loudspeakers they are paired with can be far superior. Bass-bins as I understand and use them are just another option and have some pros and cons relative to cost and application.

Let's eliminate a lot of the guessing and theorizing and get down to what you have and what you want. I think we'll be able to point you in the right direction.

You want more bass and this is a music only system. Your running a separate amp stable down to 4ohms (which is good b/c if you go bass bins you extended your options). OK.

What are your left and right mains? What is your budget?

Answer these two questions and we can nail down several suitable options.

[lcolbur1]

My left and right mains are the Dayton RS TMWW towers. I suppose my budget would be right around the $300 mark, but this is just a guess.

[ruseriousclark]

Really surprised you lacking low end response on those??? They may just be craving more power or issues with room placement. Thats a big full range design. Do you have any listening measurements on them?

In any case. If you want more low end and can build your own box, buy:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-460

and

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-804

That's a stout set up for ~300.00. About as cheap as you can get given what you are pairing them with. You'll have 30.00 in your cabinet. Use fiberglass insulation for stuffing and go with a sealed box of at least ~1cuft.

[lcolbur1]

In any case. If you want more low end and can build your own box, buy:

http://www.parts-express.com/pe/sho...tnumber=295-460

and

http://www.parts-express.com/pe/sho...tnumber=300-804

That's a stout set up for ~300.00. About as cheap as you can get given what you are pairing them with. You'll have 30.00 in your cabinet. Use fiberglass insulation for stuffing and go with a sealed box of at least ~1cuft.

Thanks for the help!