Music lovers: do you add a sub or go 3 way?

It's not that simple. You'll get disproportionate bass output and have problems at higher frequencies if you add the other drivers without a cross-over.

A passive 3-way is not just a 2-way plus another cross-over. Among other things the midrange picks up some extra output output from the woofer and tweeter.

You're not going to be able to hire someone to make a decent cross-over for your proposed configuration for less than you'd spend to scrap the speakers and start from scratch with 3-way plans.


The short answer is that you have one option likely to produce good sound

A 3-way design by someone reputable (zaphaudio.com, murphyblaster.com, linkwitzlab.com, etc.) that suits your budget and placement constraints.

and some chance of integrating a sub-woofer with your existing speakers using an electronic cross-over (Ideally you'd plug the ports and either use the speakers' two high pass poles as part of their acoustic cross-over response or cancel them with zeroes and provide more appropriate poles using a Linkwitz Transform (analog) or biquad (digital) although you may get away crossing over above where output starts coming from the port with its phase shift).

The long answer is to read and understand Floyd Toole's book _Sound Reproduction: Loudspeakers and Rooms_ so you understand what your design goals should be. It's about 500 pages. Read and understand _The Loudspeaker Design Cookbook_ by Vance Dickason so you have some clue how to get there. About 300 pages. If you aren't afraid yet buy a microphone preamp, calibrated measurement microphone, measurement software, and perhaps cross-over software. Knock together some MDF cabinets, put drivers in, measure, and make cross-overs to match. Repeat until you're happy and perhaps make nicer enclosures when you get better sounding designs. Some people find that an enjoyable hobby which keeps them busy for decades.

Knowing that lots of people build other people's designs. With your wood working skills you can do that and make good looking cabinets.

Not mine (zaphaudio ZD5)

http://www.webherrera.com/blog/2009/...maple-baffles/



My last enclosures (Linkwitz Pluto+ subwoofer)



Next ones (linkwitz Orion with Don Naples' design changes; photoshopped and sketchup details)

Never had a three way. Yet.

Why not add 2 small 10" subs and use Y-cables?

Lots of flexibility with placing 2 small 10" subs.

Decent subs have built in variable crossover from generally 45-to-120Hz, and also variable phasing (I hope "phasing" is the right word). Going lower on the crossover point generally makes the higher frequency sound from the subs less obvious.

For decent Y-cables see bottom of http://www.bluejeancable.com/store/subwoofer/index.htm

The same decent sub-woofers generally have a fixed frequency first order high-pass which makes integration more difficult and isn't steep enough to prevent over-excursion problems after a ported speaker unloads.

You can run an AV receiver or sub-woofer controller with more functionality (or build a cross-over - Siegfriend Linkwitz sells boards) but it's not a plug-and-play solution.


Y-cables from Parts Express for a couple dollars each will be fine.

Kindly post a link that will explain this in plain English.


Seems like quibbling to me to go off on one low price (but decent quality) vendor (bluejeancable) over another that is more questionable (parts express) and for which you did not give a link.

Roughly what he's getting is that just throwing a subwoofer or two onto the system, from a line-level preout or speaker-level full range outputs, is not going to fully address the solution. You're still not dealing with a crossover, and that will cause some "unwanteds" with the bookshelf speakers.

The easiest answer for the original question is either to go out and buy (or build yourself if you really want) a more full-range pair of speakers; pick whatever you like. Bookshelves are not it. The second best answer is to add some sort of AVR/pre-pro (something that does bass management) and a quality subwoofer (or two or four or whatever). And this is not "best" in terms of best reproduction, it's relative to the tone of the original question. In reality, speakers that can really dig down to 20 or 25 hz are fairly rare, and generally very expensive. By contrast, a subwoofer able to accomplish this is not really a unicorn, and with a decent bass management solution can be tied into a pair of bookshelves fairly well. This isn't to say that "towers" (like the Linkwitz speakers pictured) don't also benefit from a sub.

I see no problems with PE or Monoprice; BJC doesn't strike mas "low price" but if it works for you, that's great! (They don't strike me as "gouge pricing" either).

My simple advice is to add a powered sub (you can build one). The separate amp and controls allow for so much more flexibility. You can dial it in to accomodate room acoustics. The trick will be getting the correct amount of bass and mid bass out of the bookshelfs to blend properly with the sub. You could try modding the crossover to do that. That project would be a lot easier than engineering 3-ways out of 2-ways.

You always add a sub, better if you add more than one.