More surface area = less distortion at a given output. I started out with 2x15” in a sealed box. Too heavy to move and looked really big in the room. I moved the same drivers to 2 smaller boxes and not only is it easier to move but the bass quality is much better due to having more sources of bass output which tends to average out the peaks and nulls. I was not expecting such a big improvement in bass quality.
I’m running my 2 subs in mono from 2 channels of a stereo amp. I am crossing over low - maybe 45-50hz with a steep slope so I would not likely benefit much from stereo subs. If your xover is higher and with shallow slopes then you may hear improvements.
There are a handful of efficiency benefits, as well as size. two moderately sized subs is better in some instances than a single larger one. No summing circuit either, so one less stage of manipulation to the signal (if you care about such things) and it can be driven pretty much right from a crossover assuming gain is high enough.
I would take a pair of 10-12" subs over a single 15" any day unless it was very affordable or pretty special.
For me, a Subwoofer is 40Hz and down as the LF cutoff of my towers is 31Hz (I don't bother with one anymore). I'm used to running subs in a car, in the trunk. No stereo effect lost there. Why run 2x100W when you can run 400W bridged? And for me, a "summing" circuit for this is built into my sub crossover, and in the past in cars, I used isolation transformers, and simply shorted left and right.
Last edited:
It’s not a matter of mono/stereo in my case. I am running 2 subs in mono . Power is not an issue for me. What is an issue is achieving flat in room bass response. I have a difficult room for bass. There can easily be 20db difference in level between a peak and a suckout in my room. By having 2 sources of sub bass I am able to optimize their positions for much better frequency response. If you have never measured the response in your room it can be a real shocker to see what you have been listening to. Getting rid of the major peaks can bring huge benefits in bass intelligibility and nuance as well as allowing you to hear past the bass resonances further into the detail and emotional content of the recording. Dips in the response cannot really be dealt with by using EQ. By having multiple subs and your main speakers running full range, if they are capable of handling low bass, you have many sources of bass at different locations in the room which can average out the response at the listening position. It is not easy to set up a system like this due to amplitude and phase interaction between the sources but if you invest the time it can bring big benefits IME. So that is the reason I would prefer in my case to have 2x100w rather than 1x400. The other thing to consider is how much power do you really need and how much can your drivers take before producing high distortion and compression. The Crown amp I use has led power indicators and I have rarely seem the -10db light come on. So that means peaks in the 30w range for very loud music, rock, bass heavy blues etc. I have large drivers in large sealed boxes so the efficiency is relatively high. Small drivers in small boxes would use more power so that is all relative to each room, equipment mix and listening preference.
Multiple subs always make a bit more sense to me.
Some neat reads-
Serious Audio: Two Great Articles on Multiple Subwoofers by Dr. Earl Geddes
Stereo or Mono Subs Xover at ~100Hz
Some neat reads-
Serious Audio: Two Great Articles on Multiple Subwoofers by Dr. Earl Geddes
Stereo or Mono Subs Xover at ~100Hz
I get you. I once had a place where the acoustics were so bad that there was no bass in my place but plenty next door. I'm all in favour of multiple subs if that's what's needed for that room, but IMHO they should all run mono from the same amp, or they should be powered subs negating the need for a sub amp in the first place 
Yes choosing a tube amp for subs is not a rational process. But that is what I like about diy and audio. Otherwise I would choose a Sonos and forget about it for the next 10 years
I think I do not need really a lot of watts. If I use a stiff power supply with ample uF I hope to get away with ~30 watts or so. I do have 2 subs with each 12 inch. This design I like because it is well documented and is not very complex. Maybe I can play a bit with the design and class A > B for more power. But first I will need to collect some money, some components and then spend the time
I think I do not need really a lot of watts. If I use a stiff power supply with ample uF I hope to get away with ~30 watts or so. I do have 2 subs with each 12 inch. This design I like because it is well documented and is not very complex. Maybe I can play a bit with the design and class A > B for more power. But first I will need to collect some money, some components and then spend the time
A large power toroidal and some low-impedance sweep tubes is where I would start if building an all-tube subwoofer rig. cross-coupled plate to plate feedback from power to driver tubes, and forget the usual audiphool tube choices. Something like a big 300-500VA for the output from Antek or Triad (or Toroidy, in the EU) and E130L, 6LR6, 6HJ5, or similar tubes. Pete Millet's DCPP amplifier design with a preamplifier stage added, and a suitably overspecified output transformer may be a good starting point. PCB's are available
100 Watts would be plenty per sub (and easy enough with tubes) if running two at reasonable levels for most use. Party level or bass-head blasting I would go to more efficient subs and parallel the output tubes.
100 Watts would be plenty per sub (and easy enough with tubes) if running two at reasonable levels for most use. Party level or bass-head blasting I would go to more efficient subs and parallel the output tubes.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.