Sub Advice

[pitdiver]

Guys a question. I am thinking on purchasing a powered sub perhaps a QTX 15SA. However I am not sure how I can connect it to the Mixer/Amp set up. As I understand it you can use a crossover and go down that road but at the moment that is on the back burner. Am I right I can run a powered sub from a line level output on the mixer. eg Booth on my Numark M6 for instance.

Ocasionally on small functions where basically I am just supplying music I use my Numark M101. Can I use the Headphone output for the Powered Sub in this case.

RH

[Andy P]

When I use one of these I just connect it in line before the speaker on one side. As bass is 99% of the time recorded mono it doesn't need a stereo feed or to pick up both channels.

[Excalibur]

Guys a question. I am thinking on purchasing a powered sub perhaps a QTX 15SA.

When I use one of these I just connect it in line before the speaker on one side.

Normally I'd advise against this, but as far as I can tell from reading up about the QTX sub on an earlier question, it doesn't filter the output to the tops. Thus, both top cabs will still be getting in effect the same signal, ie full range. No extra crossovers needed.

As bass is 99% of the time recorded mono it doesn't need a stereo feed or to pick up both channels.

Correct. However, if you get a sub such as the Alto series, they have two inputs. This means you connect your two mixer cables straight into that, no problem. Then you have two options. You can connect your tops to the filtered outputs, so that they don't have to reproduce the low frequencies which muddy the sound and sap power.
Alternatively, if you simply want to add bass, you can still feed the tops with a full range signal from the sub. Whichever sound you prefer is fine.

I usually recommend the Alto, as it's about the cheapest cab with this facility. Spend more money, and the choice is vast. Spend less, and it's rocking horse poo time, unless you find something s/h at a bargain price.

Edit: Cheap subs are going to add to the overall sound, and will usually make it sound fuller and clearer. They won't shake the optics off the bar, or have your flaxen locks blowing in the breeze. That effect requires the expenditure of quite a bit of power, and similar amounts of cash.

[pitdiver]

I just want to add a bit of bass. No optic shaking or anything like that. My problem is feeding it from the mixer, Can I take a feed from the "record" outlet on say a Numark M2 mixer

[Excalibur]

I just want to add a bit of bass. No optic shaking or anything like that. My problem is feeding it from the mixer, Can I take a feed from the "record" outlet on say a Numark M2 mixer

I fear you have misunderstood the thrust of my argument. Presumably, you have two main out sockets which you feed your existing speakers with. I assume they're active speakers. With an Alto sub ( other brands are available ) you simply connect your mixer to the sub instead, and then from the sockets on there to your tops.
If you have passive tops and an amplifier, the same applies, just feed the amp with the outputs from the sub. Regard the sub as a mixer, if you like.

Using the rec outlets to feed anything of this type is not a good idea, because they usually bypass the tone control circuitry, and have a much lower output.

As long as you're using actives, Andy's suggestion of just using one sub in line with one top will work acceptably well with a single channel sub, such as the QTX, but it's not ideal. In this case, you're better with two, to match things up, and by that time, you're aproaching the cost of an Alto, which is far better equipped. If you're using passives, it's not at all a good option.

[pitdiver]

No I use passive speakers, a the moment KAM ZP12's with a KAM KXR 300V2 amp. This is the kit I will be using until possibly next year. If fitting in a sub is going to cause agro I think I may well as forget it for now. As I said in a previous post just wanted to add an extra bit of bass.

[pitdiver]

I have just been offered an Alto ZMX122 mixer. This apparently has an output to "Control Room" could I use this as a feed for a powered sub.

[Andy P]

Using control room is not ideal as it often lacks any eq. I may be wrong but you can feed into the sub before the amp is using none powered tops. The output from the sub should only be carrying signal.

[Nakatomi]

If you don't have any way to roll off the bass end on the tops things could get a bit muddy if you're not careful. As far as I know you can limit the upper range of the qtx active sub so that would help, assuming the active sub rolloff can go as high as your tops low end.

Active subs with filtered mid/top outputs cost a wee bit more than the qtx though.

[Retrodisco]

Run it off the line level output on the mixer if you have one free.

Booth output I've used before.