[stlrman]

What is the best way to integrate my sub with my monitors?What does each knob do?  My monitors go down to 50 hz
My subwoofer is a 12 inch Servo sub In a custom built cab. It's sealed ,down firing, 250 amp
First knob is high level,then low level,frequency contour,phase 0-180 degrees
Would a jl audio 110 be a huge upgrade for speed and extension ? Or none at all?
Thanks,
Todd

[milford3]

For a start do this: Phase-0.  Monitors cross to 100HZ.  Sub: 80 HZ.  And the rest is to just listen and ajust to youe ears.  Enjoy the music my friend.  Placement is key also.  Move the sub all around (this may take a week or two).  You will find a sweet spot for the sub. 

[Geo.F. in St.Louis]

I would cross monitors over @ 8ohz, likewise on the sub, phase @ 0, high level @ 0, then adjust low level towards -(minus) side untill the bass response is smooth. I have found that by reducing the highs in my system I get much, much better transient reponse, both leading and trailing edges, but do this gradually after you start to get used to the character of your sytem.

I have 8"-3-way monitors crossed over @ 80hz to 15" ported subs; the level on the subs is turned down as far as possible without turning them off. I use either 120 watt/channel solid state or 200 watt/channel tube on the monitors and 200 watt/channel solid state on the subs. I have the highs reduced by 2-steps on my 3-way electronic x-over: sweeeet! Try this, listen a while then hit me back at georgefooteiii@yahoo.com, or @ 314-327-0840 and let me know what you think.  It takes time for components to "burn in."

[charmerci]

I remember someone a long time ago suggesting that you place the sub in your listening spot - then go around the room to find where it sounds best, then place it there. (Caveat - I've never done it myself since I haven't owned a sub in decades)

[stlrman]

Thanks for the replys guys. I may hit you up sometime Geo.
Which knob is the one to set the crossover point?
Thanks,
Todd

[gooberdude]

this may not be the answer you are looking for, but i've had subs in my system for years but only recently began measuring my room & system with a room analyzer.  I have the XTZ analyzer, but there are less costly alternatives out there.

Setting phase & proper xover point can be tough by ear, and inaccurate.  Using measurements takes the guess work & hassle out of it.

One good example is i had always set phase at zero.  In my room, setting it close to 180 degrees provides 6db more output, which is a lot!  Another good piece of information is to find out how low your monitors actually play, and this is only possible w/measurements.

matt

matt

[bigbang]

REW (room eq wizard) is free and is a great help for fine tuning subs.

[K Shep]

What is the best way to integrate my sub with my monitors? 

With an equalizer.  Then use measuring equipment to dial in your system with your room.

[stlrman]

K Shep, Do you mean keeping an EQ in the system at all times?

[K Shep]

K Shep, Do you mean keeping an EQ in the system at all times?

Yes but I should have called it a crossover rather than an eq.  I use a Velodyne SMS in my system.

[neobop]

There are too many variables for one easy answer. First, will it sound better with your monitors running full range and augmenting the bass with the sub, or better putting the monitors through the x-over? We don't really know what you have except a 12"/250w servo sub with both hi and low level inputs? Do you have a separate preamp or maybe a sub out on a receiver or multi-ch set-up? Are you hooking this up from the speaker outputs on your amp/receiver?

[James Romeyn]

I remember someone a long time ago suggesting that you place the sub in your listening spot - then go around the room to find where it sounds best, then place it there. (Caveat - I've never done it myself since I haven't owned a sub in decades)

Bob Carver suggested the above advice to site his new Sunfire sub I owned circa 2000.

My goal would be at least three subs, preferably four in a distributed array. If three, Geddes advises one must be sited above ear level.  At best I had mixed results with three, but that was before the arrival of my most recent siting advice. 

If all subs had programmable EQ I'd follow the siting advice at my website with the following difference: site sub A then program its EQ, site sub B then program its EQ whilst running A fixed, site sub C then program its EQ whilst running A and B fixed, site sub D whilst running A, B and C fixed.  If you have only 3 subs stop after C. 

I presume, but please correct if wrong, it's impossible to program multiple independent subs simultaneously without proprietary JBL/Lexicon software described below.  Each sub would infinitely attempt to cancel/over-ride the other's corrections, interpreting the results as constantly changing sub/boundary relationships.  I presume, after a certain time, all subs except one would stop programming, mute, and indicate "default", allowing the last sub standing to complete its program mode.       

Above would simulate a fraction of the EQ tuning of the estimate $10k Lexicon processing and JBL's estimate $30k Synthesis System, both for distributed sub arrays.  You'd not achieve JBL/Lexicon's exotic EQ for each sub in real time, and none of the exotic phase/timing programming.   

I never tried the above.  It would be interesting to read feedback from users who can assemble 3-4 subs with programmable EQ, available for fairly low cost now.

Ultimately, IMO, multiple sub arrays with the same tuning features found in JBL and Lexicon will be the industry standard, very affordable (likely all programming built into one of the subs) and high-end full-range single-column speakers will be no more.

I can't remember the source, but somewhere I heard Bob Carver works on an array of tiny subs (size unknown) spread throughout the room and programmed as per above.  The other best known alternative is corner loaded programmed subs digitally time aligned with the mains.       

[stlrman]

Neobob, I am not positive what running the speakers full range means.
I have a 2.1 system. I will run the sub into the variable inputs on my Jolida 1501RC.
I plan on having over an audiophile friend to help me with the integration.
Before I just set the controls on the sub to where I knew it was there ,but did not overpower the main speakers, and it seemed to blend well the speaker fronts.
Having multiple subs is not really an option now. The room is the living room, and the the first room you see as soon as you open the front door.
Is there a free computer program to measure the room nodes etc.?
Thanks,
Todd

[James Romeyn]

Full range simply means no "high-pass" crossover on the main speakers, i.e. just running them wide open same as with no sub. 

Yes, free "mode calc" (mode calculator) at Ethan Winer's (sp?) Real Traps website.  Check it out.  Be prepared to be shocked at the severity of the bass modes in your room, whatever are its dimensions.  Bass modes are the worst bane in audiophile land IMHO.  Few things if any disturb music worse than 1/8 notes in the bass range playing as a 1/4 note, and overlapping earlier notes.   

[BrianAbington]

I run my mains full range.

Ported speakers should be crossed over at the frequency the enclosures are tuned to. If you go lower than that the woofer can loose control and be damaged. Sealed speakers I let them go as low as the receivers settings will go.

I then use a disc with test tones to find the point where the bass from the woofers in the speakers starts to roll off, meaning sharp decrease in volume. That frequency is where I set the sub woofer crossover, and adjust it up and down a bit at a time to see if a different setting sounds better.

I start with the woofer placed about half way between the right channel and center channel. I move it forward and back, side to side and make notes about how it sounds in all places. I try the left side, I try behind the L&R speakers, closer to the corners, along the wall several ft in front of the L&R, several feet from the couch along the wall, in front of the listening position where a coffee table would go, behind the couch, rear corners.

I compare my notes and my memory from listening to select what gives the best sound between music sound quality and movie performance. I usually wind up with it in that first zone between the C&R but the experimentation is worth it to me.

Having a woman who gives you free reign over the audio setup is also a plus as well. If she's not picky about placement then a less astheic placement is easier to explain when the WAF is not a factor.

[Early B.]

Having a woman who gives you free reign over the audio setup is also a plus as well. If she's not picky about placement then a less astheic placement is easier to explain when the WAF is not a factor.

So true. My subs are situated in the only places I'm permitted to do so. It makes placement very easy. If they sound better in a different location, I'll never know.

[neobop]

Neobob, I am not positive what running the speakers full range means.
I have a 2.1 system. I will run the sub into the variable inputs on my Jolida 1501RC.
I plan on having over an audiophile friend to help me with the integration.
Before I just set the controls on the sub to where I knew it was there ,but did not overpower the main speakers, and it seemed to blend well the speaker fronts.
Having multiple subs is not really an option now. The room is the living room, and the the first room you see as soon as you open the front door.
Is there a free computer program to measure the room nodes etc.?
Thanks,
Todd

Happy new year,
I think your Jolida is an integrated amp with a subwoofer output. If this is the case you hook your monitors up to the speaker outputs and an interconnect goes from the sub out or preamp out to the sub amp? From your description it seems like you've got it just about right. To check phase; while it is playing something with deep bass, throw the switch from 0 to 180o. You'll hear that one setting is noticeably louder in the bass. Keep it set there. If this is a variable control (like a volume control), set it where you get the most bass. You might want to turn the woofer up when checking this. Try to set the frequency control so the woofer and monitors blend without overlap and without a hole between their coverage. This is tricky and you can listen to the monitors with the sub off and compare the sound to sub on. Sometimes overlap can cause cancellations and you can wind up with less perceived bass. I recommend keeping the volume control on the sub set so you're not aware it's there most of the time listening to music. This depends somewhat on the bass capabilities of your monitors. Extensive listening will help with this goal. You want the sub and monitors to sound like a coherent integrated speaker system, not like a pair of speakers and a sub. You'll also find that deep bass content and relative volume varies widely with source material.

All the suggestions about placement, multiple subs, etc are good ones, but first you have to get started and get it sounding decent. With your set-up you could get an EQ and just put it ahead of the sub and not the monitors. That way you could EQ the bass w/o degrading the mains.

[DS-21]

The short answer is that getting it right requires good measurements first.

If all subs had programmable EQ I'd follow the siting advice at my website with the following difference: site sub A then program its EQ, site sub B then program its EQ whilst running A fixed, site sub C then program its EQ whilst running A and B fixed, site sub D whilst running A, B and C fixed.  If you have only 3 subs stop after C.

I think that's generally sound, albeit with Step Zero omitted (though perhaps implied): turn on the mains. And if they are vented, plug the ports. If they are small, they'll also likely need a highpass filter. (As a general rule, the more sources in the modal region, the better. So use the mains in addition to the subs to cover the modal region.)

After all, the single most important thing with subwoofers is integration with the mains to form a coherent soundstage. If one only sets up the subs together as a unit, and neglects the interaction of subs with mains....that's why it is sadly so rare to find a multi-piece audio system that actually sounds like music when playing a good recording of an unamplified performance. If people knew how to properly set up subs and actually did it, nobody would prefer "full range" stereo mains without subs.

Also, I think you're using "EQ" to mean "level, phase/delay, and frequency contouring." I think it's useful to separate the first two from the latter. That is to say, given subs A, B, C, and so on, I would first turn on the mains, start running sweeps (this is why the Velodyne SMS-1 and MIC-5 combination is so useful, even though as a processor it's quite primitive), and then add in subwoofer A, playing with the level and phase/delay (same thing, really) controls to get the smoothest blend with the bass lagging a bit.

Then, with the mains and sub A playing, I would fold in sub B, again using level and phase/delay controls to keep the blend smooth while filling in nulls and flattening peaks. (Sub B will almost always be playing at a lower level than sub A, which leads to the obvious deduction that sub B can be smaller/less powerful than sub A.)

Then, with the mains, sub A, and sub B playing, repeat the process with sub C, and then with D if applicable, etc.

AFTER that's done, if it's done well the overall response will be quite smooth. But to fine tune in the modal region, one could try playing with individual sub EQ's as well as the global EQ. I don't know a better way than trial and error, short of hiring Keith Yates to model the room. But I also find that, if one gets the relative levels and phase/delay settings right, one won't need to do much in the way of EQ'ing to smooth the modal region response, only to shape the overall curve and the response in the modal region.

To fine tune the "first mode" region (<50Hz in most rooms) and set the overall house curve, use the global EQ unless sub A is considerably larger and more powerful than the other subs, in which case one may want to balance their output in the first mode region with individual frequency contouring.

I presume, but please correct if wrong, it's impossible to program multiple independent subs simultaneously without proprietary JBL/Lexicon software described below.

I don't see why. All one needs is a box with both global EQ on the input and separate EQ's for each output. Once everything's set up, one can dial in a curve on the global EQ, and it will affect the whole system. A cheap miniDSP will do it, as will the Behringer boxes.

I never tried the above.  It would be interesting to read feedback from users who can assemble 3-4 subs with programmable EQ, available for fairly low cost now.

See my "Modest Multisub Measurements" thread on AVS (dunno if linking to other fora is kosher) for an example.

[DS-21]

FWIW, Dr. Geddes' latest placement and setup advice is in a PDF available on his forum (geddes-audio.com)