DBX 120A Subharmonic Synthsis... anyone Experienced one?

J

Jimmy Hardin

Junior
Jan 29, 2013
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0
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Hey guys. I am thinking about getting one of these for my subs. I use the ultrabass on my mixer and really like the sound that it gives me through my subs so i thought i would try this one and see what it will make it sound like. Has anyone owned tihs unit and what did you like or dislike about it and what was your experience with it? or is it even worth the money or time to fool with?


http://www.musiciansfriend.com/pro-audio/dbx-120a-subharmonic-synth#productDetail
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

I used one back in the 80s with my SDL5s.

The problem is that you can add some SERIOUS low freq to the subs. While that sounds like a good thing-if the subs are not "up to the task", you will end up tearing them up pretty easy.

It is like seasoning-a little can go a long way-but overdo it and you are asking for trouble.
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

It's fun. 8)~8-)~:cool:

+1 to Ivan's post - it is not for the faint of subs. If you put time into your system, though, you'll be able to keep it within bounds.
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

+1 to Ivan's point. The lower the frequency the harder it is for any speaker system to reproduce, not to mention that human hearing falls off at low frequency too.

If you have way too much amp power and way too much speaker system, this will be a way to use it up.

JR
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Ivan Beaver said:
I used one back in the 80s with my SDL5s.

The problem is that you can add some SERIOUS low freq to the subs. While that sounds like a good thing-if the subs are not "up to the task", you will end up tearing them up pretty easy.

It is like seasoning-a little can go a long way-but overdo it and you are asking for trouble.
Click to expand...

Is there a way I can tell through their specs or is it a trial and error thing?
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Max Warasila said:
It's fun. 8)~8-)~:cool:

+1 to Ivan's post - it is not for the faint of subs. If you put time into your system, though, you'll be able to keep it within bounds.
Click to expand...

Yeah , I do put a lot of time in on it from hooking it all up then dialing it all in ringing it out and just mainly getting it to sound good. Thats all i would do is try to keep the subs running at a comfortable level and just give me the thud that i am needing , nothing THAT Intense.
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Jimmy Hardin said:
Yeah , I do put a lot of time in on it from hooking it all up then dialing it all in ringing it out and just mainly getting it to sound good. Thats all i would do is try to keep the subs running at a comfortable level and just give me the thud that i am needing , nothing THAT Intense.
Click to expand...

While I am not a big fan of any added colorations, there is another class of sub processing that adds overtones or harmonics above the low bass notes. This tricks the silly humans into believing that the low bass is present too... This latter type processing is much easier on your system, while I don't endorse either... It's not nice to fool mother nature.

JR
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Jimmy, you need to look at how the 120 (and the predecessor, the 500) work. They're basically a fancy octave divider and create an analogous waveform an octave below the input signal. It's possible to have a resulting signal of ~20Hz from the low E on a bass guitar. Will your subs be happy with that if they're tuned for 40Hz? Probably not for very long... I got really friendly with my local EV speaker reconing shop until I got a good grip on the right combination of high pass filters and 500 return level... the right combination for the exact gear I was using. It would all be different with other subs...

I still own a dbx 500 Professional "Disco Boom Box" and for a long time it saved wimpy basses and terrible kick drums. It's in a rack that's been warehoused for longer than I care to think about. The original intended use of the 500 was to "restore" the LF that was filtered out when mastering for commercial vinyl records. Loud, deep sounds take a lot of groove velocity and eat up a lot of vertical real estate (grooves per inch decreases), in addition to creating tracking problems (you can't hear anything if the bass makes the stylus jump out of the groove).
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Jimmy Hardin said:
Is there a way I can tell through their specs or is it a trial and error thing?
Click to expand...
It depends on what sort of specs are provided.

It would help TREMENDOUSLY if you were to post the model number of your subs.

ALSO it help to tell how or what you are going to do with it.

Is this for live? For personal playback at home? DJ at club? recording studio? Something esle?

Without details, we cannot give any real useful answers.
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Ivan Beaver said:
It depends on what sort of specs are provided.

It would help TREMENDOUSLY if you were to post the model number of your subs.

ALSO it help to tell how or what you are going to do with it.

Is this for live? For personal playback at home? DJ at club? recording studio? Something esle?

Without details, we cannot give any real useful answers.
Click to expand...

Always dug them inserted on toms..... Thunderous ! My fav is d6 on on floor toms and d4 rack toms with something like a subharmonic synth inserted on them....
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Ivan Beaver said:
It depends on what sort of specs are provided.

It would help TREMENDOUSLY if you were to post the model number of your subs.

ALSO it help to tell how or what you are going to do with it.

Is this for live? For personal playback at home? DJ at club? recording studio? Something esle?

Without details, we cannot give any real useful answers.
Click to expand...

oh sorry about that , I am going to use it for live sound , Now don't laugh or make fun of me for posting these on there , I know i can do better, and before long i am going to start working on replacing these for another brand. so just bare with me. lol :) :?~:-?~:???: this is all of the info i can get on each. as i have said before , i am using the ultrabass effect on my Behringer sx2442. and they work out great with them. So thats why i was wanting to get one just for them.

B18%20copy.jpg


B18 • 18" Sub

18” Eminence cast frame woofer

650 watts rms 1300 watts program 2600 watts peak

8 ohms

High-quality black carpet

Steel recessed handles

Metal or plastic Corners

Metal jackdish with 2 ¼ connectors

Heavy duty steel grill

Steel stand cup

3/4 Birch plywood construction



These are Some seismic Audio subs.

[h=4]18" PA Bass Sub woofer Cabinet[/h] [TABLE="class: mz-product__specs"]
[TR]
[TD="class: mz-key"]Model[/TD]
[TD="class: mz-value"] SAP-18SFF
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Availability[/TD]
[TD="class: mz-value"] Usually Ships in 24 Hours
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Contents[/TD]
[TD="class: mz-value"] 18" Pro Audio Subwoofer Cabinet
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Condition[/TD]
[TD="class: mz-value"] New
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Application[/TD]
[TD="class: mz-value"] PA Subwoofer | DJ Subwoofer | Live Sound | Stage
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Active / Passive[/TD]
[TD="class: mz-value"] Passive
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Connector(s)[/TD]
[TD="class: mz-value"] Two 1/4" inputs and Two Speakon inputs
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Power Rating[/TD]
[TD="class: mz-value"] 500 Watts RMS; 1000 Watts Peak
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Nominal Impedance[/TD]
[TD="class: mz-value"] 8 Ohms
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Speaker Size[/TD]
[TD="class: mz-value"] 18"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Magnet Size[/TD]
[TD="class: mz-value"] 90 oz
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Handle(s)[/TD]
[TD="class: mz-value"] Recessed Metal
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Voice Coil[/TD]
[TD="class: mz-value"] 3" Voice Coil
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Frequency Response[/TD]
[TD="class: mz-value"] 20Hz to 5kHz
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Sensitivity[/TD]
[TD="class: mz-value"] 98db
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Ports[/TD]
[TD="class: mz-value"] Yes
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Grill[/TD]
[TD="class: mz-value"] Full Metal Grill
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Enclosure[/TD]
[TD="class: mz-value"] 5/8" Plywood
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Covering[/TD]
[TD="class: mz-value"] Black Carpet with Black Metal Corners
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Pole Mount[/TD]
[TD="class: mz-value"] Yes
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Height[/TD]
[TD="class: mz-value"] 28"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Width[/TD]
[TD="class: mz-value"] 22"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Depth[/TD]
[TD="class: mz-value"] 22"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Weight[/TD]
[TD="class: mz-value"] 70 lbs per Subwoofer
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Warranty[/TD]
[TD="class: mz-value"] One Year Warranty
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]List Price[/TD]
[TD="class: mz-value"] 369.99
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Features[/TD]
[TD="class: mz-value"] Speaker mounts on top of cabinet
[/TD]
[/TR]
[/TABLE]
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Jimmy Hardin said:
oh sorry about that , I am going to use it for live sound , Now don't laugh or make fun of me for posting these on there , I know i can do better, and before long i am going to start working on replacing these for another brand. so just bare with me. lol :) :?~:-?~:???: this is all of the info i can get on each. as i have said before , i am using the ultrabass effect on my Behringer sx2442. and they work out great with them. So thats why i was wanting to get one just for them.

B18%20copy.jpg


B18 • 18" Sub

18” Eminence cast frame woofer

650 watts rms 1300 watts program 2600 watts peak

8 ohms

High-quality black carpet

Steel recessed handles

Metal or plastic Corners

Metal jackdish with 2 ¼ connectors

Heavy duty steel grill

Steel stand cup

3/4 Birch plywood construction



These are Some seismic Audio subs.

[h=4]18" PA Bass Sub woofer Cabinet[/h] [TABLE="class: mz-product__specs"]
[TR]
[TD="class: mz-key"]Model[/TD]
[TD="class: mz-value"] SAP-18SFF
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Availability[/TD]
[TD="class: mz-value"] Usually Ships in 24 Hours
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Contents[/TD]
[TD="class: mz-value"] 18" Pro Audio Subwoofer Cabinet
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Condition[/TD]
[TD="class: mz-value"] New
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Application[/TD]
[TD="class: mz-value"] PA Subwoofer | DJ Subwoofer | Live Sound | Stage
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Active / Passive[/TD]
[TD="class: mz-value"] Passive
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Connector(s)[/TD]
[TD="class: mz-value"] Two 1/4" inputs and Two Speakon inputs
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Power Rating[/TD]
[TD="class: mz-value"] 500 Watts RMS; 1000 Watts Peak
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Nominal Impedance[/TD]
[TD="class: mz-value"] 8 Ohms
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Speaker Size[/TD]
[TD="class: mz-value"] 18"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Magnet Size[/TD]
[TD="class: mz-value"] 90 oz
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Handle(s)[/TD]
[TD="class: mz-value"] Recessed Metal
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Voice Coil[/TD]
[TD="class: mz-value"] 3" Voice Coil
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Frequency Response[/TD]
[TD="class: mz-value"] 20Hz to 5kHz
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Sensitivity[/TD]
[TD="class: mz-value"] 98db
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Ports[/TD]
[TD="class: mz-value"] Yes
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Grill[/TD]
[TD="class: mz-value"] Full Metal Grill
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Enclosure[/TD]
[TD="class: mz-value"] 5/8" Plywood
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Covering[/TD]
[TD="class: mz-value"] Black Carpet with Black Metal Corners
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Pole Mount[/TD]
[TD="class: mz-value"] Yes
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Height[/TD]
[TD="class: mz-value"] 28"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Width[/TD]
[TD="class: mz-value"] 22"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Depth[/TD]
[TD="class: mz-value"] 22"
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Weight[/TD]
[TD="class: mz-value"] 70 lbs per Subwoofer
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Warranty[/TD]
[TD="class: mz-value"] One Year Warranty
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]List Price[/TD]
[TD="class: mz-value"] 369.99
[/TD]
[/TR]
[TR]
[TD="class: mz-key"]Features[/TD]
[TD="class: mz-value"] Speaker mounts on top of cabinet
[/TD]
[/TR]
[/TABLE]
Click to expand...
Well using it on those will be a good "excuse" to get some new subs. You will need them after they quickly get torn up.

Don't expect an electronic solution to fix bad physics.
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Ivan Beaver said:
Don't expect an electronic solution to fix bad physics.
Click to expand...

Hey Ivan,

As a representative of Danley, I don't think you get to make blanket statements about another company's product like this - no matter who they are. You can make whatever technical suggestions you like, but they should be objectively defensible when discussing someone else's baby.
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

These subs are the ones that I have as of right now . I am planning on soon to switch over to the carvin LS Series 18's . How would those work with the unit in question? Here is the specs for the carvin subs.


System Type: 18-inch Sub, bass-reflex
Frequency Response: 29 Hz - 265 Hz (-10DB); 35 Hz - 150 Hz (-3 dB)
Coverage Pattern: omni
Crossover: Low Pass
Crossover Frequency: 150 Hz
Power: Full Range 500w continuous /1000w program /2000w peak
Recommended Amplifier Power: 800 - 2000w
Sensitivity (1w @ 1m): 98dB
Maximum SPL: 127dB
LF Driver: 18-inch woofer
Nominal Impedance Full Range: 8 ohms
Enclosure: 18mm Multi-Ply Hardwood
Suspension/Mounting: Top: 1-3/8-inch Pole Mount Cup
Finish: Black DuraTuff[emoji769]
Transport: 2 Recessed Handles
Grill: Black Powder-Coated Steel
Connectors: Two NL-4 Neutrik Speakons, Two ¼ TS phone jacks
Dimensions: 600mm (23.5") high, 505mm (19.75") wide, 580mm (22.75") deep
Net Weight: 63 lbs





Sent from my iPhone
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

I was wondering if that post was a joke, but if the OP is serious, a sub harmonic effect will probably tear it up faster if not carefully limited.

#1 determine how the sx2442 ultra bass effect works.

From the manual "Combines sub-harmonics processor, bass exciter and limiter."... So in addition to adding lower frequency information, the "exciter" adds overtones, and then the whole thing gets limited. Probably dialed in to not kill speakers.

#2 DBX output... frequency synthesis is in 26 to 56Hz range,,,(from 54 to 110 Hz input)

Your posted speaker spec shows a frequency response of 20 Hz to 5kHz so on paper you are fine.... While experienced professionals might point out that the quoted frequency response has no qualifiers (like +/- X dB). Oops... that spec is for a Siesmic audio sub.... what is the spec for your sub? I went on the Behringer website and could not find a B18. I did find a B1800X Pro that use an 18" driver... They spec a 40Hz to 300Hz frequency response with a -10dB qualifier. So if that box is down as much as 10db at 40 Hz, adding a bunch of 26-56Hz content is not likely to end well. :-(

To be more like your ultra bass, perhaps add an exciter and limiter too.... If you just add extra lower frequency content you will get a good test of that boxes LF power handling capability, or shred it.

I repeat my earlier suggestion to add a bass enhancer that adds higher frequency overtones to trick the listener instead of adding even lower frequency content that your speaker can not reproduce. If you want real bass reproduction get a more serious speaker.

JR
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Jimmy Hardin said:
These subs are the ones that I have as of right now . I am planning on soon to switch over to the carvin LS Series 18's . How would those work with the unit in question? Here is the specs for the carvin subs.
Click to expand...
Jimmy, you need to forget about a subharmonic synth box. They add sound in frequency bands your current and proposed subs can't handle, and assuming you're thinking about this because you want more low-end, will actually make it worse, as your subs will be wasting energy trying to reproduce frequencies they really can't. The result will either be less bass output, or early speaker death, depending on your level of self-control.

Answering your other question, the Carvin sub you mention is another low-grade box, which may or may not be any better than what you already have. Save your money and get a pair of real subs someday. A pair of JBL PRX718-XLF will run circles around the Carvins.
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

OK my post is a little out of sequence... but wrt the Carvin

They say -3dB (half power) at 35 Hz. -10dB (a lot less) at 29Hz So your new added LF content between 26-56Hz is mostly below the speakers passband.

I am repeating myself, I guess people don't take me seriously, or I am a bad communicator.

For that class of loudspeaker, stick to bass effects that add higher frequencies they can actually play, not lower frequencies they can't...

If you want actual lower frequency playback buy a professional grade speaker.

JR
 
Re: DBX 120A Subharmonic Synthsis... anyone Experienced one?

Tim McCulloch said:
I still own a dbx 500 Professional "Disco Boom Box" and for a long time it saved wimpy basses and terrible kick drums.
Click to expand...

I think the key piece of information here is that the subharmonic synthesizer is for improving substandard sources not speakers (and amplifiers).

As for the question "has anyone experienced one", I suspect we all have if we've seen any major Hollywood movies over the last few decades.

I had a tour of Warner Bros. mix theatres during an AES show in LA, about 25 years ago. Each theatre was about the size of an average mall multiplex theatre, and had a huge Harrison 3-man console opposite the screen (one section each for dialog, music, and effects). The outboard racks behind the consoles were rather sparse, but they all contained a Yamaha SPX-90, an Eventide H949 and a dbx 120 (and not much else, that I remember).

GTD
 
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