Hi all.
I want to try using a passive sub (already own a JBL ASB6112) for my music listening at a computer desk. I've got spare amps and was thinking of using a Biamp TersiraForte DSP as the crossover.
When setting up the crossovers in the DSP, should I set the sub out to 80hz and below and the mains 80hz and above? Or, should there be some overlap?
BTW, does anyone have experience using a DSP for a crossover? This is a very expensive unit, but can get for free. Will it color the sound much?
Thanks!
I want to try using a passive sub (already own a JBL ASB6112) for my music listening at a computer desk. I've got spare amps and was thinking of using a Biamp TersiraForte DSP as the crossover.
When setting up the crossovers in the DSP, should I set the sub out to 80hz and below and the mains 80hz and above? Or, should there be some overlap?
BTW, does anyone have experience using a DSP for a crossover? This is a very expensive unit, but can get for free. Will it color the sound much?
Thanks!
The crossover points, underlap or overlap, filters, delays and equalization used in DSP all depend on the response of top speakers and room location, and your desired response.
For instance, your sub could be used well above 80 Hz to match up with small speakers that may have little output below 300Hz, and the response of the sub will vary depending on it's location in the room and proximity to walls.
For low level desk use, you might want a 6-20dB "loudness contour" bass boost, while at a loud level, a "flat" response pre-set may be engaged, with a higher frequency high pass (low-cut) filter to keep the sub's excursion under control.
DSP has the potential to add no, or as much "color" (deviation from the original signal) as you could want.
My DSP experience with other models won't be of much help creating a design template for the Biamp TersiraForte appropriate for you, but may be of assistance if you get to that point.
Art
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Thank you Art.
I'm using home built XLS Encores from Danny Richie. There pretty large and have decent bass. I just want to see what they'll do if I take away some of their bass duties.
I'll have to decipher what you said above as I'm not well versed int his stuff.
I'm using home built XLS Encores from Danny Richie. There pretty large and have decent bass. I just want to see what they'll do if I take away some of their bass duties.
I'll have to decipher what you said above as I'm not well versed int his stuff.
You can put the sub anywhere in the room, esp in a corner if the XO is sharp slope and not too much distortion from the unit to reveal its location (that's because you could hear those 160 Hz harmonics pretty easily). 80 Hz is easy for most mid-ranges to play but a little computer speaker might struggle and might be designed for a big boost at 80 Hz to provide an illusion of bass. Really helpful to get the bass out of a mid-range passband. So as Art suggested, higher XO freq might be sensible.
Really no way to run a sub except with active XO (which requires bi-amping*) and hard to understand any modern DIY system without DSP.
B.
*anybody out there who doesn't have a spare amp sitting around or doesn't live near a Salvation Army second-hand store?
I have two passive subs with a cheap electronic x-over that enables x-over point and level adjustments to the subs amp. The mains are both biamped and heavily modified by mini-dsp. I found it is relatively easy to adjust the subs "by ear" and totally depends on your room and taste.
Curious to know how you got on BeerGuru!? I'm coming across a few of these biamp products and considering them for crossover myself.
AKC360 which model do you use in yoour setup? There seems to be a huge range..some with AEC, some with Dante..it's quite confusing! I just want analog and digital input and at least 6 channels out!
My low pass is set at 100 hz. My subs integrate perfectly with my large stand mounts. My larger speakers like it best at 80hz.
As a person already said, listen to your system and set the sub low pass by ear. Its easy and it sounds like you have everything at your disposal already.
As a person already said, listen to your system and set the sub low pass by ear. Its easy and it sounds like you have everything at your disposal already.
I'm going to make some assumptions because you mentioned your desk. I'll assume the XLS speakers are on or near the desk and the sub is under the desk.
From your close listening position the XLS speakers can adequately cover 95% of the audio range. It is also likely the sub is twice as far from your ears as the mains. I have a similar arrangement. The best results were achieved by setting the mains to be full range. (With an active crossover use 50-60Hz, the XLS are inefficient below this frequency anyway and the drop-off slope will be closely aligned). In a normal music program there's not much below 50Hz, when there is the sub performs its reinforcement duties).
In practical terms the sub contributes very little at normal listening conditions but comes to life when the music is cranked up. In my opinion, the lower the crossover frequency the better.
The question for you: Which units produce the quality @100Hz, the encores or the JBL?
From your close listening position the XLS speakers can adequately cover 95% of the audio range. It is also likely the sub is twice as far from your ears as the mains. I have a similar arrangement. The best results were achieved by setting the mains to be full range. (With an active crossover use 50-60Hz, the XLS are inefficient below this frequency anyway and the drop-off slope will be closely aligned). In a normal music program there's not much below 50Hz, when there is the sub performs its reinforcement duties).
In practical terms the sub contributes very little at normal listening conditions but comes to life when the music is cranked up. In my opinion, the lower the crossover frequency the better.
The question for you: Which units produce the quality @100Hz, the encores or the JBL?
Hi Rrobot, it's the Forte AVB Ti model. I would have liked a Dante model but no great loss as I use it with usb audio in at the moment. Most of the Forte devices have at least 8in and 8out analogue.
Theres going to be some overlap, but it should be so subtle that you don't detect it audibly.
You won't know where the happy mediums will lay until you have everything on hand, plugged ready to play.
Your mains, and in room response will determine where to set dsp, your ears will let you know at the time where to set things and leave them, where its listenable. You will be able to do initial setup within minutes after you get the hang of how everything works. But it could take longer to tweak and fine tune the system in small increments and adjustments. When I add an additional sub I usually think I finally have it where I like it best, only to move a few inches a day or two later. I will probably end up shifting a new sub around long after initial set up. Until my ears feel contented. Placement is also one of the bigger factors when doing your initial set up. When you find the sweet spot you won't be able to detect any overlap, it should transition from the sub to the mains so smoothly you should have trouble pinpointing when the mains take over, and visa versa.
The MiniDSP are pretty good with user friendly interface, as long as you have a computer to upload the software your all set, if you go with one of those that is. I'm all analog at this time but I still visit the digital dark side from time to time.
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