Hi-if subwoofer with line level pass through

[MrOtto]

JBL LSR310S has a -109dB THD+N D 80Hz cutoff DSP filter

Measured JBL LSR310S output signal distortion with MOTU M4

Hi all, Preface: Take this all with a grain of salt. I don't know what I'm doing and I'm sure there will be things to tweak and improve with my measurement. I have a JBL LSR310S along with a pair of Genelec 8030Cs. I've been curious about what the JBL LSR310S subwoofer is doing to my signal...

www.audiosciencereview.com

I have one and use it to filter out below 80Hz to my JBL305p MKII

 

[ZolaIII]

@sweetchaos that's not the high pass for mains or output, it's self high pass for supposedly room gain compensation (like you have switches for it on most studio monitors) as sloping is so gentle it can't even be used as self high pass to woofer Fs (you have to use PEQ slot for it). So the SVS Pro series doesn't have low level (RCA) unbalanced I/O with embedded fixed 80 Hz high pass out.

 

[sweetchaos]

Understood.

You get a “high pass filter”, and you get a “high pass filter”. Everybody gets a “high pass filter.”

I’m going to separate this self high pass filter into its own section/column. To avoid the confusing it with the high pass filter for the mains/output.

I was sort of lazy and combined both on the same column. I see it needs to be separate now.

 

[Ellebob]

Kali WS6.2 or JBL 310 would both be good choices. Not sure price in your country.

 

[ooheadsoo]

I realize this is completely not what you're asking for, but if you shell out for a minidsp 2x4, you can have complete freedom of subwoofer choice, as well as freedom of crossover points and slopes, as well as plenty of PEQs you can add for your room modes. I only bring this up because it's hard to find the ultimate flexibility in a bargain subwoofer... Or even in more expensive subwoofers.

 

[TomG]

My SVS sealed 12' has a pass through but I don't know the specifics. Not used for a while

 

[HarmonicTHD]

I realize this is completely not what you're asking for, but if you shell out for a minidsp 2x4, you can have complete freedom of subwoofer choice, as well as freedom of crossover points and slopes, as well as plenty of PEQs you can add for your room modes. I only bring this up because it's hard to find the ultimate flexibility in a bargain subwoofer... Or even in more expensive subwoofers.

I agree 100%.

Investing in a sub and not in PEQ / Room Correction misses so much opportunities. Like proper phase alignment with mains, room mode reduction, optimized cross over fitting the mains and the room. Next to speakers this is the most bang for the sound buck. Everything else effects sound orders of magnitudes less.

If the budget doesn’t allow it yet then rather wait and save up a bit.

 

[CapMan]

I might be barking up the wrong tree, but I’ll give it a go.

I’d like a subwoofer, where you output stereo RCAs from your pre-amp/DAC/whatever, then the sub’s crossover does its job and strips out the sub bass, then outputs over stereo RCAs to your amp.

The idea being that it removes the need for bass management in your amp; this is done in the sub.

It’d help if the subwoofer were mind-boggling good and extremely cheap.

Does such a thing exist?

The Devialet expert allows you to configure a full bandwidth passthrough on the subwoofer output in the online configurator.

Expensive solution maybe

 

[jeffmackwood]

Last December I started a thread over on CAM with the title "Subwoofers with High-Level Pass-Through Circuits With HPF."

If and when I learn of additional subs that meet that criteria, I add them to the first post in the thread.

There are far fewer subs available that meet that criteria, than there are subs with low-level pass-through circuits with HPF, and knowing about them is important, for reasons detailed in the CAM thread. (Of course, there's also the vast majority of subs that have no HPF/pass-through circuits at all.)

If anyone knows of a sub, or subs, that should be added to my list, please add a post about it/them in that CAM thread and I will look into it/them and add to the list if and as appropriate. I'm only creating and maintaining that one thread on CAM because, as far as I can tell, CAM does not close such threads over time, and I am always able to edit my initial entry.

Jeff

ps. I applaud sweetchaos for the incredible time and effort it must take to maintain his spreadsheet(s). But if I might add that, again for reasons detailed in my CAM thread, just knowing that a sub has a HPF is only slightly useful, as what's really needed is knowing if it's on low-level (line/RCA) or high-level (speaker) pass-through circuits, for implementation of what I've long referred to as "proper bass management" purposes.

 

[phoenixdogfan]

I might be barking up the wrong tree, but I’ll give it a go.

I’d like a subwoofer, where you output stereo RCAs from your pre-amp/DAC/whatever, then the sub’s crossover does its job and strips out the sub bass, then outputs over stereo RCAs to your amp.

The idea being that it removes the need for bass management in your amp; this is done in the sub.

It’d help if the subwoofer were mind-boggling good and extremely cheap.

Does such a thing exist?

Yes there is. The original generation SVS PB/Sb 2000 & 1000 subs allowed a feed straight from the dac and had a two leg internal crossover. The Crossover rolled off the highs at 80 hz at 12 db per octave so that anything below 80 hz would be filtered from the mains. In other words the bass, won't pass back to your main speakers. That signal would come out of the rca jacks and just be connected to the amp for the mains. Meanwhile a low pass signal which would not allow anything much above 80 hz would pass to the subs, with controls on volume, phase, etc. SVS still sells them. With even one, you will not require an external crossover, or any sub outs on your amp. An ordinary DAC and power amp, that sub, and two mains is all you will need to get started.

 

[ZolaIII]

I am getting puzzled with this and title is to blame. It should be simple line out!
So @phoenixdogfan SVS non Pro line has pasive fixed 80 Hz high pass filter and Pro has line out or pass trough not changing anything. I find fixed HP useful at least for first time and if you must, line out is for chucking up more sub's in line and nothing else and if it's active feed (ADC - DAC - output).

 

[jeffmackwood]

Yes there is. The original generation SVS PB/Sb 2000 & 1000 subs allowed a feed straight from the dac and had a two leg internal crossover. The Crossover rolled off the highs at 80 hz at 12 db per octave so that anything below 80 hz would be filtered from the mains. In other words the bass, won't pass back to your main speakers. That signal would come out of the rca jacks and just be connected to the amp for the mains. Meanwhile a low pass signal which would not allow anything much above 80 hz would pass to the subs, with controls on volume, phase, etc. SVS still sells them. With even one, you will not require an external crossover, or any sub outs on your amp. An ordinary DAC and power amp, that sub, and two mains is all you will need to get started.

I can't speak to those specific SVS subs that you mention, however I can say that both the SVS PB13-Ultra and SVS PC13-Ultra (I own one of each) have line-level pass-through circuits with a fixed 12 dB/octave 80 Hz HPF. There's a switch that allows the HPF to be defeated, if the user wants to use those circuits to daisy chain multiple subs together.

Those are both extremely competent subwoofers and, with reference to the OP, still fetch a not-cheap price on the used market.

In addition, SVS does offer an extremely affordable "upgrade" to the subs' plate amp. In my case the original plate amp in the PC-13 Ultra had failed. The new plate amp (STA-1200D) brought it up to their current PC-4000 capability - for a small fraction of the new price. However, while you gain quite a number of features (like app-enabled control) in the process you lose the HPF capability (which I did not need with that sub).

As I mentioned in my post above, there are quite a number of used subs on the market, from a variety of manufacturers, with line-level pass-through circuits with HPF. Unfortunately, I've not come across a comprehensive list so a bit of digging will be required. I'd start by using sweetchaos' spreadsheet to identify which subs have HPF, and then find and read their owner's manuals to confirm whether the HPF is on a line-level pass-through circuit, or not.

Jeff

 

[phoenixdogfan]

I am getting puzzled with this and title is to blame. It should be simple line out!
So @phoenixdogfan SVS non Pro line has pasive fixed 80 Hz high pass filter and Pro has line out or pass trough not changing anything. I find fixed HP useful at least for first time and if you must, line out is for chucking up more sub's in line and nothing else and if it's active feed (ADC - DAC - output).

That's correct. I can verify that because I've own 2 OG SVS SB 2000's and have since 2017. Before I used any digital crossover whatsoever, I just sent RCA line level L-R from my DAC to the input of the OG SB 2000 and the "high pass" did a passive 12 db Octave at 80 Hz. On the low pass end it is active, crossover point, phase, and level output selectable. All the crossovers can be bypassed if you have some external arrangement. That's what I do today with them b/c I let Dirac DLBC set the crossover for subs and mains.

 

[jeffmackwood]

Going back again to the OP's question "Does such a thing exist?"...

While listening to my living room system this evening I noticed its Velodyne Chrysalis Photon-10 subwoofer and remembered that it has both low- and high-level pass-through circuits. A quick check of the owner's manual told me that while the high-level ones are straight pass-throughs, the low-level ones have a fixed 6 dB/octave 80 Hz HPF. While I'd prefer 12 dB/octave or higher, it would be better than no HPF. (I don't use that feature in that system; I have a stand-alone external crossover instead.)

It's a very capable compact sub with low frequency extension of 23 Hz (-3 dB).

Outlaw Audio took the Photon-10 and rebranded it as their ECS-10. They are identical.

The unfortunate thing is that neither the Photon-10 nor the ECS-10 seem to come up for sale very often on the used market. Satisfied owners not wanting to part with them perhaps?

Jeff

 

[Chrispy]

Generally you just need to find a sub/amp with the features you need....the actual crossover via a sub I think was more common years ago, not so much now. Then there's add-on dsp units to do it....

 

[TheBatsEar]

I’d like a subwoofer, where you output stereo RCAs from your pre-amp/DAC/whatever, then the sub’s crossover does its job and strips out the sub bass, then outputs over stereo RCAs to your amp.
The idea being that it removes the need for bass management in your amp; this is done in the sub.

It’d help if the subwoofer were mind-boggling good and extremely cheap.

I would not go that route, but instead get a MiniDSP 2x4HD or MiniDSP Flex. You'll thank yourself later, as you can truly integrate your speakers with the sub AND the room. Yes, it costs money, but it's so worth it.

I have two SVS SB-1000 (bought used, try Hifishark).

I also have two very cheap subs (https://www.audiosciencereview.com/forum/index.php?threads/elac-cinema-5-2-subwoofer.40758/) that do the same trick for me (but with less power obviously). After DSPing the heck out of them i can't tell them and the SB-1000 apart.

 

[ZolaIII]

Well Wharfedale WH-D10 can be found cheap from time to time and has low level RCA I/O with 80 Hz high pass filter and it's closed enclosure one (have two of those). Again that's just for a first time and if you must. Proper digital crossovers need much more.