Active line level crossover with subwoofer out - HELP
Hi.
Helping my friend with another challenge. Looking for a line level crossover. His preamp does not have a subwoofer out.
What he wants to do is have a high pass filter between the preamp and his power amp. This so his Spendor BC1’s are spared anything below 40 or 50hz. And, the crossover needs a low pass filter to spare the subwoofer the high frequencies. Thoughts? Thanks!
Built the Xover yesterday - w some cheap caps - and it worked perfectly! Bought 4 different values of cheap caps so we could hear how the system sounded in situation. Those can sit in place until the "good ones" are ordered/delivered
Numbers and specs are great, but, it has to he heard in the environment to really know how its working.
Sub has integrated nicely. Bass is much tighter/faster/resolved. Sound stage is much better - wider/deeper.
For what is essentially a "lifestyle" system, its sounding really good! Think I may be putting similar high pass system in my 2nd system. Small speakers that would hopefully benefit from those low frequencies "mucking up" the works.
I've used a Marchand electronic crossover in my desktop system for several years. It really gets the job done nicely. I did some not-so-rigorous comparing of the sound w/ & w/o the crossover. I couldn't distinguish any sonic differences with it in vs out of the circuit.
There are a number of models to choose from. Mine has a variable crossover (very handy). But I've heard the models that use a fixed crossover have that nth degree more purity of sound...? Who knows.
Prices from 2016 were $800 for my XM66 (new). If you can settle on a fixed frequency, the XM9 is $600. Both show up used occasionally (XM66 rarely; XM9 not quite as rarely).
Thanks! Sent Quad an email to confirm no issues with running two separate and very different amplifiers from the single preamp out. Really hope this is a viable option!!!
A simple solution is to get a set of filters built into RCA plugs and a RCA splitter on the pre-out. They are much used in car audio setups and work well. Search on eBay for rca plug crossover.
A simple solution is to get a set of filters built into RCA plugs and a RCA splitter on the pre-out. They are much used in car audio setups and work well. Search on eBay for rca plug crossover.
I believe it does all you need at a reasonable cost. There's one on usaudiomart.com. Just make sure the power supply is to original specs as some may have replaced it with a cheaper generic.
Thanks! This will require some more research! If this works, I could feed the preamp out to a DIY splitter box, and put the high pass line level filter to the amp, and the straight signal to the sub all inside a nice looking box.
He’s got Spendor BC1’s for a reason, for their organic sound when used just simply with source and amp.
Don’t go sterilizing the sound by putting mini dsp and or digital xovers in the signal path, as they have lousy d/a converters in them and if your friend has a good dac that sound will be lost along with the Spendors sound.
Get a pair of these passive HP filters (pick your frequency) on the input of the Spendors amps and use an active subs xovers/plate amp to blend it in to whatever you pick to roll off the Spendors at. Or if the sub doesn’t have an active xover then the use the LP filters on the sub/s amps as well from the same place.
My concern is if the sample rate of this device will nullify the resolution value of my DAC. The miniDSP HD apparently is 32bit & 192k. The new $60 dsp from Parts Express doesn’t say.
Yeah, this is an issue. This is why I run purely digital EQ (roon right now) or only in the subwoofer.
These DSP based EQ systems have to deconstruct the incoming analog signal, do math on it, and then have a DAC to turn those numbers back into voltages. Not really some one who spent a lot of money on a DAC wants to do.
Using a digital only EQ solution, which does the math BEFORE your fancy DAC gets around this, but doesn’t have a solution for your subwoofer. I use
For the OP, who has 2 speakers in two different locations, plus a sub, though, he’s really going to need EQ to match the L and R plus integrate the sub. Having a fancy DAC is the least of his worries.
Of course, other solutions include a digital preamp with built in EQ. :) Anthem makes them as well as integrateds, and built in sub out, with automatic configuration.
Thank you for all the input, thoughts, ideas and popcorn worthy (at times) lively discussion!
Some more info...
My friends place is not set up as a critical listening system/room.
(One speaker is in a bookshelf, the other on a stand further away, the sub is placed in a seemingly good spot, vaulted ceilings, listening area is off to one corner where "desk is and, to make things interesting, there is a large pre war Steinway grand piano in the room...)
This is very much a lifestyle system. That doesn’t mean, however, that the goal isn’t the same as all systems which is do what you can with what you got and try to optimize as best as possible. My goal is to work with what is there, with some hopefully minor changes, in order to have the sound that is flooding the room sound good!
So, because of the shape of the main area and the rather unorthodox set up, bass nodes are not really a big problem. (Walked around the space many times, and there are no "blank" spots or "areas of pain in the bass")
Another bit of info, forgive the pun, there are currently four sources. Turntable, CD to a Dac, Tuner and a Bluetooth device for You Tube/Guest phone stuff...
Mostly valuable opinions here. I, too, am investigating an actual active X-over to take everything below out of the signal to my amp and LRS's and send it to at least @ powered subs. Those subs can be positioned to reduce nodes. The miniDSP HD has a x-over, HPF & LPF and by plugging in a PC, Mac or phone app, I believe, 25 bands of parametric EQ. My concern is if the sample rate of this device will nullify the resolution value of my DAC. The miniDSP HD apparently is 32bit & 192k. The new $60 dsp from Parts Express doesn't say.
perkri, you started another uplifting debate with your simple question :-)
Your friend can also e.g try the blusound node2 streamer/dac which has a sub out before the pre amp. Or the Martin Logan/Paradigm P AMP which I recommend because then you also get the ARC room correction system. The P AMP is fine for driving smaller speakers at normal SPLs. Actually I use it for both Tannoy DC10A and ATC 19 for near-field listening (not exactly small).
To the P AMP you may then connect 28 subs for a really decent bass...
DSP makes the miserable space I've been relegated to employ as a
'listening area' (I'd be hard pressed to call it a 'room')
tolerable....so my bias is obvious, and enough said.
Exactly. Sure, we all want to be purists, but the reality is that EQ works.
A light hand, focusing on the most terrible problems in the bass, along with fully thought out speaker integration is a good thing.
Love the lava lamp in the .../systems/8367. ;) Must be a system tweak not considered before...🤔
DSP makes the miserable space I've been relegated to employ as a 'listening area' (I'd be hard pressed to call it a 'room') tolerable....so my bias is obvious, and enough said.
Whatever route you go with EQ : DSP or analog - get you best signal to background noise possible - run EQ in the hyper low noise wee hours of the morning. very few audiophiles understand the baseline s/n of the room they listen in. Use the slow weighting on your SPL meter...
for many this may also lead to the realization that noise management may be a much much bigger sonic improvement than an expensive power conditioning gadget... of course, some of us do both....
PS - I do like the Mytek products, but for the most part I’m not fanatical about them. They have class-leading specs AND sound really good but over the last 10-15 years a lot of great sounding DACs have hit the market.
The only DAC I’m really against are the standalone Oppo lines. I made one or two bad comments about them on Audiogon about them, and the company went under. ;-)
Fixing bass issues in the analog domain with 11 bands of active subwoofer EQ in stand-alone and floorstander speakers for twenty years.... drumroll Vandersteen Audio....
re: nodes
can you fix = yes can you eliminate = no
every room has nodes
the 11 bands are not octave based they were chosen based on typical nodes in American rooms...
Not usually how a four output miniDSP works. Usually the outputs are for high and low frequency, so with that configuration it is for 2 satellites and 2 subs, with configuration for high pass, low pass, timing, global EQ as well as EQ per driver. It’s’ important to double check with miniDSP as the mixing is controlled by the app, so ask them if you want to do anything fancy with the bigger units.
OP:
If I remember right, you are a proponent of standalone DACs (specifically Brooklyn),
I like mine, my biggest fear with integrated streamers is support for new handheld OSes and new online services. For instance, if you buy a streamer/receiver, in five years, how many of the online services it supports will still work?
DIY swarms,
Yes to DIY speakers, not swarms. Yes, they work, but they are also complicated in that they require 4 subs, and appropriate cabling. My own personal solution is usually 1 to 2 subs, with bass traps AND EQ.
My (limited) understanding of room nodes is that they are affected by the placement of the subwoofer (or subwoofers, as in a swarm). If that is true, can a single mini-DSP fix the room nodes regardless of subwoofer location? Or do you need one mini-DSP for each sub?
I never said a miniDSP would fix everything all by itself. I was quite narrow in my claim. If all you have is 1 sub, adding EQ can get you far. Of course, optimal placement helps, but after this you may still be left with enormous (20 dB) narrow peaks at the listening location. That is what the EQ alone can fix. Clip them, and you can raise the overall sub volume. This alone is an enormous improvement. How much of course depends on how bad the room is to start with.
Room treatment, AND speaker placement AND EQ however can go even further. It can even out the response across the room, not just one location, and you can even treat nulls.
I see this as a continuum:
Poor bass due to overall bass level dominated by peaks.
Enjoyable bass
Great bass.
One subwoofer, good placement and an EQ can often get the hobbyist with limited space and money far into the "enjoyable bass" region. Appropriate room treatment (GIK Acoustics Soffit Traps for instance), additional subs are what moves the needle into great bass.
So, I don’t think the swarm fanatics are wrong about swarms working. I think they are wrong that it is the only possible answer for the hobbyist.
@heaudio123 Thanks for the info.@erik_squires -- If I remember right, you are a proponent of standalone DACs (specifically Brooklyn), DIY swarms, and dedicated multichannel subwoofer amps, in addition to miniDSPs. Assuming that's so, do you put the miniDSP between your sources' digital output and the dedicated sub amp? If so, I assume you use a second digital out from your source to feed the Brooklyn DAC; do you also use a filter after the DAC to dampen the bass below a given cutoff frequency for your main speakers? Finally, do you use a different output from the miniDSP to each of the subs, and tune each one differently? Sorry for so many questions...
My (limited) understanding of room nodes is that they are affected by the placement of the subwoofer (or subwoofers, as in a swarm). If that is true, can a single mini-DSP fix the room nodes regardless of subwoofer location? Or do you need one mini-DSP for each sub?
Millercarbon lack education and personal experience in a home or professional environment with this, so their opinions are incorrect.
Can we all, possibly even Eric, agree this is a home environment? https://systems.audiogon.com/systems/8367 Sure looks like a home to me. In fact, living in it, yeah, sure enough, its a home! Gone off the deep end he has. Again.
But what about professional experience? Well to be honest I never have done this as my sole source of support. But I have been hired and paid to design and install systems. Its no secret. I’ve posted about it before. I’ve had multiple people come to me with questions, all assuming I am some kind of industry insider. Well I was a presenter at CES one year.
But to even have to be going there seems to me entirely the wrong approach. Either your ideas are valid and compelling, or they are not. If the ideas are solid then you should have no qualms whatsoever defending them on their own merits. The problem is this has been tried and failed, and so all eric has left is to try and shoot the messenger.
Basically what this comes down to is the classic example of do you want the best sound or do you want the best equipment. We all know eric is into equipment. Its all he ever talks about. Even when he talks about sound, its never really the sound he’s talking about but the measurement of the sound. Which isn’t quite the same thing now, is it?
So do you want a system that sounds good? Or do you want a system that looks good? Its your system. DYODD. Choose wisely.
erik_squires"I know you don’t believe in acoustics,"
I do not know what you mean by this if you mean by "believe in acoustics" have I accepted acoustics as my own personal savior no, I have not done so nor do I plan to but of course you are free to believe, worship, and pray as you choose provided the rules of you're nation so allow.
"You just continue to repeat tropes which were dead in the 90s. "
This is just another amusing, laughable, silly retort from the same person who insist the opinions of other's are "wrong."
You are confused, disoriented, and profoundly illogical opinions can not be "mistaken" they are opinions although in this case what we are talking about are facts also you do not know anything about my professional, academic, and scientific achievements, accomplishments, patents, and interests.
I know you don’t believe in acoustics, and you have yet to ever post anything with measurements, and experiments to prove your point.
You just continue to repeat tropes which were dead in the 90s.
erik_squires"clearthink (George hifi’s alt?? ) and Millercarbon lack education and personal experience in a home or professional environment with this, so their opinions are incorrect."
You are confused, disoriented, and profoundly illogical opinions can not be "mistaken" they are opinions although in this case what we are talking about are facts also you do not know anything about my professional, academic, and scientific achievements, accomplishments, patents, and interests.
"
Fortunately I have personal, home and professional experience in the motion picture industry as well as I am guided by acousticians who have written on the subject."
You continue to remain confused, disoriented, and simply wrong.
You can add 1,000 Db of correction, you can turn on the lights in you're room as bright as you want or turn them off to absolute darkness you can play your TV loud and/or wear plaid pants the room nodes will still be their, silly!
EQ can not fix, correct, or eliminate room nodes the nodes will always be there all you will do is add distortion and an even more uneven net frequency response plot.
clearthink (George hifi’s alt?? ) and Millercarbon lack education and personal experience in a home or professional environment with this, so their opinions are incorrect. Fortunately I have personal, home and professional experience in the motion picture industry as well as I am guided by acousticians who have written on the subject.
They’ve also failed to read multiple postings I’ve made citing appropriate links. They are guided completely by feels.
I’ll summarize my position, guided by hands on measurement, listening and acoustics:
You can use an EQ to clip resonant modes. This allows the overall subwoofer level to be lifted.
With bass traps, you can even solve nulls.
Miller is, as always, flat out, laughably wrong. He and george number 9 will never know it though. The rest of it is so riddled with half truths and falsehoods it’s not worth attempting to dissect.
erik_squires"Cool part is when you learn to EQ the bass and realize you can fix your room modes."
clearthink:
EQ
can not fix, correct, or eliminate room nodes the nodes will always be
there all you will do is add distortion and an even more uneven net
frequency response plot.
Right. Clearthink is absolutely correct OP and you would do well to listen.
The single most important factor in getting good deep articulate fast and smooth bass response is the number of drivers. The more subs the better. That includes the bass drivers in the full range pair.
The idea of improving the performance of the stereo pair by using a crossover to reduce the load on the amp and speakers, I get that. Its true. The problem is it comes at a cost. Not only the cost of the parts, being much more complex it has to cost more. But also cost in terms of sound quality. If your goal is sound quality that is not the way to go.
What you want to do instead is leave the pre alone and simply add a sub out. The simplest, easiest, and most cost-effective solution is what's called a Line Out Converter or LOC for short. Do a search, you will find them all over.
The LOC is nothing more than 2 resistors per channel. It does nothing more than reduce speaker voltage down to line voltage, ie about 2V. You can see one here done on my Melody tube amp. https://systems.audiogon.com/systems/8367 Scroll down you will see a picture of the actual mod, two resistors per channel, you can even make out the values and copy this if you want. Or if you want a more complete description and circuit diagram go here https://www.epanorama.net/circuits/speaker_to_line.html
Unlike all the other options mentioned so far this one is true high end. It will make the system better- not different, not worse, but actually better. It is easy. And it will cost about $2. The only real questions are do you want it built in like I did, or outside? And how good do you want it to look? Mine is built in because it worked for me but that's the beauty of mods, you can do it your way.
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