How do you high pass your main speakers?
I have been very happy with the distributed bass array I added to my system, but from what I hear, the optimum method of integration is to high pass the main speakers.
Two questions:
1. What are my options for accomplishing this? Does this need to be a feature built into my amplifier or is there another component that needs to be inserted in the chain.
2. What crossover point would be ideal? What frequency and amount of rolloff would be best if my speakers are ATC SCM19's which have a frequency response of (-6dB) 54Hz-22kHz.
Cheers,
Tony
@ditusa Nah |
Hi, You need to use line level OUT to ______ a device that separates only the low bass frequencies, and that device then passes only the remaining upper bass/mids/highs back TO the Preamp or back TO an integrated amp. A tape out/in loop; a processor out/in loop; a unit with preamp (line level) out, and line level input jacks Thus the amp and the main speakers only try to make upper bass/mids/highs. ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; integral crossover: here's a Raven Blackhawk Integrated Amp with an integral high pass, 80 hz crossover: sends 80 and below out to separate amp(s), like self-powered sub(s). Crossover point is not adjustable, 80 hz is their single setting. then the blackhawk amp and the main speakers only try to make 80hz and above https://ravenaudio.com/product/blackhawk-mk3/ ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; simple self-powered subs have built-in crossovers, you go preamp line out, to sub's line in, then sub's line out (low bass missing) to preamp line in. preset sub's adjustable crossover and preset sub's volume (, then your preamp changes the volume of main and subs together
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; external crossover use a loop out of preamp to external crossover, back into your preamp. or line out to external crossover and line in of an integrated amp a tape loop, processor loop, line in/out loop crossover and volume Ideally you want an adjustable crossover to find the best setting with your main speakers and your low bass speaker(s), and adjustable volume, remote volume ideal. .................................... separate amps for the sub(s) somewhere, how volume controlled? |
Ideally you would want to insert a high pass filter AKA electronic crossover, between your preamp and amplifiers. If your amp is an AVR this feature I believe is built into most of them. If you are not using an AVR you have a few options at varying price points. A lot of people seem to like the miniDSP, DBX makes an economical analog crossover and there are other options, including some that can sell for several thousands of dollars. I’m not sure that there is an ideal crossover point, kinda depends on the style of music you like, how loud you like to play, the kind of subs you have and to some extent your room acoustics, If your subs are close to your mains you could crossover as high as 200 Hz if your subs can cycle that high. If your subs are not inline with your mains you would want to crossover no higher than 80 Hz. I play a lot of bass centric music at rather loud volumes so I cross my front subs at 173 Hz and my rear subs at 78 Hz. |
Marchand XM446 balanced high pass filter. Here is another interesting option. |
@tony1954 wrote:
Preferably you’d need a DSP unit (digital crossover)/electronic crossover inserted between your source/preamp and power amp to your main speakers, instead of high-passing your mains through the (potentially available) high-pass filter function of your subs.
Your ATC’s are passively filtered already, and running a DSP prior to your amp in addition - to some degree dependent on the specific DSP unit chosen - is really the least of a filter function interference compared to a passive filter. What you gain high-passing your mains, on principle - certainly with a XO-point no lower than ~80Hz, and relative to the chosen filter steepness - is two-fold: the ATC’s are freed of a large chunk of LF signal, meaning less excursion, more headroom and a cleaner sound in this (great) driver’s band. And, similarly the amp driving your ATC’s will be rid of LF-signals, so it’ll operate more effortlessly and with lower distortion as well. Will it be worth it? Who knows, only you can decide given your specific setup context and different factors that are at play here. I’d be inclined to say though: leave it as it is. You’re happy with your DBA-implementation - good, that's something to be appreciated. Make no mistake: I’m an ardent proponent of high-passing main speakers in the 80-100Hz range crossing over to subs (to make the most of the added headroom this allows for), but I do this fully actively sans any passive XO’s, and so my speaker setup as an outset, incl. separately housed subs, is really approached as a whole, interconnected system per channel - like you would a single box; high-passing the mains in my case is not an extra "layer" of filtration, but rather designing each channel, in its different bands, as a complete setup from ground up. |
Thanks for the response. Actually my MiniDSP crossover is set to 80Hz for the subs so there would be a redundancy of frequencies from that 80Hz threshold and where the ATC's roll off around 54Hz. Perhaps it might be best to just tweak the crossover point a little bit lower to mitigate any spike between 54Hz and 80Hz. |
@tony1954 Why did you select 80Hz for the crossover? Wouldn't lower be better to avoid the duplication as you say? I ask because I am still adjusting my subs crossover frequency and have it closer, but still above, the roll off freq of my main speakers. My main speakers are -3 db at 31 Hz and I think my sub is set to 40 or 50 Hz. Thoughts? |
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You can insert some Harrison Laboratory fMod hi pass filters into the line (RCA) from your pre amp to the amp(s) driving your main speakers. They have hi-pass cutoffs at a range of frequencies and aren't too expensive so you can get some at 30, 50, 70, 100hz.... I got the 50 and 70's when I put some subs on my system. 70 seemed to work best for me. They filter at 12db per octave so you still get some music below the cutoff level. That'll take stress off your main amp(s) and leave those frequencies and below to your bass array. |
There are a number of ways. #2 built into the subs (rare) #3 external analogue (my choice, JL audio CR-1, wilson sub controller, Bryston makes one or at least did). #4 adding the right resister to your wire like a crossover before the speaker
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As for the frequency to highpass? Anything you want. Really anything. I adjust mine from 40hz to 100hz and it all sounds fine. Just listen and see what sounds best. Do the speakers or subs have more detail at 60hz? Most my speakers with 8” drivers I ended up at 60hz. My current speakers with 15” drivers I ended up at 40hz. |
If you have preamp outputs and amp inputs, you can use this inexpensive device to act as a very configurable electronic crossover: Dayton Audio DSP-408. Get the Bluetooth dongle with it. I hear it’s sound can be improved by using a 15V power brick instead of 12V supplied, but I haven’t tried it myself. This unit is pretty geeky, so if you are not so inclined, pass, but the same is true for miniDSP. If you want an analog crossover with this kind of flexibility, JL Audio makes the CR-1, but it is not inexpensive!
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I don't mind people experimenting, BUT don't do something that can't be reversed easily. You seem to be saying that yo don't like your speakers or that yo know better than the engineers that designed them. I must ask what started this line of thinking for you? Was it something that you were told or read. I would dump that like a hot rock. I guess if you have the money to spend it is ultimately your choice, but just to accommodate some frivolous fantasy seems to be wasteful. OR maybe you really do have CR@PPY speakers. so what the heck, experiment away! |
"You seem to be saying that yo don't like your speakers or that yo know better than the engineers that designed them." "OR maybe you really do have CR@PPY speakers. so what the heck, experiment away!" "No one reding your post has any idea what yo are hearing so how can anyone hear make such a decision." If ignorance is bliss, you must be one happy dude. |
Hey @bumpy48 - The value of the capacitor is based on the input impedance of your amplifier. You can use this calculator, filling in the top with the input impedance (probably 25k or higher) and the Hz with the cut-off. 80 Hz is a good value there.
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Sounds like your speakers don't go very low and probably mate very well with your subs. I like to touch the signal as little as possible and my prejudice is that an electronic crossover might do more harm than good. The recommendation to use an exectronic crossover in this application comes most often from a dealer selling said crossover, or someone repeating what they have heard from this dealer. btw, the dealer is often mischaracterized as an expert. Excuse my skepticism. YMMV. Jerry |
I personally believe you should set your crossover point by ear and not by what your friend or neighbor think it should be. I use a Celodyne servo sub with my Quad 63’s and feel it works very well. I start low on the crossover frequency and raise it until you can hear the sub kick in with music playing. Then I back off about 7-10 Hz unroll it sounds right to my ears. Seems to work well for me. |
tony1954 If you have a point to make, I would suggest you state it. I made some very clear points and you can’t address any of them apparently. so I am assuming that you just like talking trash about peoples input. As I stated If you have the money to spend play any silly games you wish, but you would have to write a complete essay to even begin to describe what you are hearing or hope to achieve. You give One single parameter that by itself is useless. I mentioned just a couple of items that you probably don't have the background to deal with and only wished to give a little caution before you make some EXPESNSIVE mistakes. But you'll are smarter than everyone here. Of course that is why you are asking questions of the public to begin with correct? You see I actually studies Electronics Engineering in College and have been designing speakers since the late 70s and I have even told stories about mistakes I have made doing some of the same types of things people are asking here, just to show that messing with something isn't always the best answer. |
Also Tony, Before you go complaining to management as some have in the past, I would suggest you actually READ what I have and HAVN'T said. Notice that I never cut down anyone else advise. Other that to caution you and to give you some SOUND advise on reviewing YOUR motives, I didn't cut you down Your equipment, or your choices. I suggested that MAYBE your speakers might be deficient or inferior, but you opened with that! I just gave one of dozens of reason that there are NO SIMPLE SOLUTIONS to what you are attempting to do. |
That practice has worked well for me. Knowing the frequency response curve of my speakers does help as a starting point. When I finish setting up my two subs, I subtly miss them when they are turned off. A remote control to adjust the sub’s volume +/- 1,2,3 helps optimize for different listening levels and musical material. |
You are correct. The ATC don't go much below 55Hz, but I knew that before I bought them. I agree 100% with your assessment. I just thought I would ask the question so I could see if there was something I was missing. I also used the speakers as the front speakers in a HT application via HT bypass so limiting there response is not ideal. All things considered I am very happy with the sound quality as the system is currently configured, so I am guessing I may just play around with a slightly lower crossover frequency for now. |
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Does your integrated amp have a pre amp out / amp in feature? If so just run the Harrison filters with rca jumpers. I'd suggest the 70hz ones for you. That said, I kind of agree with the folks who say to just carefully dial in your bass array. The beauty of your setup its you could try both to see what you prefer. Good Luck! |
I have been thinking about tri-amping, so this topic has been on my mind. An interesting device I’ve seen can be found at this link. https://sublimeacoustic.com/products/k231-stereo-3-way-active-crossover I have purchased, and I’m currently having these devices checked over and cleaned up. Firstly, a Sansui AU-5900. I love this vintage integrated amp, and it produces a sound very pleasing to me. The key piece is the Sansui CD-5, A three-way crossover, with variable crossover points. I plan to use the pre-out on the integrated into the CD-5, and then use the Integrated +2 additional amps. Additionally, I have purchased a Sansui BA-90, and a BA-60 for amplification. Some of the questions I have: what crossover points?… good thing the CD-5 is adjustable. Also, do I want to run the highs, lows, or mid range back into the integrated? If anybody wants to discuss this rare, vintage, and quirky set up further, feel free to DM me, I don’t want to hijack the thread. But I am actively in the process of figuring this out. Good luck to the OP, I fully support that you need to separate the signals and have your amps only drive the separated frequencies. |
I tried a Bryston active high-pass between my Ayre preamp and amp and didn’t like the resulting sound. When I asked Ayre about it, Charles Hansen castigated me for placing an active component between his preamp and amp -- a zero feedback issue. He did approve of the passive balanced Marchand 80 Hz 24 dB high-pass I now use, and the Ayre sound is preserved. A Velodyne SMS-1 provides acoustic room correction for a pair of HGS-15s. |
I am glad to hear that Charlie Hansen (RIP - another bicyclist lost too early due to a vehicle incident) approved of the passive balanced Marchand high-pass filter that I recommended earlier in this thread. That filter seems to do no harm in my system. The effectiveness of using a high-pass filter, and the best-suited cut-off frequency and slope, will be largely dependent on the main speakers. Main speakers that do well handling high current and rolling off at their lowest frequencies without issue are possible candidates to be run full-range with a sub rolled in at an appropriate frequency. Main speakers that do not do well at the lowest frequencies, and speakers where the bass driver(s) also handle midrange duties, are more likely to realize a sonic improvement by using a high-pass filter to limit the depth of the low frequencies that need to be handled by the mid-bass driver. My Aerial LR5 speakers offer the advantages of being a 3-way design (where the low frequency drivers do not also handle the mid-range) and having bass drivers that extend low, down to around 40Hz. They are also quite dynamic and designed to handle high power. The designer, Michael Kelly, suggested running them full range and rolling the Aerial SW-12s in to fill in the lowest frequencies. I have found that set-up to work well but when something else in my system (DAC, preamp, cables, etc.) results in a more bass-heavy presentation, then adding the Marchand high-pass filter (45Hz cut-off) between my preamp and amps does seem to help without causing a sonic penalty. |
I’m familiar with ATCs (mine pair is the ATC SCM12 Pro passive monitor). These are sealed/acoustic suspension designs with terrific bass that disappears rather abruptly below the resonance frequiency, which I believe is in the mid-40s. As for the high pass, after trying all manner of workarounds, I ended up buying a used but perfect-functioning electronic crossover, the Marchand XM66, which has 24 dB/octave slopes (ideal for your application) and a variable crossover. I’m accustomed to setting mine anywhere from 70 Hz to 80 Hz. That means: -- all frequencies below the crossover point go to my subwoofer (JLAudio e110); -- and all frequencies above the crossover point go to the ATCs, or the other pair of speakers I use on my desktop, the vintage KEF 103.2s, also a sealed 2-way design I chose this crossover frequency because the sub is so capable in that range; while the ATCs, wonderful though their bass is, are working harder the lower the frequencies go to the resonant frequencies. So I relieve them of their hardest workload. This electronic crossover is very transparent acoustically. I really can’t distinguish between it being in-line vs not being in-line. That’s my recommendation: an external crossover with high crossover slopes. Note that Marchand also makes electronic crossover with fixed crossovers (via internal cards you can purchase). And example of that is the XM9. The most elaborate of their crossovers, the more expensive XM44, allows you to individually select crossover cards at the frequency and slope you specify. |
@tony1954 wrote:
Some prefer a slight overlap between the subs and mains, but I would use the supplied lower knee specs by ATC for your SCM19's and work from there setting an appropriate low-pass point juggling through the range here. The ATC's being a sealed design with a shallow lower end roll-off I suspect you would be better off lowering the LP from 80Hz and experiment with slope steepness. Using a DBA arrangement and setting delays, depending on the specific implementation, must be close to a nightmare to get right - although some may argue it's less important, but I digress. Your ears must decide, so whatever works, works (in my own actively configured speaker setup I use the same LP and HP frequency between the subs and mains with 36dB/octave Linkwitz-Riley slopes, so very little "redundancy" at the crossover. Proper delay settings here is of vital importance). Doesn't your MiniDSP have extra output channels? You already have all you need then to experiment high-passing your mains. |
I would try the ATC speakers crossed over between 65-75 Hz with a 2nd order Butterworth filter on the miniDSP. The sub should be crossed over at 65-75 Hz with a 4th order Linkwitz-Riley type crossover.- either in the miniDSP, or using the subwoofer's own crossover (assuming here the sub has a 4th order low-pass cross over option). The idea is for the ATC's natural roll-off and that of the miniDSP to combine together. The combo will be equivalent to 4th order and close to a Linkwitz-Riley alignment. (If you have a home theatre processor, this can also be achieved by setting the ATC's to small.) Start with the polarity of both the ATC and the sub as positive. Depending on where you locate the subs relative to the ATC, you may also need to play with the phase adj knob on the sub if it has one. |
@tony1954 Great year! I'm 02/12. I have been crossing over to subwoofers since the Dahlquist LP1 was released in 1979. The LP 1 used an active 2nd order low pass filter and a passive 1st order high pass filter. They gave a kit of capacitors and you had to solder the right ones into the unit based on your main amp's input impedance. Fc = 1/2PiRC R is the input impedance of the amp and C is the capacitor in Farads which you had to select based on the crossover frequency you wanted. This is a first order or 6 dB/oct filter which is very slow. You can do this by putting the right sized cap in series with the input of your amp. I soldered them in all the time and I recommend this for those who have subs that only have low pass filters. You can get analog two way crossovers like the unit JL Audio makes but even better is digital bass management which allows you to time and phase align the subwoofer as well as allowing much steeper slopes without distortion and Room Control. These units are made by MiniDSP and dBx. There are also full feature digital preamps that include bass management from Trinnov, DEQX. Legacy, MiniDSP, and Anthem. @ditusa's link is excellent and you should read it through. In order to fine tune a subwoofer's crossover you need to be able to select both frequency and slope of both the high pass and low pass filters independently. My ancient TacT digital preamp gives you a selection of crossover frequencies from 20 to 300 Hz in 1 Hz intervals, 1st through 10th order and you can change them on the fly with the remote control! Today only the DEQX gives you this kind of flexibility. The goal here is to use the highest crossover frequency you can using the equipment you have. If you can hear the subwoofer, tell there is one in the system other than feeling the lowest notes then you still have work to do. The higher the crossover point the more likely it is you will hear the subwoofer. The slower the slope the more likely it is you will hear the subwoofer. Turn off the main speakers and listen to just the sub. If you can hear midrange coming out of it you have a problem. You have two choices. Lower the crossover point or speed up the slope. I use Sound Labs ESLs. I currently high pass the SLs at 120 Hz 6th order and low pass the subs at 110 Hz 8th order. Because removing the low bass from the main speakers lowers distortion I never recommend using a crossover lower than 80 Hz. If the main speaker is a full range driver like my SLs you do not want to go lower than 100 Hz. The next problem is time and phase alignment. If you do not have the ability to adjust this digitally the best starting place is to keep all your speakers and subwoofers equidistant from the listening position. Place you two subwoofers at intervals between the main speakers right up against the wall. Using a tape measure measure the distance between the subs and your listening position. Now adjust your main speakers so they are the same distance away. If you want them farther off the wall you will have to move them out laterally. If you can not make this set up sound right then the smartest way to proceed is by getting a calibrated USB microphone and see what is happening. You can then adjust the speaker positioning to minimize group delays. Or you can get a Digital preamp that will come with a measurement mic and let the computer do everything for you. The other beauty about digital preamps is that they usually provide digital EQ capability which allows you to make your system sound exactly as you want it to without adding any distortion. You also do not need a separate DAC as they are included. The MiniDSP HSD is only $1,200.00. At this moment I think the soon to be released DEQX Pre 8 and Pre 4 are going to be best. They have not released the prices yet. I am going to be Beta testing the Pre 8 shortly. |
Rereading this thread, I stil think that there is no need to do anything. You won't improve your sound because your current speakers don't go low enough to worry about. My guess is things sound really good right now. But I want to caution about the advice in this thread to hit your signal train with a sledgehammer of electronics. I've posted before that I consider the signal path sacred and it should be touched as little as possible. Running your signal through an endless rack of electronics is a sure way to end us with that common "consumer" sound. If you do decide to so something, I highly recommend the path @erik_squires has suggested which messes with the signal the least and give your speakers the best chance of continuing to do a great job above 80Hz. Jerry |
Hi everybody! I'm also contemplating high passing (some of) my speakers. Regarding the capacitor advice of @erik_squires: would it be possible to add it directly before the speakers? Of course, a different value would be needed. Sorry if this is stupid, I have no background in electronics. My reasoning is like this: 1. If I'm going for the preamp-->capacitor-->power amp route with my integrated amplifier (with pre-outs and power-ins) then I would also need another interconnect cable as I cannot simply insert the capacitors in the RCA or XLR connectors in the back of my amp. The cable would need to be butchered. Plenty of extra contacts and soldering in the signal path as well as the particular voicing and the extra expense of the additional interconnect turns this into something less simple and elegant than I'd like. Not to mention that I'd have to use both the unbalanced and the balanced pre outs in this case at the same time (pre to power and also pre to subwoofer) and I don't know if this is totally without sonic consequences. 2. For connecting the speaker cables I prefer the bare wire option anyway, after trying WBT bananas and spades that is. I'd simply have to solder one speaker wire to one leg of the capacitor, while the other leg would go to the biding post (maybe at the amp end of the speaker cable in order to avoid too much vibration induced by the speaker?) 3. Or maybe this could be done inside the speaker, between the crossover and the woofer itself?
Of course, in this case only the woofer would benefit from having to deal with less deep bass while the power amplifier would not be spared of the task... |
@donquichotte - Technically yes, but the cap size would be huge. It’s also not a very good or efficient idea. YG Acoustics has actually made a speaker like this, though really really not sure why, except maybe they were worried about over driving the woofer. By putting a high pass filter before your amplifier you minimize the voltage swing the amp has to make, but putting it after means the amp still has to produce the same range of (+) and (-) voltages. In other words, putting a high pass filter before your amp gives you more headroom, allowing it to play louder before reaching the limits
Well, yes, that’s called a crossover. 😂
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