August 28, 2023 at 9:24 pm #1625
August 29, 2023 at 6:16 pm #1632
Presently, I’m using Ypsilon Hyperion monoblock amplifiers. They are the best that I have heard, but they should be, given the price. My second favorite was the Lamm M2.2 monoblock amplifiers. Both of these are about 220W hybrid amplifiers. Personally, I think that the Sound Labs need at least 200W; I think the maximum power that’s recommended is around 600W, so I wouldn’t go above that.
August 28, 2023 at 7:41 pm #1623
Some people believe that the bass puts burden on SLs and degrade the SQ of the midrange and recommend using DSP and subs to transfer the LF entirely to the sub. What do you think about this? In this case, the sub is not just adding to SL but replacing SL LF.
August 29, 2023 at 6:12 pm #1629
August 28, 2023 at 8:43 pm #1624
While not exactly what you inquired about, here is my experience with subwoofers and EQ:
I was told that getting the subwoofers would be the easiest part, but that integrating them with the ESL’s with proper high-pass filters (HPF) and low-pass filters (LPF) would be more challenging. There were all sorts of recommendations about HPF’s, including passive vs active vs analog vs digital. The LPF was easier, as it’s integrated into the subwoofer itself.
It seemed that integrating a HPF would be most challenging, and all methodologies would change the sound quality (SQ), and since my system was very transparent, detailed, and musical, I didn’t want to interfere with the superb SQ, whether that be integrating a capacitor into the interconnect feeding my amplifiers, or changing a pre-amplifier to some sort of DEQ device with unlimited fiddling with orders of filters, etc.
Ultimately, I decided not to even bother with using a HPF, and, as you can determine from my description below, I am very content with the SQ and musical presentation without any HPF.
Before the purchase of my subwoofers, I was told that the subwoofers and electrostatic speakers are poor matches, and I was prepared to follow through with complex HPF, etc, if necessary, but either I’m just lucky with my placement, and set up, or the Martin Logan Balanced Force subwoofers just match perfectly with my Sound Lab electrostatic speakers, with simply placing the subs in a standard stereo position. Consequently, I’m reluctant to start with endless fiddling when it’s perfect now, with only a slight stagger to the subs. (I did note that if the subs were placed symmetrically, that there was a band of low frequency sound that got cancelled out between the two subs.)
After a couple of months of listening, I got the Martin Logan Perfect Bass Kit (PBK), which is room EQ software that can either be automated or manually set up using a microphone measuring from 5 different points in the room.
Firstly, l have really been appreciating the marked improvement in texture that the subwoofers give to all musical instruments with just the standard operation using the LPF set at 55 Hz in conjunction with my Sound Lab electrostatic speakers. Regardless, I followed through with proper room EQ set up using the PBK, and at first I was rather pleased: the bass sound did sound more refined, slightly more precise, and not quite as thick at the lowest register.
Without any EQ, my room has an increased signal from 20-40 Hz, and then dramatically drops between 40-50Hz, before slightly rising back up to ideal flat signal after 60 Hz or so. After the PBK, the Room EQ flattened out the signal rather markedly, to make it appear almost ideal.
When I first listen with the Room EQ, as I mentioned, the bass sounds more refined, and perhaps slightly more precise, but it does seem to detract from some of that more visceral component of the lower frequencies. If I only listen for an hour or less, then I am content with the Room EQ; however, I noticed that if I have a longer listening session for a few hours or more, that I get rather significant ear (listening) fatigue, which has never before been a problem with my system. So I turn the Room EQ off, and listen to the standard subwoofers without any EQ, and the fatigue immediately disappears…so I’ve reverted to listening to the subwoofers without any EQ, and I think that it sounds superior, although it measures worse!
So, that somewhat supports my opinion that audio measurements are an idealized representation of what some people think music should sound like but they are mostly wrong…
August 27, 2023 at 9:40 am #1619TWBModerator
WOW! What a tremendous number of great responses!
June 29, 2023 at 12:18 pm #1532
What does everyone think about using 1 subwoofer vs 2?
June 29, 2023 at 12:57 pm #1533
I’m a big believer in multiple subs. It gets around the “slow” perception and more importantly smooths real world bass response. Two is better than one, and three or four are better yet. I also think there’s an advantage to different Qs in each sub as that further averages room bass response.
June 27, 2023 at 7:50 pm #1531yoshiParticipant
I have used a single Rel 505 with the original pristine 2 with reasonable phase and integration success.
I updated my panels to the bass focused panels and the backplates to the max extent possible with the physical constraints of the enclosure, including a toroid 1, new bias module, caps and inserted a fixed resistor instead of the tweeter potentiometer. All had a marked improvement in performance, particularly in the bass.
now, I find the Rel sub is a challenge to get a correct phase balance with the new panels. The Rel adds base extension and midrange fullness to the new panels, but with the negative effect of precise imaging and some bass incoherences, likely from phase impacts for a slower driver and rear placement and some bass cancellation or phase effects from the dipole bass in the room.
I have tried to get the best fit in my small room for over a year timeline,
but to no avail . there is always a negative impact on the overall image presentation with the sub on, and some improvement in the bass extension and midrange fullness with the sub on. a real mixed bag, I can’t get the full benefits of both set ups.
I set the Rel crossover quite low, at close to the minimum, which I estimate at 30-35 hz. Any higher setting and the effects muddy the upper bass. It just doesn’t sound as open, or transparent with the sub in the chain.
Lastly, I found that placing the sub behind the panels created bass cancelation, which was immediately audible. I put in 180 phase shift which improved the bass performance, but still had what I felt was phase imbalance. I resolved to move the sub between the panels, somewhat out from the front wall to minimize phase impacts and adjusted output to just match the panel output for a smooth volume integration. Still, at the end of the day, it compromises the apparent speed and imaging of the bass focused panels. It does add deep bass extension and drive, but with an imaging and transparency price.
So, I switch it on for some music, but it goes off for critical listening.
Just some comments from my experience. I’m never done with tweaking the system, so the adventure continues…!
June 26, 2023 at 8:33 pm #1530
FWIW, I did some adjustments after a few hours of listening: I currently think that the HPF set at 65 Hz works best. (I chose 65 Hz because that is the lowest note the cello plays.) I presently think that the subwoofers do interfere with solo piano music, and so will probably opt to turn the subwoofers off for solo instrumental music, and possibly duets also.
The subwoofers really seem add the most to any complex, orchestral music, as everything seems to become much clearer, more crisp, detailed, and dynamic. In fact, overall SQ must have something to do with more than just the theoretical frequency of instruments, as I found that while integrating the subwoofers, all instruments, including the human voice, became much clearer, and I was hearing instruments that I hadn’t heard before, which were in the upper frequency ranges.
June 26, 2023 at 11:06 am #1528ernestovParticipant
ACHiPo, do you use a hi-pass filter with your swarm subwoofer configuration at all? I have REL 812’s and REL does not believe in using hi-pass filters. They recommend just feeding a high level signal to their subs off the main speakers terminals and adjusting the low pass cross-over and volume controls on their subs.
June 26, 2023 at 8:01 pm #1529
This is how I’m running my subs as well, although just to eliminate hum, not because of a philosophical reason.
June 26, 2023 at 11:06 am #1527zgas-musicParticipant
Am using a Hsu subwoofer with my M1s that I acquired last year. I also used it with my Quad ESL63s. Integration is done thru my Anthem STR preamp and am using Anthem Room Correction up to only 350Hz to deal with bass. I’m very happy with the results.
My reasons for using the subwoofer….
– While the panels reach down to 30 Hz or so, they have a limit to how loud they can get until the speaker membrane strikes the stators – a very ugly sound. I hear it with transients from drum sets that are close mic’d. I’m setting the crossover at 100Hz currently. But tweaking as I go. I listen to some smooth jazz and pop material at 80-85 db. The M1s won’t play full frequency that loud by itself.
– Like the Quads, my M1s are hugely power hungry. Sending low frequencies to the subwoofer takes a lot of load off the panels and lets them scale up more easily.
Even with the subwoofer, sometimes the panels just can’t play where I want them to before breaking up. The sound levels are about what you might hear from the band in a mega church. Not a rock concert.
Interested to hear if others experience this and have found solutions. When I wrote to Dr West about this, he had no help other than suggest I replace my panels, which won’t happen.
Can someone with the PX and Bass Focus panels comment on this? @Bigtwin? How’s it going with your new SLs?
June 26, 2023 at 10:48 am #1526
June 26, 2023 at 10:05 am #1525
Dr. West says subwoofers are flabby and slow and therefore wouldn’t go well with the speed of Sound Lab speakers. Do you agree?
June 26, 2023 at 9:04 am #1524
Well, I went the “easy” route for the subwoofers that I just acquired, and with my minimal work, I must say that I am impressed. I acquired 2 Martin Logan Balanced Force 212 subwoofers, and placed them just inside (medial) to the Sound Lab ESL’s, and slightly closer to the front wall (about 24″ away). I set the low pass filter at 41 Hz, and just played some vinyl. The low end was much smoother, and more rounded, with a full sound, as opposed to the slightly thin sound that the SL ESL’s are otherwise predisposed to at the lower end. I didn’t bother with any real DEQ, etc yet or any HPF for the SL ESL’s. Presently, I’m content and impressed with the improved SQ of my system just by simply adding subwoofers.
I did note that when I moved the subwoofers out into the room more, that the bass disappeared, as some interference was obviously occurring. Fortunately, the initial placement simply worked.
One detractor: warped records, even if only slightly warped produce a huge low frequency signal that is unlistenable with the subwoofers.
April 11, 2023 at 6:54 am #1432rdiiorioParticipant
For years with a single pair of KLH Nines I used a 15″ JBL B380/BX63A but not needed once I had more panels (ultimately i had 6 panels).
When I listened to my A-3’s I didn’t use the sub either. I, like you, preferred the simplicity, cohesiveness and speed of the electrostatic transducers.
April 9, 2023 at 6:41 pm #1431STParticipant
I use two subwoofers. one is Rythmik F12 and another is a passive Rockford FOSGATE Punch 10 subwoofer. one is ported and another is sealed. Integration is done via DAW ( my main player) for precise time alignment and crossover. Here is the video captured by binaural mics. You need a good headphones to actually hear the difference.
Rythmik vs cheap subwoofer; Sealed vs ported subwoofer.
April 9, 2023 at 2:18 pm #1429MikkoParticipant
Yes, as of right now I am using the Deqx for the preamp. I have a very heavily modified tube preamp I’d like to add back in at some point. I like the “distortion” of tube.
I wondered about the hit in SQ also, but when you have these filters adjusting for room gain and also correcting the speakers whatever penalty that could be there…I can’t hear it.
I’m not home now, when I am I will look at what I’m using for hpf. There is a program that goes along with the Deqx unit and you can have pretty much anything you’d like.
I’ve not had the time to fully mess with it and the learning curve is steep. You can hire a person who is a representative and they via remote zoom etc… tune the system in real time with you.
You’ll need a mic, which I bought. Overall I’m pretty happy with how it sounds with my rudimentary configuration.
April 9, 2023 at 1:56 pm #1428
I assume that the DEQX is in your pre-amplifier position. Does using the DEQX negate the use of a pre-amplifier? I would imagine that would impact the overall SQ, but allow more precise adjustment of the HPF to the SL speakers. What order HPF are you using with the DEQX? I was hoping to be able to use first order HPF to the SL speakers with a capacitor/resistor interconnect, but then use something like a fifth order LPF to the subwoofers, with the LPF crossover around 50-60 Hz.
April 9, 2023 at 9:32 am #1424lotus123Participant
@kevinzoe So how close did you get in getting seamless integration of subs and Soundlab?
April 9, 2023 at 6:02 pm #1430kevinzoeParticipant
When I started trying to integrate my subs, I just used the sub’s own controls for Vol, Phase, Crossover Freq and Slope and the OmniMic’s Frequency Response chart as my measurement of winning or losing. I called this the Bronze level of integration.
Later on I bought a Bryston Crossover unit with 6/12/18dB slopes and various hard wired frequencies to high- or low-pass the mains and subs respectively. This was a step up over the Bronze level in terms of clarity and became my Silver level.
Then I bought an 8 channel DAC by exaSound and used it with JRiver to provide speaker level adjustments and relied upon JRiver’s DSP to implement parametric EQ to flatten out the frequency response curve but it lacked time alignment precision. This was another quality step up and was my Gold level.
About a year or so ago I invested in Audiolense XO which generates FIR correction filters in both freq and time domains. Now even my main’s woofers and mids/tweeter were time aligned as well as both subs. The precision of time alignment has produced the best bass I have ever heard. This is my Platinum level.
Now one might say relative to the Bronze level that “I can get my subs phase aligned with my mains at the crossover frequency” but without using impulse response measurements they are likely saying “yes, I’m in phase but 1 or more cycles behind the mains” resulting in bass sounding thick or slow or not quite in beat with the music from the mains. You need to be in phase AND cycle aligned.
So, yes the subs are seamless and if you’re in the TORONTO area swing by and I’ll demo it for you …..
April 9, 2023 at 7:44 am #1423MikkoParticipant
I use a pair of SVS PC4000’s angled slightly to the edge and behind my A1’s. I integrate them with a Deqx Premate. I also use a pair of mondo real traps behind each A1 and a pair behind my chair mounted on the wall. I’d strongly suggest adding a Deqx for the infinite tuning… it’s truly something else.
April 9, 2023 at 4:30 am #1421kevinzoeParticipant
Hi all. I own A3PX speakers and a pair of Rythmic F15 subs. My CD collection is ripped to a laptop and played via JRiver whose DSP functionality is used for EQ and to play a FIR (Finite Impulse Response) convolution file generated by Audiolense XO software to correct frequency response, time alignment, and crossover duties. Setup steps to help the sub newbies (e.g. DrBond) were as follows:
> My Prerequisites: multi-channel DAC (e.g. 8ch.), acoustically treated room and acoustical measurement capabilities for which I use the OmniMic for general freq response and decay time measurements and Audiolense for FIR filter generation
> identify all possible subwoofer candidate locations in my room and put a piece of painters tape with a letter by each location
> place sub at a candidate location and take about 15 frequency sweep average measurement and save the file with the candidate Letter in the file name
> repeat for all possible sub candidate locations.
> compare each candidate location to identify the best spots for my two subs where “best” is based on the following criteria: (1) loudest SPL at lowest frequency, (2) smoothest frequency response that is basically a straight horizontal line or tilted downward as frequency rises (i.e. 20hz is louder than 100hz), and (3) if there are any nulls that they occur higher up in frequency so that they can be bypassed via the crossover or filled in by the mains
> with subs in their new spots for best frequency response, I turn my focus on time alignment. Changing software to Audiolense I run Impulse Response sweeps and note the relative delay times that it generates. I want the sound from both mains and both subs to hit my ears simultaneously to avoid “slow” bass that is half-a-step or more behind the beat of the music. Take the longest delay time and subtract from it each of the speaker’s and sub’s delay time and enter them in JRiver’s DSP area where each channel can be optimized because of the multichannel DAC. For example, say sub #1 is way behind me and off to one side and is 8ms delayed while the front mains are delayed 2ms and sub #2 is 3ms delayed. Delay values for JRiver would be Mains 6ms (8-2=6), Sub #2 would be 5ms (8-3=5) and sub 1 that is farthest away is 0ms (8-8=0).
> now with subs in the best spots for frequency response and time aligned with the mains, I can focus on the crossover. I’ve learned not to assume that crossovers should be the standard 80Hz/24dB filter slope, in fact sometimes staggered or overlapping crossover frequencies is best based on room and speaker/sub locations within it. I was driving the SL speakers with a tube amp so wanted to relieve the tube amp of the low bass notes, so typically my high-pass crossover was between 40-50Hz for the mains. Sub’s low-pass crossover frequencies were where the measured frequency response with the closest main was the smoothest and I’d have to play with various frequency and slope combinations which in real-time with OmniMic to view the changes is a piece of cake and fun to do. I found that 1st and 2nd order slopes (6dB/12dB per octave) on the subs blended best generally speaking especially when the subs were farther rather than closer to the SL mains. Having a sub far from a main speaker and using a 24dB slope can create a ping-pong effect where you hear a bass note from the main then the sub as a bass plays a scale or run down (or up) the notes. Feathering in the sub’s bass with the mains to avoid this ping-pong effect is a combination of things: 1st or 2nd order slopes which require a lower crossover frequency so the subs aren’t localized by playing higher frequencies, and volume adjustment of the sub.
> after identifying the crossover settings for subs and mains I enter the info into Audiolense to take another impulse response measurement that’s converted via FFT into a frequency response. I create a target curve and Audiolense then does its magic to fit the measured frequency response to the target curve using the time delay values and crossover settings from above.
The above is not for the feint of heart or newbies as it involves a long learning curve about several factors, but it is the best way I know of for optimizing sound quality and can be done in other tools like DIRAC or Anthem’s ARC software. I believe that my approach is more flexible.
For those that don’t have DIRAC/Anthem, or Audiolense, then I’d suggest at a minimum using JRiver or ROON with a 2channel DAC and an acoustical measurement toolset (OmniMic or REW for example) so you can time align things and use parametric EQ to cut peaks for smoother frequency response. All of the other tools and steps above just take this to the next level of performance…..
April 9, 2023 at 7:27 am #1422
@kevinzoe, your approach sounds good and rigorous.
I used the subwoofer crawl method. I placed the first Rythmik sub on the listening chair with controls centered and both Sound Labs playing. I then played bass heavy music (Ray Brown’s Soular Energy is good for this). I then crawled around the room listening for the best bass and marking spots with tape. I chose the most convenient location with the best bass, placing the first sub there. I then placed a calibrated mic at the listening position. Using a combination of REW impulses, pink noise, and frequency sweeps I adjusted the sub’s phase, volume, and low pass filter for the flattest measured bass response. Pink noise playing with an SPL of a frequency minima you can see while adjusting the subs is very handy for this once you get things close.
I repeated the crawl method with the second Rythmik sub. (The best locations turned out to be the same as the first sub). I placed the second sub, and dialed in the settings for it. It’s pretty cool to see the peaks and nulls reduce as the sub’s phase and volume are adjusted. The dual 10” DIY sub was placed in a convenient “good bass” location and slaved to the 2 Rythmiks summed to mono.
Over the subsequent weeks and months I tweaked the volume and low pass frequency a tad on each of the Rythmik subs as I played different music and heard things that didn’t sound quite right.
One thing I like about this approach is that it improves the bass not only at the listening position, but everywhere in the room.
April 8, 2023 at 9:19 pm #1420atedeschiParticipant
I wanted to run the A1s full range, so I opted to place the subs well out of their immediate proximity. I originally bought them to fill in at the very lowest octave and never wanted them to have to compete with the stats at a higher crossover frequency. The speed differential becomes very audible as the sub is asked to play at higher frequencies, so I play them at their minimum, 50 Hz. Since low bass isn’t very directional, I opted to place them at the very back of the room, and I find that they fill in quite well and don’t interfere with the A1s, who play well down into the 20’s.
April 8, 2023 at 8:58 pm #1419ernestovParticipant
DrBond well described the purpose of using subs w SLs I just got a pair of RELs myself I am thinking of placing them one to right of the right channel 745 and one to the left of the left Chanel 745. What are your thoughts on placement? What crossover frequencies did you experiment with?
April 8, 2023 at 8:10 pm #1418atedeschiParticipant
After several years of using A-1s without subs, I added a pair of Golden Ear Super Sub X that I placed at the very rear of the room. The room is quite long at 50′, so they do well to provide lower bass balance fill. I roll them off at 50Hz at a very low volume. Tried them behind the SLs and found that they never played well together.
April 8, 2023 at 7:38 am #1417
I’ve been learning more about subwoofers, and it seems like I will be adding some soon, but the details are proving quite difficult to work out. I’m leaning towards passive subwoofers, with a separate amplifier receiving signal from the pre-amplifier. Interestingly, some people prefer a crossover at 100 hz, and others prefer 50 Hz with a very steep LPF. Then there’s the discussion about the HPF to the SL speakers also.
March 28, 2023 at 12:45 pm #1413D10Participant
My room is not so big – 20″ x 14″. RELs are placed asymmetrically because I could not fit them otherwise. RELs have unique design where you connect amplifier’s output taps directly to Subs so SL and subs receive identical signal. Subs use only signal not power from amplifiers. REL 212/SX are active design powered with 1000w each. On the back of the subs you have 2 knobs to adjust crossover point and volume output – very simple to use.
March 25, 2023 at 8:51 am #1412
With two of those REL subwoofers, you must have a very large room!
I’ve never used subwoofers before: how exactly do you set up the crossover frequency? Is it a dial on the subwoofer itself? And I assume that you just connect them to the other pair of binding posts on the amplifiers.
March 18, 2023 at 6:37 am #1408D10Participant
Here are some of my thoughts about SL and subs:
– Generally SLs do not need subs! It is perfect enough design that can cover entire frequencies spectrum
– Do subs help ? Yes! But primary not in bass like many people think. They help in 2 important things :
2. Instruments body and texture
– Question is where to put crossover point. SL have one of the best midranges on the market, matched only by Quad 57. If you go up with crossover point you will ruin lower/upper bass and midrange as well. My crossover point is 25Hz. Now you can ask why that so low point has anything with midrange – it does ! Huge! The key is overtones from mids that come very low. You can not hear them individually but in the context of music as a whole – they have big influence
I have pair of REL 212/SX and with their design they match flawlessly with my SL U-745
March 11, 2023 at 8:31 am #1407
I find that the “swarm” approach of multiple subs works well in my room. Each sub is set up and positioned and phase/volume adjusted individually to minimize room modes. In addition to spacial reinforcement, multiple subs minimize the work each sub needs to do since the overall effect is additive.
The swarm subs had a bigger impact with my Kef Ref 207/2 dynamic speakers, but I find the SoundLabs benefit from them as well.
I have 2 12” Rythmik subs stacked centered between and ~2’ behind my Majestic 745s. I have a DIY dual 10” opposed sub positioned in the null to the right of my primary listening position. This is slaved to the Rhythmiks. Low pass is set at 40 Hz and bass in the room goes below 20 Hz. The main benefits are venue ambience and a bit more excitement/emotion on bass and drum heavy music.
March 9, 2023 at 10:20 am #1393kilkilParticipant
Before the Soundslabs, I had Quad2905 in my main listening room and had a Rythmik direct-servo Sub just to add a little rumble to the low end, i had the low pass crossover set to 44hz.
The Soundlabs (922) have much more bass than the Quads and after a listening session, I decided I didn’t have a need for the Sub.
Now the Quads are in my office and because the room is smaller, they have more bass and they are generally used for low level background near field listening, and I opted to sell the Sub.
March 9, 2023 at 9:05 am #1387TWBModerator
While Sound Labs are considered a “full range” speaker and can go as low as 24hz in the larger sized panels, some owners have opted to add one or more sub woofers to their system. Personally, I have never felt the need. Opera, Classical, Jazz, Blues, Country, Piano, Hawaiian, Choral, TexMex, Folk and Rock & Roll are my favorite genres, but I have never felt the need for the additional slam some audiophile/music lovers crave. The additional complication and clutter involved with subs is also a deterrent.
Please weigh in with your thoughts and experience!
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