Description

I have not updated this in more than a year. Finally sold the Sarastro 2s to a friend. The Sarastros were not a good match to my room. The rear firing config. excited the longitudinal mode significantly. They have some non-linearities that I cannot effectively compensate for given my room limitations. This is not to the speaker's fault as they sound much better at my friend's larger listening space. To say the speakers are too big for the room would only be partial truth.

This is not due to lack of effort. I went thru acoustic consulting with Rives and then local expert Bob Hodus. Read up on Handbook of Room Acoustics and Sound reproduction. After the consultations, I did a lot of experiments to improve the room acoustics. Rm is 22'x14' x 10'. Dimensions are not bad but one side wall has windows occupying >2/3 of surface area. There are also a door & a fire place along the mid axis of the room, two walls were interior walls which are less robust in bass reinforcement. Room is at mid level with living space above and below. Previously, after reading the Get better sound book, I had settled for a listening location at 4ft from backwall. This allowed for boundary bass boost which overcame a bass cancellation problem (mid axis, quater wavelength listener to boundary) at 35-40hz. However, primary length mode at 25hz (7db) muddled up the sound. Despite treating the rearwall, the comb filtering effect from the rearwall markedly reduced transpancy and smoothness.

Rives Audio: I went with level 2 consultation and also bought the room measuring kit to allow for repeated measurements along the way. I was quite weary of the actual translation of mathematical modeling into the field. Richard was very helpful in educating me to use ETF and BARE. He was excellent in recommending RPG products, different type of curtains, blinds for different applications. Rives also had all the contruction methods for bass traps and diffusors. Although I preferred the looks of built in traps and diffusors, I went the way of RPG and GIK. My friends had ripped out acoustic constructions that they didn't like and that's just too painful for my wife. Room tuning is complex and requires much trial and error. Base of my previous experiences, I was also worried about resonances of wood diffusors (ceiling and sidewalls). Rives ultimately set the listening location at 9ft from the rear wall. The result was much improved clarity and smoothness along with reduction of room modes. The suckout at 35-40hz is still present but reduced in bandwidth and severity. Richards felt that is acceptable in my case as there is smoothing in human hearing. Bass was flat on psychoacoustic curve on BARE. (I thought this has something to do with combination of gating and smoothing. I could produce a similar curve on Fuzzmeasure when I played with smoothing and gating time.) Rives also had even handed approach in balancing RT 60, freq response, absorption and diffusion.

Bob Hodus: I seeked the help of local expert Bod Hodus in hope of eliminating the suckout entirely and also to provide a second opinion before engaging in a sofit / ceiling construction proposed by Rives. Bob was a pleasure to work with and very willing to educate. His approach was entirely hands on. He focus mainly on frequency response curve and uses absorption mostly. Using continuous test sweep, we went thru inumerable listening locations, reconfiguration of bass traps and speaker locations. At the end of the day, he got rid of the suckout entirely, low bass 20-40hz was linear without boost or suckouts. It is done by sitting 12 ft from the rear wall. THat left me with only 10ft betw me and the front wall, not a lot of room to position the rear firing Sarastros. I was excited with the new result and invited listening group over. All felt low bass was excellent but trade off was made in clarity of midrange as speakers are too close to the wall.

I thought about this for a while and kept rereading the Handbook of Room Acoustics. "Bass is best thought of as waves or pressure zones and high frequencies are more similar to light rays (hence the term specular reflection)." Although my room is symmetric in dimension, the asymmetric construction allowed for the most even bass pressure distribution at the 12 ft point. What if I were to set up the speakers along the opposite wall and check if bass linearity persist at the same spot. Sure enough, the bass alignment remained the same and I got 12ft betw me and my new front wall. This allowed for more room for the speakers to breath. It also prompted me to choose a speaker with no rear wiring port/woofers. I went with the Isis after auditioning Rockport, YG, Magico. I am quite happy with my third pair of Avalons.

After the bass foundation was set, I proceeded to adorn all surfaces and experimented with a few tweaks.

Frontal wall: Tried RPG skylines, hemifusors, abfusors, wood constructed diffusors, BAD Arcs. The wood constructed diffusors were the worst. They diffused effective but they also sounded. THere was marked resonace in 150-200hz range measurable on both Fuzzmeasure and ETF. Subjectively, they were like adding more speakers in the room. They enriched the wood tone during playback. With more of them, the main speakers disappeared as more of these diffusors made sound. This was pleasing for a short while. I think there are marketed room tweaks that work on similar effect. They extend the midrange resonance to balance out the slap echo in the highs and bass boom in many untreated room. The 7inch skylines were very good and produced smooth midrange and treble (largest effective bandwidth). They brought a lot of focus to the center stage if you put them in the center (suggested by Rives). I almost installed them permanently until I played the XLO test disc. It consisted of Bill Johnson walking around the room while percussing a gong. With skylines at the center, he could not walk away from the center but he could walked far away to the side. THe extruding blocks of the skylines were actually vibrating during playback. It was ruining the subtle spatial clues need for proper localization. I suspect the effect would be less if I was further away from the front wall. The hemifusors were better in this regard as there are no extruded blocks to vibrate. The BAD ARCs were the best as they were combination tools (absorb + diffuse). The soundstage was the most organized and yet able to portray variations in depths. Abfusors were almost as good but why pay more for the same thing. I later constructed a dome with 3 to 4 BAD ARC panels of varying curvature and width to be placed at the center. This dome pushed the centerstage forward and increased focus ( effect can be modified by changing width and curvature). I could see why so many rooms have this. This did not work for me as I was quite close to the speakers (8 ft). I ended up with three panels evenly spread out in front.

Sidewall: Tried aborption panels first. They decreased reflections and created more focused but smaller soundstage in comparison to the diffusors. They decreased the amplitude of the reflections as seen on the ETF impulse response but the reflections were still very focused in the time domain. With combo tools like BAD ARCs, the reflections were decreased in amplitude and also spreaded out over time. It tricked the ears into thinking the boundaries were farther away. Not treating the first reflection point of the ipsilateral speaker created a wide soundstage in a different way. The sound source appeared wider but price was paid on impulse response and soundstage specifity. Treating the 1st reflection of the contralateral speaker was just as important as the ipsilateral reflection point. The crosstalk was reduced. ie, the left ear heard less of the right speaker.

Backwall: I used a few RPG skylines to great effect. The slight resonance is no longer an issue as they are behind me and ten feet away. Later, I tried 5 columns of Ikea expedit shelfs positioned in at an angle. This worked even better with better bandwidth. Depth was increased to 12inch and area of coverage was increased. I had two very narrow band suckout(less than one sixth octave) from only the left speaker at 50 Hz and 110Hz. These completely disappeared after installing the Ikea shelfs. Only part of each shelf was filled with a mix of cds and LPs to maximize the diffusive effects. One drawback, they increased midbass reverb at 60-80hz via combination of blocking the fire place, altering overall room acoustics and there own resonances. I had to increase bass traps at the corner.

Ceilling: Very important yet frequently overlooked area. Before treating the ceiling, the soundstage would rise when orchestra went full tilt (Similar effect to broadening of sound source). Hemifusors and skylines were similar in effect. When they fell off, hemifusors survived much better as there were no extruded blocks to be broken. One of my more embarressing moments when hosting. Lucky it did not land near the tonearm during play. I had considered doing suspended wood panels or maybe acrylic panels. After having the Expedit shelfs increased bass reverbs, I am not going that route on the ceiling. Just imagine if a wood panel came loose from the ceiling.

Bringing it together: All these traps, diffusers, combo tools are used to optimize soundstage, impulse response and frequency response. They frequent have unintended effect on reverb at a particular bandwidth. The soft diffusors were great as they did not make sound of their own. However, they markedly curtailed the high frequencies (>10khz) reverbs as they increased soft surface area of the room significantly. Large hard surface adds resonance of their own and alter room acoustics. Attention needs to be paid to maintain RT60 in an even handed manner. This is at least as important as freq response curve. As the RT60 trends down for a higher resolution sound, it is very easy to kill the high frequencies and quite difficult to bring down mid and low bass reverb.. At one point, my system sounded lean in bass. I had five large removable wood panels installed to block off all windows in the room and installed a 2 inch solid wood door with soundproofing. Surprising, the amplitudes of the room modes and bass alignment are not significantly different but the RT 60 at the bass 40-80hz were drastically prolonged. The noise floor of the room dropped to 40 db but it was like a tomb. The bass was muddy and standing waves were very problematic. In this exercise, I learnt that at least in my situation, the room dimensions governed the amplitude and freq. of the modal response but the degree of reverb is largely controlled by the structure. It is very hard to paaively trap mid and low bass reverb (

I am sure my experiments and observations are flawed. Feel free to point out any deficiencies so I can learn and benefit.

Speakers previously owned: B&W 805, JM lab Diva BE, Avalon Opus Ceramique, Thiels, Harbeths, Quad 2805, Avalon Diamond, Verity Sarastro 2

Amps previously owned: Boulder 1060, Vac phi 300.1, Jadis DA88S, Pass lab X350.5, Naim 250.2, ASL 1009 and ASL hurricane, Mcintosh 275.... etc. Heard in my sytem: ML432, Lamm M2.2, etc/

Preamp previously owned: ARC Ref3, Ref 5, BAt 51se, Naim 282. Heard in my system:,Shindo, Halcro

Previous Phono: AYre px5e; ARC PH7, ASR exclusive 2010. Heard in my system: Lamm, Nagra VPS, Shindo, Halco, Allnic

Previous carts: Zyx Universe, airy; My Sonic lab ultraeminent, airtight PC1. Heard in my system: Goldfinger, PC1 supreme

Previous tonearm: Graham 2.2, Davinci 12", triplanar 7

Previous tables: SME 20/2; Avid Acutus

Here is my opinion and preference about different carts that have gone thru my system. Just opinions and I am no expert. My preference is limited by my ability to setup (sub)optimally and by phonostage matching.

My preference in carts have changed and current favourites are Lyra titan i and dyna v1T.

Zyx Universe: Very refined and detailed but not enough macrodynamics and bass.

Airtight PC1/Supreme: Most amount of bass. A little on the warm side. Played well on all three arms, worked well with tube + ss phono. Sounds good with many different loading. Lacked a little detail and refinement comparing to other top carts. The supreme is slightly more refined comparing to the regular PC1. Slow transients.

My Sonic Lab Ultraeminent: This used to be my favourite cart.. More detailed and energetic than the Airtight line up. Quantity of bass is less but quicker. Excellent bass power carried into the decay. Transient attack is not as fast as XV1T or Titan I and perhaps not as open sounding. In combination with the Davinci, it conveys the most ambient info and float the soundstage best.

Dynavector XV1T: I think this is the most neutral cart.. Faster transient attack than MSL/AT and more open sounding. Bass is impactful with less energy in the decay. I like this one on the phantom best. On the Davinci, the midrange is marginally richer (maybe wood wand) but the lightening transient and focus were attenuated.

Titan I: My number one cart after finding an excellent match with DV 507 arm. Fast and open like the XV1T (both stiff body contruction) but with even better grip on the Bass. The transient changes on double bass is very well portrayed from the attack to the decay. It portrayed wide tonal and macrodynamic contrast and make the performance very exciting. More focused and controlled than PC1. To my surprise, I never find it bright when properly adjusted. In terms of setup, the window of optimal performance may be small but not too hard to arrive at. You know when u get this one wrong. I like this less on the Davinci & phantom. The triplanar and Davinci adds a little warmth and roundedness that it does not need. The Graham could not control resonance as well and had a little top end glare. With the 507mk2, the heavy arm and flux damping dissipate the energy perfectly. Just all the glories, nothing more and nothing less.

Coralstone: I never intended to get this one because of the warm fuzzy reputation of Koetsu. My dealer offer a partial trade deal and I could not resist. Another surprise, it is very detailed with a fluid midrange and extended topend. Bass power is slightly less than Titan/ultraeminent but not too fat behind. Only have this on the Phantom so far. Very difficult to align because the stone block my line of sight. I probably have not optimize this one due to neck spasm. It is also better played on an arm with Azimuth adjustment to minimize crosstalk.

Goldfinger v2: Another excellent cart.. Very limited experience but a friend was kind enough to bring it over for a spin. Similar sound to the MSL. Heaviest cart i have handled.
Read more...

Components Toggle details

    • TW Acustic Raven AC
    3 motor
    • Esoteric X 01 Limited
    CD/SACD
    • Graham Engineering Phantom 2
    Unipivot
    • Einstein The tube Mk 2
    Linestage
    • Einstein TT Choice
    phono
    • Luxman M800a
    Two as monoblocks
    • Stealth Indra
    XLR
    • Studer A810
    Reel to reel
    • Finite Elemente Reference double width
    I will not spend this much on a stand again
    • Grand Prix amp stand
    not bad
    • Avalon Acoustics Isis
    Isis
    • Dynavector 507mk2 SE
    black
    • Lyra Titan i
    stereo
    • Lyra Kleos
    stereo
    • Dynavector XV1 T
    cart
    • Minus K BM 8
    0.5hz
    • RPG skylines, hemifusors, BAD ARC
    diffusors
    • fuzzmeasure 10ft from wall behind listener
    8ft from speakers
    • fuzzmeaure 7-8ft from wall behing listener
    10ft from speakers
    • fuzzmeaure 4ft from wall behind listener
    15-16ft from speakers
    • Spiral Groove SG2
    Centroid

Comments 109

128x128
Glai, I decided to check your Virtual System after reading your post regarding your problem with the Canterburys. You have done way more than most to try and tame your room. It's a shame you're still having problems.

You have a wonderful system, with the resources you are willing to use to get the desired result, I'm certain you will get there in the end. I wish I could immediately suggest a solution, but, alas, there is none forthcoming. With all you have done to improve your listening room, I feel extremely fortunate with how my system/room perform together.

By the way, I would think the Luxman mono blocks should be a good match with the Canterburys.

Best of luck, regards,
Dan 

Ag insider logo xs@2xislandmandan

Center
Great system and room!
Very interesting to read about your findings and decisions.

calle_jr

Center
Owner
Yes, 200W spectral is sufficient for Eidolon Diamond but it will still be more dynamic with more power.

I have briefly demo the spectral gear with MIT cables but did not achieve the synergy that I hoped to achieve.

glai

222222&text=pt
I too would choose the faster transient response, inner detail and focused imaging. I have a 200 watt Spectral amp I don't plan on changing. Will that drive Eidolons/Diamonds in your opinion?

ptss

Center
Enjoyed reading your system thread, great collection of equipment. Sure it sounds special and most importantly enjoy the holidays.

needfreestuff

Center
Owner
Only one thought. So much $$$$$

glai

222222&text=pt
Thanks. I believe Tesseract now rules. Any thoughts?

ptss

Center
Owner
Much has to do with the ergonomics of the speakers and my room (24x14x10ft). The speakers (setup along short wall) yielded the most flat bass response when placed 4'2" to 4'6" from the wall behind the speakers. Distance is measured from the center of the bass cone. This was calculated by RPG room optimizer and verified by real time measurements. The listening position that yielded the most even bass response ( both amplitude and decay time) is near the center of the room.

The older Rockport (Ankaa, Aquilla) have woofers on the side and ports in the back. That means I am going to be sitting very close to the midrange unit and the tweeters along the front speaker baffle. The Veritys have rear firing woofers and port which means the same thing. I was worried about driver integration when listening distance to too close to the speakers.

The Avalon has woofers along the front baffle and downward firing port which allows the most distance from the listening location to the front baffle of the speakers. There is enough distance for proper driver integration.

Aside from ergonomics, I picked the Avalon Isis because they are not a difficult load, and they have fairly high sensitivity. I feel they have slightly faster transient response, more focused imaging and more inner detail than the Rockports. The larger Rockports have better bass dynamics but need a heroic amp. They are also little supple and laid back sounding for me. This is a purely subjective opinion and I am sure many Rockport setup are fantastic in all aspect. I just don't have the space or the resources.

At the time I was shopping for speakers, Magicos came out with Q5 which I found a little sterile sounding. I did not like the Wilsons with the older focal tweeter. I recently listened to the Magico Q3, S5 and the Wilson Sasha 2 and they make great sound.

glai

222222&text=pt
Thanks. What encouraged you to choose the Avalons? You know, comparatively?

ptss

222222&text=pt
Enzo, would 'mad scientist' seem appropriate too?

ptss

Center
Owner
To answer a question from another thread.

My system have changed a fair amount and I have not updated the system page. The Rockports, Veritys that I auditioned are not the most current versions. I am happy to share my experience and you can decide whether they are helpful or flat out wrong.

Verity and Rockport used modified Audiotechnology drivers and there are some similarities in tone or transient response. Much of their difference in sound lies in the use of crossover configuration. Rockport use high order cross over and have less overlap between drivers. This restricts the driver output within their ideal operating frequencies and results in even off axis dispersion. The speakers are not difficult to place, imaging is solid and consistent when different instruments are switching in and out of play in the orchestra. IMHO, this approach pays a small price in speaker sensitivity,impedane swings, ultimate transparency, or immediacy in impulse response. Early in the hobby, I seeked speakers that conform to the principles of low distortion. Later, I like speakers that balance the low distortion ideals while being a sympathetic load to the partnering amplifier. Rockport's cabinets are more inert than the Veritys. Inert cabinets enhances dynamics and allow the speaker to disappear to a certain degree. I personally feel the speaker disappearing act has to do with the direct to indirect sound ratio (reflected sound). If the room is properly diffused, the reflections contribute to imaging, sonority and allow the speakers to disappear. If you put a speaker in an anechoic chamber where reflections are absorbed, you will be able to localize them no matter what the cabinets are made of. The converse is also true. Fairly cheap speakers like definitive tech. ,which is a bipole, disappear fairly well. The bipolar output has more indirect sound.

Veritys use low order crossover. Frequency overlap can yield uneven frequency response within the room when speaker setup is not optimal. Drivers are properly phase aligned in speaker design but their individual boundary interactions within the room and can lead to cancellation. When this effect is not properly addressed during room placement, it results in tonal shift/imbalance. The larger models employ ribbon tweeters which have wide horizontal dispersion but narrow vertical dispersion. The dispersion pattern is quite different than the midrange. The midrange driver plays very high (5khz) and very low (<100hz) in order to move the crossovers out of the midband. There is restricted dispersion at the high end of the midrange output. These are compromised made to optimize impulse response and phase response. The designer believes human ears are most sensitive to artifacts introduced by crossover from the critical midrange to lower treble. The results are speakers that are very transparent and immediate. The cabinets are not quite as heroic as the Rockports but they disappear just as well (IMHO). The difference in driver dispersion and frequency overlap requires critical room tuning and speaker placement. The rear facing bass driver excites room modes and also requires much care.

The Veritys sounds particularly exceptional with recordings that preserve phase info. (Provided you are playing the correct phase)

Which speakers would take you further depends on your listening taste and priorities, your flexibility and expertise in address room acoustics.

glai

222222&text=ph
Glai, thanks for your response. Our systems do have many similarities. You definitely are hitting the exact points I'm thinking about. Searching for slightly more dynamics and texture but hate to lose the amazing Avalon imaging and soundstaging.

philb7777

Center
Owner
Philb777,

Thank you for your kind words. Your system is great as well. there are much similarities between our systems.

The rockports speakers I have listened to are Aquila, Ankaa, Mira Grand 2 and Antares. I think they are version 1s.

The Rockports are capable of larger dynamic swings and richer texture. They cast broader images. They are very linear with fairly little overlap between the individual drivers. (may be high order crossovers)

The Avalons have more immediacy, and pinpoint imaging, perhaps a trace more transparent. With the wrong setup, they can sound bleached or stringent. The Isis has more than enough dynamics for my taste.

The Avalons are configured with downward firing ports. The ports have fairly low output which allow for less modal excitation and easier placement in my room.

I could be happy with either. Please keep me posted with your search

glai

222222&text=ph
Glai, you have a wonderful system and I am so impresed with the lengths and thought you put into your room. You should be very proud of what you accomplished!

Quick question - I am currently an Eidolon Diamond owner for the last 10 years and I am begnning the quest for a new loudspeaker if I can find one that does all the things the Eidolons but surpass them too. Not sure if a loudspeaker at the similar price point exists, but I am having fun looking! I see where you auditioned quite a few loudspeakers before settling on the Isis and owned two other pair of Avalons previously. Could you expand on your auditioning of the Rockports and how the Rockport sound compared and contrasted with the Avalon sound?

Thanks in advance for any info.

philb7777

Center
Owner
Lapierre,

Thank you. I manage to sell the Luxman at big loss.

I glued the RPGs to the ceiling. I waited the glue to be half dry and stick them up. Much easier on the rotator cuffs.

Still spinning

glai

222222&text=la
Glai catching up on your thread once again. Congrats on the Luxman 800A monos.

How did you reattach the RPG skylines and Hemifusors where the would stay in place?

Spin the Yellowjackets.

lapierre

Center
Owner
Ralph,
The Luxmans had a rich tonal saturation with a smooth, presentation. The M800a in monos also had more bass impact than the ayre MXR. They usually sound nice with the Avalons with large variety of source equipments and cables.

The Ayre has faster transient attacks and tracks the microdynamics better with more detail. Bass is also quite articulate. However, the amps are very sensitive to vibration control, cables, front end matching. It was easy to make bad sound with the Ayre but after some struggles, I am happier with the Ayre.

I have been satified with the ARC Ref 250 as well.

These three amps were better match to the Isis than many others I have tried: Rowland, MBL, Spectral, Classe, Bryston, Conrad Johnson, Boulder, etc.

Do your custom speakers have similar drivers and crossovers? O/w the amp mathcing experience may not translate.

The luxman XLR is pin 2 negative so be aware in case you go balanced latter. CAT is SE so no problems. Ayre works better balanced. Luxman may have wider bandwidth when using SE connections (see stereophile measurements).

Good luck and enjoy

glai

222222&text=ra
Hello Glai,
really nice setup and system.
I´ve seen Ayre MX-R amps on the Isis pic and know that you own the Luxman M-800a.
Can you give me some insight in your thoughts and experiences with both amps as i am interested in buying one M800a or a set of Ayre MX-R monos for my personal system (i am audio dealer in Germany).
I use Accustic Arts Drive II and TubeDAC SE and a CAT Legend Preamp, all Echole cabling and Masteround 845 highly modified tube monoblocks and a custom made speaker.
Thanks,
Ralph

ralphww

222222&text=tm
Nice system and setup Glai. Do you still use the real to real? Haven't owned one in years, kind of miss them.

tmsorosk

Center
Owner
Lapierre- Fuzzmeasure is quite simple to use, more friendly than ETF. I use a macbook pro, behringer microphone, dual mic pre.

Hessec- I did not listen to the 1.1 before buying the 2.1. The more expensive models has stainless steel ring + more layers in the plinith. This reportedly improve bass macrodynamics. I bought mine and the bardo base on a friend's recommend. I trust and admire his knowledge and I have learnt much from him. I had the stage 3 Bardo (glass platter, upgraded PS). The advantage of magnetic drive is apparent in pace and timing. It did not exhibit high torque direct drive issues of my highly modded technic SP10mk2. The Bardo has a low noise floor as the drive does not contact the platter directly. However, the motor is still resting in the same frame (not the most massive) that the tonearm and the platter rest on. I believe the motor vibrations still creep into the analog system indirectly. The Bardo had significantly less bass dynamics than the SG2 due to noise in the low freq.. If you are interested, check out the miiler lab test on many tables and arms on hifi news web site which is very informative. I got better performance from the Bardo by placing them on cerabases (one right under the motor and one near the tonearm mount. They rest on granite platform on top of minus K. I believe this better drains the motor noise from the system and yielded better dynamics. The low torque design can work with minus k or vibraplane type system. The results from Sp10 is not so good as high torque generate motion in a compliant system.

I have sold the Bardo. I strongly prefer the SG2 over the Bardo. I suppose the Oasis can improve on the Bardo. I read somewhere that Stage 3 Bardo or Oasis can have dynamics close to the Brinkmann Balance. Another friend of mine has the Balance and the dynamics are miles ahead.

My friend who recommended the Bardo did not experience significant dynamic limitations. He is really much more knowledge and probably better utilize the equipment yielding better performance.

dev - I have seen pics of my new toy and hopefully not adding too many months to a 13 month wait. I hope to implement the centroid in a different table but the very large arm base is not the easiest.

glai

222222&text=la

Gial can you tell me your experience in using Fuzzmeasure?

Was wondering how intuitive the user interface is and also what hardware you used for room measurement?

Room close to being finished painting. Hopefully this weekend to start listening to music.

lapierre

Center
Owner
Andromedaaudio-

Thanks for clarifying. You must be aware of the time delay and 2 pi vs 4 pi effect associated with front baffle diffraction. There are many good reads on the internet. Some people went to length proving or dispproving the effect.

Let me share my experience with the Avalons and what I have a handle on. How much is due to curtailing diffraction vs off axis dispersion? I don't know.

I measured the speakers on and off axis, with and without felt, with and without grill.

The felt along the baffle limits the off axis radiation pattern of the high freq more than midrange. In my rather narrow room, the comb filtering effect from the boundaries particular the side wall is markedly reduced. Looking at the freq response with no averaging or 1/48 octave averaging. The amplitude of the saw-toothing is reduced with felt in place. The choice of room treatment material became less critical, somewhat similar to narrow dispersion designs like horns or electrostatics. I am surprised that the effect is also noted alongthe wall behind the speakers and ceiling. Subjectively, felt on sounds more coherent and has more focus in the midrange and bass, treble is less splashy. The soundstage is less wide comparing to no grill no felts. I compensate by toe-in less to get enough reflection off the sidewall to maintain sounstage width.

I supect with the felts on, the off axis dispersion is more limited but more even across the frequency spectrum. This lead to more coherent sound. Ideally one would want the direct sound and reflected sound to be qualitatively similar. Just having wide dispersion without tonal evenness would adversely affect the perceived tonal balance.

In the stereophile measurements, JA sometimes said that lack of on axis output may be compensated by off axis flare in the same frequencies. I would not want a speaker with this particular characteristic if I can help it.

glai

Center
Owner
Albert,

It really sounded bad. Those shelfs extended the measured RT60 of 40hz to 150hz to 0.8sec. Without the shelfs, it was 0.45 to 0.55 sec. Bass was muddy, diffuse and hanged in the room forever. No punch or pace. I suspect our ears are more sensitive to the dynamic leap of each note rather than just constant sound pressure. If the previous note never went away, the dynamic leap of the next note is diminished. Not to mention the in and out of phase interaction.

I do not know the exact mechanism of this. Maybe the shelfs are partitioning the room leading to different reverbs in two zones. Another possibility is the shelf actually acted as diffusors with bandwidth extending into the bass. I remembered reading some expert opinion regarding an ideal frequency point to transition from absorption to diffusor. So diffusion in bass freq may not be desirable. A third possibility is shelfs are vibrating. I would appreciate it if you can shine some light in this.

The records also absorbed too much high frequencies.

Prolonged bass reverbs with disproortionately dull highs makes for the disaster in sound.

glai

222222&text=de
Hi Glai, what happened to your Galiber don't see any mention of it.

dev

222222&text=he
Wow, Thank you for that response!!!!!! Terrific reply. Did you hear the SG1.1 before buying the SG2? Do you think the Bardo is in the same league as either the Raven or Spiral Groove?

hessec

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