Open Baffle Mark Audio project
Printed From: Graham Slee Hifi System Components
Category: And the rest
Forum Name: Transducers, Speakers, Mics...
Forum Description: Interested in bi-amping, tri-amping, crossovers, speaker design, miking techniques, EQ - the list goes on
URL: https://www.hifisystemcomponents.com/forum/forum_posts.asp?TID=4094
Printed Date: 19 Apr 2024 at 7:24pm
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: Open Baffle Mark Audio project
Posted By: Drewan77
Subject: Open Baffle Mark Audio project
Date Posted: 27 Dec 2016 at 5:34pm
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I have spent the past couple of days studying feasibility for the new four-way Open Baffle project I mentioned on the 'Bitzie speakers' thread & decided to go ahead even though I can see a lot of challenges ahead. A Lot. I already have four Beyma 15LX60V2s for bass duties & taking advantage of Stefans' offer, have ordered a pair of MA 12Ps for mid bass-midrange & MA 7Ps for upper mid-treble. I will also order a pair of Proprius amps to power the 7Ps & have sufficient Spatia speaker cable to wire up & connect. I purchased a couple of aluminium strips to form part of the rear frames and have test-proved that I can accurately bend and tap these so everything is do-able but it's going to be a long process... Next will be to draw up the baffle dimensions, rebates and driver cutouts over & contact the bamboo CNC workshop I used previously. My greatest challenge will be the size and weight of these things - 20mm bamboo is heavy, the Beymas' are absolute monsters & with four large panels each plus rear frames there is no way I will be able to lift these onto 1m high platforms to conduct measurements and calibrations. I will therefore have to build each speaker up on an outdoor platform (dry day  with all amps/cabling exposed) using a step ladder and then reassemble in the listening room once measurements are completed.I am probably crazy doing this but it's been something I just couldn't get out of my head since Stefan joined this forum (damn it). The final straw was a friend in Leeds who already uses MA drivers. His speakers & others I heard at the Cranage Audio show sounded fabulous. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Replies:
Posted By: Ash
Date Posted: 27 Dec 2016 at 7:02pm
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Couldn't you like... umm... simplify things a bit? Maybe listen to the individual drivers first and take note of their strengths? Second pair of Proprius is a good idea though. Can't have too many of those...  I'll think about ordering my second pair in January.------------- We do not see things as they are. We see things as we are. |
Posted By: Drewan77
Date Posted: 27 Dec 2016 at 7:56pm
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No Ash, it's about the sense of a real performance which includes sufficient volume of air moving 'fast'. I don't quite get that on the lowest octaves & that's why I'm doing this. Over the years, I went from speakers with passive crossovers to two-way active to three-way active, including Open Baffle. Each time as the load on amps & drivers has reduced, cleanness & transient performance has increased significantly. For example, if an amp and 12P is asked to handle a relatively narrow range, say 800hz-2000hz then neither will be trying to reproduce multiple other frequencies at the same time & the driver cones will have fewer competing excursions. OK, then other issues at the crossover points will normally come into play - phase, time alignment, beaming etc but the equipment I use corrects that. It's not simplicity or otherwise that concerns me (although active OBs are relatively simple), what matters to me is 'believability' when playing music, especially at volume.
------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 31 Dec 2016 at 11:44am
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Taking advantage of the holiday period, I have managed to spend time on this... - Mark Audio drivers delivered from KJF & dimension checked for drawings. - Drivers, including Beymas burning in at low level for a few weeks using an old AV multi channel amp.* - Proprius ordered. - Baffles drawn up & will contact the bamboo CNC workshop next week. Lead time is normally quite long. - Timber sourced & aluminium strip ordered for rear frames, - Various countersunk s/s bolts, nylock nuts, washers & threaded base inserts for spikes ordered. - 3 pairs of speaker binding posts purchased. - I already have Spatia cabling. I can't do anything else until the baffles are manufactured & Proprius are ready. The frames will be constructed together with the baffles.  I will initially build in the configuration shown in the RH illustration above but may move the second bass driver to the top depending on weight/stability & handling (as per Pure AudioProject OBs). The measurement and correction phase will need to be done in the final configuration. *correction. SWMBO just came back from town & past the dining room door... "turn that dreary noise off"
------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 31 Dec 2016 at 12:49pm
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Great stuff Andrew. I can see the appeal of the clarity of the OB approach as my Alpair 12P's (previously Ash's) are mounted on open baffles at the moment. Very nice although running at quite low level as almost new. It is weird to hear the reflected sound from the objects behind the speakers! ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Ash
Date Posted: 31 Dec 2016 at 1:41pm
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Any speaker that beats my AKG K1000 sound is good enough for me. I don't think I'm as fussy as Andrew. I just like transparent, well proportioned and musical sound. It doesn't necessarily have to feel live as a lot of recorded music isn't live. Believability is just a scaled up version of the previously mentioned characteristics. A pair of 12P drivers on open baffle are good enough for me but they do need bass assistance, for which I'd opt for a helper woofer, probably in a sealed enclosure. ------------- We do not see things as they are. We see things as we are. |
Posted By: BackinBlack
Date Posted: 31 Dec 2016 at 2:55pm
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I've been fascinated by this Grand Orgue design by Visaton for some time but put off by the elliptical "full range" drivers, which although I haven't heard just don't look right(modern). The bass driver arrangement is quite attractive as it gives a compact open baffle arrangement. They also have a Petit Orgue, similar layout but with only 2 full range and 2 bass drivers per unit. Often thought that it could be a basis for a design using MA drivers. See: http://www.visaton.de/en/bauvorschlaege/breitband/grandorgue/index.html" rel="nofollow - http://www.visaton.de/en/bauvorschlaege/breitband/grandorgue/index.html 
------------- Just listen, if it sounds good to you, enjoy it. |
Posted By: KJFAudio
Date Posted: 02 Jan 2017 at 9:51am
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Starting to come together this, I'm really looking forward to seeing it evolve. You might want to consider curving the array as it's so tall or even giving the drivers some way of tilting, although I guess you'll be able to beam steer a bit with delay. ------------- UK/EU dealer for Mark Audio Drivers and Manufacturer of speaker kits |
Posted By: morris_minor
Date Posted: 02 Jan 2017 at 11:39am
You mean like this:   ------------- Bob Majestic DAC/pre-amp Accession MC/Enigma, Accession MM, Reflex M, Elevator EXP, Era Gold V Solo ULDE, Novo, Lautus USB and digital, Libran balanced, CuSat50 2 x Proprius + Spatia/Spatia Links |
KJFAudio wrote:Posted By: Drewan77
Date Posted: 02 Jan 2017 at 12:33pm
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I thought about that Stefan but I'm able to manually adjust time delay per driver set by down to 0.001ms (the processor algorithms will do timing/phase automatically once I get a semi-anechoic measurement so this should prove unnecessary). 'Anechoic' readings are best taken outdoor in the winter when the birds are quieter but I suspect it will be several months before I am ready, which is a pity. I once did this in the summer and every tree around lit up in unison like a twitchers discotheque! To average-out random sounds like that this means at least 24x thirty second bursts of loud rising frequency which makes the valley behind our garden sound like an alien attack is incoming! In the winter, it's easier with fewer, shorter bursts. Basically, the further the speakers are from any other surfaces, including soft ground, the better the reading & the greater the frequency range that can be corrected. I have been able to achieve a clean 36ms reading before any reflection (a tiny wiggle from the mic stand only) which means accurate data right down to 28hz and even the subs sound significantly tighter once calibrated. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 04 Jan 2017 at 10:26am
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Prompted by Grahams' other thread, I have been doing some basic baffle step simulations for these speakers. Fortunately, using DSP I can mitigate many of the issues that he is wrestling with but it's nevertheless an interesting exercise. Starting with the largest drivers, OB rear out-of-phase cancellation can be clearly seen in the first graph below: -6dB at 40hz (I have also shown the same parameters for a box speaker version for comparison. This only calculates the step effect and doesn't take into account any other aspects of the drivers themselves). Beyma 15":  OB:  Box:  Edge step cancellation can be reduced on OBs to varying degrees by applying relatively short open side 'wings' and this is what I plan to do. I don't have the means (or the brain!) to simulate this but on my existing OBs these have a very beneficial impact so I will prototype a few variations, the goal being to take these particular drivers down to around 40-50hz and align my existing subs below that. I still consider myself a relative novice with this subject but have enough understanding, experience and most of all the processing hardware to enable this to work well. In general terms it's better to a apply larger processor dB reduction rather than >3dB additions & using separate amplification, then equalise output of the various driver sets. Simulations for the Alpair 12P & 7P baffles: 12P:   7P:   ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 02 Feb 2017 at 4:57pm
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1. I now have everything necessary to build these speakers: - Drivers (partly burnt in) - Baffles (manufactured by Stefan at KJF Audio, in the photo the panels aren't yet aligned by grain) - Proprius Amps (partly burnt in running the tweeters on existing OBs) - Materials for the rear frames, including timber, aluminium bracing, bolts/nuts, mounting feet etc. - Spatia cabling & speaker binding posts Unfortunately, domestic chores have intervened & this weekend will be spent wallpapering so 'normal service' will resume with these next week.  2. Seeing Grahams' ongoing tribulations with his room/cabinets, I decided to take some measurements of a single Alpair 7P & then correct the frequency response using an HDP-5 processor (to see just how far this little driver can be 'pushed' in its naked state, although I will only be using it for high frequencies). Taken from a near-field in room measurement with the driver surrounded by a mattress, outdoor seat covers, cushions, middle room & ear listening height. A calibrated Earthworks M23 mic was used.  The three frequency plots show: - The raw driver measurement. - Flat correction created by the processor. - Final in-room measurement with a correction filter applied. Note how room effects overlay the correction filter but nevertheless, frequency changes from the native driver are significant. The processor algorithms also automatically correct timing & phase errors across all frequencies so everything is as it should be. Although this was a simple setup without any form of baffle, comparing a piece of music playback via the raw driver & then the corrected driver, the difference was significant (as I would expect). Midrange/mid bass was now apparent, together with a smoother overall sound. It was actually very pleasant and listenable.  That last plot shows how the driver was now basically 'flat' down to just above 100hz which would of course create less processing strain once assisted by a baffle. Showing group delay plots, firstly from the correction filter & then the final measurement, there is a slight room impact on both at ~800hz & ~6khz. Group delay on this driver prior to correction was several magnitudes higher. In all other respects: impulse response, step response and phase, digital processing has also 'corrected' the Alpair 7 to some degree.  I have shown all this as an example of just how far digital speaker correction has come and what is possible. When I build these speakers, I will run them actively in-room for a few weeks with just basic crossover & manual time alignment until I'm satisfied that the drivers and Proprius are fully run-in. After that I will disassemble, re-build and measure outdoor on a dry day. Then I will run some more sophisticated calibrations back in the listening room, firstly to achieve a flat frequency response and then slightly tweak to my listening preference. To be continued... ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 05 Feb 2017 at 6:33pm
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Thanks Chris. Helpful to see DEQX earning its way and I like the wood panels. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Fatmangolf
Date Posted: 05 Feb 2017 at 6:36pm
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If anyone's interested REW can do a similar correction if you ask it to identify the filters needed to correct an uneven response, probably more useful for bass management rather than integrating open baffle drivers as DEQX clearly does well. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: ICL1P
Date Posted: 05 Feb 2017 at 7:37pm
Who's Chris? ------------- Ifor ===== Reflex M & ACCESSION M, CuSat50, Majestic DAC, a Proprius pair. |
Posted By: Fatmangolf
Date Posted: 05 Feb 2017 at 8:20pm
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Indeed I should have written Andrew as you clearly realised Ifor. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 08 Feb 2017 at 9:50am
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Just spent a couple of evenings on this - progress so far:
Frame construction with Alpair 7 baffles at the correct angle for seating position head height. The wooden side runners may prove to be rather flimsy when I try to move the finished speakers - I will have to be careful. Fastening hardware is stainless steel including nylock nuts (at the moment I'm using temporary wing nuts & square nuts until I'm satisfied everything fits).
Baffle mounting screws are held in place by small rubber O-rings so that panels can be fitted from the front. There are also decoupling spacers between baffles & frame (I intend to leave the bottom baffle/driver in place when moving these & maybe the top one as well if it's manageable).
Threaded inserts fitted to baffles for the four 15" drivers can be seen in the image above. The Alpair packaging included front mounted self-cutting bolts which is a neat touch. These will fit flush to the front rebates. Soundcare SuperSpikes used as mounting feet, fitted to M6 threaded inserts. The feet are internally decoupled which also allows easy tilt adjustment. I have taken the precaution of snugging up several nylon cable ties around the timber at the base as I suspect this may be a weak point. I will trim these later.
Rear uprights with speaker terminals mounted on wooden plates:
Aluminium side braces cut, angled & drilled at the front end only so far. I found that bending these to 45deg weakened the aluminium too much so I'm unable to fold round behind the rear support, These will have to be bolted through from the sides using threaded inserts angled into the wood. It's probably going to be fiddly so I'll start by assembling these with wood screws and if everything works, drill out & glue threaded inserts in place so hex head bolts can be used.
------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Richardl60
Date Posted: 08 Feb 2017 at 2:18pm
| Impressive!! |
Posted By: Fatmangolf
Date Posted: 08 Feb 2017 at 10:53pm
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Very good styling IMO. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 09 Feb 2017 at 7:55am
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Last night I finished off the angled runners for the top baffle, started to align the side braces to the front uprights & locked the bottom baffles into place on each speaker. I also found a solution for bolting to the rear support.
Clamping the angled sections in place, then drilled, glued & screwed:
Initial assembly of the side braces (after 'negotiation' to be able to use the kitchen table, more decorating this weekend I'm afraid
Baffle mounting bolts with decoupling spacers. These will also hold the bolts in place whenever I remove a baffle.
It occurred to me that rather than try to bolt the side braces with a gap to the rectangular rear support, I could use my cutting table & strip this back to the correct 35deg angle - a sort of 'bring the mountain to Mohammed' solution (bring the mounting to more-angled….sorry). Made a small test piece and held it roughly in place so it looks like it will work. It's going to be important that when a baffle is removed, the side braces don't exert pressure on the front uprights to push them apart or inward. All the baffle bolts need to slide easily back into the original holes when reassembled during measurement.
An approximate image of how a final speaker will look (bottom braces resting on a wood offcut). The rear support will be cut down to finish flush with the top side braces. When I triangulate this, the speaker terminals will have to face forward as in the picture. Not a big issue to me.
As the main load bearing braces are double thickness, I next need to remove these and araldite/clamp together before trimming to length/drilling the rear holes. As I only have 2 large clamps and there are eight of these, this may take a few days. In the meantime, I will get 2 more timbers for the rear uprights & trim them to angle & length. I will keep the originals 'just in case'. ------------- Older than I once was, younger than I'll be ............................. Andrew |
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Posted By: Ash
Date Posted: 10 Feb 2017 at 11:27pm
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Great photos Andrew. I could make something along the lines of a mini version of this for a 12P/12PW pairing that'll sit neatly on a desktop. ------------- We do not see things as they are. We see things as we are. |
Posted By: Richardl60
Date Posted: 11 Feb 2017 at 7:27am
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Highly rigid a very good point in the design. |
Posted By: Drewan77
Date Posted: 11 Feb 2017 at 7:42am
I cut the new rear supports yesterday using a larger block but had to remove the guard from the saw & took it very slowly (pleased to report that all my limbs still seem to be in place).  In between household duties this weekend I will paint these/attach the speaker terminal blocks and continue to araldite/clamp the main side braces - the bottom and middle one on each speaker are 9.5mm total thickness, the other pair are single thickness. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 14 Feb 2017 at 1:47pm
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Things progressed slowly over the weekend as I had other priorities but after several hours work last night, here is the latest update. All side braces trimmed, bonded together (when double thickness) and remaining bolt holes drilled - these still need a final spray finish. Rear uprights were blocked in place with pieces of timber to maintain height with the baffles & threaded inserts have been drilled and screwed in place.  Now wider material is being used for the rear uprights, speaker binding posts now fit on the back of these as can be seen in the bottom picture below. Both frames are now completed & loosely bolted together. Over the coming days, all of the aluminium side braces will be removed, sanded down and re-sprayed black. Then the frames can be fully assembled with the correct washers & locking nuts   ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Fatmangolf
Date Posted: 14 Feb 2017 at 6:55pm
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That looks great Andrew, fine work. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Drewan77
Date Posted: 17 Feb 2017 at 6:51pm
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Finished the build late last night and have done an initial indoor measurement & calibration this afternoon. Completed rear frames: 15" drivers were mounted to their baffles prior to fitting, the Alpairs were added to the fronts after this picture was taken. I'm pleased that all the holes & threaded inserts lined up correctly & the weight of the Beymas did not pull things out of alignment.  Cabling connected (everything is GSP Spatia, including some 'internal' wiring that I bought from John C a couple of years ago):  Side view of a completed speaker:  Proprius amps powering the Alpair 7s @ frequencies above 2khz:  Initial readings taken in the centre of the room (each speaker moved to this position with some basic sound absorbtion). The mic was re-aligned to each driver during measurement, in this pic, the midrange Alpair 12. Crossovers are at 250hz 16th order and 2khz 20th order, both linear phase.  Raw data for the two speakers, measurements in-room as shown above, not perfect but OK to get me started. LH:  RH:  Impulse response was reasonably clean until 10.7ms with a small floor reflection affecting the reading. This means that the data is reasonably accurate down to around 120hz so I have only corrected from 150hz to 6k for now. For comparison I have shown an outdoor measurement of my older OBs below this which is 'anechoic' to 31ms (corrupted only by tiny ripples after that). I plan to do a similar outdoor measurement of the new speakers sometime in March or April, weather permitting. They will be on a 1m high platform above the lawn & nothing to create significant reflections.   ..& here's frequency response after group delay, time & phase alignment 150hz - 6khz. The uncorrected excursions from the upper response of the Alpair 7s are caused by predominantly ceiling reflections as these are very tall speakers - outdoor measurements will resolve that later. Although bass extends fairly flat to around 50hz, the room reflection at 10.7ms would affect a calibration & I know from previous experience that this would add a nasal quality which is completely absent from a typical OB speaker:  So, I guess the real question is, how do they sound so far? Very good indeed - not too dissimilar to my other OB speakers but with faster and more open bass, well integrated with the transient dynamics of the midrange which is what I was aiming for. These drivers also have quite a long way to go before they have completely loosened up. I have time aligned both existing subs to 40hz with 4th order LR crossovers, still noticeable if I switch them out. Overall this setup sounds absolutely huge in both height and width & even though I am not tampering much with the Alpair 7 / Proprius response at this stage I must say the treble is already lovely sounding (Boris Blank Anthology FLAC album being used for setup which is very clean, dynamic and well mastered ) . These have a way to go but already I am getting probably 80-90% of the result I believe I can achieve later and with a free weekend ahead there will be plenty of opportunity to listen....
------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Richardl60
Date Posted: 17 Feb 2017 at 8:55pm
| Impressive again Andrew keep up the good work. |
Posted By: Fatmangolf
Date Posted: 18 Feb 2017 at 9:23pm
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Thanks again for sharing this Andrew. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: KJFAudio
Date Posted: 19 Feb 2017 at 8:36am
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Great work Andrew. I'd be inclined toward just using an minimum phase 1st order between the 12p and the bass drivers centred around the baffle step frequency. Using such steep filters especially at the bass end take a lot off correction power with FIR and assuming you have a limited amount of taps available they may be better spent on a little bit of judicious phase amplitide correction and save the rest for room correction. Don't you know how many taps there are to work with in the Deqx? Also as at the other end you are crossing between driver that are so similar in character you may find shallower filters are fine there too, the steeper filters will create stronger pre ringing which will continue ringing for a while. ------------- UK/EU dealer for Mark Audio Drivers and Manufacturer of speaker kits |
Posted By: Drewan77
Date Posted: 13 Jun 2017 at 2:01pm
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I have finally reached the point where these speakers are 'finished' in their current configuration*. My immediate neighbours are on holiday so new calibration measurements have been taken outdoors & in spite of a few uncooperative birds (and an aeroplane!), I was able to run multiple long frequency sweeps which averaged out everything except the speakers. The raw anechoic response is completely flat +/-0dB @ 30hz- 9.2k & apart from a very narrow, high Q null @ 11.8k, it's +/-3db from 18k-25k (the limit of the M23 Earthworks mic). DEQX algorithms corrected phase, timing, amplitude & group delay across all drivers & frequencies. I never cease to be amazed by the resulting music from any speakers treated in this fashion. The four 15" drivers have taken an age to loosen up and run in properly & I also changed the high end crossover settings, created new correction filters, made a few room adjustments and did a new in-room measurement/bass eq adjustment. These are now almost unbelievably transparent, fast & full range with height, depth and (some) width to the soundstage. Voiced exactly as I want and no apparent room effects on any material that I have played or at any volume so far. Although I am obviously biased, Stefan will be calling in after the Cranage show so I can get a second opinion. Below are the listening chair plots (the room has naturally caused deviations from the outdoor measurements above, even allowing for acoustic & subtle bass eq treatment. Nevertheless the results are impressive, still almost 'flat' & they certainly sound great). 3-Way OB speakers:  Two subs:  Combined, final result (with time/phase aligned crossovers between both speakers/both subs):  * I would like to try these at some stage with my NEO3 ribbons instead of the Alpair 7s and also change the configuration to have one of the 15" panels at the top, with the mid/treble drivers nearer head height - easy to do with this design of OB. No real reason for this but it will be fun to do sometime - I loved the NEOs' which may just have a very slight edge on the Alpair 7s' - they certainly measure flatter, without that null & in fact corrected to +/- 0dB right up to almost 25k. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: KJFAudio
Date Posted: 13 Jun 2017 at 5:25pm
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Nice little write up, I'm really looking forward to popping in to see these. Stefan ------------- UK/EU dealer for Mark Audio Drivers and Manufacturer of speaker kits |
Posted By: KJFAudio
Date Posted: 26 Jun 2017 at 8:45pm
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I had the pleasure of going to Andrew's House last night to have listen to his speakers ( and look at some of his lovely art). It was quite late and was at the end of a long weekend exhibiting at Northwest Audio Show so I don't think my brain was quite as queued into the music flow as usual so my help probably wasn't as constructive as I normally try and make it, sorry Andrew. Anyway, the speakers sounded great, the height and depth of the image really is astounding. Andrew has chosen his seating point to give him the best bass response and it really does sound very natural and believable, maybe at the expense of side to side imaging which does locate extremely well sitting slightly further forward but the bass does't sound quite as good. The integration of the sub bass to bass is I think the best I've heard. The integration of the rest is seamless as well as very very coherent. I've heard quite a few customer builds since I started selling the Markaudio drivers but this one certainly had the largest scope, well done Andrew. Stefan ------------- UK/EU dealer for Mark Audio Drivers and Manufacturer of speaker kits |
Posted By: Drewan77
Date Posted: 26 Jun 2017 at 10:31pm
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Thanks Stefan, it was very good of you to come over after such a busy two days & I'm gratified that you were so positive about what you heard. It's all very well having other visitors enthusing about what they hear but I appreciate critical and experienced ears like yours (even if still recovering from the excesses of Saturday!) ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Drewan77
Date Posted: 29 Nov 2017 at 8:35pm
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I mentioned in an earlier post that I may replace the Alpair 7s with the Neo 3 ribbons. After listening to music over an extended period, the response of the Alpairs didn't quite match my memory of the Neo's (which I had used in the previous OBs for several years). With vinyl, the astonishing & delicate percussion sparkle which I was used to via the Accession was missing so I bit the bullet and decided to change things. Initially I planned to take outdoor calibration measurements on a dry day last week but by the time everything was set up in the garden, it had become too windy to get a clean response, even using 36 frequency sweeps per speaker (about 2 minutes) which averages out all rogue sounds like occasional birds/distant aircraft/exasperated wife etc. The wind became almost gale force by midday when I was ready so I abandoned that. I set it up again yesterday, which was dry and wind free - with the added bonus that this followed several days of continuous rain, meaning the lawn was soft & wet, reducing possible floor reflections even though the speakers/mic were raised well above it.   Twittering birds are scarce at this time of year too & I must say that the results were by far the cleanest I have taken. After letting DEQX do its thing 0hz - 20k with frequency, phase, crossovers, group delay and impulse, a second set of verification measurements gave the 'semi-anechoic' response below. This is genuine, not a fake! The Neo's are powered by a pair of Proprius at 3024hz/300dB to the Apair 12s & because the speaker is measured as a 3 way, the interface is corrected automatically and seamlessly. Proprius & ribbons seem like a real marriage made in heaven.  It's not just about measurements of course so this afternoon I started to listen to a selection of LPs and CDs. It sounds marvellous so far, the sparkle is back and the system really does sound remarkable. N.B. I apologise that I post far less frequently than previously - the system needs no further adjustment and retirement gives us the opportunity to spend a large part of the year away with the family/grandchildren overseas. I listen to more music but spend much less time behind a computer screen and that has to be a good thing! ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Richardl60
Date Posted: 29 Nov 2017 at 9:35pm
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Very good! Do you think that low temps or dampness may impact iron the drivers and therefore the results at all? |
Posted By: Drewan77
Date Posted: 29 Nov 2017 at 10:11pm
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I suppose that must be possible Richard but fortunately the sun was shining, it was the warmest part of the day, the previous day was sunny without rain and the last thing I did for both speakers was bring them out of the house, onto the platform. In all around 10 minutes before measurement started so I doubt these were influencing factors. Even when I carried the speakers back into the room, the rear metal frames still felt at room temperature. I also do the measurements using 3m speaker cables with all electronics still in place on their racks in the music room. ------------- Older than I once was, younger than I'll be ............................. Andrew |
Posted By: Richardl60
Date Posted: 30 Nov 2017 at 6:33am
| Bases covered! |
Posted By: Fatmangolf
Date Posted: 02 Dec 2017 at 10:19am
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Thanks again for sharing this Andrew. Very informative and impressive results, I have ribbon tweeters in my GX300's and love their sound too. ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |