From Colin's (Toppsy) post from Audio-talk:
Own Label 54oz Felt Underlay - 15 07m2
Dave,
You recommend?
Own Label 54oz Felt Underlay - 15 07m2
Dave,
You recommend?
Anybody know where this can be acquired in the states? Google is not that helpful.
Listening impressions after week 1:
OK, so after 100+ hours of breaking in things are now starting to improve immensely. Lower frequencies are starting to come out of their shell and there is much more dynamism to the sound generally. They are still very 'reserved' at very low volumes but the moment you turn it up a bit they really are wonderful. I did some comparisons between these and my old AE Aegis One (pretty good budget standmounters in their day) and the difference became even more obvious. The AE's probably go deeper but are way less controlled and really quite boxy in comparison to the natural extension of the Alpairs.For the first time I heard the muddiness that the AE's deliver against the absolute precision of the Alpair. Soundstage is much better with much more finesse. I still reserve the option to put them in the Pensil boxes but for now I'm more than happy for them to continue opening up. I'm genuinely surprised at how much impact breaking them in has had. I'm normally cynical of a lot of hifi nonsense (I don't believe a word of the cabling and interconnect voodoo) and was concerned that break-in is actually just psychological (a combination of getting used to the sound and the willingness of the mind to persuade itself that what it has 'invested' in should be better). However, although I didn't measure it, there is clearly a different sound now from day 1.
I did realise 1 final thing that may have gone wrong - to do with the brace behind the driver. When I was assembling and testing it I could hear that as I fitted the driver and tightened up the screws the sound thinned out massively - if I loosened the mounting screws a bit the sound returned to 'normal'. Obviously the driver was being squeezed against the brace and this was limiting the sound. So I sanded out the brace cutout to leave the drivers room to breathe. Is this right? Other Mar-ken plans seem to suggest the driver should be physically touching the brace? Is that right? If so, why did they sound so bad when they were in contact?
OK, so after 100+ hours of breaking in things are now starting to improve immensely. Lower frequencies are starting to come out of their shell and there is much more dynamism to the sound generally. They are still very 'reserved' at very low volumes but the moment you turn it up a bit they really are wonderful. I did some comparisons between these and my old AE Aegis One (pretty good budget standmounters in their day) and the difference became even more obvious. The AE's probably go deeper but are way less controlled and really quite boxy in comparison to the natural extension of the Alpairs.For the first time I heard the muddiness that the AE's deliver against the absolute precision of the Alpair. Soundstage is much better with much more finesse. I still reserve the option to put them in the Pensil boxes but for now I'm more than happy for them to continue opening up. I'm genuinely surprised at how much impact breaking them in has had. I'm normally cynical of a lot of hifi nonsense (I don't believe a word of the cabling and interconnect voodoo) and was concerned that break-in is actually just psychological (a combination of getting used to the sound and the willingness of the mind to persuade itself that what it has 'invested' in should be better). However, although I didn't measure it, there is clearly a different sound now from day 1.
I did realise 1 final thing that may have gone wrong - to do with the brace behind the driver. When I was assembling and testing it I could hear that as I fitted the driver and tightened up the screws the sound thinned out massively - if I loosened the mounting screws a bit the sound returned to 'normal'. Obviously the driver was being squeezed against the brace and this was limiting the sound. So I sanded out the brace cutout to leave the drivers room to breathe. Is this right? Other Mar-ken plans seem to suggest the driver should be physically touching the brace? Is that right? If so, why did they sound so bad when they were in contact?
The braces can certainly be problematic - more so with Mark's drivers than most I've played with - due to the delicate balance he's engineered between structural rigidity and self-damping with the design and materials used in the basket frames.
If you dry fit the brace to back of magnet without screwing the driver in place, the subsequent compression of the gasket can be enough to make exactly the difference you noted. After making that mistake more than once, I tend to allow for a small gap between the magnet and brace, and use a tab of duct seal or blu-tac etc to "couple" the two surfaces .
As for the break-in period, I've apparently not heard a fully broken in set of 10.3s yet myself. With so many designs and drivers, we don't always have multiples of one model on hand for break-in and listening - our 10.3s recently came back from after an extended demo loan, and by all accounts have substantially mellowed and opened up. Time to make a trip up the mountain for a sit down.
If you dry fit the brace to back of magnet without screwing the driver in place, the subsequent compression of the gasket can be enough to make exactly the difference you noted. After making that mistake more than once, I tend to allow for a small gap between the magnet and brace, and use a tab of duct seal or blu-tac etc to "couple" the two surfaces .
As for the break-in period, I've apparently not heard a fully broken in set of 10.3s yet myself. With so many designs and drivers, we don't always have multiples of one model on hand for break-in and listening - our 10.3s recently came back from after an extended demo loan, and by all accounts have substantially mellowed and opened up. Time to make a trip up the mountain for a sit down.
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The largest force that causes the box to (potentially) resonate is the reaction energy from the driver moving. The holey brace means that the energy is shared across significantly more panels so there is less to excite a resonance.And shunted away from the baffle, which with such a large hole in it, is the weakest panel in the box.
dave
Latest update:
So I now have a problem - the speaker making bug. I keep desperately thinking of new speakers I 'need' that would require DIY-ing. I believe this is a common problem experienced by many on this very forum.
Anyway, in terms of my CGR Mar-Ken's I was almost decided that I'd move them into the Pensil design to try and get more LF. I'm not massively keen on the cross-sectional dimensions but have modelled around and it probably is the best balance of proportions, just seem too wide. Anyway, during this process I noted the dual driver Pensils built with CHR's. This sounds (from the description) and looks awesome.
Now I'm in 2 minds. Do I go for the 10.3's in a Pensil box, or go crazy and buy 4 CHR70's and put 2 each in the adapted Pensil box. Would the dual driver CHRs deliver the wider response and 'oomph' that I miss? What would be the best solution for getting more sound out of the 2 speakers. I guess much of this will be theoretical as I doubt many have built or heard a dual CHR70 pensil!
And then I'll probably be building some Alpair 6's in either the medium Ikea salad bowls or a curved BR for desktop near-field use. Then I'm sure my home theatre setup could do with a new (better, DIY) centre speaker. Aargh.
Oh and I spent a few hours playing with WinISD.
So I now have a problem - the speaker making bug. I keep desperately thinking of new speakers I 'need' that would require DIY-ing. I believe this is a common problem experienced by many on this very forum.
Anyway, in terms of my CGR Mar-Ken's I was almost decided that I'd move them into the Pensil design to try and get more LF. I'm not massively keen on the cross-sectional dimensions but have modelled around and it probably is the best balance of proportions, just seem too wide. Anyway, during this process I noted the dual driver Pensils built with CHR's. This sounds (from the description) and looks awesome.
Now I'm in 2 minds. Do I go for the 10.3's in a Pensil box, or go crazy and buy 4 CHR70's and put 2 each in the adapted Pensil box. Would the dual driver CHRs deliver the wider response and 'oomph' that I miss? What would be the best solution for getting more sound out of the 2 speakers. I guess much of this will be theoretical as I doubt many have built or heard a dual CHR70 pensil!
And then I'll probably be building some Alpair 6's in either the medium Ikea salad bowls or a curved BR for desktop near-field use. Then I'm sure my home theatre setup could do with a new (better, DIY) centre speaker. Aargh.
Oh and I spent a few hours playing with WinISD.
He, he, welcome to the club!
Most likely this "disease" will develop and you shall venture into DIY amp kits and DACs too...
Regarding your questions/comments on a dual CHR-70 tower vs a single Alp 10.3:
- The Alp 10.3 is likely to give you greater resolution (in any cab), and go lower in a Pensil box
- The dual-CHR box will probably image slightly better vs a Pensil (narrower cabinet, especially with 45 degree chamfers); the CHR is more forgiving to inferior quality recordings (btw, I have the CHR-70.2, not the new CHR-70.3)
Choices, choices...
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Unless you're considering something like the Castle Microtower dual driver implementation, I'd recommend a single of the 10.3s in either Pensil or FHXL
One "issue" with Mark's drivers is that the cast resin flanges are wider than stamped or cast metal flanges used by most other makers, and require wider minimum baffles to fit - but I got over that pretty quick after hearing A7s and EL70s.
Of course there's no sane reason not to build them all, is there now? This is DIY, and as many of our wives will attest, 'sanity" has nothing to do with it.
One "issue" with Mark's drivers is that the cast resin flanges are wider than stamped or cast metal flanges used by most other makers, and require wider minimum baffles to fit - but I got over that pretty quick after hearing A7s and EL70s.
Of course there's no sane reason not to build them all, is there now? This is DIY, and as many of our wives will attest, 'sanity" has nothing to do with it.
If you're looking for more 'oomph", might I suggest adding a diy powered sub? My A7s are set up with a sub and provide enough "oomph" to get the neighbors house a rockin
I've been playing around with an a12p/sub combo as well and she can really.. And I mean REALLY rock. While I love full range, I really love "fast" setups. To me (I speak for myself) they are a perfect ballance between the fullrange and multiway strengths.
I've been playing around with an a12p/sub combo as well and she can really.. And I mean REALLY rock. While I love full range, I really love "fast" setups. To me (I speak for myself) they are a perfect ballance between the fullrange and multiway strengths.
Do note that the Pensil built was for a single CHR, but with 2 drivers stuffed in (so it is not really a Pensil anymore). That should cause a reduction in bassbecause the box is half as small as it should be.
Scott did design a proper dual CHR box in reaction -- http://www.diyaudio.com/forums/markaudio/249666-chr-70a-gen3-dual-driver-pensil-5.html#post3910859
I also have doubts about anyone who has lived with A10.3 being satisfied with CHR.
dave
OK. Point taken. I just keep reading and seeing more options and the decisions get more difficult. l want to avoid adding a sub if possible as it adds multiple complications, so lets rule out a FAST setup. I'll go with the Pensil setup when time permits and hopefully pick up some Alpair 6's when I'm in US in a few weeks, cutting down on shipping etc.
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