Hi all,
Hopefully this is the appropriate place for this query.
I've been happy with the general balance I've achieved in my recent CHN 110 pensil via modifying stuffing/placement/toe-in etc. I currently have them hard against a rear wall in a relatively large room.
I am however noticing (and measuring) a shallow hump (~2-3db) from ~500hz-2khz. This gives the impression of welcome presence/detail on some recordings, while on others it is becomes fatiguing, especially anything with complex material in that frequency band.
I had been wondering, in the spirit of modifying/improving my system, whether a CHN 50 could be added above the CHN 110 and passive cross-over developed. This would enable me to modify the FR via the crossover circuit (possibly could get away with first order), and I would imagine also bring some other benefits (i.e. dispersion, power handling of certain material). I'm guessing a x-over point circa 4-500hz could work.
My main question is what is the implications of doing this with respect to the cabinet design? I am assuming the woofer (CHN 110) would be fine, but what would it mean for the CHN 50? Could it fire into the same cavity or would it need to be isolated in some way (which I assume would mess things up for the woofer)?
Just throwing around ideas at this stage, but curious to know if anyone has tried something similar.
Cheers,
Matt
Hopefully this is the appropriate place for this query.
I've been happy with the general balance I've achieved in my recent CHN 110 pensil via modifying stuffing/placement/toe-in etc. I currently have them hard against a rear wall in a relatively large room.
I am however noticing (and measuring) a shallow hump (~2-3db) from ~500hz-2khz. This gives the impression of welcome presence/detail on some recordings, while on others it is becomes fatiguing, especially anything with complex material in that frequency band.
I had been wondering, in the spirit of modifying/improving my system, whether a CHN 50 could be added above the CHN 110 and passive cross-over developed. This would enable me to modify the FR via the crossover circuit (possibly could get away with first order), and I would imagine also bring some other benefits (i.e. dispersion, power handling of certain material). I'm guessing a x-over point circa 4-500hz could work.
My main question is what is the implications of doing this with respect to the cabinet design? I am assuming the woofer (CHN 110) would be fine, but what would it mean for the CHN 50? Could it fire into the same cavity or would it need to be isolated in some way (which I assume would mess things up for the woofer)?
Just throwing around ideas at this stage, but curious to know if anyone has tried something similar.
Cheers,
Matt
It would have to be isolated. And i would rather add a good dome tweeter than an other fullrange driver crossed at 2kHz with a lower order CR. That also does not need it's own space. I did experiment that way with an SB26ADC i have laying arround and it ad some high frequencies, but i thought it's better without.
And that bump mostly means you did not add enough stuffing i think. I also had it first with my MLTL with the same CHN110, but adding some extra stuffing resolved it as it was caused by internal resonances in the MLTL that are not enough damped, the Pencil is a variation of a MLTL so i think it's a similar issue that can be resolved in a similar way. Now it's relative flat (within 6dB) even without filters or added tweeter (cone or fullrange).
And that bump mostly means you did not add enough stuffing i think. I also had it first with my MLTL with the same CHN110, but adding some extra stuffing resolved it as it was caused by internal resonances in the MLTL that are not enough damped, the Pencil is a variation of a MLTL so i think it's a similar issue that can be resolved in a similar way. Now it's relative flat (within 6dB) even without filters or added tweeter (cone or fullrange).
Thanks for that - I suspected as much re the driver addition. Might have to go back to the drawing board on that one.
I'm not entirely sure about the stuffing being the culprit for the FR but it's definitely possible. I'm getting good suppression of the higher resonances based on my measurements at the vent and there is a reasonable amount around the driver so I'm not sure if there would be too much coming back via the driver itself. In saying that I am using significantly less than the recommended stuffing.
Cheers,
Matt
I'm not entirely sure about the stuffing being the culprit for the FR but it's definitely possible. I'm getting good suppression of the higher resonances based on my measurements at the vent and there is a reasonable amount around the driver so I'm not sure if there would be too much coming back via the driver itself. In saying that I am using significantly less than the recommended stuffing.
Cheers,
Matt
I don’t like domes so i disagree with waxx.
It is easy to try this out. Build a small (2 litre) sealed box that allows you to get as close as possible to the CHN110. Given they are in a Pensil ideally on the side at driver height but on top would be easiest. But would not have the closest centre-to-cente or be at the right listening height.
Given how good the CHN110 is, it is hard to say if you will gain more than you lose. If you can get them close XO can be between 300-1kHz. Best done actively,
Try it, let us know how it sounds.
If you really want a WAW with CHN50 i’d look for some dedicated woofers.
dave
It is easy to try this out. Build a small (2 litre) sealed box that allows you to get as close as possible to the CHN110. Given they are in a Pensil ideally on the side at driver height but on top would be easiest. But would not have the closest centre-to-cente or be at the right listening height.
Given how good the CHN110 is, it is hard to say if you will gain more than you lose. If you can get them close XO can be between 300-1kHz. Best done actively,
Try it, let us know how it sounds.
If you really want a WAW with CHN50 i’d look for some dedicated woofers.
dave
Thanks Dave - yes I agree the CHN 110 is great; I'm a little hesitant to go modifying the cabinet unnecessarily, so your suggestion sounds good.
I'm a fan of the WAW idea in general. It would be interesting to hear how the CHN50 in a sealed box pairs with an MLTL. Will definitely update if I get further with this idea.
Matt
I'm a fan of the WAW idea in general. It would be interesting to hear how the CHN50 in a sealed box pairs with an MLTL. Will definitely update if I get further with this idea.
Matt
But for a waw i would use a different driver down low for a waw, a real woofer or subwoofer (depending on the crossover frequency). A CHN50 would pair well with a Dayton RS225-8 or SB23MFCL45-8 or so crossed arround 500Hz.
I have to say, i'm very happy with my MLTL with that driver, but you need to stuff the cabinet enough to counter the internal resonances that give a bump in that region you have problems with. So again, add more stuffing before you do something else.
I have to say, i'm very happy with my MLTL with that driver, but you need to stuff the cabinet enough to counter the internal resonances that give a bump in that region you have problems with. So again, add more stuffing before you do something else.
Btw, i'm doing now a WAW with the CHR70A and the SB23MFCL45-8 in a large bookshelf reflex style for a guy (paying design) and that will go low. I can't publish the details because he pays me for the design, but he agreed to publish this render of the cabinet (30x57x36cm outer dimensions). This should be flat between 20kHz and 30Hz. Crossover will be minidsp HD (dsp) at 300Hz and amps will be a 4 channel class AB amp he is building himself. With a Waw with a real (sub)woofer you can do a lot, a lot more than with a fullrange driver like the CHN110 as woofer.
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Agreed, but the CHN-110 is a good woofer in its own right and he has it playing already. An easy experiment to get going.
A quick µMarSP. 2.5 litre sealed, should give a Q near bessel. It can be slapped on top (easy) or somehow next to the side near the CHN110 (harder). Or on top (or inside) the next box with dedicated woofers (if the experiemnt goes tat far).
http://www.planet10-hifi.com/downloads/uMarSP-plan-171021.pdf
Just playing will enable you to add a lot to your knowledge base.
dave
Thanks for the responses.
Waxx - I did end up adding back a little more stuffing. I think it's slightly better through the midrange, but haven't measured as yet.
I've ordered the CHN50's - just have a wait a few weeks for delivery being at the bottom of the world. I did also look at the various 70 versions but there seemed to be more mixed reviews.
I've started modeling up a cabinet, that should sit nicely on top and figured it could be tilted downwards towards the listening position. I'll struggle to get within 1/4 wavelength for optimum c to c distance for x-over (passive at least) given that would be circa 250hz.
I agree there may be better woofers but the CHN110 has plenty of excursion, and if I'm not messing with the cabinet there is nothing to lose. I'll have no problem repurposing a 3inch driver.
Cheers,
Matt
Waxx - I did end up adding back a little more stuffing. I think it's slightly better through the midrange, but haven't measured as yet.
I've ordered the CHN50's - just have a wait a few weeks for delivery being at the bottom of the world. I did also look at the various 70 versions but there seemed to be more mixed reviews.
I've started modeling up a cabinet, that should sit nicely on top and figured it could be tilted downwards towards the listening position. I'll struggle to get within 1/4 wavelength for optimum c to c distance for x-over (passive at least) given that would be circa 250hz.
I agree there may be better woofers but the CHN110 has plenty of excursion, and if I'm not messing with the cabinet there is nothing to lose. I'll have no problem repurposing a 3inch driver.
Cheers,
Matt
I agree, but the guy already had the drivers but did not design his speakers right so his actual speakers are not right. He asked me just to make a real design with those to fix it (he will build it himself). he is a construction worker who can do woodworking and soldering, but does not know a lot about speaker design or the math behind it.
What i wanted to say, you can do similar with the CHN50 or an other FR that looks better on paper. With the CHN110 as woofer you can't go that low. I pushed it in my MLTL to 32Hz, but that is realy pushing it and only works on low volume.
While waiting for drivers to arrive I made a start on a sealed enclosure. I'd wanted to try a CNC multi-laminate idea, so thought it was a good opportunity to do this on a small scale - and yes it was definitely inspired by another much more ambitious build on this site. In saying that, this design isn't highly considered but I'm hoping that the external shape will reduce diffraction and the internal shapes will serve to mitigate standing waves (in theory at least). Each speaker will be six 18mm layers high, and layers will alternate to provide a more complex internal geometry.
Box volume will be ~2L as per Dave's suggestion. I CNC'd the template from 9mm ply and will build the final form from 18mm ply. I'm using the template to cut the ply with a flush trim bit. I could have done it all via CNC but the machine I have access to isn't mine and is fairly light duty so was looking to be a long process.
One down, 11 to go, then top/bottom plates, speaker cutout, external finishing, terminals, and then should be done.
As an aside, I also experimented with some kerf bending - however, dunking it in hot water did not have the intended effect and was the end of this experiment
Box volume will be ~2L as per Dave's suggestion. I CNC'd the template from 9mm ply and will build the final form from 18mm ply. I'm using the template to cut the ply with a flush trim bit. I could have done it all via CNC but the machine I have access to isn't mine and is fairly light duty so was looking to be a long process.
One down, 11 to go, then top/bottom plates, speaker cutout, external finishing, terminals, and then should be done.
As an aside, I also experimented with some kerf bending - however, dunking it in hot water did not have the intended effect and was the end of this experiment
Attachments
Made a little progress on these. One side 'stack' is complete. Unfortunately my router bit is starting to get blunt, so might need replacing before I can complete the other side.
I like the concept but next time (floor standing MLTL??) it will be CNC all the way! It's also going to be difficult to tidy up the exterior so maybe a fabric wrap or similar is in order.
I like the concept but next time (floor standing MLTL??) it will be CNC all the way! It's also going to be difficult to tidy up the exterior so maybe a fabric wrap or similar is in order.
Attachments
Quick update - drivers finally arrived after a rather long voyage. Finished up enclosures and wrapped in fabric which I then opted to paint black...possibly not the best choice.
Have been listening to the CHN50s for a couple days and am really impressed, even in such a bass limited application. Neutral FR and good dynamics to my ears, possibly not the last word in HF extension, but will need to run a mic over them at some point to see what they are doing.
Still pondering next steps. I modeled up my Pensil in HR and it would seem I could actually mount the CHN50 into the existing enclosure, and the volume loss (assuming small sealed box) wouldn't be significantly detrimental to low end extension.
As as aside - one of my nice shiny CHN 110's appear to have sustained some damage. Nobody owned up to it but I have my suspects
Have been listening to the CHN50s for a couple days and am really impressed, even in such a bass limited application. Neutral FR and good dynamics to my ears, possibly not the last word in HF extension, but will need to run a mic over them at some point to see what they are doing.
Still pondering next steps. I modeled up my Pensil in HR and it would seem I could actually mount the CHN50 into the existing enclosure, and the volume loss (assuming small sealed box) wouldn't be significantly detrimental to low end extension.
As as aside - one of my nice shiny CHN 110's appear to have sustained some damage. Nobody owned up to it but I have my suspects
Attachments
For anyone interested, I got to do a couple basic measurements last night. No problems with HF extension - on-axis there is a significant rise from 15k which smooths out nicely off-axis. Impressed with the overall flatness of response.
Attached measurement was taken at 1m and gated at 6ms from memory, around 10 degrees off-axis. I'm pondering whether I am better to build a two way of some sorts using the CHN 50 and the CHN 110, rather than mangling the existing Pensil cabinets...decisions...decisions...
Is there any potential issue with combining a sealed top/HF driver, with a ported/mltl bass driver?
Attached measurement was taken at 1m and gated at 6ms from memory, around 10 degrees off-axis. I'm pondering whether I am better to build a two way of some sorts using the CHN 50 and the CHN 110, rather than mangling the existing Pensil cabinets...decisions...decisions...
Is there any potential issue with combining a sealed top/HF driver, with a ported/mltl bass driver?
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