Having previous experience with Alpair 10P in a Mar-ken end Pencil enclosures i plan to give a try to the new Markaudio CHN-110 in a 23L vented enclosure that i already have from a previous project. I plan to tune it similarly to the Pelorus since it has similar dimensions.
Now, i also have a nice Seas 19TFF tweeter that seams as match for a two way configuration but unfortunately i'm no crossover wizard to be sure that this wil work. I know the basics of calculating one just the Impedance curve of the CHN troubles me. It also has two coil inductances stated, namely one @1K and one @10K which confuses me in calculating a possible Zobel network.
Ideally i would like to keep the crossover to first order Butterworth (theoretically the drivers do allow it).
Any help and opinions concerning these matters are very welcome.
Oliver
Now, i also have a nice Seas 19TFF tweeter that seams as match for a two way configuration but unfortunately i'm no crossover wizard to be sure that this wil work. I know the basics of calculating one just the Impedance curve of the CHN troubles me. It also has two coil inductances stated, namely one @1K and one @10K which confuses me in calculating a possible Zobel network.
Ideally i would like to keep the crossover to first order Butterworth (theoretically the drivers do allow it).
Any help and opinions concerning these matters are very welcome.
Oliver
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You will need to measure the on-baffle frequency and impedance responses to design the filter properly (or have one designed).
If you want 1st order, that will also depend on baffle configuration and how complex you wish the filter to be -you will likely require Fs impedance compensation on the tweeter to prevent excess excursion (1st order high pass filters do not prevent excursion from increasing below the X-o frequency), and for it to be a true 1st order acoustic slope, at least a 4KHz crossover, and possibly 8KHz, which increases the potential for lobing through the transition band. If you want a conventional TM (tweeter at the top) with a flat baffle, then an all-pass delay will likely be necessary on the tweeter despite the relatively shallow cone of the CHN110 due to the Z-axis offset. As an alternative, you could use a sloping or stepped baffle to provide the necessary offset / delay. The simplest solution would be to invert the configuration; have the listening axis on the CHN110 and the tweeter below it, which should also provide sufficient delay if designed & positioned correctly to allow the phase to line up.
If you want 1st order, that will also depend on baffle configuration and how complex you wish the filter to be -you will likely require Fs impedance compensation on the tweeter to prevent excess excursion (1st order high pass filters do not prevent excursion from increasing below the X-o frequency), and for it to be a true 1st order acoustic slope, at least a 4KHz crossover, and possibly 8KHz, which increases the potential for lobing through the transition band. If you want a conventional TM (tweeter at the top) with a flat baffle, then an all-pass delay will likely be necessary on the tweeter despite the relatively shallow cone of the CHN110 due to the Z-axis offset. As an alternative, you could use a sloping or stepped baffle to provide the necessary offset / delay. The simplest solution would be to invert the configuration; have the listening axis on the CHN110 and the tweeter below it, which should also provide sufficient delay if designed & positioned correctly to allow the phase to line up.
Looks like tuning somewhere between 40-45 Hz, lower if you use a circular vent, but it eill br long. I would personally put a high ratio, highR vent at 45 Hz, maybe even a bit higher, but given yu arr rtrifitting the box perhaps not practical.
My first thot on adding a tweeter is that it may decrease performance, pehaps just up or back firing, no filter on the CHN.
dave
Thanks Scott for your input. Now I know why a lot of the old Mission bookshelf speakers had inverted Midwoofer/tweeter configuration.
I have a couple of weeks until the CHN-110s are available again at Soundimports. Enough time to decide which way I will finaly go. I like the simplicity of building a full range speaker but on the other hand I miss the refinement that a good incorporated tweeter offers.
I have a couple of weeks until the CHN-110s are available again at Soundimports. Enough time to decide which way I will finaly go. I like the simplicity of building a full range speaker but on the other hand I miss the refinement that a good incorporated tweeter offers.
Do not so quickly dismiss the top end of the CHN-110, and not having an XO impose itself on the performance. Listen FR to start.
dave
dave
Hi Dave, thanks for sharing your thoughts on my subject.
What are the pro's of a higher vent R and tunnig fr?
I was considering to add a 50mm dia and 110mm long vent, that should get the Fb round 42-43Hz. The speakers will be placed about 25cm near wall and will be driven with a 35W Prima Luna amp (high output impedance).
What are the pro's of a higher vent R and tunnig fr?
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If you are calculating it with 23L enclosure volume than that's correct Dave.
In my calculation I subtract about 0.5L for the volume that the driver's magnet and the vent self roughly occupy and then I round off the length at 110mm. It is actually the same vent that Scott uses in his 24L Pelorus enclosure.
I am aware that bigger vent diameter will lower the noice but what will sonically change if I tune it at 45Hz as you suggest? I still havent mounted the vent so now is a good time to make the wright choice 😕
In my calculation I subtract about 0.5L for the volume that the driver's magnet and the vent self roughly occupy and then I round off the length at 110mm. It is actually the same vent that Scott uses in his 24L Pelorus enclosure.
I am aware that bigger vent diameter will lower the noice but what will sonically change if I tune it at 45Hz as you suggest? I still havent mounted the vent so now is a good time to make the wright choice 😕
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I have done the calculation/drawings many times, once you properly chamfer the inside of the drive rcutout, the extra volume from that is REALLY close to what the driver bits take up so i don’t bother anymore.
dave
dave
I don't think the CHN110 needs a tweeter, it's one of the better behaving fullrange drivers that i know up high, and with the shallow cone the dispertion is very good. I run it in a MLTL without any filtering or so and altough the driver is cheap, it's my favorite speaker now that i have. I also have several Alpair 10.3 builds and did build others also (that i don't have anymore). I also run it with a 35W Prima Luna Prologue 4 amplifier actually (see picture, the black speakers are the MLTL's)...
I made sims for vented also, and 27L is actually perfect for this driver, add a 7cm diameter round vent of 18.6cm long and you got a flat response to 40Hz.
23L can be used also, but i would not use a 5cm diameter vent as the air velocity will be way to high and on high power it will start making port noises. For 23L i would make the port 7cm diameter and 19.5cm long for the same tuning.
I made sims for vented also, and 27L is actually perfect for this driver, add a 7cm diameter round vent of 18.6cm long and you got a flat response to 40Hz.
23L can be used also, but i would not use a 5cm diameter vent as the air velocity will be way to high and on high power it will start making port noises. For 23L i would make the port 7cm diameter and 19.5cm long for the same tuning.
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For reference, some of the CHN110 designs that I've done in image & attached pdf.
The standmounts & semi-floorstander all use 50mm internal diameter ducts; a larger cross section results in the vent primary standing wave occurring at what I consider an excessively low frequency with relatively high peaking, which I try to avoid like the plague (or Covid-19). While the air velocity through the duct is higher through the smaller duct CSA, the duct positioning and limited outright SPLs a 5 3/4in driver is capable of achieving without excess compression compensate & avoid audible issues.
The standmounts & semi-floorstander all use 50mm internal diameter ducts; a larger cross section results in the vent primary standing wave occurring at what I consider an excessively low frequency with relatively high peaking, which I try to avoid like the plague (or Covid-19). While the air velocity through the duct is higher through the smaller duct CSA, the duct positioning and limited outright SPLs a 5 3/4in driver is capable of achieving without excess compression compensate & avoid audible issues.
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I like that Kewel a lot, but I have to restrain myself from building big speakers again.
Your right, first i'm gonna follow your advise and leve the CHN FR and see what happens.
Dave, you actually gave me an excellent idea on how to expend the volume of the enclosure to 24L which will match exactly the volume and the tuning of Scott's Pelorus standmout.
And what the tuning concerns now I have a clearer picture in my head, so I'm gonna follow what the doctor prescribes 😉.
I've just mounted the vent and took some photos from the enclosures. I also got the material to make the baffles but we finally have some nice weather here so I prefer to spend this weekend enjoying it🙂. after all i have enough time 'till the drivers are available again.
Your right, first i'm gonna follow your advise and leve the CHN FR and see what happens.
Dave, you actually gave me an excellent idea on how to expend the volume of the enclosure to 24L which will match exactly the volume and the tuning of Scott's Pelorus standmout.
And what the tuning concerns now I have a clearer picture in my head, so I'm gonna follow what the doctor prescribes 😉.
I've just mounted the vent and took some photos from the enclosures. I also got the material to make the baffles but we finally have some nice weather here so I prefer to spend this weekend enjoying it🙂. after all i have enough time 'till the drivers are available again.
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Here is me with another dilemma.
As i stated previously i'm going to pair these speakers with a Prima Luna amp that has high (ish) output impedance. So what will be appropriatie wiring in my case??? One that will add some resistance??? soundimports.eu has QED Profile 42 Strand wire that states 0.046 Ω/m of resistance. Will this work if i have total of 3m this wire between the amp and and the CHN-110?
As i stated previously i'm going to pair these speakers with a Prima Luna amp that has high (ish) output impedance. So what will be appropriatie wiring in my case??? One that will add some resistance??? soundimports.eu has QED Profile 42 Strand wire that states 0.046 Ω/m of resistance. Will this work if i have total of 3m this wire between the amp and and the CHN-110?
I use my CHN110 MLTL with a Prima Luna Prologue 4 (precestor of the Evo100 power amp) with very generic 1.5mm stranded OFC copper wire and have no issues at all.
A relatively high output impedance implies you probably won't want to be adding any extra series R into the circuit or the alignment may shift a bit and the midbass become a little over-prominent. Granted, as output impedance rises, the amplifier behaves more like a current source & is a bit less affected by R in the circuit. Nevertheless, assuming you don't want any EQ value from the wire, I generally recommend you keep voltage drop below about 0.5 (or dB loss below 0.1) and preferably less. So with a 6m loop length, technically that's a minimum of about 17.8ga for the CHN110, although I'd aim for 15.5ga or larger myself. I like to have some leeway.
Note that it's possible, albeit unlikely, that you may clip the amplifier on loud (likely LF) transients as the max. current draw is technically higher than the amplifier is rated at. Being a valve design, this is unlikely to cause an issue though, and I suspect you'd be rather more likely to run out of travel with the 110 in a vented box faster than you'd run out of power.
Note that it's possible, albeit unlikely, that you may clip the amplifier on loud (likely LF) transients as the max. current draw is technically higher than the amplifier is rated at. Being a valve design, this is unlikely to cause an issue though, and I suspect you'd be rather more likely to run out of travel with the 110 in a vented box faster than you'd run out of power.
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Thanks Waxx for your empiric input an a huge thank you Scott for shedding some theoretical light on my dilemmas 
Apparently the drivers won't be in stock in any EU shop until august so i ordered the drivers from KJF. In order to get the speakers running a couple of months earlier i had to fall victim of the Brexit and pay a total price of three for couple of the CHN-110.
However, i mounted the drivers yesterday and left them running on low volume. I wander how long do they need to settle down?
Some things I've noticed:
There are few discrepancies in the CHN-110 dimensions on the woden design plans that can be misleiding, namely the driver is shown to have one mm larger diameter and the outer rim thickness is shown as 4mm and should be 2.8mm.
For flush mounting, in practice you don't need the extra 1mm for the gasket. A total of 3mm flush depth will result in flat baffle/driver surface.
However, i mounted the drivers yesterday and left them running on low volume. I wander how long do they need to settle down?
Some things I've noticed:
There are few discrepancies in the CHN-110 dimensions on the woden design plans that can be misleiding, namely the driver is shown to have one mm larger diameter and the outer rim thickness is shown as 4mm and should be 2.8mm.
For flush mounting, in practice you don't need the extra 1mm for the gasket. A total of 3mm flush depth will result in flat baffle/driver surface.
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I apologise that I (Dave also, but I accept full responsibilty) have misled you through our error.
No apologies needed, I noticed it just on time not to make the mistake.
These https://www.markaudio.com/wp-content/uploads/2019/12/CHN110-detail-box-plans.pdf
Scroll down to the last page and compare te measurements with the ones on the CHN-110 specs sheet.
These https://www.markaudio.com/wp-content/uploads/2019/12/CHN110-detail-box-plans.pdf
Scroll down to the last page and compare te measurements with the ones on the CHN-110 specs sheet.
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