XO2 - LR2 @ 1500hz w/ 0.14ms delay to woofer
0-15-30-45 @ 1 Metre - I'm pretty happy here, I am sure the funny business at 500hz is a characteristic of the woofer as a shift also shows here on the data sheet and is below the point of baffle diffraction (?):
Midbass / Tweeter / Inverse Null - I really don't know how much stock to put in the inverse null approach as I can only achieve working responses when I apply delay to the midwoofer:
Impulse response - It looks just like the ones from the books so I'm happy!
Phase and Distortion - Caveat: I am not entirely sure how to read phase, it looks smooth. I realise I have not given the system enough oomph to test distortion properly but it looks more even with this XO.
Any and all feedback welcome!
0-15-30-45 @ 1 Metre - I'm pretty happy here, I am sure the funny business at 500hz is a characteristic of the woofer as a shift also shows here on the data sheet and is below the point of baffle diffraction (?):
Midbass / Tweeter / Inverse Null - I really don't know how much stock to put in the inverse null approach as I can only achieve working responses when I apply delay to the midwoofer:
Impulse response - It looks just like the ones from the books so I'm happy!
Phase and Distortion - Caveat: I am not entirely sure how to read phase, it looks smooth. I realise I have not given the system enough oomph to test distortion properly but it looks more even with this XO.
Any and all feedback welcome!
Attachments
Hey, on your question on phase, I tend to look at group delay - it is quite useful for debugging anomalies around the crossover region - a flat group delay on both drivers makes for a more predictable response and might also help you identify the driver delay.
Not that you have any problems here - nice and smooth responses.
I’d be interested in knowing how you get such a nice low frequency measurement without issues with reflections - apologies if you have already described it in your post. I saw some outdoor pictures, which seems brave...
Not that you have any problems here - nice and smooth responses.
I’d be interested in knowing how you get such a nice low frequency measurement without issues with reflections - apologies if you have already described it in your post. I saw some outdoor pictures, which seems brave...
On THD, I’m just learning how to get meaningful measurements, but have a couple of observations:
- for loudspeakers, I’d be tempted not to measure relative to the fundamental. It has the effect of emphasising harmonics corresponding to a peak in the fundamental - which may mislead you into thinking there is an issue at a particular frequency.
- I’ve noticed your rising distortion at higher frequency is most likely measurement noise. I’ve noticed the same in my UMIK-1. It is worth increasing the level and seeing what happens. I’ve ended up measuring thd using nearfield measurements to avoid mic noise.
- you may know all this!
- for loudspeakers, I’d be tempted not to measure relative to the fundamental. It has the effect of emphasising harmonics corresponding to a peak in the fundamental - which may mislead you into thinking there is an issue at a particular frequency.
- I’ve noticed your rising distortion at higher frequency is most likely measurement noise. I’ve noticed the same in my UMIK-1. It is worth increasing the level and seeing what happens. I’ve ended up measuring thd using nearfield measurements to avoid mic noise.
- you may know all this!
Hey Ant, cheers for the tips, I'll bare that all in mind!
When you say low frwuency what do you mean? I generally gate around 4.5/5ms and completely destroy my front room to get it in the centre of a 3.5x4.25m room with a 2.4m high ceiling. I worry my measurements are a bit wiggly but it's what I have at my disposal.
When you say low frwuency what do you mean? I generally gate around 4.5/5ms and completely destroy my front room to get it in the centre of a 3.5x4.25m room with a 2.4m high ceiling. I worry my measurements are a bit wiggly but it's what I have at my disposal.
DFM2535 + B&C ME10 Horn
I thought I'd give another horn a go so here are my prelimenary measurements to see whats up. There is not indication what is horizontal or vertical orientation on the horn other than a couple of lines on bezel. Make of them what you wish.
ME10 90x60 Horn
Bezel lines vertical are not too different from the STH100 horizontally, just a bit choppier. Horizontal is a different ball game.
...and because it's pretty - overlayed.
I'm considering trying the RCF ND350 - not that the peerless isn't lovely. I have just have limited experience.
I thought I'd give another horn a go so here are my prelimenary measurements to see whats up. There is not indication what is horizontal or vertical orientation on the horn other than a couple of lines on bezel. Make of them what you wish.
ME10 90x60 Horn
Bezel lines vertical are not too different from the STH100 horizontally, just a bit choppier. Horizontal is a different ball game.
...and because it's pretty - overlayed.
I'm considering trying the RCF ND350 - not that the peerless isn't lovely. I have just have limited experience.
Attachments
Last edited:
Ah, that’s nice. I’m usually struggling to get clean responses below 1kHz due to reflections (except for “near field” measurement below 20cm). The luxury of a big room! How do you deal with the first reflection from floor-bounce?
Yeah, same for me. Mine have wiggles below 1k despite gating. It's a real sanity breaker.
I use a woolen blanket from your neck of the woods and sofa cushions for floor bounce. Nothing I can do about the ceiling. I have a few rockwool panels around the walls of of my front room which help imaging when in listening position but I'm wondering if I need to bother now I have a horn based system. The wife would approve.
Cushion, blanket and panels can be seen here, I have since changed to shottiing down the room not across and I move the sofa to the side.
That's a very good driver, though it's not suited for low crossover points
1200 Hz is ok for low output levels, 1500 Hz is better.
You might consider the more recent ND340, which is even cheaper and delivers more output at the low end. The motor is slightly stronger (BL= 7.9 vs 7.5 T·m) and the polymide diaphragm is softer than the polyester used for the ND350, which usually sounds a bit more foregiving.
If low efficiency/sensitivity isn't objectionable, the Purifi PTT6.5X is one the best small mid woofers that's also capabele of sub bass.