We finally got some measurement. The SPL level is not calibrated, so please ignore the absolute value. Data are raw and not filtered. Measurement is done outdoors. The setup is probably not perfect, but it will do for now, as we just want to check pipe length and filter values.
Attached is the SPL plot with notch filter at HF. Filter is 3R9 // 0.39mH // 28.8uF. Pipe is 36mm diameter and 113mm long.
Distance from chassis to microphone about 1m.
Patrick
Attached is the SPL plot with notch filter at HF. Filter is 3R9 // 0.39mH // 28.8uF. Pipe is 36mm diameter and 113mm long.
Distance from chassis to microphone about 1m.
Patrick
Attachments
I posted at the Needle thread our Ap6 Needle.
http://www.diyaudio.com/forums/showthread.php?postid=1883414#post1883414
Here are the measurements for the Needle for comparison. The notch filter is as per Henkjan's suggestion, namely 0.33mH, 1.8R, 22uF.
Patrick
http://www.diyaudio.com/forums/showthread.php?postid=1883414#post1883414
Here are the measurements for the Needle for comparison. The notch filter is as per Henkjan's suggestion, namely 0.33mH, 1.8R, 22uF.
Patrick
Attachments
Listening impressions
Comparing the Needle to the Bass Reflex, the former can go deeper in bass, and the difference is audible. But I personally like the tighter bass of the Bass Reflex more. The Needle sounded a touch too floffy for me. After the measurement, we have packed the damping material quite a bit tighter, but have not tested again due to time limitations.
Without the filters both speakers have a lot more presence, but probably too much. It is a matter of taste, so one can play with the notch to get the preferred balanced.
We are happy that we pretty much got everything first time right, and have just ordered 24 sets of Mundorf cross over parts. (Yes, we are already up to number 24 in our pilot production.)
Patrick
Comparing the Needle to the Bass Reflex, the former can go deeper in bass, and the difference is audible. But I personally like the tighter bass of the Bass Reflex more. The Needle sounded a touch too floffy for me. After the measurement, we have packed the damping material quite a bit tighter, but have not tested again due to time limitations.
Without the filters both speakers have a lot more presence, but probably too much. It is a matter of taste, so one can play with the notch to get the preferred balanced.
We are happy that we pretty much got everything first time right, and have just ordered 24 sets of Mundorf cross over parts. (Yes, we are already up to number 24 in our pilot production.)
Patrick
well... that's up to the listner, but (I can only speak for the needle) I can understand your remark, the first try of the notch for the needle measured (almost) completely flat but the final notch just sounded a lot better. main differense was the value of the resistor, if you want a completely neutral sound choose a slightly higher value for the resistor
As reported earlier in one of the Alpair 12 threads, I was in Hong Kong a couple of week ago to install a high-end mini system for my sister, and took the opportunity to visit Mark Fenlon at his office in Tsai Wan.
Firstly a few words about the mini system. It is basically a copy of Peter Daniels GC Patek, but I was using the LM3886 from Brian GT, and have extended it to include matching PSU, volume control with LDRs driven by CCS, Daniels DAC clone with logic driven source selector, and a CR Rom based transport with the controller kit from Huang. Speakers are AP6 BR, in two favours (bookshelf and on sand-filled stands). It sounded good enough as a mini system. The requirement was not audiophile, but simple and reliable.
Mark’s office was on the Hong Kong Island in an industrial building, and the whole place was stacked full with speaker chasses, as you would expect. He was kindly enough to spend a couple of hours with us, demonstrating different chasses in different enclosures, as well as telling us stories about his previous association with Jordan, the OEM speaker business, speaker development methods and production details and quality and cost control tricks. After all, all three of us are mechanical engineers.
We had a chance to listen to the new AP12, but unfortunately not the AP7, and had the construction explained to us in detail. We also listened to the older products, including the Japanese Lindhof AP5 BR and the AP5/AP10 combination. While one had to be amazed as to what sound the AP5 BR can produce, I was myself most attracted to the AP5/AP10 combo. So smooth, so seemless and effortless, with good presence and excellent transients. I have to say I am still very tempted to try that out, even though it will be an expensive solution.
All in all, a very memorable experience. I want to thank this very friendly English gentleman for his endless dedication and quest for perfection, making available to us all affordable and superbly nice sounding chasses. It is not a very glamorous life, and I can assure you not a very rewarding one financially either. The world would be a nicer place with more people like him around.
Patrick
Firstly a few words about the mini system. It is basically a copy of Peter Daniels GC Patek, but I was using the LM3886 from Brian GT, and have extended it to include matching PSU, volume control with LDRs driven by CCS, Daniels DAC clone with logic driven source selector, and a CR Rom based transport with the controller kit from Huang. Speakers are AP6 BR, in two favours (bookshelf and on sand-filled stands). It sounded good enough as a mini system. The requirement was not audiophile, but simple and reliable.
Mark’s office was on the Hong Kong Island in an industrial building, and the whole place was stacked full with speaker chasses, as you would expect. He was kindly enough to spend a couple of hours with us, demonstrating different chasses in different enclosures, as well as telling us stories about his previous association with Jordan, the OEM speaker business, speaker development methods and production details and quality and cost control tricks. After all, all three of us are mechanical engineers.
We had a chance to listen to the new AP12, but unfortunately not the AP7, and had the construction explained to us in detail. We also listened to the older products, including the Japanese Lindhof AP5 BR and the AP5/AP10 combination. While one had to be amazed as to what sound the AP5 BR can produce, I was myself most attracted to the AP5/AP10 combo. So smooth, so seemless and effortless, with good presence and excellent transients. I have to say I am still very tempted to try that out, even though it will be an expensive solution.
All in all, a very memorable experience. I want to thank this very friendly English gentleman for his endless dedication and quest for perfection, making available to us all affordable and superbly nice sounding chasses. It is not a very glamorous life, and I can assure you not a very rewarding one financially either. The world would be a nicer place with more people like him around.
Patrick
The shelf top version .....
The bottom plate is 15mm solid aluminium, on which the filter elements are bolted. The TO247 metal film resistors uses the plate also as heat sink.
Three feet supports the speaker kinematically, with 3 bearing steel balls mounted on fine threaded screws and seating on hardened steel dishes with a small dimple in the middle.
Patrick
.
.
.
The bottom plate is 15mm solid aluminium, on which the filter elements are bolted. The TO247 metal film resistors uses the plate also as heat sink.
Three feet supports the speaker kinematically, with 3 bearing steel balls mounted on fine threaded screws and seating on hardened steel dishes with a small dimple in the middle.
Patrick
.
.
.
Attachments
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.