Follow up in this project:
I tried the Mark Audio Alpair10P. It is a very nice driver but not to my taste. What was really shocking was the bass F-R. I had to measure it twice to be sure of my readings. Measuring 3 ft away with one speaker only and then at the listening position 9 ft away with both speakers. F-R was about the same except the 100-200Hz range.was elevated 7 dB at the listening position. Maybe due to the flat cone design have better dispersion in this area? It also seemed less punchy than the Seas.
I have tried elevating the bass response with different tone controls and DAC with eq. but anything above a couple dB boost, bass gets slow and muddy. So it's a matter of finding the best compromise.
The other issue about the bass was that my cabinet was too big. While getting more bass below 50Hz, the larger cabinet produced way too less bass around 63-100 Hz. Just going to a correct sized cabinet gave more balanced bass and not so bright sounding overall.
I tried the Mark Audio Alpair10P. It is a very nice driver but not to my taste. What was really shocking was the bass F-R. I had to measure it twice to be sure of my readings. Measuring 3 ft away with one speaker only and then at the listening position 9 ft away with both speakers. F-R was about the same except the 100-200Hz range.was elevated 7 dB at the listening position. Maybe due to the flat cone design have better dispersion in this area? It also seemed less punchy than the Seas.
I have tried elevating the bass response with different tone controls and DAC with eq. but anything above a couple dB boost, bass gets slow and muddy. So it's a matter of finding the best compromise.
The other issue about the bass was that my cabinet was too big. While getting more bass below 50Hz, the larger cabinet produced way too less bass around 63-100 Hz. Just going to a correct sized cabinet gave more balanced bass and not so bright sounding overall.
Planet 10, I get what you are saying and that sound right. Except I've never seen this happen with any other speaker. Could the design of the Alpair be creating this room mode? There IS a strong resonance for sure at 40Hz and the whole room vibrates. No surprise as my room is small 13 ft x 15 ft.
Vinylkid58 you got me. It is .25 ft3 so I know it is not producing the full bass. I was told it would be good enough to evaluate with the understanding deep bass would not be there and also not natural sounding.
I should try more things like passive notch filters but not gotten to it yet.
Vinylkid58 you got me. It is .25 ft3 so I know it is not producing the full bass. I was told it would be good enough to evaluate with the understanding deep bass would not be there and also not natural sounding.
I should try more things like passive notch filters but not gotten to it yet.
If that's a vented box, it's too small IMHO. Vent diameter & length?
If it's tuned on the high side, you'll get the big fr bump in the 100-200Hz region you describe.
jeff
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0.25 ft3 = 7 litres. Too small.
Should be near twice that.
Power just went out so i can’t access my modelling.
dave
Should be near twice that.
Power just went out so i can’t access my modelling.
dave
Yes is vented with a 1" dia x 4" long port. I calculate 42 Hz.
I was hoping a small room would boost L-F and low listening volume of 70dB with 80dB peaks would allow more bass without overdriving it. But that is still not enough.
If a separate driver is needed to get decent bass.Where is the least damaging place to put an x-over?
The Frequency Spectrum, Instrument Ranges And EQ Tips. Maybe 200Hz at the top of the bass?
Metal drivers have advantages but they have bad breakup at the top of their pass band. So how small does the driver have to be to avoid this breakup?
How about a 2" as a mid / tweeter run full range and an 8-10" woofer x-over at 150-200 Hz. I don't need HF over 15kHz.
Seas Orbit FL4RCN/F 40mm Aluminum Cone Fullrange. or Aurasound NSW2-326-8A-120 2" Full Range
paired with
SEAS Excel W22NX001-GRAPH (E0077) 8" Graphene Cone Woofer or SEAS Excel W26FX-001 (E0026) 10" Aluminum Alloy Cone Woofer
The other option is just get a small high quality woofer and sit the 2" driver box on top of it.
The big question is if the 40mm can blend with a woofer in terms of dynamic range, speed, and tonality. It is interesting there are no super-expensive 2" drivers like there are with tweeters and the 3" and larger drivers. I asked Seas about this. Why they don't make an Excel-quality 2" driver? Replied "These are still luxury high-cost product in this segment."
Thoughts?
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At 40Hz the threshold of audibility is about 55dB. Don't expect to hear too much when your are just 15dB louder than that. Most musical tracks would have 40Hz content that is below the threshold of audibility when the average playback level is just 70dB.
That said the Purifi PTT4.0X is about as good as it gets in this size.
That said the Purifi PTT4.0X is about as good as it gets in this size.
Try measuring it close to the cone. That will tell you about the bass of the driver and rear enclosure, minus the room modes and baffle interaction.
The SB65WBAC25-4 is a very good 2.5" driver.
And I would not try to push these 2"~3" drivers down to their resonant frequency. Try to cross between 300-500Hz. Use the woofer higher to give more meat to the sound.
And I would not try to push these 2"~3" drivers down to their resonant frequency. Try to cross between 300-500Hz. Use the woofer higher to give more meat to the sound.
That is helpful in explaining why the Mark Audio needed to be play 75dB+ for the bass to kick in.
Never heard of this before. Looks great except the 10dB peak at 5kHz.
Yes, I think so. Measuring 3 ft away with one speaker only and then at the listening position 9 ft away with both speakers. F-R was about the same except the 100-200Hz range.was elevated 7 dB at the listening position.
But how about at 70-75dB listening levels? Better for distortion but I am thinking 200hz or lower would be better for sound quality. 500Hz is getting into the midrange. With a 4.5" single driver, I measure pink noise 74dB at 1 ft = 66dB at 3 ft = 64dB at 9 ft with both speakers driven.
Pretty much bang on. Doesn't look great, but there isn't a big bump above 100Hz. You have your speakers jammed up against the wall?
Here's a sim.
Thanks for the sim. Nice to see some correlation. No, they are 50" out. Sounds kind of strange but in my small room I actually get a good combination of bass and sound-staging.
Just a theory, but if you have seen vibration analysis of a long thin metal bar, you will see resonant nodes at certain distances. Likewise I think some whiz-bang acoustical engineer could simulate places in the room which could give more bass than expected.
I take it back, mot to small a box.
7 litres(net) is just about right for max flat sealed is a decent alignment for a high ratio vent, but not bad with plumbing pipe.
But a 7 litre box is a tight fit with the big bezeled A10… how close is the back wall of the box?
dave
7 litres(net) is just about right for max flat sealed is a decent alignment for a high ratio vent, but not bad with plumbing pipe.
But a 7 litre box is a tight fit with the big bezeled A10… how close is the back wall of the box?
dave
Box is 12H x 7.5"W x 10"D. Not sure about the internal distance if that is what you are asking.
late, but no crossover, double horn, impuls combensation by invers 2 driver, down ~35 Hz, corner placement, look my KORNETT
