Hi,
I have a pair of Peerless CSX 10 inch drivers (850146) that I plan to use as lower mid and bass. Crossover I think will be a 24db LR at around 500~600Hz ( active c/o ).
I have been tempted to build a TL enclosure for this. But a sealed box of about 44L gives me a F-6db of about 40Hz and Q of about 0.60 . This would be fine for my room . The room gain will bring up the LF respose very nicely and the transient response should be very good.
However a TL could possibly be better sounding than the sealed box. Is that right ?
Since the crossover is at about 600Hz and rolloff at 24dB/octave , would the TL make a significant difference to the sound ? The TL box would turn out to be 'much' bigger.
Some of the driver parameters are :
Fs = 22.6Hz
Qms = 2.56
Qes = 0.4
Qts = 0.35
Vas = 144 lit
Cms = 0.96mm/N
Mms = 51.9 g
Sd = 330 sq cm
Rdc 5.5 ohms
Any suggestions ?
Thanks.
ashok
I have a pair of Peerless CSX 10 inch drivers (850146) that I plan to use as lower mid and bass. Crossover I think will be a 24db LR at around 500~600Hz ( active c/o ).
I have been tempted to build a TL enclosure for this. But a sealed box of about 44L gives me a F-6db of about 40Hz and Q of about 0.60 . This would be fine for my room . The room gain will bring up the LF respose very nicely and the transient response should be very good.
However a TL could possibly be better sounding than the sealed box. Is that right ?
Since the crossover is at about 600Hz and rolloff at 24dB/octave , would the TL make a significant difference to the sound ? The TL box would turn out to be 'much' bigger.
Some of the driver parameters are :
Fs = 22.6Hz
Qms = 2.56
Qes = 0.4
Qts = 0.35
Vas = 144 lit
Cms = 0.96mm/N
Mms = 51.9 g
Sd = 330 sq cm
Rdc 5.5 ohms
Any suggestions ?
Thanks.
ashok
Trying to keep it alive.
I am trying to keep this post alive till someone with info will see it and reply.
I notice that many people have used the 850146 but so far no TL/sealed box comparisons. I am tilting towards the sealed box with 0.6 Q and having some room gain . If anyone thinks that the TL is MUCH better in bass , please let me know. The sealed box is much easier to accomodate so the TL must be MUCH better to warrant more money, time and floor space.
Thanks,
Cheers.
I am trying to keep this post alive till someone with info will see it and reply.
I notice that many people have used the 850146 but so far no TL/sealed box comparisons. I am tilting towards the sealed box with 0.6 Q and having some room gain . If anyone thinks that the TL is MUCH better in bass , please let me know. The sealed box is much easier to accomodate so the TL must be MUCH better to warrant more money, time and floor space.
Thanks,
Cheers.
Measured parameters
Hi,
I ran the drivers for 24 hours with a 20 Hz signal and then measured the following :
Readings in brackets are for the second driver.
Fs 25.9 Hz (24.88)
Re 5.2 ohms (5.2)
Qms 6.22 (6.1)
Qes 0.44 (0.43)
Qts 0.41 (0.40)
Mms 52.47 (59.0)
Cms 0.72 (0.69)
Vas 99.5 lit ( 95.5)
Bl 10.1 (10.40)
The sealed box is MUCH smaller and I already have abox that size which I built for something else. So I will try that out first and see if it works out well.
Will post results later.
The box is 52 liters.
Thanks.
Cheers.
Hi,
I ran the drivers for 24 hours with a 20 Hz signal and then measured the following :
Readings in brackets are for the second driver.
Fs 25.9 Hz (24.88)
Re 5.2 ohms (5.2)
Qms 6.22 (6.1)
Qes 0.44 (0.43)
Qts 0.41 (0.40)
Mms 52.47 (59.0)
Cms 0.72 (0.69)
Vas 99.5 lit ( 95.5)
Bl 10.1 (10.40)
The sealed box is MUCH smaller and I already have abox that size which I built for something else. So I will try that out first and see if it works out well.
Will post results later.
The box is 52 liters.
Thanks.
Cheers.
Ashok:
I must say, with all this talk lately about Peerless varying from listed specs, those Thiele-Small numbers you measured for those two Peerless woofers are remarkably consistent with the listed specs and with each other. OK, the Fs was a bit higher, the Vas was a bit smaller-but these two things will conterbalance each other.
Anyway, just to add to your list of options, here is a ported box of 60 liters, not far from 52 liters, tuned to 27 Hz. It is 4 dB down at 30 Hz. You could port a 52 liter box and have results pretty close. I don't know how you feel about ported boxes, just thought I would throw that in. Plus, if you tune the box even lower, the results can blend in with room gain for even more extended response, not to mention lessened cone excursion requirements.
I must say, with all this talk lately about Peerless varying from listed specs, those Thiele-Small numbers you measured for those two Peerless woofers are remarkably consistent with the listed specs and with each other. OK, the Fs was a bit higher, the Vas was a bit smaller-but these two things will conterbalance each other.
Anyway, just to add to your list of options, here is a ported box of 60 liters, not far from 52 liters, tuned to 27 Hz. It is 4 dB down at 30 Hz. You could port a 52 liter box and have results pretty close. I don't know how you feel about ported boxes, just thought I would throw that in. Plus, if you tune the box even lower, the results can blend in with room gain for even more extended response, not to mention lessened cone excursion requirements.
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FWIW, I did a ML-TL awhile back for someone using the published specs and they were stunned by the pipe's output, with solid performance into the 20s. Plugging your measured specs in actually yields a slightly more efficient FR, though I seriously doubt it's an audible difference. Too much if you live in an apartment or condo, but great if you have a house. Of course if it has too much output for your room, it can be attenuated to suit by damping the vent, but I've known few folks who dialed it out once they experienced what they'd been missing. 
Anyway, it's a little over a 100L, but is tall (~141.7cm plus baseplate), so doesn't have a big footprint (~30.5cm square plus baseplate). Let me know if you're interested in building it.
GM
Anyway, it's a little over a 100L, but is tall (~141.7cm plus baseplate), so doesn't have a big footprint (~30.5cm square plus baseplate). Let me know if you're interested in building it.
GM
Bass reflex and sealed solution.
Kelticwizard,
Thanks for running the numbers through. I also found that the measurements were quite close and my 12 inch XLS drivers are even closer to the published specs. So not all Peerless(made in Denmark) are off specs by a mile. The measurements were made using Clio v4.52 .
I will add a duct to the 52 liter box as it seems to produce OK results. I am using Bass Box Pro. It is easy to seal it to see how the two compare in the same location.
My current unit will be about 40 inches from the rear wall and 30 inches from the side wall. The other unit is totally assymetric. It is 40 inches away from the rear wall . The side wall is about 15 feet away ( two rooms with only a partial wall in between).
Will post the listening test.
GM,
I would be interested in the TL design. After the current test , I will have no box for the other driver. So I might as well make aTL. Then I can compare one driver in a sealed box, a reflex box and a TL running semi wide band -- up to 600 Hz. I still expect the TL to top the list . I wanted to make as small a TL as possible without loss of low end or any bass quality.
A one squarefoot footprint is very small. What start/end cross-sectional area do you use. 1.0:0.75 Sd??
Thanks.
Ashok.
Kelticwizard,
Thanks for running the numbers through. I also found that the measurements were quite close and my 12 inch XLS drivers are even closer to the published specs. So not all Peerless(made in Denmark) are off specs by a mile. The measurements were made using Clio v4.52 .
I will add a duct to the 52 liter box as it seems to produce OK results. I am using Bass Box Pro. It is easy to seal it to see how the two compare in the same location.
My current unit will be about 40 inches from the rear wall and 30 inches from the side wall. The other unit is totally assymetric. It is 40 inches away from the rear wall . The side wall is about 15 feet away ( two rooms with only a partial wall in between).
Will post the listening test.
GM,
I would be interested in the TL design. After the current test , I will have no box for the other driver. So I might as well make aTL. Then I can compare one driver in a sealed box, a reflex box and a TL running semi wide band -- up to 600 Hz. I still expect the TL to top the list . I wanted to make as small a TL as possible without loss of low end or any bass quality.
A one squarefoot footprint is very small. What start/end cross-sectional area do you use. 1.0:0.75 Sd??
Thanks.
Ashok.
>A one squarefoot footprint is very small. What start/end cross-sectional area do you use. 1.0:0.75 Sd??
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It's a straight pipe terminating into a smaller one:
54.28in long.
112.4in^2, so you can make it 10.6in on a side or whatever combination of dims you prefer.
Driver down 20in from top.
Vent is 4" dia x 8" long if exiting the bottom. If you want it to exit the bottom front, then once you settle on the width/depth dims, I can closely estimate a slot vent.
Stuff to suit. I recommend starting with 28-30oz distributed from the top of the pipe down to just below the driver.
All dims are inside.
Due to its high aspect ratio, a massive baseplate is a good idea, as is a massive top cover to mass load the cab somewhat. 19mm Baltic Birch is much preferred over MDF. I also recommend using this screw load adjuster: http://melhuish.org/audio/images/press-screw.gif
GM
====
It's a straight pipe terminating into a smaller one:
54.28in long.
112.4in^2, so you can make it 10.6in on a side or whatever combination of dims you prefer.
Driver down 20in from top.
Vent is 4" dia x 8" long if exiting the bottom. If you want it to exit the bottom front, then once you settle on the width/depth dims, I can closely estimate a slot vent.
Stuff to suit. I recommend starting with 28-30oz distributed from the top of the pipe down to just below the driver.
All dims are inside.
Due to its high aspect ratio, a massive baseplate is a good idea, as is a massive top cover to mass load the cab somewhat. 19mm Baltic Birch is much preferred over MDF. I also recommend using this screw load adjuster: http://melhuish.org/audio/images/press-screw.gif
GM
Some results finally.
I finally fixed the driver into the box. The duct was 71mm inner dia and tuned to 27 Hz. The duct is in two pieces connected by a 90 degree joint.
I can use it as a sealed unit by stuffing the front end of the duct.
Listening results: There are a few.
I used Yani's album "Reflections of Passion" and Linda Ronstadt's "Winter Light". Both have deep bass and I like some of the transients in Linda Ronstadt's album. Not the best albums but OK for now.
The 10 inch driver sounds great directly from the amp. Yes the HF and upper vocals are missing BUT nothing is NOISY ! That's great because many 6 inch and 8 inch drivers can't pass this test ! They can get VERY noisy without an appropriate crossover.
The bass is very nice. The reflex version can get a bit boomy ( not too much ) but the sealed version sounds much better AND seems to go deeper . So in a box I might prefer the sealed unit.
the sound is also better in sealed mode. Now to add the Planar Neo8 to it. I think this looks like it will end up as a great sounding system. Crossover around 500~600 Hz.
I will post measurements later.
Cheers.
I finally fixed the driver into the box. The duct was 71mm inner dia and tuned to 27 Hz. The duct is in two pieces connected by a 90 degree joint.
I can use it as a sealed unit by stuffing the front end of the duct.
Listening results: There are a few.
I used Yani's album "Reflections of Passion" and Linda Ronstadt's "Winter Light". Both have deep bass and I like some of the transients in Linda Ronstadt's album. Not the best albums but OK for now.
The 10 inch driver sounds great directly from the amp. Yes the HF and upper vocals are missing BUT nothing is NOISY ! That's great because many 6 inch and 8 inch drivers can't pass this test ! They can get VERY noisy without an appropriate crossover.
The bass is very nice. The reflex version can get a bit boomy ( not too much ) but the sealed version sounds much better AND seems to go deeper . So in a box I might prefer the sealed unit.
the sound is also better in sealed mode. Now to add the Planar Neo8 to it. I think this looks like it will end up as a great sounding system. Crossover around 500~600 Hz.
I will post measurements later.
Cheers.
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