Hello,
I've got the "Standaard" speaker package from Speaker&co from holland.
It has a Peerless CSX-217T with a fs of 28hz and a Qes of 0,29 together with an Qts of 0,27 and EBP of 96 it is well suited for Bassreflex.
Now I want to temper the bass a little bit (It's a bit to aggressive). Can I still make a Closed Box version of it, looking at the T/S parameters? Or should I put some dampening wool in the Bassreflex port?
What is the best option to take? Would the ScanSpeak flow resistance be any good in a small Closed box with the peerless?
Greetz. Henri
I've got the "Standaard" speaker package from Speaker&co from holland.
It has a Peerless CSX-217T with a fs of 28hz and a Qes of 0,29 together with an Qts of 0,27 and EBP of 96 it is well suited for Bassreflex.
Now I want to temper the bass a little bit (It's a bit to aggressive). Can I still make a Closed Box version of it, looking at the T/S parameters? Or should I put some dampening wool in the Bassreflex port?
What is the best option to take? Would the ScanSpeak flow resistance be any good in a small Closed box with the peerless?
Greetz. Henri
Entered the CSX-217T into WinISD with specs from this page:
http://www.lautsprechershop.de/hifi/index_en.htm?/hifi/peerless_en.htm
Any idea what volume it's in and what it's tuned to? I'm assuming you don't, but just thought I'd ask anyway..
WinISD does show an EBP of 96.6, and suggests a BB4/SBB4 alignment..
BB4/SBB4:
25 liters @ 28 Hz
-3 dB at 60 Hz
-6 dB at 41 Hz
-10 dB at 30 Hz
-18 dB at 20 Hz
C4/SC4:
23.6 liters @ 30 Hz
-3 dB at 58 Hz
-6 dB at 41 Hz
-10 dB at 31 Hz
-18 dB at 21 Hz
QB3:
21.43 liters @ 40.47 Hz
-3 dB at 49.24 Hz
-6 dB at 41.32 Hz
-10 dB at 34.6 Hz
-18 dB at 25.5 Hz
Sealed alignment (depends on the circumstances I guess, but I wouldn't do it with this one)..
7.07 Qtc
13.55 liters
-3 dB at 78 Hz
-6 dB at 59 Hz
-10 dB at 45 Hz
-18 dB at 27 Hz
Is there any way possible that you could simply find a way to reduce the volume of the space inside the enclosure? If so, just try sticking something small and solid in there, but not too big. Line the walls with acoustic damping material, but don't get it in the way of the port. Put it back together and listen, and see if there's any change for the better. If there is, and you like the way it's going, try experimenting with decreasing volume from the cabinet as you did before, until you like what you hear. Then, you could try to do something a little more permanent inside the cabinet if you felt you needed or wanted to. Anyway, that's what I'd try first. Goodluck..
http://www.lautsprechershop.de/hifi/index_en.htm?/hifi/peerless_en.htm
Any idea what volume it's in and what it's tuned to? I'm assuming you don't, but just thought I'd ask anyway..
WinISD does show an EBP of 96.6, and suggests a BB4/SBB4 alignment..
BB4/SBB4:
25 liters @ 28 Hz
-3 dB at 60 Hz
-6 dB at 41 Hz
-10 dB at 30 Hz
-18 dB at 20 Hz
C4/SC4:
23.6 liters @ 30 Hz
-3 dB at 58 Hz
-6 dB at 41 Hz
-10 dB at 31 Hz
-18 dB at 21 Hz
QB3:
21.43 liters @ 40.47 Hz
-3 dB at 49.24 Hz
-6 dB at 41.32 Hz
-10 dB at 34.6 Hz
-18 dB at 25.5 Hz
Sealed alignment (depends on the circumstances I guess, but I wouldn't do it with this one)..
7.07 Qtc
13.55 liters
-3 dB at 78 Hz
-6 dB at 59 Hz
-10 dB at 45 Hz
-18 dB at 27 Hz
Is there any way possible that you could simply find a way to reduce the volume of the space inside the enclosure? If so, just try sticking something small and solid in there, but not too big. Line the walls with acoustic damping material, but don't get it in the way of the port. Put it back together and listen, and see if there's any change for the better. If there is, and you like the way it's going, try experimenting with decreasing volume from the cabinet as you did before, until you like what you hear. Then, you could try to do something a little more permanent inside the cabinet if you felt you needed or wanted to. Anyway, that's what I'd try first. Goodluck..
Anechoically, with 40 liters at 35 Hz, response should be about 30 Hz at -8 dB, and 20 Hz at -21 dB. That tuning is almost like an EBS alignment that's too high with a woofer that won't work well for it in a normal listening room. Anechoic response is nearly flat at -1.5 dB without any roll off from 40-70Hz before it falls off too quickly. The added room gain is probably causing the bass in that region to sound boomy, muddy, or over emphasized. With that said, the volume of these enclosures needs to be cut nearly in half. Whether or not you're willing to build new cabinets is, of course, completely up to you. As previously mentioned, line the walls with acoustic dampening material, and rather than sticking small solid objects in the cabinet like I said a minute ago...tossing some big books in there, or something similar, would probably be more beneficial. 
Jeez, my room is small, only 4.2-4.5 meters deep by 3.6-3.8 meters wide, and I put speakers on the short wall at the front of the room over 1 meter away from the wall, sitting about 2/3 the length of the room, lol. Anyway, a lot of people prefer having the port on the back or bottom of the enclosure if at all possible. In your circumstances, that might boost room gain a bit, which is something you may or may not want if you rebuild the enclosures. If you absolutely can't move them any farther out, I'd probably just put it on the front near the bottom. It's really just personal preference though.
IMO, that driver/box combo can't be described as "well suited" for much. The box is way too big and even with optimum box and alignment, the LF response is pretty limited, about -3dB at 49Hz. Sealed requires an even smaller box, and the response is rolling off well into the area where it affects male vocals. Two somewhat different thoughts- team it up with a real woofer and call it the mid-bass it really is, or put it in a sealed box to avoid the boom, then (if you have the power) get one of the inexpensive and very good Marchand LF compensator/equalizer kits or pcb to fix the response.
I've tried closing the port, but with a volume of 40Liter it just sounds awfull.
I have the filters all made up allready, so an extra low/sub wouldn't be my first choice. The QB3, 21.43 liters @ 40.47 Hz, option would be the best.
Can I put wool dampening in the port to reduce the speed, or would I only increase the volume/length of the port, so a wrong tuning would result?
I have the filters all made up allready, so an extra low/sub wouldn't be my first choice. The QB3, 21.43 liters @ 40.47 Hz, option would be the best.
Can I put wool dampening in the port to reduce the speed, or would I only increase the volume/length of the port, so a wrong tuning would result?
Interresting, in what way? You should have anything but a boombox in this config, instead a very dry bass.
But I begin to understand I think. You want a warmer bass with a bit overshot (higher Q)?
A variovent is usually used with very high Q drivers, the flow resistance being a loss for the closed box system resonance. Not an option in your case IMO, with an even dryer bass.
I think I do understand my "problem", The Bass is indeed a bit boomy, but dry as well. I think I'll try the 21 Liter @ 40Hz tuning.
that way I don't have too much bas, but I'll still have a good freq. response from 65-200Hz.
Can it be that the port has been tuned to 40Hz with 40Liters? It does sound that way, or the drivers freq response is allready a bit low at the 100-200Hz.
I haven't found an freq. response graph for the driver jet.
P.S.
I'm busy building a 22,5Liter Box (Mid needs 1.25 liter closed) to try it...
Should be finished in a few days, I'll let you all know.
that way I don't have too much bas, but I'll still have a good freq. response from 65-200Hz.
Can it be that the port has been tuned to 40Hz with 40Liters? It does sound that way, or the drivers freq response is allready a bit low at the 100-200Hz.
I haven't found an freq. response graph for the driver jet.
P.S.
I'm busy building a 22,5Liter Box (Mid needs 1.25 liter closed) to try it...
Should be finished in a few days, I'll let you all know.
Hi,
Hi,
Can you describe the “awful” sound you got with 40L closed box? Do you play loud?
It's going to be interesting to hear how you like the sound with 21L/40Hz. For sure you will get good power capability around 40Hz.
As previously mentioned by others, a nice tuning would be a low tuning in existing 40l box, i.e. shelf response that room gain usually straightens up nicely. But low tuning with a small driver that has limited x-max will result in limited power capability in a band slightly above tuning freq. We must also look at power response if the speaker is going to play loudly.
Many years ago I helped a friend finding new 8” woofers to replace old broken ones. I choose this particular Peerless woofer as drop in replacement and had good success. Resulting alignment was even “worse” with a slight “disco” peak (beware) but damn, contrary to belief it sounded really nice without realignment. Taste is difficult.
Hi,
Can you describe the “awful” sound you got with 40L closed box? Do you play loud?
It's going to be interesting to hear how you like the sound with 21L/40Hz. For sure you will get good power capability around 40Hz.
As previously mentioned by others, a nice tuning would be a low tuning in existing 40l box, i.e. shelf response that room gain usually straightens up nicely. But low tuning with a small driver that has limited x-max will result in limited power capability in a band slightly above tuning freq. We must also look at power response if the speaker is going to play loudly.
Many years ago I helped a friend finding new 8” woofers to replace old broken ones. I choose this particular Peerless woofer as drop in replacement and had good success. Resulting alignment was even “worse” with a slight “disco” peak (beware) but damn, contrary to belief it sounded really nice without realignment. Taste is difficult.
4fun said:
Greets!
True, but the assumption here is that the room was boosting the over-damped ~EBS alignment to an under-damped one, so power limited linear excursion shouldn't be an issue. His new ~T/S max flat alignment OTOH will probably suffer from high distortion if driven below its relatively high Fb unless corner loaded. Still, in theory a vented alignment should be tuned to at least the lowest frequency it's expected to reproduce at 'x' power.
Agreed, though it depends on the music reproduced. That alignment typically sounds horrible on classical or other recordings with minimal EQ.
GM
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