vented or TL or any other such variant requires that the woofer be able to damp itself as the box is not there to act like a srping.
this means it is preferable for drivers being used in vented or TL to have a lower Q (lower than 0.5 is the norm and often lower than that).
in both a TL as well as a vented box the back wave of teh driver is ot absorbed, as it is done in a selaed box, but allowed to exit the box.
ML... is also a variant of TL right?
this means it is preferable for drivers being used in vented or TL to have a lower Q (lower than 0.5 is the norm and often lower than that).
in both a TL as well as a vented box the back wave of teh driver is ot absorbed, as it is done in a selaed box, but allowed to exit the box.
ML... is also a variant of TL right?
Re: Re: Still me...
Hum, I didn't think about that. Good point.
I also prefer the '102 because the Q is lower. The freq. response for this driver is:
I think I will stick with this driver
planet10 said:
Hum, I didn't think about that. Good point.
I also prefer the '102 because the Q is lower. The freq. response for this driver is:
An externally hosted image should be here but it was not working when we last tested it.
I think I will stick with this driver
navin said:
A TL is usually by its nature well damped. A TL likes a Q of 0.3-0.5 or so. A ML-TQWT is a variant of the Voigt pipe (aka TQWT, TQWP -- these like a Q of 0.45-0.7 or so) that actually works. Both the TL & the Voigt are subsets of speakers best classed as quarter-wave enclosures where a 1/4 wave pipe is used in an attempt to enhance the bass and damp the cones resonance at Fs.
Critically damped is a Q of 0.707. Any driver in this range will have its inherent Q when mounted on an open baffle. Qs higher than this tend to be underdamped. They can still provide good results. I had some salvaged 6" with a Q of 1.1. I put them in a box of over 2 cu ft and loaded them aperiodically and they sound pretty good (cap XO to an open back Audax 25mm dome)
dave
many car woofers have high Qs; i suspect the deginers of these drivers expect aperiodic loading of a car door or a very large sealed box like a trunk.
dynaudio used to make high Q drivers too and then use the aperiodic vent to reduce the Qts.
what i was trying to ask / say is....
if the back of the driver is loaded by a bass relfex box, or 1/4 wave pipe or such system instead of a sealed box (small) there is no "sping" effect of the sealed box to keep the cone in check so the driver must be able to do this without the help of a box. the driver of a TL, vented box etc... should be designed not to need the spring effect of a sealed box. these drivers normally have low Qs. Focal tends to make such drivers.
dynaudio used to make high Q drivers too and then use the aperiodic vent to reduce the Qts.
what i was trying to ask / say is....
if the back of the driver is loaded by a bass relfex box, or 1/4 wave pipe or such system instead of a sealed box (small) there is no "sping" effect of the sealed box to keep the cone in check so the driver must be able to do this without the help of a box. the driver of a TL, vented box etc... should be designed not to need the spring effect of a sealed box. these drivers normally have low Qs. Focal tends to make such drivers.
navin said:
A TL is damped by the lines quarter-wave resonance. A vented box is damped by the air inside except around the Fb where the driver becomes "unloaded"
dave
Ok, now it is time to bring back this thread to life...
Almost all the wood is cut, I got all the drivers and the crossover parts.
Totem specs says that they use a Linkwitz-Reiley "optimized" crossover. I interpret "optimized" as a normal Linkwitz-Reiley crossover + an impedance compensation network for the drivers. Do yo agree?? Anyway, I will try both.
Apparently Totem uses paper-oil bypass caps. Do you think the sound will be very different if I don't use this? I doubt but it should be interesting to experiment. The bad thing is that these caps are quite expensive (I need 4). What do you think?
Thanks
Almost all the wood is cut, I got all the drivers and the crossover parts.
Totem specs says that they use a Linkwitz-Reiley "optimized" crossover. I interpret "optimized" as a normal Linkwitz-Reiley crossover + an impedance compensation network for the drivers. Do yo agree?? Anyway, I will try both.
Apparently Totem uses paper-oil bypass caps. Do you think the sound will be very different if I don't use this? I doubt but it should be interesting to experiment. The bad thing is that these caps are quite expensive (I need 4). What do you think?
Thanks
DIY progress...
Few pictures on the progress. The front baffle is fixed only with screws to tweak the system until the last minute. It is now time to design the crossover, party!
Few pictures on the progress. The front baffle is fixed only with screws to tweak the system until the last minute. It is now time to design the crossover, party!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
^
An externally hosted image should be here but it was not working when we last tested it.
The veneer is now finished. One of the channel is painted. I need to install the black feet and the crossover and ... that is all!!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
When I did some listening test while I was "debugging" the box I found a very good stereo imaging and surprising bass. I am sorry to be not more precise, I am better to describe it in french. The crossover that I was using was built with cheap parts and now I have all my solen parts, so the sound should be equal and probably better.
I will come back soon with the completely finished loudspeaker.
I will come back soon with the completely finished loudspeaker.
- Status
- Not open for further replies.