Recently I inherited a transmission line cabinet from a friend; well made, and sturdy, and I have since decided to redesign it so that the 8" driver is facing forward instead of up. Unfortunately, the interior was designed for an up-driver. I have attached a crude cross-section of its partitions and some dimensions.
First question: are the interior dimensions suitable for an 8" driver that has an Fs of 47.7 HZ and a Qts of .4625?
And secondly (and most important) will having a 6" gap between the top of the main (slanted partition) directly behind the driver, and the top the cabinet work as the first chamber? Or will that chamber have to be redesigned? If so, how? Please see attached.
Thanks in advance.
First question: are the interior dimensions suitable for an 8" driver that has an Fs of 47.7 HZ and a Qts of .4625?
And secondly (and most important) will having a 6" gap between the top of the main (slanted partition) directly behind the driver, and the top the cabinet work as the first chamber? Or will that chamber have to be redesigned? If so, how? Please see attached.
Thanks in advance.
I'm trying to take the woofer up to 4khz and then use a ribbon tweeter on top of the speaker in a separate enclosure with a simple crossover on top of the cabinet. The TL cabinet will only be for the woofer.
I am also trying to keep the woofer close to the top of the cabinet to keep the woofer and tweeter together to reduce lobing. I know that if I put the woofer closer to the middle of the cabinet, I would not have a question to ask but the distance between the woofer and tweeter would be great and cause more lobing.
I am also trying to keep the woofer close to the top of the cabinet to keep the woofer and tweeter together to reduce lobing. I know that if I put the woofer closer to the middle of the cabinet, I would not have a question to ask but the distance between the woofer and tweeter would be great and cause more lobing.
It should work fine. The driver is off set from the start to reduce excitation of odd harmonics. This Will be marginaly affected by the change in placement. However, it does not seem to be anything critical.
Vas, anyone? It is rather important in determining total Vb and gain. 😉 If your driver is similar in this to the original, along with Fs, effective Qt, then it will behave more or less per the original, with some differences in the levels of the excitation of the fundamental & harmonics due to the altered driver location.
Really?! That's great. So the fact that the woofer is not completely "centered" in the partition/chamber to its rear is not a problem? Please explain to me your concern about the Vas and the total Vb and gain.
Thanks to both respondents.
It's exactly what you would expect. Like any vented, sealed alignment, assuming a static Fs & effective Qt, volume compliance (Vas) determines bulk, ergo if it rises you will require a larger box volume to achieve a given gain BW & visa versa.