Mini Statements Questions

[soundtrek]

I am getting closer to starting my build and I am considering a cabinet with curved sides. I have a few questions to aid in my design considerations. All the questions pertain to dimensions and how or if they can be adjusted without effecting crossover tuning, port tuning, baffle step compensation, etc. I really want to build curved sided cabinets but also want to make sure I don't adversely effect the tuning and ultimately the designed sound quality.

1. How much can the front baffle width be adjusted (increase or decrease)?

2. How much can the depth of the cabinet be adjusted (increase or decrease)?

3. How much can the volume of the cabinet be adjusted (increase or decrease)?

I have started to secure the parts and was able to get the RS180s drivers when they went on clearance. I want to spend some time working on some curved sided designs but need to know how much variance is allowed in the above areas.

Thank you all for you help.

[Jim Holtz]

I am getting closer to starting my build and I am considering a cabinet with curved sides. I have a few questions to aid in my design considerations. All the questions pertain to dimensions and how or if they can be adjusted without effecting crossover tuning, port tuning, baffle step compensation, etc. I really want to build curved sided cabinets but also want to make sure I don't adversely effect the tuning and ultimately the designed sound quality.

1. How much can the front baffle width be adjusted (increase or decrease)?

2. How much can the depth of the cabinet be adjusted (increase or decrease)?

3. How much can the volume of the cabinet be adjusted (increase or decrease)?

I have started to secure the parts and was able to get the RS180s drivers when they went on clearance. I want to spend some time working on some curved sided designs but need to know how much variance is allowed in the above areas.

Thank you all for you help.

These are all questions that Curt will have to weigh in on. The critical factors are cabinet width, depth and volume. If you stray too far, you're redesigning the speaker.

Shoot Curt an email.

Jim

[soundtrek]

Jim,

That is what I thought, thanks for the heads-up. I will wait for a reply from Curt.

[soundtrek]

Sorry about the last post, I totally looked over the recommendation to send Curt an e-mail. I will do that.

[snmhanson]

I just finished up some Monitors with curved sides. I compensated for the loss in volume by adjusting the height (made sure to leave the drivers in the same place relative to each other though - I just added 3/4" to the top and 3/4" to the bottom). The baffle width and speaker depth are the same as the original plans. I also ported it per plan specs and didn't make any changes to the crossover. To my ears they turned out great, although I don't have any quality speakers to compare them to. But my listening impression is that they are heads and tails above the Def Tech Mythos that they replaced. Here is my thread if you are interested and haven't seen it yet: http://www.htguide.com/forum/showthread.php4?t=36789

Good Luck!

Matt

[Curt C]

I replied to your email, but as others may also be curious, I'll respond here as well:

Any change will make some difference. How audible that change will be is difficult to say without actually building the different variations. My best suggestion would be to stay as true to the original as you can within the confines of your modifications.

That said, here are my best guesses:

Baffle width: Probably +/- an inch won't upset things too much. Try modeling the diffraction on a program like the Edge, a freeware download from Tolvan data. The overall variation average is nearly the same, but the frequency of the peaks and dips will move around somewhat.

Cab depth is more forgiving. The only issue here is the mid tunnel length. Longer will be better than shorter, but again I can't predict what the audible changes will be. I'd guess +/- 2" would be acceptable.

Cab volume: You'll want to stay pretty close to home here. More is better than less, but in any case the port length will need to be adjusted for significant volume changes. A few liters here or there won't make much difference though.

However:

Assuming your curved sides will end up reducing the volume, there is a simple solution in simply switching to the new RS180's. Their published parameters suggest you can reduce the enclosure volume by 20% to 25% by using them instead of the RS180S. This may just play nicely into your curved side plans.

Let me know if I can be of further assistance.

C