Should I use baffle step compensation for a DIY surround speaker x-over design?

[marchel]

Hi,

This my first post, But I have been reading this site since 2000.

I'm going to build 4 dedicated surround speaker using vifa ring radiator and dayton 7" reference woofer. The speakers will hang on walls of a dedicated HT room. The dimension of the boxes will be about 14" high , 12" wide and 5" deep.

Since they will hang flat on the wall, but would protude 5" into the room. The question now is , Do I still need to use baffle step compensation in the X-over design of these speakers?

Thank you.

[bjorno]

…Should I use baffle step compensation for a DIY surround speaker x-…

I believe you should because the most usable information for surround is below 2 kHz and in my opinion surround sounds wrong if the mid’s or trebles are set exaggerated up tilted.

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1(1)

[marchel]

Wow,

I did'nt expect a reply with calculation like that,

Thank you so much for your time , Bjorno.

I guess I'll just have to go through with it, I'll then just have to adjust the value of R in the BSC to suit my taste or use a selector to select different R values.

Thank you.

[BHTX]

Originally posted by marchel
Wow,
I did'nt expect a reply with calculation like that

Yeah, I wish I were a little better at math.

[Jay_WJ]

Hi,

I do not think the RS180 and the XT are a good match. RS 180's distortions rise above 1 kHz and the XT's rise below 2 kHz. The XT requires at least 2 kHz LR4 XO. An optimal XO point for the RS180 is less than 2 kHz IMO.

If you haven't already ordered the drivers, consider my RS180 design. It has reduced BSC and no-BSC options. No-BSC option in fact has some BSC (about 1 dB) and the reduced BSC option has about 2.75 dB BSC.

[marchel]

Thank you for the insight, jay.

You're right,


I've just researched about the woofer and most of the users xo it at around 1.5K and under any circumstances, not higher than 2k .

Anyway, I havent yet oredered the drivers.

I'm wondering though, Is the Seas tweeter you used , While rated with 500hz Fs and recommended by seas to be good from 1.5k on up. Does'nt it suffer from audible power compression and soft dome break-up distortion by crossing it at 1.5k on loud volume levels?

[sreten]

Hi,

The above might be an idea to reduce the ripple caused
by a relatively small driver on a relatively large baffle.
(Note I'm not suggesting the angeled rear)

The Seas tweeter works fine in the application.

/sreten.

[Jay_WJ]

Originally posted by marchel
I'm wondering though, Is the Seas tweeter you used , While rated with 500hz Fs and recommended by seas to be good from 1.5k on up. Does'nt it suffer from audible power compression and soft dome break-up distortion by crossing it at 1.5k on loud volume levels?

No, the Seas has no problem handling a LR4 1.5 kHz xo point. I don't hear any distortions even at an ear hurting volume position.

[marchel]

thank you.

[Svante]

Originally posted by marchel
Hi,

This my first post, But I have been reading this site since 2000.

I'm going to build 4 dedicated surround speaker using vifa ring radiator and dayton 7" reference woofer. The speakers will hang on walls of a dedicated HT room. The dimension of the boxes will be about 14" high , 12" wide and 5" deep.

Since they will hang flat on the wall, but would protude 5" into the room. The question now is , Do I still need to use baffle step compensation in the X-over design of these speakers?

Thank you.

There will be a baffle step of 6 dB at high frequencies in this design, but also a gain from the back wall of 6 dB at low frequencies. Between them there will be a gap.

There are methods to fill in the gap somewhat, one of them is to make the box as shallow, high and wide as possible. Another is to make the baffle and back wall non-parallel.

Below is a simulation of a box with your dimensions (except the yellow curve which has a the left side depth shortened to 1.25"