Speaker Driver Max. Excursion

[jaypeecee]

Hi Folks,

I am new to this forum, so 'hello everyone'!

I have a question concerning loudspeaker drivers. To be specific, it concerns the Fostex FE167E full-range driver for which Xmax is given as 0.6mm. However, when using this speaker in a bass reflex design (by Fostex) and, at comfortable listening levels, I notice that the driver cone is quite clearly moving as much as 4mm (estimated by eye) on drum beats. Audibly, there is nothing untoward - no obvious distortion or other unwanted sounds.

So, my question is - should I be concerned?

Thanks.

JPC

 

[highfigh]

Hi Folks,

I am new to this forum, so 'hello everyone'!

I have a question concerning loudspeaker drivers. To be specific, it concerns the Fostex FE167E full-range driver for which Xmax is given as 0.6mm. However, when using this speaker in a bass reflex design (by Fostex) and, at comfortable listening levels, I notice that the driver cone is quite clearly moving as much as 4mm (estimated by eye) on drum beats. Audibly, there is nothing untoward - no obvious distortion or other unwanted sounds.

So, my question is - should I be concerned?

Thanks.

JPC

Your drum beats (no doubt the kick drum) may be below the port tuning frequency. In this region, there's very little control over the excursion and this can damage the suspension if it's excessive. Which version did you go with- the self-contained or the one with the port in the stand?

 

[lsiberian]

Hi Folks,

I am new to this forum, so 'hello everyone'!

I have a question concerning loudspeaker drivers. To be specific, it concerns the Fostex FE167E full-range driver for which Xmax is given as 0.6mm. However, when using this speaker in a bass reflex design (by Fostex) and, at comfortable listening levels, I notice that the driver cone is quite clearly moving as much as 4mm (estimated by eye) on drum beats. Audibly, there is nothing untoward - no obvious distortion or other unwanted sounds.

So, my question is - should I be concerned?

Thanks.

JPC

I think your exaggerating with your eyes and the estimate is conservative, but I do suggest you low pass the speaker above the tuning frequency. No reason to blow your speaker.

 

[jaypeecee]

Your drum beats (no doubt the kick drum) may be below the port tuning frequency. In this region, there's very little control over the excursion and this can damage the suspension if it's excessive. Which version did you go with- the self-contained or the one with the port in the stand?

Hi highfigh,

Thanks for the reply. I went for the self-contained option.

JPC

 

[jaypeecee]

I think your exaggerating with your eyes and the estimate is conservative, but I do suggest you low pass the speaker above the tuning frequency. No reason to blow your speaker.

Hi Isiberian,

Many thanks for your reply but I don't quite understand your statement that "I think your exaggerating with your eyes and the estimate is conservative...". There seems to be a contradiction here but perhaps it's just me. Anyway, what's the best way to "low pass the speaker above the tuning frequency"?

JPC

 

[highfigh]

Hi Isiberian,

Many thanks for your reply but I don't quite understand your statement that "I think your exaggerating with your eyes and the estimate is conservative...". There seems to be a contradiction here but perhaps it's just me. Anyway, what's the best way to "low pass the speaker above the tuning frequency"?

JPC

Actually, if you think it's close to 4mm of excursion, I would verify it before doing anything else.

If you're not planning to use a subwoofer and are using a two channel receiver or amp, the only ways to limit the bass response are:

-Change or eliminate the vent
-Use a passive high pass filter (you lose output but if you only use a 6dB/octave filter, it's not as bad)
-If the receiver has pre out and power amp in, you can use an active crossover
-If you're using a receiver that's designed for home theater use and has a setup menu, it should have a way to select Subwoofer Y/N, speaker size, and crossover frequencies. If you set it to Sub Y, Speaker size = Large and crossover at about 40Hz-60Hz, it should cut the excursion down without detracting from the sound quality. There's no reason to send frequencies to speakers that can't reproduce them, so it generally will result in better sound and longer speaker life.

 

[TLS Guy]

Hi Folks,

I am new to this forum, so 'hello everyone'!

I have a question concerning loudspeaker drivers. To be specific, it concerns the Fostex FE167E full-range driver for which Xmax is given as 0.6mm. However, when using this speaker in a bass reflex design (by Fostex) and, at comfortable listening levels, I notice that the driver cone is quite clearly moving as much as 4mm (estimated by eye) on drum beats. Audibly, there is nothing untoward - no obvious distortion or other unwanted sounds.

So, my question is - should I be concerned?

Thanks.

JPC

I would not worry, I hear those drivers are very robust. So we have another full ranger; welcome.

 

[lsiberian]

I would not worry, I hear those drivers are very robust. So we have another full ranger; welcome.

I thought they were. I'm glad you've confirmed that.

 

[highfigh]

Anyone else out there have personal experience with these?

 

[jaypeecee]

I would not worry, I hear those drivers are very robust. So we have another full ranger; welcome.

Hi TLS Guy!

Thanks for this. I now feel reassured.

Yes, I'm a full-range convert having tried the FE167E. I would like to experiment with some other full-range drivers, notably the Jordan JX92S and perhaps others. Does anyone have any experience with the JX92S and do you have any other recommendations?

Thanks again.

JPC