15s8530 - reaching xmax?

[BNK]

I notice on high volumes (with LP less than ~60hz) that the woofers make a noise because they reach their xmax limit.
Does it mean that is too much for them?
The scan do have low fs and can get lower bass but I guess it's only for love levels?

[richie00boy]

Fs is no indication of how well a speaker can handle high SPL. Yes it is too much for them. You may be able to improve matters by box design.

[BNK]

Thanks.

I wrote about the fs as some indication of the 15w reaching low frequencies (rather than high SPL).

So I guess 5.25" shouldn't be used to handle high spl (in home/car terms) with frequencies lower than 60-70hz?

The only experience I had with them before was with a closed box MTM center. The amp doesn't send lower bass to this channel so I notice any problems.

In the above matter I used them in a car on the rear walls instead of the original 6x9 . In this case the only control I had was the acoustastuff filling and wall covers.

Originally posted by BNK
love levels?

I meant low levels

[richie00boy]

Ah it's a bit clearer now I was thinking it was a 15 inch woofer! No don't expect much bass from such a small driver.

[BNK]

Their specs are so close to the 7" revs. That's what so confusing.

I do have the 7" in a transmission line (self design for a friend) and I don't recall xmax problem there.
Such a small difference in size, such a big difference in drivers behaviour ?!

I wonder how you handle it.
Do you HP the woofer (and LP) or just limit the power going in although you can get higher mid SPL?

[djarchow]

The 15W will exceed it's excursion limits at 70 Hz with 40 watts in a sealed or vented enclosure. About 20 watts will exceed xmax below 50 Hz.

In comparison the 18w will will exceed it's excursion limits at 64 Hz. with 40 watts in a sealed or vented enclosure. About 20 watts will exceed xmax below 40 Hz.

I really like the revelator drivers but I would be very willing to trade some of the low frequency extension for the ability to play louder without exceeding xmax like the 18w8545

Regards,

Dennis

[BNK]

In that case 2.5 way using a 8545 for bass only (below 70hz) is better than using the rev for bass below 70hz.
I always suspected that but never checked it out.
I do have 8545 in my main speakers for lower bass (vented box).
I think their bass is awsome, but sometimes they do get to their xmax on very low frequencies (20-30) at high SPL.