Hello,
I'm building a bass reflex enclosure for the Seas L19RNX1
H1878-08 L19RNX1
I have simulated it on winISD and regardless of what I do with the enclosure parameters, xmax is hit @ 40W. Id like it to be a solid 90W, which is were the tweeter has had enough. The L19 is rated for 200W RMS, so it can definitely take the heat. Is there a way to increase power handling for a driver in a br enclosure? I'm worried 40 watts won't be enough volume for a 86 dB sensitivity driver...
I'm building a bass reflex enclosure for the Seas L19RNX1
H1878-08 L19RNX1
I have simulated it on winISD and regardless of what I do with the enclosure parameters, xmax is hit @ 40W. Id like it to be a solid 90W, which is were the tweeter has had enough. The L19 is rated for 200W RMS, so it can definitely take the heat. Is there a way to increase power handling for a driver in a br enclosure? I'm worried 40 watts won't be enough volume for a 86 dB sensitivity driver...
Are you hitting Xmax above or below port tuning?
If above, you'll need to tune higher. Frequency response will suffer.
Chris
If above, you'll need to tune higher. Frequency response will suffer.
Chris
I has thinking about the "hump" above tuning frequency. With a lot of changes I get it up 75W, but the response then is obviously horrific.
Hmm, the pioneers determined that a Vas/1.44 tuned to Fs was the optimum vented box size Vs BW, transient response and according to Hornresp, 30 W = 101 dB/m/2pi mid-band, Xmax limit in the ~40-80 Hz BW.
90 W needs a proper 32 Hz BLH.
GM
Yes: limit the low frequency extension.
You can do this by tuning to a higher frequency. If this results in a hump around tuning, use a highpass filter to reduce the hum as well as frequencies below tuning. Keele published a nice paper on a 6th order vented alignment (VB+2nd order HP filter) that highlights the benefits. You can get high SPL, high efficiency, and high power handling using that approach.
If you are using a sealed box, it is somewhat the same. Put the driver in a smaller box and then HP filter it (if there is a hump). This will increase Fb and Q, but there is unfortunately no free lunch in the tradeoff between extension and power handling.
You can do this by tuning to a higher frequency. If this results in a hump around tuning, use a highpass filter to reduce the hum as well as frequencies below tuning. Keele published a nice paper on a 6th order vented alignment (VB+2nd order HP filter) that highlights the benefits. You can get high SPL, high efficiency, and high power handling using that approach.
If you are using a sealed box, it is somewhat the same. Put the driver in a smaller box and then HP filter it (if there is a hump). This will increase Fb and Q, but there is unfortunately no free lunch in the tradeoff between extension and power handling.
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Then so be it.
That´s what that speaker can handle, period, you can´t beat physics.
You can reach 200W if you wish, just not at ONE frequency and a very very narrow band around it.
Look at the whole response,not just that narrow band.
It will be of NO audible consequence with any normal program material.
That´s an impressive speaker, don´t "listen with your eyes" 😛
That.
Yes, it was mentioned above.
You probably won´t like it.
Oh, come on, that happens only at a very narrow band and then it only starts distorting. It´s X_max, not X_damage and in any case I very much doubt your program consists of s synthesized Bass track at that exact frequency plus assorted cymbals and cowbells.
On any normal program, forget it.
You designed an excellent cabinet, with excellent components, it will very much please your ears, don´t let your eyes spoil it.
Using a HP filter and increasing the tuning is a possibility, but it will be more expensive and sacrifice a lot of the low end extension I wanted...
If you want LF extension, you've gotta move air.
+1 on JMF's point that the excursion maximum happens only when you're getting full power at that one frequency. Depending on your program material, it's not likely to be a huge issue.
It sounds like you're designing a PA speaker (maximum output) using HiFi components. What're your actual design goals here?
Chris
+1 on JMF's point that the excursion maximum happens only when you're getting full power at that one frequency. Depending on your program material, it's not likely to be a huge issue.
It sounds like you're designing a PA speaker (maximum output) using HiFi components. What're your actual design goals here?
Chris
You're going about this the wrong way. For home hifi you should decide how much extension you want (the -3dB of the bass rolloff), and how loud (SPL) you want it to play before hitting xmax. These two requirements are typically at odds with each other. If you want more bass extension, the woofer is going to have more excursion at low frequencies and xmax will probably be reached at a lower power level, limiting the maximum SPL in the midrange/treble. However, the actual amount of power required to hit xmax is irrelevant if all your other criteria are met. I have speakers with woofers of a similar size that hit xmax at only 15Watts. They extend to below 30Hz and are uncomfortably loud when xmax is being reached on most music. I'd rather have the bass extension at all times instead of limiting xmax and having their maximum volume in the midrange and treble go from 'uncomfortably loud' to 'a little bit more than uncomfortably loud'. Have you heard a tweeter playing at 90Watts system power? It's stupid loud.
A bandpass enclosure might minimise excursion and give you extension, but will have higher group delay (laggy and unresponsive sounding bass). This I would avoid because it is just unnecessary for home usage for the woofer size you have - a basic sealed or ported should give better sound and still go loud enough for 99% of people.
Imho the only times you should aim to limit xmax is for two reasons:
-You're designing a system for PA usage where maximum SPL is more important than extension - if the extension is not good enough you add another cabinet with a larger driver that will handle the lows.
-You're designing a system for a person who has no mechanical sympathy for the speakers or the self control to stop turning up the volume when xmax is reached. Also hope that they don't use an equaliser/bass boost to compensate for the fact that the speakers have lousy bass extension.
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