Should I use a crossover on the Peavey PV 118?

[Cody AOC]

So I am really convinced on getting myself a Peavey PV 118 subwoofer and people say if I want deeper tighter bass I use a crossover and so I thought if I used the Crown XLS 1502 since it has a crossover I might be able to use it so I can get 80 hz or deeper. But the thing is i don't know if it has a crossover for subwoofers? Does anyone else know what it has in crossover wise?

 

[GordonW]

The current XLS series amps have a crossover that can do a low-pass frequency as low as 30Hz (and as high as 3KHz). So, it'd be easy to get something that would work with the PV118.

Regards,
Gordon.

 

[swechsler]

Is this for home use or for sound reinforcement? If it's the former, I think this is probably not the best solution. This sub is designed more for high volumes rather than ultra low, accurate bass.

 

[Cody AOC]

Is this for home use or for sound reinforcement? If it's the former, I think this is probably not the best solution. This sub is designed more for high volumes rather than ultra low, accurate bass.

well I am going to use this in my house but it's with playing loud because i have not ever trusted home audio subwoofers because iv played many of them loud not clipping power and somehow they end up blowing or the amp goes out and can't be fixed.

 

[swechsler]

If you look at the spec sheet for this sub, it only goes down to 49hz at -3dB. That's not very impressive. Of course you can do whatever you want, but you're not going to get really deep bass with this. Maybe look out for a secondhand JBL synthesis subwoofer, they're passive so you can use your own amp.

 

[Cody AOC]

If you look at the spec sheet for this sub, it only goes down to 49hz at -3dB. That's not very impressive. Of course you can do whatever you want, but you're not going to get really deep bass with this. Maybe look out for a secondhand JBL synthesis subwoofer, they're passive so you can use your own amp.

how would it sound without using the crossover from my amplifier? oh and 49 hz is good enough since my pa speakers only have go down to 50 hz just all I need is an increase in bass. since my budget is not big and I don't have impresive pa speakers they are some samson 12 inch 2 ways

 

[swechsler]

Yes, you do need a crossover, whether you use a built-in one or separate, it won't really make a difference in the sound. A subwoofer crossover is the same as a low-pass crossover, that is, it lets the lows through and prevents the higher frequencies from coming through, the only difference is what frequency you choose. Since the XLS-1502 apparently has a built-in low pass filter, this will do what you need.

 

[Cody AOC]

Yes, you do need a crossover, whether you use a built-in one or separate, it won't really make a difference in the sound. A subwoofer crossover is the same as a low-pass crossover, that is, it lets the lows through and prevents the higher frequencies from coming through, the only difference is what frequency you choose. Since the XLS-1502 apparently has a built-in low pass filter, this will do what you need.

Thanks

 

[GordonW]

If you set the crossover frequency on the Crown at 30Hz, the effective f3 of the system would be from about 30Hz to 49Hz, rolling off above and below that range.

This is true, due to the summation of the curves. Below 30Hz, the crossover response is flat, but the speaker cabinet response is going down at about 18 to 24dB/oct. or so. So, you get the speaker rolloff as the slope of the curve- the response rolls off below 30Hz.

Between 30Hz and 49Hz, the crossover response is going DOWN as frequency increases, but the cabinet response is going UP. Those two roughly cancel out, and make for a relatively flat response in that region.

Above 49Hz, the cabinet response is flat, but the crossover is going down. This makes the response roll off above that frequency.

Of course, you'd lose a couple effective dB of sensitivity- but with the Peavey being something like 96dB sensitivity- that's probably not much of an issue.

So, if you don't really need the sub to go higher than 50Hz, and don't care if it doesn't go much lower than 30Hz- then it would work.

EDIT: Oh, almost forgot- if you do this, it's safer if you change the port vent frequency of the speaker, so that it's at least as low as you're trying to 'force' the response to go down to. So, it would be a good idea to increase the vent length of the ports in the Peavey, so that the box is tuned to 30Hz or lower.

Regards,
Gordon.

 

[Cody AOC]

If you set the crossover frequency on the Crown at 30Hz, the effective f3 of the system would be from about 30Hz to 49Hz, rolling off above and below that range.

This is true, due to the summation of the curves. Below 30Hz, the crossover response is flat, but the speaker cabinet response is going down at about 18 to 24dB/oct. or so. So, you get the speaker rolloff as the slope of the curve- the response rolls off below 30Hz.

Between 30Hz and 49Hz, the crossover response is going DOWN as frequency increases, but the cabinet response is going UP. Those two roughly cancel out, and make for a relatively flat response in that region.

Above 49Hz, the cabinet response is flat, but the crossover is going down. This makes the response roll off above that frequency.

Of course, you'd lose a couple effective dB of sensitivity- but with the Peavey being something like 96dB sensitivity- that's probably not much of an issue.

So, if you don't really need the sub to go higher than 50Hz, and don't care if it doesn't go much lower than 30Hz- then it would work.

EDIT: Oh, almost forgot- if you do this, it's safer if you change the port vent frequency of the speaker, so that it's at least as low as you're trying to 'force' the response to go down to. So, it would be a good idea to increase the vent length of the ports in the Peavey, so that the box is tuned to 30Hz or lower.

Regards,
Gordon.

Thanks that i'll keep in mind