buddy of mine is looking at the RLp 18, or a pair of RLp15's.

he is worried about upper frequency extension, i planned on building a box with a swappable\pluggable port. i was wondering what people are using for box sizes, and what the best volume would be for a sealed and ported box.

any recommendations\expierences would be greatly appriciated.

thanks a bunch

Since you are talking a sub, to what range is your upper frequency extension?

80-100 low mid bass

The enclosure will have relatively little effect on upper frequency response; this is mostly controlled by the inductance of the voice coil, which behaves as a low pass filter. A rough calculation of the frequency at which rolloff will begin can be completed using the listed parameters; I'll try to get to this a bit later, but based on the listed inductance (Ls), I don't think roll off will be too much a of a problem for you in that range. It certainly would not be my preference, as I prefer to cross the sub-stage over much, much lower, but it is workable.

It certainly would not be my preference, as I prefer to cross the sub-stage over much, much lower, but it is workable.

I agree 80-100hz is not sub-bass, but mid-bass.

The formula Neil was talking about;

Fc = Re/(2pi*Le)

But I agree....tell your friend that he needs better mids if he is planning to rely upon the subwoofer to cover up to 80-100hz.

agreed get some decent mids to help in that area

80

thanks guys

i didnt ask for oppinions about his midbass setup. he will be getting a sufficent frontstage. i asked about what box volumes would yield a smooth frequency extension above 50hz.

so, for people who have expierence with the rlp18, what kinds of boxes have you put it in, and what sounded the best.

i know what midbass is guys. i dont have personal expierence with the rlp 18, i was asking for advice on what box volmues and port tuning\size would be a good start.

When your talking about SUB bass, I don't think you would be concerned about anything above the 50hz ish range (especially in an 18" driver). Some purist would even think 50hz is too high for Sub Bass.

When your talking about SUB bass, I don't think you would be concerned about anything above the 50hz ish range (especially in an 18" driver). Some purist would even think 50hz is too high for Sub Bass.

i dont know about you. but my idqs can play well over 100hz. i dont have the crossover set that high, but its got a low slope.

but 99% of people arent purists. they want the subs to play a bit of upper frequencies. most people dont want to spend $300 on their front stage. thats life.

nevermind i even asked. i was just curious about people who owned the 18 and had expierence with box types.

When your talking about SUB bass, I don't think you would be concerned about anything above the 50hz ish range (especially in an 18" driver). Some purist would even think 50hz is too high for Sub Bass.

i dont know about you. but my idqs can play well over 100hz. i dont have the crossover set that high, but its got a low slope.

but 99% of people arent purists. they want the subs to play a bit of upper frequencies. most people dont want to spend $300 on their front stage. thats life.

nevermind i even asked. i was just curious about people who owned the 18 and had expierence with box types.

Let's just leave it as constructive criticism of your intents and focus on what you're asking.

The enclosure will have very little to do with your upper frequency response. I think it's best to stay with a sealed enclosure with a Qtc of around 0.800, depending on the vehicle, of course, to ensure a little better integration with all higher frequencies than your lowpass filter.

When your talking about SUB bass, I don't think you would be concerned about anything above the 50hz ish range (especially in an 18" driver). Some purist would even think 50hz is too high for Sub Bass.

i dont know about you. but my idqs can play well over 100hz. i dont have the crossover set that high, but its got a low slope.

but 99% of people arent purists. they want the subs to play a bit of upper frequencies. most people dont want to spend $300 on their front stage. thats life.

nevermind i even asked. i was just curious about people who owned the 18 and had expierence with box types.

I'm aware that many subs can play into that range. I was just curious as to why you would want you sub playing that high. I think your money would be well spent buying a driver that's made for that freq. Just trying to help and also understand whaere your coming from. That's all. Good luck.

When your talking about SUB bass, I don't think you would be concerned about anything above the 50hz ish range (especially in an 18" driver). Some purist would even think 50hz is too high for Sub Bass.

i dont know about you. but my idqs can play well over 100hz. i dont have the crossover set that high, but its got a low slope.

but 99% of people arent purists. they want the subs to play a bit of upper frequencies. most people dont want to spend $300 on their front stage. thats life.

nevermind i even asked. i was just curious about people who owned the 18 and had expierence with box types.

I'm aware that many subs can play into that range. I was just curious as to why you would want you sub playing that high. I think your money would be well spent buying a driver that's made for that freq. Just trying to help and also understand whaere your coming from. That's all. Good luck.

It seems clear to me: a good front stage that would be able to adequately crossover at a lower frequency is outside of his friend's budget.

Your Correct.

The RL-p's should not be troubled reaching up to an 80 - 100 Hz crossover point. Ideally I would suggest a sealed box, around 2.1 cu ft on the RL-p15 and 4 cu ft on the RL-p18.

thanks mike

exactally what i needed to know

Edited April 26, 200718 yr by req