just got 2 15 L7s now i need an amp

[DarkFox 10+ year member]

Also... just want to throw in my 2 cents here. I, whenever possable, prefer to run subs off the same amp. I do this becuase:

1. No Phase matching

2. No line matching

3 No voltage or "gain" matching

4. As they age, you wont have to adjust all over again as the amps wear

I would just run them on a XX-Colossus II. You can wire the subs together for a 2ohm load, be getting 3200W to the pair. I mean 1600W a piece is nice, not overloading them TOO much. If you push as much power to them as you are thinking then if they blow, they might do so in such a way that overpowering is apperent and voids your warranty. Plus the amp will only cost you 750. If you have money to spair, and you can easily replace the sub, then overpower them as much as you want. I wouldnt go much more then what I said though. All IMO of coarse though. Dont forget to send me a link when you build your box either!

 

[yacob.naif 10+ year member]

Also, is that plot for an output curve @ 35hz, it looks a lot higher.....

If SPL is your main objective, get 10's or 12's instead.

I personally tried tuning my 15's @ 42hz, and i hate them, they have no output compared to 12's tuned in the 40's. Tune 32 or 33hz in 4.5, or get 12's if you want SPL tuning, trust me, i made the same mistake. The 15's naturally want to play in the 30's to the extent where notes in the mid 30's are STILL louder than notes in the 40's and 50's despite being in a box tuned to 42hz, they don't want to play that high.

 

[DarkFox 10+ year member]

no, thats tuned to 34 HZ. And what the hell are you thinking? You would go with 10s over 15s for SPL? you need to do more reseatch my friend.

 

[DarkFox 10+ year member]

by output I assume you are are talking about the audible sound not its actual output. You dont hear the subs dropping low so you assume that its SPL is low. Really you tuned to high and your cutoff freq is too high so anything below your tunning freq is very poor and your SQ is poo poo. however if you went to a comp and used like a 50HZ tone I bet you would do ok. I'm gonna go into winisd, and plot, same boxed tuned to 42 hz, I bet it is extreamly boomy from 38 to about 44Hz. Just guessing there but I bet its cutoff freq is horrable

Edit: Ran the numbers, tunning to Heymans specs, the cutoff (meaning almost no output) was at 35Hz and the box had a very sharp (boomy) rise at 48Hz. Pretty good guess huh?

 

[talon2nr7588 10+ year member]

what are the specs for an IA 20.1 at .5 ohms?

 

[HotCarl 10+ year member]

If SPL is your main objective, get 10's or 12's instead.

thats almost sig worthy.

 

[DarkFox 10+ year member]

not supported according to there page

 

[DarkFox 10+ year member]

I had to agree with carl on that one

 

[talon2nr7588 10+ year member]

how about 2 BXI1606Ds instead

 

[DarkFox 10+ year member]

i would still go with the 1 Colossus instead of the two of those.

1. Same power

2. I always prefer 1 amp

3. Bigger amp, more surface area, better heat dissipation

4. From what I have heard (not IMO) the XX series is MUCH better then Brutus

only downside is it is 250 more for the Colossus then the 2 Brutus together.

 

[yacob.naif 10+ year member]

thats almost sig worthy.

15" L7's don't meter for ****, ask around, nobody will tell you differently

i realize it's not always the case, but 12 and 15" L7's use the same motor, so the 15's are better for lowend, less meter-friendly bass, but the 12's have the edge in the force-per-square inch department, and yield higher spl numbers

don't give me ****

"louder to the ear" and "higher db" on a meter are two completely different things, you know this. the human ear and a microphone don't see eye to eye on what's "loud"

 

[yacob.naif 10+ year member]

by output I assume you are are talking about the audible sound not its actual output. You dont hear the subs dropping low so you assume that its SPL is low. Really you tuned to high and your cutoff freq is too high so anything below your tunning freq is very poor and your SQ is poo poo. however if you went to a comp and used like a 50HZ tone I bet you would do ok. I'm gonna go into winisd, and plot, same boxed tuned to 42 hz, I bet it is extreamly boomy from 38 to about 44Hz. Just guessing there but I bet its cutoff freq is horrable


Edit: Ran the numbers, tunning to Heymans specs, the cutoff (meaning almost no output) was at 35Hz and the box had a very sharp (boomy) rise at 48Hz. Pretty good guess huh?

And no, "SQ" is fine, and no, it's not peaky in the slightest. Like i said, output is just plain higher in the low to mid 30's, regardless of the box being tuned to the 40's. And so you know, transient response suprisingly stayed intact despite of being tuned so high, due to the heavy speaker, very smooth transitions. My complaint was mainly in the fact that output is very low for two 15's.

I'm not telling you what to do, wasn't trying to, wasn't looking for a fight here, the natural resonance of the speaker wants to peak in the mid-to-low 30's in a 4.5 cube box. I can still hit 28hz audibly, and 35hz is loud as hell, even in a 42hz box.

 

[pd298 10+ year member]

L7's are rated at 1000rms, not 750.

 

[yacob.naif 10+ year member]

L7's are rated at 1000rms, not 750.

and THIS has been the debate of many threads, many memebers of which threads i haven't seen on these forums since.

read the users manuals, they're rated at 750 in a ported enclosure, they were correct in saying so

 

[pd298 10+ year member]

I've never seen that before. CVX and L7 use the same motor and the cvx are rated at 1kw?