small sub, low f3.. any ideas? Peerless XXLS?

[makthom]

Hi,
I am completly new here. I would like to built my own sub and i'm looking for a good driver and its application.
Sub is designed for HT and music- very universal 50/50.
I would like it to be as small as possible because I don't have much space, and of course it would be nice for this sub to have very low f3.

I was interested in new peerless xxls 12" with passive radiator 12" 425g (the application is on the tymphany's webpage). Do you know f3 of that solution?
How low does this driver can go? I would like to extend the bass response more then in this application. What do i have to do?

Of course I'm still open for other ideas (about 150USD for a driver). Maybe NHT1259? Which one do you think is better? Whice one does reach lower frequencies? Maybe something different?
Thanks for you help.

[simon5]

The Acoustic Elegance AV12 would be nice, but a bit over budget at 175$ per driver.

http://www.aespeakers.com/products_av12.php

[makthom]

yeah, look great, probably that wil be my second sub. Unfortunately my budget is slighty tight. And besides the vision of having such a monster in my home terryfing me. I'm looking something with smaller rms output. I think that everything i can afford will be plate amp about 250W /4om.

Did anybody tried peerless with different then dedicated PR?

[simon5]

You don't need to go with a PR, you could do a sealed design, you'll have less output but it will cost less, you can add the PR when you have more money if you wish so.

[makthom]

Thanks simon5 for your answer in different topic. I will start writing only in this.
I'm using in sumulations this PR from Stryke 45$
Thiele Small parameters:
Fs (Hz) 4.9
Qms 51.96
VAS (ltrs) 978
Mms (g) 1050
Cms (mm/N) 1.0
Sd (cm&#178 830
Xmax (in) 2" p-p

I was doing some simulations in Bassbox.
One driver is popular NHT1259 (I know, it should be sealed but with 1 PR it doesn't look so bad).
The second one is Peerless XXLS 12" 830847:
Fs = 21,8 Hz
Qms = 10,24
Vas = 144,2 liters
Cms = 0,48 mm/N
Mms = 110,9 g
Rms = 1,48 kg/s
Xmax = 12,5 mm
P-Dia = 244, mm
Sd = 466, sq.cm
Qes = 0,37
Re = 2,5 ohms
Le = 1,8 mH
Z = 4, ohms
BL = 10,2 Tm
Pe = 350, watts
Qts = 0,36
2.83-V SPL = 92, d
It's designed for using in vented systems but I tried it with 2 PR.

The volume for NHT1259 is 80 liters ( 2,825 cu.ft), and for Peerless 95l (3,355 cu.ft).
The f3 for NHT1259 is 24,04 Hz and for Peerless is 24,08.

Here are results for NHT1259:

F3


Spl


Cone displacement


Delay


And the same stuff for Peerless:

F3


Spl


Cone displacement


Delay



As you can see Peerelss has way higher spl. What is worrying me is cone displacement. It'is about 1mm bigger then supposed to be in about 31-32 Hz. For Peerless it's about 1,5mm. Of course everything is with the 300W applied. Another thing that Peerless very fast reaches its limit again with 19,5 Hz. Should be I worried with that? What should I do to correct it? Does the delay in low frequencies matter?

All I can say about that design that I really like Peerless SPL. The similar has LAB 12. I will have probably only 250 or about 300 W@ 4ohm, so I don't know...

About AV12. I just think that it has too much power for me. I will not use it and besides amp for it would be exepensive.
What do you think about those projects?

[simon5]

It's not because the subwoofer can take 500W RMS that you need to use a 500W RMS amplifier, it will do very very fine with 250W RMS.

As I can see, it's now only 150$ on the website.

BTW, 95 liters is not a small subwoofer, I didn't know you can tolerate such a big box, you could go vented and save money.

You would need to get a standard 4" diameter Precision Port and keep it full length for a tuning of 22.5 Hz and have the same frequency response for 14$ instead of 2 x 45$ = 90$.

Good luck!

[simon5]

Originally posted by makthom
What is worrying me is cone displacement. It'is about 1mm bigger then supposed to be in about 31-32 Hz. For Peerless it's about 1,5mm. Of course everything is with the 300W applied. Another thing that Peerless very fast reaches its limit again with 19,5 Hz. Should be I worried with that? What should I do to correct it? Does the delay in low frequencies matter?

To correct cone displacement, use 250W instead of 300W hehe! Or you can tune a bit higher to use the full 300W or use a smaller box with the same tuning.

The woofer will have overexcursion under 20 Hz, maybe your amplifier will have a included rumble filter to help with this. If not, you could make one. Not alot of music and/or movies have things under 20 Hz, so you could just watch out and use lower volumes when the subwoofer can't keep up. You can also tune lower to help with this problem.

About delay, some people prefer to stay under 20ms, some don't care, lower is better. Another solution is to tune under 20 Hz so the group delay is not in the audible range.

Good luck, again!

[69stingray]

Parts Express has a nice Woofer selection Guide , in which you can sort by F3. Just click on "Vented F3" in the top row.

The NHT and Adire subs are the most popular, you will not find them at Parts Express. NHT can be found at Madisound . Here is a link to Adire's website.

From the Parts Express list, both these Hi-Vi subs are below 25Hz and are only 10"


Hi-Vi 10.8 10"

Hi-Vi D10G

[sardonx]

I've read the Peerless/PR combo starts to roll off pretty high but the slope is very gradual so it still reaches pretty damn low.

You could use a pair of high quality woofers in small sealed enclosures and EQ the bottom end with something like a Marchand BASSIS and use lots of solid state power.

I know it's over your budget but i thought i'd mention it. It's what i'm planning on doing... one day.. heheh. It costs a lot but it would be so worth it.

sardon