Ianbo,
Do you have any familiarity with modelling H-frame OB in horn resp?
It doesn't seem to really "do much" for this subwoofer, over a u-frame. And it indicates that it reaches xmax with just a few watts of power. I was considering whether a H-Frame would be a better design for the woofer, but I can't really seem to get a comparable sim out of horn resp.
Do you have any familiarity with modelling H-frame OB in horn resp?
It doesn't seem to really "do much" for this subwoofer, over a u-frame. And it indicates that it reaches xmax with just a few watts of power. I was considering whether a H-Frame would be a better design for the woofer, but I can't really seem to get a comparable sim out of horn resp.
Sorry, I haven't grappled with hornresp.
If you're planning to use these for regular domestic music listening, rather than as party speakers or HT, I doubt you'd ever reach xmax. According to Basta, the 18SW450 will be excursion limited at around 25 watts rms. However, it's reaching the excursion limit down around 17 Hz. With music programme, you're not going to get high level signal down there, unless you have very strange programme material. (I do own one CD which with a high level subsonic signal at one point - a mastering error, presumably. It's 'High' by The Blue Nile, for reference.) And in the passband, that power is getting you 103 dB at 1m, even with a small flat baffle, and no allowance for floor reinforcement. (And I'm using 7.6mm for xmax, i.e. coil minus gap divided by 2, which is more conservative than SB's figure.) In practice you could feed it 50 watts or more and never reach xmax with music programme material. With home theatre it would be a totally different matter, of course.
If you're planning to use these for regular domestic music listening, rather than as party speakers or HT, I doubt you'd ever reach xmax. According to Basta, the 18SW450 will be excursion limited at around 25 watts rms. However, it's reaching the excursion limit down around 17 Hz. With music programme, you're not going to get high level signal down there, unless you have very strange programme material. (I do own one CD which with a high level subsonic signal at one point - a mastering error, presumably. It's 'High' by The Blue Nile, for reference.) And in the passband, that power is getting you 103 dB at 1m, even with a small flat baffle, and no allowance for floor reinforcement. (And I'm using 7.6mm for xmax, i.e. coil minus gap divided by 2, which is more conservative than SB's figure.) In practice you could feed it 50 watts or more and never reach xmax with music programme material. With home theatre it would be a totally different matter, of course.
Hi Tigeranand,
I have built with the 18SW450. I have ended up going with H-Frames for now.
50cm x 50cm, with 40cm depth (20cm Front & Back of the woofer).
They have only been in a temporary home, so I'm hesitant to give too much information, as they definitely have room to grow with regards to placement, and I am also just starting to learn REW and Minidsp EQ for the first time.
But DAMN they are effortless. They make so much bass when they need to, completely disappear when not called upon. I haven't really "opened them up" yet, but they get plenty loud as it is. I have some very quick and very dirty measurements, that included a terrible noise floor, so I will only show the basic response. I don't even know if I have good measurement technique as yet.
Raw 18SW450 at 20hz - 1000hz.
My first attempt at EQ. Yes I know the cross between Bass & upper isn't very smooth yet.
I think I actually added a small cut at 65hz to take the lump out of the bass response after this measurement.
Overall it sounds great to be honest.
The MAOP has a surprising amount of output for the baffle it's on, but definitely drops off below about 200hz. This is a bit tough as the H-Frame has it's resonance at about 200-250hz, so it's a balancing act to get it right. And again, I might not have a clue what I'm actually doing, but it's certainly fun.
I'm moving house in 2 days, and once settled will begin a proper campaign of testing and equalising.
My Wiim Pro Plus has also arrived, so I'll finally have my gain structure sorted properly as well which is an added benefit.
I'm very excited by this new chapter of my audio hobby.
I've done my first open baffles, first 18" drivers, first two ways and first active crossovers & EQ all in one go. So many things to wrap my head around!
I've also got some other drivers stashed away that I am going to swap the MAOPs out with for the fun of it.
Pluvia 7HD & Scanpeak 10F/8424G00. I also have some RS225-4 that I might try making a 3 way out of, though I know they aren't particularly suitable. Active & OB makes it so easy to experiment and rapidly iterate. I'll likely also try a simpler U Frame design for the woofers at some point as well.
I have built with the 18SW450. I have ended up going with H-Frames for now.
50cm x 50cm, with 40cm depth (20cm Front & Back of the woofer).
They have only been in a temporary home, so I'm hesitant to give too much information, as they definitely have room to grow with regards to placement, and I am also just starting to learn REW and Minidsp EQ for the first time.
But DAMN they are effortless. They make so much bass when they need to, completely disappear when not called upon. I haven't really "opened them up" yet, but they get plenty loud as it is. I have some very quick and very dirty measurements, that included a terrible noise floor, so I will only show the basic response. I don't even know if I have good measurement technique as yet.
Raw 18SW450 at 20hz - 1000hz.
My first attempt at EQ. Yes I know the cross between Bass & upper isn't very smooth yet.
I think I actually added a small cut at 65hz to take the lump out of the bass response after this measurement.
Overall it sounds great to be honest.
The MAOP has a surprising amount of output for the baffle it's on, but definitely drops off below about 200hz. This is a bit tough as the H-Frame has it's resonance at about 200-250hz, so it's a balancing act to get it right. And again, I might not have a clue what I'm actually doing, but it's certainly fun.
I'm moving house in 2 days, and once settled will begin a proper campaign of testing and equalising.
My Wiim Pro Plus has also arrived, so I'll finally have my gain structure sorted properly as well which is an added benefit.
I'm very excited by this new chapter of my audio hobby.
I've done my first open baffles, first 18" drivers, first two ways and first active crossovers & EQ all in one go. So many things to wrap my head around!
I've also got some other drivers stashed away that I am going to swap the MAOPs out with for the fun of it.
Pluvia 7HD & Scanpeak 10F/8424G00. I also have some RS225-4 that I might try making a 3 way out of, though I know they aren't particularly suitable. Active & OB makes it so easy to experiment and rapidly iterate. I'll likely also try a simpler U Frame design for the woofers at some point as well.
I'm going to guess that the first boxes you unpacked had your audio gear? 😉
The 18SW450 appears to be a very attractive option, although for some reason not currently available in the USA (that I can find).
Let us know your progress as you get settled in!
The 18SW450 appears to be a very attractive option, although for some reason not currently available in the USA (that I can find).
Let us know your progress as you get settled in!