Home Theater Forum and Systems banner

21 - 40 of 237 Posts

·
Registered
Joined
·
3,068 Posts
Discussion Starter #22
Ryan,

The reason I have left it like that is because I may add an extra baffle on the front or extend the front of the port ( a bit like the ED A7-900 ) and then put the grill underneath. I am going to see what port noise I might get from it as it is first and then decide.

cheers

Graham
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #24
Ryan,

Sure are matey. Yep I am hoping for more low end. It will be my first ported sub/s so as with the sealed sub its a big learning curve for me and I am taking a few risks with the spec of these subs with regards to port velocity, port resonance but hey that is what makes it interesting.

Hopefully fingers crossed it should work out ok. I will find out tomorrow.

cheers
Graham
 

·
Banned
Joined
·
1,074 Posts
well I've been dealing with port velocity myself, and I've always wondered about port resonance... I just don't see it as a problem, yet.... I got mine crossed for ya too!
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #26
Ryan

Ive read so many threads debating on this subject and whether having a low port resonance is audible or not and so on. I think from reading sub junkies sub, his 1st port resonance is about 100hz I think and he's never mentioned any issues. Not sure what he is crossing his sub at.

My main problem was to get a higher 1st port resonance of say 200 or above it made the tuning quite high when modelling the Q drivers which I didn't want.

My 1st port resonance is about 138hz. According to MikeP if I cross the sub at 80hz I should be fine.

My port velocity without a hpf is 30 m/s at 11.5hz which is the max excursion on my 13.5hz tune and only 17 m/s at 15hz. With a hpf it is only 20 m/s max.


I should finish the sub today. Just got to sort out the speaker wire/plate, egg crate foam and just the bottom and its done. I will probably leave it overnight tonight to dry completely and test it tomorrow.

cheers

Graham
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #27
A little update......

I have now put the bottom on and filled/sanded all the holes. I need to sand and fill again once that has dried. I will then sand down everything again to smooth off for when I add the wood veneer.

I have put the speaker plate on and cable tied the speaker wire ready for when the driver goes in.

Tomorrow morning I will add the egg crate foam (need to buy some adhesive spray) and just put the side on, then fill and sand. Job done ish!

I emailed the european seller for the reckhorn B2 and got a quote of 59 euros plus 15 euros for delivery just in case I need one. If I do get any port noise then adding the reckhorn will reduce the velocity alot.

The bracing is really solid. More solid than I thought it would be especially as it only has a 1.5" frame.

Probably used more screws than I was going to but Im just not confident enough to use just glue.
Maybe in the future I may do one with normal wood glue to see the difference.

cheers

Graham
 

Attachments

·
Registered
Joined
·
3,068 Posts
Discussion Starter #29
Dylan,

Just the egg crate to add and put on the side and Im done. Fill and sand the side and I can start testing. I have just looked at the application notes on the tempest x2 drivers and the difference between what is measure at 1m (in winisd too) is alot lower than in room response so am I to think there will be a fair bit of gain on top of what my graph in winisd is showing in the real world.

cheers

Graham
 

·
Registered
Joined
·
262 Posts
Great work Graham, this will be one great subwoofer. And to think there will be 2 of these beast's.

The slotted ports are the way to go I think they help to finish the box off nicely.
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #31
Thanks David, I am looking forward to getting the first one fired up asap as I haven't had a sub for about 4 weeks now. As I am having two of these and the fact they will be the same means I can put the one sub in the both positions they will be in and run the two REW measurements to see how they will measure up and I can also fire them either into the wall or away from the wall to see what will sound best. One good thing is that I already know that the right front corner is almost as good as the left front corner as that was where I had my PB13 originally.

cheers

Graham
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #32
Hi guys,

I managed a get a few more things done today. Glued the egg crate inside except the side bit as I had not screw/glued that at the time. I have done the last side now and have done one lot of filling. Going to go outside in a mo to sand and fill again. I stood it upright this afternoon and it actually looks like a sub now. Sorry a BIG sub. It does look big. I will take some pics in a mo to show you.

I also need to route along some of the edges as a couple of bits stick out. Dodgy cutting by the diy store. And then all done. I will defo be testing it tomorrow so I will post some graphs up then.

I actually can just lift it by myself, well when I say I can lift it, that's about it. I wouldn't be able to carry it from the garage into the house.

cheers

Graham
 

Attachments

·
Registered
Joined
·
3,068 Posts
Discussion Starter #34
Cheers matey, here's a few of the sub complete. Sorry for the bad pics but I don't any power in the garage so I had to use my car's headlights.


cheers

Graham
 

Attachments

·
Elite Shackster
Joined
·
7,142 Posts
Quality work Graham, really neat looking. I look forward to your initial testing and seeing what you make or it.
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #36
Thanks Dan,

Sorry for the naff pics. I will post some graphs tomorrow. I haven't routed the exit port yet so I don't know if that will have any effect on noises etc.... we will see.

cheers

Graham
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #38
Right its now in the living room. Just need to wire it up and put in the driver and pow! Light her up.

Will get back soon.

cheers

Graham
 

·
Registered
Joined
·
3,068 Posts
Discussion Starter #39
First impressions there is alot more low end bass than the sealed sub. I mean alot more. I need to set it up properly to see how it fares. Will check back soon.

cheers
Graham
 

·
Banned
Joined
·
1,074 Posts
First impressions there is alot more low end bass than the sealed sub. I mean alot more. I need to set it up properly to see how it fares. Will check back soon.

cheers
Graham
I never say "I told you so".
Ever.

I TOLD YOU SO! I TOLD YOU SO! I TOLD YOU SO!

:D I'm happy and excited for you! So are you happy now that you got some awesome Fi Audio Q drivers??? huh? huh?

LOLZ
 
21 - 40 of 237 Posts
Top