Help me decide path... - Page 2 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #11 of 16 Old 11-25-15, 01:50 AM Thread Starter
Shackster
 
Join Date: Oct 2015
Posts: 8
My System
Re: Help me decide path...

I guess this is a really dumb question.

I'm wondering if I should use a high pass filter for the subs I choose. I have no need or desire for the frequencies much below 20Hz (audible).

Should I even worry about that? Do receivers/amplifiers frequency response even go down much below 20Hz to a point where the subwoofer starts to unload or bottom out or any other issues?

Based on some configurations I've checked out, using a high pass filter seems to have a significant affect on the enclosure size, or am I wrong about this?

Also, if it is something I should be concerned about, which amplifiers use an active high pass crossover?

Kind of strange situation. The subwoofer frequencies, when produced correctly and accurately produces an illusion indiscernible to it's location, seems to have the greatest impact on overall sound quality and depth when compared to other frequencies, yet is nearly impossible to create artificially. My 0.02 cents.
ziggy1971 is offline  
Sponsored Links
Advertisement
 
post #12 of 16 Old 11-25-15, 10:14 AM
Shackster
 
Join Date: Sep 2010
Location: Edmonton Alberta
Posts: 43
Re: Help me decide path...

Quote:
ziggy1971 wrote: View Post
I guess this is a really dumb question.

I'm wondering if I should use a high pass filter for the subs I choose. I have no need or desire for the frequencies much below 20Hz (audible).

Should I even worry about that? Do receivers/amplifiers frequency response even go down much below 20Hz to a point where the subwoofer starts to unload or bottom out or any other issues?

Based on some configurations I've checked out, using a high pass filter seems to have a significant affect on the enclosure size, or am I wrong about this?

Also, if it is something I should be concerned about, which amplifiers use an active high pass crossover?

Kind of strange situation. The subwoofer frequencies, when produced correctly and accurately produces an illusion indiscernible to it's location, seems to have the greatest impact on overall sound quality and depth when compared to other frequencies, yet is nearly impossible to create artificially. My 0.02 cents.
If your going with a sealed box no you shouldn't need to worry about a subsonic filter, the box will control the sub if your not over powering it.
If you go sealed it is a must as cone excursion goes through the roof at the tuning freq.

If you go with the Behringer iNuke or the Crown XLS they can be set for no high pass. If you get either with a DSP built in you would also have EQ for smoothing out your responce and or adding in a bit of boost down low for a sealed box.

I feel your pain on the buying stuff in Canada, here in Edmonton there is zero out there for a DIY building stand point. You will have to ship everything in depending where your located. Both of these are based in Canada, for the amps if you would rather not ship there should be local places to buy would just need your location.

http://www.creativesound.ca/products...=CSS&category=
http://solen.ca/

I went with the JL 13W7 for my build (have my second driver on it's way now) and a Behringer amp, it's a pretty nice driver. About 85% the same as the one they use in there home sub line.
I had to go small sealed for my setup for WAF.

Finhead is offline  
post #13 of 16 Old 11-25-15, 01:37 PM
Senior Shackster
 
Join Date: Sep 2015
Location: Las Vegas
Posts: 431
My System
Re: Help me decide path...

High Pass filters can be a necessity... but as mention above it depends on the type of box you're building. A sealed box will tend to roll sub-sonic signal off for you, but it depends on the driver and the size of the box. You can build an "optimum" box, that is to say a box that doesn't begin to roll off until the driver has reached Fs... but drivers can and will respond below Fs (with adequate power and EQ). In order to extend below Fs, simply increase the box volume. (2x box volume = ~25% lower F3).

In a ported enclosure, you can achieve the same effect by increasing the box volume and the port length.... but here's where one must be cautious:

Venting an enclosure or dramatically increasing the volume of a sealed enclosure reduces the tendency of the air in the box to counteract the motion of the driver. In order to respond to lower frequencies at an apparently similar SPL, the driver must displace more air. Since the size of the cone is fixed, that means longer excursions. The lower a frequency you ask for, the longer the excursion... until you reach Xmax. At that point, you begin to stress the driver... deformation of the cone, stretching the surround or the spider, etc. You can ask for more, and most drivers will deliver... but it generally doesn't sound good. Also, you risk reaching Xmech, which is the absolute limit of the cone's travel. Here, you're usually smacking the back of the voice coil former into the backing plate on the motor. Damage is inevitable.

Also, as Finhead noted above, in a ported enclosure the port tuning frequency will exhibit very large increases in driver excursion... possibly introducing the Xmech problem. And the lower that tuning frequency, the more extreme the excursion.

So, if you want a driver to respond at an acceptable level below its rated Fs, you must be very careful about how much power you deliver. A High Pass Filter does that job for you. The other approach would be to listen at or below reference level, and enjoy a nice clean signal instead of listening at high levels and risk damaging equipment.
DqMcClain is offline  
 
post #14 of 16 Old 11-27-15, 09:27 AM Thread Starter
Shackster
 
Join Date: Oct 2015
Posts: 8
My System
Re: Help me decide path...

This is what I've got so far.
2x 15" drivers, each in its own box with the following specs:

Total height: 23 inches from the floor
Total width: 22 inches
Total depth: 26 inches
Total box size: 4.864 cu. ft.

2x 3 inch ports, 31.67 inches long (with 90 deg elbow)

Fb = 15.21 Hz
F3 = 16.88 Hz

Suggestions? Thoughts?




Let me know if the graphs look like a realistic target or if I should make more changes.
ziggy1971 is offline  
post #15 of 16 Old 11-28-15, 01:11 PM Thread Starter
Shackster
 
Join Date: Oct 2015
Posts: 8
My System
Re: Help me decide path...

Quote:
Finhead wrote: View Post
If your going with a sealed box no you shouldn't need to worry about a subsonic filter, the box will control the sub if your not over powering it.
If you go sealed it is a must as cone excursion goes through the roof at the tuning freq.

If you go with the Behringer iNuke or the Crown XLS they can be set for no high pass. If you get either with a DSP built in you would also have EQ for smoothing out your responce and or adding in a bit of boost down low for a sealed box.

I feel your pain on the buying stuff in Canada, here in Edmonton there is zero out there for a DIY building stand point. You will have to ship everything in depending where your located. Both of these are based in Canada, for the amps if you would rather not ship there should be local places to buy would just need your location.

http://www.creativesound.ca/products...=CSS&category=
http://solen.ca/

I went with the JL 13W7 for my build (have my second driver on it's way now) and a Behringer amp, it's a pretty nice driver. About 85% the same as the one they use in there home sub line.
I had to go small sealed for my setup for WAF.

I think you meant ported/vented in the second line, but I get what you meant.

That's a really nice looking sub; I wouldn't pay $1000 for one sub though, but to each their own and I would want a grill of some kind or have it down-firing to protect the cone from damage. I guess it depends on placement also.

I've always been partial to ported boxes (I have no idea why); and there's pro's and con's to both sealed and vented enclosures.

I've also checked out some of the amps and I think I'll go with a Behringer iNUKE NU3000DSP. I've looked at some of the specs and it seems to have the filtering I'm looking for and even has PC software that I can use to tweak it. It's also available here locally for ~$380 CAD. (I'm in Winnipeg)

My only concern with this amp would be the input/output connections. Hooking up the XLR to RCA simply needs an adapter. But I'm not sure how to connect the speakers yet, I've never used this connection before so I'll have to figure out how to do it.
ziggy1971 is offline  
post #16 of 16 Old 11-28-15, 01:25 PM
Shackster
 
Join Date: Sep 2010
Location: Edmonton Alberta
Posts: 43
Re: Help me decide path...

Quote:
ziggy1971 wrote: View Post
I think you meant ported/vented in the second line, but I get what you meant.

That's a really nice looking sub; I wouldn't pay $1000 for one sub though, but to each their own and I would want a grill of some kind or have it down-firing to protect the cone from damage. I guess it depends on placement also.

I've always been partial to ported boxes (I have no idea why); and there's pro's and con's to both sealed and vented enclosures.

I've also checked out some of the amps and I think I'll go with a Behringer iNUKE NU3000DSP. I've looked at some of the specs and it seems to have the filtering I'm looking for and even has PC software that I can use to tweak it. It's also available here locally for ~$380 CAD. (I'm in Winnipeg)

My only concern with this amp would be the input/output connections. Hooking up the XLR to RCA simply needs an adapter. But I'm not sure how to connect the speakers yet, I've never used this connection before so I'll have to figure out how to do it.
Yes sorry I meant ported.

LOL no way would I ever pay $1000 for a sub either unless it was for a LMS5400 Ultra, but I don't have the room for one so I opted for the tiny encolsure 13W7. I Now have 2 13W7's and one 12W7, I'm in the process of making 2 more boxes. I picked up each one for less than $500, which IMO is a great deal considering new they are $1680 here in town.

I've been running my TC LMS 15" without a grill for 7 years with zero issues, but I don't have any young kids and my dogs don't mess with it at all.




Yes the iNuke seems to be a great choice, I have had a EP1500 driving my TC LMS 15" for 7 years now without issue. Just bought a NU6000DSP a few weeks ago to drive 2 13W7's and will be ordering a NU3000DSP to drive the 12W7.

Speakers are just wired in with a speakon connector super simple, just fallow the diagram on the back of the amp. Connector is like $5

IMO if your in Winnipeg I would go with a Mach 5 driver 100% since your local there would be no shipping. That is if you can fit the size box you would need, if I didn't have restrictions on the size box I couls have I would have ordered 2 of the UXL-18's in a heartbeat. 2 of those driven by a inuke would be very nice.

http://www.istonline.ca/mach5_main.html
Finhead is offline  
Reply

Bookmarks

Tags
decide , path

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome