Boomy Sub - Page 3 - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 20th August 2004, 05:41 PM   #21
diyAudio Member
 
Join Date: Aug 2004
Location: helsingborg
bloody hell have you more brains than money!!????

CUT A BIGGER HOLE IN THE BOX AND INSULATE IT MORE!!!!
(of course a MONO amp would have been a better choice!)
  Reply With Quote
Old 20th August 2004, 05:52 PM   #22
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
uk, it might be more useful to give the technical information you want to convey without adding the personal stuff, OK?
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 26th August 2004, 05:41 PM   #23
diyAudio Member
 
Join Date: Aug 2004
Location: perth
Hi memito.
I ran your speaker and spec through my speaker software. 1.25 ft cube box is ok. it does have a slightly under damped responce but this is good in a box otherwise it will sound very dry. critical damped box would be close to 1.75 CU ft. but you are very close allready so I would not build another box. If you are sounding boomy it may be a number of other factors, Such as placement, poor quility amp wires or inductor if you are using one. also if you are using electronic or passive cross over make sure it is not set too low frequency. the high frequency component of the drum hit is the part that gives makes it sound sharp. I would try running the speaker in home stereo situation since it looks like an 8 ohm speaker.
just to expand on the other factors affecting boom:- extra resistance in the wiring,choke and the actuall resistance in the power amp output stage will actually affect the Qes, Qes is the amount of electrical damping of the speaker, Qes is measured assuming the resistace of the speaker wires, Choke, and amp is ZERO ohms. And this will affect Qts since qts = 1/((1/qes)+(1/qms))
so if your amp output impedance is .25 ohms your speaker wires are .2 ohms and your choke is 0.8 ohms then you have 1.2 ohms. this will increase your Qes from 0.45 to 0.53. which will make your QTS .499. therefore requiring a box of 2.6 cu FT to be critically damped.
  Reply With Quote
Old 26th August 2004, 08:55 PM   #24
diyAudio Member
 
Bill Fitzpatrick's Avatar
 
Join Date: Jun 2001
Location: Eugene, OR
Just as an experiment, I put a sub in the trunk of my car and then listened to it from the passenger compartment. It did indeed sound boomy. Despite all the advise you have gotten, I still think the problem is having it in the trunk.
  Reply With Quote
Old 28th August 2004, 05:19 AM   #25
diyAudio Member
 
Join Date: Dec 2002
Location: Utah
MEMITO,

There are probably a combination of things that are causing you to have the boomy bass that you speak of. Some have to do with your speakers and some the amps and some the car itself.

OK, let's start with the speakers. First off, to get punchy bass you need high transient response from the speaker. This is obtained from at least four ways. First the speaker needs to have a powerful and well designed magnet system. Some designs in car audio are more for looks to wow the unsuspecting customer. Also boom is what sells to people in the car audio market. You may wish to find a better speaker from a reputable speaker manufacturer designed to play music. I have not run a box plot on your speaker but generally speakers with high qts like .45 need a very large enclosure to sound good. The closer the total system Q is to .707 which is the critically damped Q the more accurate the speakers will be. Most commercial car stereo subs are designed at around .9 - 1.2 becasue this gives them a bass hump near the bottom of the frequency spectrum.

If you look at Spiros data which is good you will see that in reality you have to include the other parts of the system to estimate the total Q of the driver. It will not really be .45 after wire and corossover and electronic impeadance is accounted for. This is why drivers with qts in the .40 and above range really need larger boxes to work right. 2-3 cubic feet sounds about right to me for a speaker of your specs.

Next the box. The typical car subwoffer box is way and I mean way inadequately designed for high quality bass. The walls are to thin and underbraced. Square boxes are aften used but they have the worst sound because they emphisize one frequency.

There is a lot of vibrational energy wasted into the wood of the sub and if your box is designed like most commercial enclosures that you see in the shops it is inadequately built.

Stuffing the box with dacron will help somewhat because it will break up standing waves inside of the box and remove some of the boxy sound but the improvement is more often heard in the lower midrange where braking up the backwave improves mid bass and midrange clarity.

OK, next is the amplifiers. Car audio amps don't generally generate enough current to take a strong hold of the speaker. Remember that the magnetic field strength is determined by the amount of current that the amplifier puts out. There is a lot of marketing hype in this area to sell watts as if it is the only thing that matters. Unfortunately many manufacturers uses differing methods to rate the amps and they are often highly misleading.

You will also have people telling you out there that all amps sound the same and a watt is a watt. This is pure B.S. There are large, and I mean large differences in how amplifiers sound and how good of bass they have.

You may have insufficient current delivery to your amps by having too small a wire. Both power and ground need to be the same size and of the large size compared to the speaker cables.

Finally the car itself. If you try to put too much bass into your car it will have some tendency so sound boomy just because of the standing waves inside the car. The low bass frequencies are larger in length than your car is so the net result is many flase bass modes. This is a problem with all cars. It is better to size the subwoofers to the car and use powerfull amps and well designed boxes to get that strong tight natural sounding bass that you would like.

Hezz
  Reply With Quote
Old 28th August 2004, 06:22 AM   #26
diyAudio Member
 
Bill Fitzpatrick's Avatar
 
Join Date: Jun 2001
Location: Eugene, OR
I repeat. The sub needs to be in the car, not the trunk. Didn't anyone actually read his original post? He said he put the sub in the trunk.
  Reply With Quote
Old 28th August 2004, 06:03 PM   #27
diyAudio Member
 
Join Date: Dec 2002
Location: Utah
MEMITO,

Bill is right. Somehow I missed the most obvious thing. You cannot just put the sub box in your trunk and expect to get good sound. You will have to remove the back seats and create a large opening from the trunk to the passenger compartment. Otherwize you will need to mount the speakers so they fire into the passenger compartment.

Hezz
  Reply With Quote
Old 29th August 2004, 02:36 AM   #28
diyAudio Member
 
Paradise_Ice's Avatar
 
Join Date: Jun 2004
Location: cosmological consciousness
Yep i agree, the subwoofer will sound muffled, its like somebody trying to talk with there hands over there mouths, madness.
But when has that ever stopped anybody?
  Reply With Quote
Old 31st August 2004, 12:18 PM   #29
Hayden is offline Hayden  Australia
diyAudio Member
 
Join Date: Aug 2004
Location: Mackay Australia
Wouldn’t the trunk make it boomy? I think so
Or try a smaller sub with more power like 10 inch thunder 9500????
or maybe he like his sub?
  Reply With Quote
Old 3rd September 2004, 04:11 AM   #30
diyAudio Member
 
Join Date: Dec 2002
Location: Utah
The simplest why to check to see if the woofers are OK is just to put the box in the back seat for a while and listen.

If necessary the speakers might be mounted on the rear deck if it is large enough. Those speakers are designed to work in rather small boxes and a box can be built under the rear deck of the right size. This is some heavy modification so a lot of guys just put the sub in the back seat if it is not being used much.

There are other things you can do it just depends on how much work you want to do or money to spent and how important good sound is to you.

Hezz
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Boomy sound ruferto Everything Else 16 31st March 2009 08:42 PM
Help with loose & boomy 1st sub Marzen Subwoofers 10 28th July 2005 09:34 PM
Sounds boomy... Baki Car Audio 4 20th March 2005 05:21 PM
boomy box? r_s_dhar Multi-Way 5 10th November 2003 09:19 AM
Boomy TLs Ropie Multi-Way 5 19th July 2003 10:44 AM


New To Site? Need Help?

All times are GMT. The time now is 09:18 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2