Questions about Crossover for the new woofer driver

[S.C]

Hi guys, me again ! I had followed the advise you guys gave me in my last thread I want to install a new woofer driver into my old broken speaker.. It was really helpful. Then I ordered this Dayton http://www.partsexpress.com/pe/showd..._ID=7769&DID=7 and installed it into the box. I was satisfied with the sound at the first time. However, I realized that the bass seems weak, even in rap, dance music later on.
Now I am planning to make a new crossover for this speaker to improve the sound. I need your help! I searched the froum with "crossover", but I still got no clue what designs are out there, or what is good for my speaker. Also, I want to make it cheap enough for me to afford.
A feature in the old speaker also bothering me to choose what crossover I'm gonna make. It is a control of tune or something, i don't know. When I turn it to minimum, the speaker's tweaker will close to no sound. When I turn it to maximum, the tweaker will sound clear, and the high-range will be detailed. However, the bass is the same old sound. Will I be able to find a design which will allow me to use that control for tune....?

[MazzPotential]

Hi S.C.

Can you be more clear in defining the sound you're looking for?
If i understand you correct you what to enhance your sound by re-designing the old filter.
Personally i thing this is way too complex to perform based on communication thru this forum. It takes fundemental knowledge of analog filtering and you need measuring equipment. I.C. painfull hard work!!!!!
The control you're describing is, what i think, a L-pad. Nothing more than two resisters connected in a specific pattern. I allows you to alter the sensibillity of the tweeter. Thus not altering the sound spectrum it self. You are correct in you're observation that it does not effect the woofer.
Anyway....
I am not familiar with you speaker set? By reading the previous thread, the size of your woofer is that of a moderate speaker. If your hunger for more " low-kick" is unstoppable i thing you should consider a sub-woofer driver by a sub-amplifier. This allows you the much wanted "control" . Sensibillity, cut-off frequency, gain, bass-boost, etc. All the control at your fingertips.

Hang in there,

Mazz

[Bull]

Yep I know why you don't have the bass your looking for because it's a 6 and 1/2 inch.That size of driver doesn't accurately reproduce bass notes and can't do sub bass below 80hz at all well.
18 inch,15 inch,12 inch all good to reproduce sub bass.
10 inch,8 inch reproduces mid bass well
6 1/2 inch reproduces low mid well
5 1/4 inch,4 inch,3 inch reproduces mid well

As you have the boxes already you could either try and find a 6 1/2 inch with a longer throw cone[bigger x max] to give better bass.Or build a subwoofer using a 12 inch or 15 inch driver driven by a seperate amp or monoblock power amp if you have the money.

You can also try other tweaks to get beefier bass using your current speaker [with the 6 and 1/2 inch].
Mount the speakers on solid metal stands and put 4 spikes under each speaker,buy thick speaker cable 12 gauge or 14 gauge,and also upgrade the internal speaker wire inside the cabinet to 14 gauge for the bass[to improve the bass].
Upgrading the crossover to an 12db octave or 18db octave for the bass will help through because the less upper midrange you put through the 6 1/2 incher the cleaner the bass will sound without all that 1khz-5khz nasty harshness.

Hope this is helpfull

[S.C]

Oh oh, I remember what my cousin told me that my woofer produce high range too, which is not good for the woofer drive. We tried to connect my GC to the speaker, then connect a 15in drive to the woofer link. I found out the 15in not producing entirely bass, but high range too. First, I want the woofer don't reproduce high range frequency. Sound, I want to make it more blance. It just don't get enough kick like my civic stock woofer does. what's wrong with it?

[S.C]

Originally posted by Bull
Upgrading the crossover to an 12db octave or 18db octave for the bass will help through because the less upper midrange you put through the 6 1/2 incher the cleaner the bass will sound without all that 1khz-5khz nasty harshness.

I think that is what I wanted to do, but how to make a crossover? Should I buy it, or make a simple one?

[Bose(o)]

Ummm, SC, I think you are very confused...I know I am. Your current speakers are Supposed to reproduce the spectrum as a full-range attack. This is why your 6.5" driver produces some of the "high-range" which is actually mid-range probably up to 2khz.-3khz. at a playable level. The tweeter is in charge of everything above this point. All drivers, including woofers with 4th order LR low-pass filters on them will produce higher frequencies. Just not at a loud enough level for you to perceive these sounds when another speaker, suitable for sounds above the xo point is playing.

[S.C]

Oh......., if I'm right, there are no ways to reduce the "mid-range" in my woofer drive. Unless I give up the mid-range entirly, and the music will become unnatural. So is it true that mid-range will damage the woofer drive like my cousin said for time? However, will I get improvement if I upgrade the crossover like what Bull said? Is it why 2 way speaker bad because they can't really handle "mid-range" ?

[MazzPotential]

First I'll try to answer you questions.

Will I get improvement if I upgrade the crossover like what Bull said?

Let me try to explain this:
The loudspeaker you have is designed "as is". Every component is there for a reason. The bass/mid and the high range driver have a specific frequency pattern related to it's sensibillity/sound level.

(Keep in mind that you can "add" sound. Simular like you can add voltages. e.g. 5[vdc] + 5 [vdc] = 10 [vdc]. The only difference is that sound does not have a linear relationschip. You add sound on a log-scale. e.g. 80 [db] + 80 [db] is NOT 160 [db] but some what like 83/86 [db]. There are calculation rules for this.)

If you combine a bass-speaker (Like fig 1) and a high range (like fig 2) without a filter you most likelly get a sensibillity graph like fig 3. The bass/mid will overlap the high range.

In words. There is a certain overlap in frequency range which will give you a to high sound volume within that range.
If you want to alter this delicate balance you have two ways in doing so.
1) By ear
2) by calculation and ear.

1) You can alter the components on the filter or install a complete new one. By judging your ear you can tell if you were lucky or not.
This trail and error method is only stuff for professional trained ears. If you succeed, within 5 tries, in doing so then consider ya self the most luckiest man on earth. Probably you'll be switching components till you're 80yrs old.
2) By calculation and ear. You need specific speaker parameters. Called Thiele/Small parameters. With these parameters you can calculate fairly closely to te wanted result. Some fine tuning based on listening sessions will result in a perfect balance.

I hope you haven't lost track here because this is just the beginning. Till now we've only shed light on the frequency response topic. If you alter the filter components you will not only alter the frequency response but the timing and phase will alter accordingly. Explenation.........maybe another time.

Anyway, all the more rason NOT to mess with the filter (Atleast if you're interrested in quality sound).

Is it why 2 way speaker bad because they can't really handle "mid-range" ?

You're speaker should handle mid-range just as good as bass or high frequency sounds. Since you have a moderate size speaker, playing at loud volumes you bass will probably cannot keep up with the mid and high range sound. At low sound level it should play good.
We could start a discussion on the choice for 2-way, 3-way or more.... But that won't anwser yopu question within this time and space.

To me you have three choices:
1) Shred the current speakers and build new ones.
From a DIY standpoint:
2) Try to take the midrange laod away from the bass by adding a mid-range speaker and a new 3-way filter......or
3) Try to take away the ultra-low and low bass away form the bass/midrange by turning your bass/mid-range a more full midrange. Then add a sub-woofer.

Hope not to confused you too much????

Greatings, Mazz


PS : If you have questions just keep asking.

There cannot be a stupid question, just a stupid answer......

[Bose(o)]

For my loudpseakers, I added a capacitor (albeit a large one) to block out the lower frequencies and added in a woofer. Now, I'm adding a sub-woofer, but will not block-out subssonic sounds from the woofer as I will need an active xo to keep things realistic. The non-linear and linear distortions decreased rapidly and could play much louder than before.

There's no such thing as a stupid question {edit}, just stupid people.

[S.C]

Thx Mazzpotential, Your statement make me clear a lot now. I think I just gonna change some wire only, but not changing anything in the filter. I think Mid-range for this speaker is a waste of money. I think I will save some money for a sub instead. I think I need one more GC mono block........ or amp for sub.....