Sub Woes

[philwsailz]

Hah hah hah....

Sometimes things just defy us, and the EUREKA moment comes for no apparent reason.
Glad you are finding some progress and encouragement!

Say, silly question from me. the amp or amp section you are using to drive the sub... You have the crossover set to LO-PASS, and all that other stuff we normally do for a sub amp right?
We had never asked, but we should ask the questions just to make sure that your electronics are configured properly to run the low-end of the system..

Congrats! Follow up and keep us posted as you get it going better!

Phil

[chpthril]

Hah hah hah....

Sometimes things just defy us, and the EUREKA moment comes for no apparent reason.
Glad you are finding some progress and encouragement!

Say, silly question from me. the amp or amp section you are using to drive the sub... You have the crossover set to LO-PASS, and all that other stuff we normally do for a sub amp right?
We had never asked, but we should ask the questions just to make sure that your electronics are configured properly to run the low-end of the system..

Congrats! Follow up and keep us posted as you get it going better!

Phil

I believe he has answered "yes" to this, but I also wanted to make double sure because the Cadence amp he is using, all though it is a 1 chnl/mono, it does have Hi and Low pass on it. This would certainly cause the very symptom.

[tige']

Yes, it is in Lo-Pass.

If I want to hook up 2 subs to this (just to see what I get). They would both be 4 ohm speakers. How do I wire them. Do I just run another set of speaker wires from the first sub to the second, keeping the + & - on the correct terminals?

Also, I am think of adding an EQ now. Any input on these? I have seen a Soundstream and a Clarion EQ that weren't too out of line price wise. Or, there is also the WS420 but that might be more than I need. (Though the mic would be nice so I could yell at the kids!!)

Thanks!!

[chpthril]

Yes, 2 4ohm subs wire in parallel (+to+, -to-) will net you a 2ohm load on the amp and give you and output of 700W, 350W to each sub.

In addition to those EQ, Kicker has 3.......the KQ30, KQ9, and KQ5. They are great for expanding the tining for ones listening preference, but also boost the H/U's line voltage to the amps.

http://kicker.com/equalizers

[tige']

My amp manual states that the input level adjustment range is 150 mV to 5 Volt.

If the EQ has a 7 volt or more output voltage will it still work OK?

[chpthril]

Most EQ have an adjustable line level input so you can set it to match what the amp accepts. The voltage listed would be the max output.

[philwsailz]

The KQ5 is goig to be the friendliest to use. It is a half-din unit that can be mounted thru or below the helm.

[tige']

OK, time for an update....

After spending a BUNCH of time with this sub and getting it to sound the best I could, I had my wife get in the boat and listen to it. She didn't like the sound of it either (and this was after everything I tried but the EQ - which is on hold for now).

I mounted it in a different place, even went and bought the same exact sub to see how it would sound (and it was the same), then I bought an Infinity car sub (1052 I think) just to compare. It sounded better then the Alpine and gave me some hope that I wasn't just imagining what a sub should sound like.

After all this, my wife told me to quit screwing around and go buy a new sub - gotta love that woman!

So, I decided to get the sound I wanted I needed to go to a 12" sub and built a better enclosure (which is what everyone was telling me all along). I ordered a 12" Wetsounds sub (sorry Phil and Mike). I ripped everything out that I had done (and ruined my trick carpet idea in the process, oh well)

I built an airtight glued and screwed MDF enclosure then gave it three coats of resin on the outside and 2 on the inside. (can't find 13 ply marine grade wood locally)

Mounted the sub in there yesterday and I finally got the sound I was looking for!! This thing sounds great - but we're not done yet....

I mounted a speaker terminal block on the side of the enclosure and while I was playing with the settings I removed it to see what it would do. I think it sounds better with it off - which I guess means this would sound better if I added a port.

So - more questions...(I attached a new pic for reference, I added a Polk Audio grill to help protect it)

With my triangular shaped box, I am not sure where the best place is for the port. It would have to go on the front or side.

If it goes on the front it would have to go to the top on the right or left of the speaker because there is no depth at the bottom. They recommend a 3" hole but I don't think I have room for a 3" hole, maybe 2 1/2" - 2 3/4" or something like that..

On the side it could go almost anywhere in front of the terminal box but it is supposed to be 9" deep and I am not sure how far in I can go before I hit the speaker. I marked where I was thinking but I have no idea what would be best.

Any tips or recommendations?

Thanks guys!!

[tige']

I just remembered from Phil's vented enclosure thread about being able to use pvc and angled fittings. I may be able to come out of the front bottom and angle up with a 45 degree fitting??

I am still open for other suggestions or tips (maybe slotted) and the best location.

Thanks again - I am soooo close!!

[chpthril]

I mounted a speaker terminal block on the side of the enclosure and while I was playing with the settings I removed it to see what it would do. I think it sounds better with it off - which I guess means this would sound better if I added a port.

What sounds better with what unplugged?

[tige']

Sorry for the confusion, I could have worded that better!!

When I take the four screws out of the speaker connection block and pull it out the sub enclosure (leaving a hole in the box) it sounds better than when I have it screwed in and the enclosure is air tight.

The bass is deeper, louder and richer with it out.

[rushin]

I would like to hear about this as well, the vented enclosure is supposed to be bigger volume wise........and the port bigger..............

Did you have to do any modification to the polk grill for it to fit? How does it fit?

off to e-bay...

[wetsounds1]

I responded to your email this morning but figured I would post here to help others out. I would recommend against porting it now. The enclosure is a bit small based on the specs we have for a ported enclosure.

So really to port a box, you want to build it from the beginning as a ported box.

What happened when you pulled the terminal cup is it opened a vent. Not tuned to anything so no telling what freq was peaked but sounds like you had a freq peak and get louder at that freq. This would be a one note wonder situation. Which is what happens on poorly built ported boxes. The type that are not tuned properly, will boost a particular freq. So they sound louder. BUT, only at that freq.

This is true to many of the pre fab ported boxes. Many are tuned with at about 55 HZ. So compared to a sealed, they "sound" louder in that 55 HZ range. Which gives the perception of louder, when in reality, it is just that one note and to get that note louder, you lose sound quality

So you did not gain any volume, just that freq. And overall, you would lose accuracy and musicality of the woofer. Now you have deep and tight and clean. If not built to be ported and you add a port, it could result in disaster. And sound a lot worse.

I really think that keeping it sealed and the tuning you can do with the head unit or an eq later will get you what you want.

Tim
Wet Sounds

[tige']

The Polk Audio grill fit like it was made for it. It screwed right on, the only think is that it doesn't go clear to the back of the speaker, maybe 3/16" away but you can only see it if you look at it from the side.

Thanks Tim, I got your e-mail. I just need to convince myself of this....

I will play with the speaker some more but I would swear it sounded better and at a wide range of frequencies. I even tried different music and different sources.

I need to get some other people in the boat and get their opinon. Maybe it is just in my head??

[philwsailz]

I totally agree with Tim.

A simple hole is not an effective port, and usually causes severe power handling problems below fb, (box resonant frequency) as well as tons of noise.

Go sealed.