Trying to figure out how to get this less boomy...

[Nazo]

Ok, so I started from a Klipsch Promedia 2.1 system -- though the only recognizable components are the control module and the amplifier (which isn't even visible normally.) I've changed the mid-range drivers among numerous other things such that it's no longer really even the same system. I'm extremely happy with the mids and highs from the system now, but I'm still having trouble with the lows. In particular, I'm sick of getting boomy sound and want a relatively flat bass response for music listening (I could not care less if it sounds bad by some people's standards in movies or something, music is the key here. For that matter, I don't really even watch movies anymore...)

The first thing I did was to try to switch to a properly sealed enclosure. I built a new box using 3/4" MDF. At the time I had no idea really about all of this, so I started out with an enclosure that would have the same internal volume as the original (but then the original was vented, so this perhaps wasn't the brightest idea.) This did seem to help a bit though as the original sound was just awful. I next tried getting a different driver. Due to rather severe budget limitations I decided to try the Dayton Audio DC160S-8 6.5" driver. It does appear to be better than the original at least, but still a bit boomy in some things with a lot of a bass guitar or certain drums.

[AndrewT]

download the freeware WINisd pro.
Look at what a sealed Qbox=0.7 response looks like.
Now compare your drivers and enclosures to the Q=0.7 response.

If your Q>0.7, then that will give bass emphasis to a narrow range of bass frequencies.
The higher the Q the worse this problem gets. Many manufacturers design in a high Q to give bass emphasis instead of bass extension. They are terrible to listen to.

Q<0.7 can sound a bit bass light, (the response rolls off very gently and early).
I was advised to look for a vented enclosure tuning that very roughly copied a Bessel function (Q~0.5). This when in room produced deep strong bass and did not sound light at all. More importantly, it did not have bass boom, nor one note bass, nor that male voice with bass emphasis.

[bjorno]

Originally Posted by Nazo

..I decided to try the Dayton Audio DC160S-8 6.5" driver. It does appear to be better than the original at least, but still a bit boomy..

Hi,

Here is an enclosure that would harness BW extension and SQ thats not boomy:

b

PS: An example on how to build:

Collaborative Tapped horn project - Page 249 - diyAudio

[richie00boy]

I reckon the boominess is not a lot to do with the box, but to do with the crossover.

[Rademakers]

I was thinking; the room.

Regards Johan

[Cal Weldon]

First things first. Pack the box full of insulation and try it again. If you use fiberglass or rock wool it doesn't hurt to have a piece of cheesecloth or an old pillow slip to cover the back of the driver first. Also, your .1 amplifier likely has a bass boost feature that you might want to override if the insulation trick doesn't work. This may require help from someone with a schematic and a little experience.

[Nazo]

Perhaps I described it wrong. I'm referring to the way that at times when there's a lot of bass it sort of distorts. Usually it's only really excessive things like videos with explosions or etc and even then usually they have to go too far. Very rarely does it happen in music, but, needless to say, it's quite annoying when it does. It is true that the original system did it too though, and it was vented, so I'm not entirely sure whether or not this is the solution. In the end, the problem may just be that the driver itself really isn't all that great for real bass since it is, after all, a mere 6.5" driver. Well, clipping isn't the best word. It's not actually clipping like being driven too far to the point of threatening to tear up so much as it just distorts. (I'm not really sure how else to describe it though as "just distorts" isn't really a very good description.)

Most importantly though, I've a bit of a budget problem atm. Namely, I don't really have much to spare at all. That means I can't really buy enclosures or that sort of thing unless they're pretty cheap (read crap.) I'd be getting something that's not even MDF probably. Anything I do beyond something really cheap (such as the vent pipes which really aren't all that much even on Parts-Express) is probably going to have to be done myself. However, I don't think I can build another enclosure at this point (not only am I out of wood -- though I can get more if I need to -- it ends up requiring quite a lot of time to actually do and atm I don't think I have that kind of time.) I can build another enclosure if it is just absolutely necessary, but in other words I'd rather find a way to make this current one (which really should already be more than it needs) work if at all possible. (And for the record btw, I still have the old smaller enclosure that I built to have roughly the same internal volume as the original except being made of MDF versus that being LDF and being a sealed enclosure versus that being vented if it would work any better or anything, but it is rather small compared to what I have now.)

Oh, and no, it's not the room. Just how bad would your room have to be that it would actually affect the subwoofer driver itself?

Originally Posted by Cal Weldon

First things first. Pack the box full of insulation and try it again.

Sorry, I know I tend to post very long posts. I did say that I have filled it with fiberglass. The walls of the enclosure are also lined with 1" Sonic Barrier.

Also, your .1 amplifier likely has a bass boost feature that you might want to override if the insulation trick doesn't work. This may require help from someone with a schematic and a little experience.

And who might that be? Lol. Does it have such a "feature" though? It seems to me like there's no need for a bass boost when you have an actual subwoofer level control right on the main module. If you want more bass you just turn it up, right? Regardless, I don't know of anyone who could provide such details. I do wonder about this though as it could perhaps explain the issue.

[dave_gerecke]

I can't give any details to help you in your quest, but I can give you a link to a site that has the schematics for the electronics of the Klipsch Promedia.

Klipsch Promedia V2.1 Amplifier Repair

Peace,

Dave

[Cal Weldon]

Thank you for the update. Problem is simple. Amp too small, woofer too small, volume knob too big.

[AndrewT]

Originally Posted by Nazo

Perhaps.............the driver itself really isn't all that great for real bass since it is, after all, a mere 6.5" driver. ............

a 6.5inch driver is used by some as a midrange driver.
Four 6.5inch drivers might make a fairly good bass speaker for domestic use, but not down to sub bass.