twice my speakers

Archived from groups: rec.audio.pro (More info?)

I have a homemade enclosure with a 15" JBL D-130 (not my home - someone
else's).
I really like the sound of the 130 in that cab but it's got two
problems.

Firstly, playing bass through it I blew the speaker.

Secondly, it doesn't fit in my car (it's too deep to get through the
side door or to fit in the trunk).

It lasted a long while playing bass through it, but I thought I might
be better off with a 2x15 instead of a 1x15 in order to be a bit
gentler on the speaker.

So here's my question:

If I were to build a new cab with ports at the base the same size and
depth as the original and made the box twice the height, but half the
depth of the original (possibly with with added volume to account for
the space occupied by the 2nd speaker), would I have a cab that was
tuned the same but allowed enough baffleboard to install two speakers
(and as a fringe benifit, would be shallow enough to get through my car
door)?

Archived from groups: rec.audio.pro (More info?)

"apa" <tacoma57@hotmail.com> wrote in message
news:1127169226.754145.46320@f14g2000cwb.googlegroups.com...
>I have a homemade enclosure with a 15" JBL D-130 (not my home - someone
> else's).
> I really like the sound of the 130 in that cab but it's got two
> problems.
>
> Firstly, playing bass through it I blew the speaker.
>
> Secondly, it doesn't fit in my car (it's too deep to get through the
> side door or to fit in the trunk).
>
> It lasted a long while playing bass through it, but I thought I might
> be better off with a 2x15 instead of a 1x15 in order to be a bit
> gentler on the speaker.
>
> So here's my question:
>
> If I were to build a new cab with ports at the base the same size and
> depth as the original and made the box twice the height, but half the
> depth of the original (possibly with with added volume to account for
> the space occupied by the 2nd speaker), would I have a cab that was
> tuned the same but allowed enough baffleboard to install two speakers
> (and as a fringe benifit, would be shallow enough to get through my car
> door)?

If I understand your logic, you want to keep the overall box volume the
same, but install two drivers? If so, you will have to find speakers with
lower Vas requirements than the one you are replacing, otherwise you will
end up with a very messed up alignment. It will sound like those Neons
crammed with 1 kW amps and 8 15" subs (e.g. 150 Hz peak). If you want low
and extended bass, you will need to do a little homework to determine the
appropriate drivers for such a configuration.

Craig

Archived from groups: rec.audio.pro (More info?)

In article <1127169226.754145.46320@f14g2000cwb.googlegroups.com>, "apa" <tacoma57@hotmail.com> wrote:
>I have a homemade enclosure with a 15" JBL D-130 (not my home - someone
>else's).
>I really like the sound of the 130 in that cab but it's got two
>problems.
>
>Firstly, playing bass through it I blew the speaker.
>
>Secondly, it doesn't fit in my car (it's too deep to get through the
>side door or to fit in the trunk).
>
>It lasted a long while playing bass through it, but I thought I might
>be better off with a 2x15 instead of a 1x15 in order to be a bit
>gentler on the speaker.
>
>So here's my question:
>
>If I were to build a new cab with ports at the base the same size and
>depth as the original and made the box twice the height, but half the
>depth of the original (possibly with with added volume to account for
>the space occupied by the 2nd speaker), would I have a cab that was
>tuned the same but allowed enough baffleboard to install two speakers
>(and as a fringe benifit, would be shallow enough to get through my car
>door)?
>

Like the other comment, put the driver parameters into a program
to get real requirments. Solid state or tube? Putting two woofers in series
sort of makes them bulletproof with a solid state amp, and will play just as
loud. I would also consider making two cabinets to make it easier to move about.

greg

Archived from groups: rec.audio.pro (More info?)

apa wrote On 09/19/05 15:33,:
> I have a homemade enclosure with a 15" JBL D-130 (not my home - someone
> else's).
> I really like the sound of the 130 in that cab but it's got two
> problems.
>
> Firstly, playing bass through it I blew the speaker.
>
> Secondly, it doesn't fit in my car (it's too deep to get through the
> side door or to fit in the trunk).
>
> It lasted a long while playing bass through it, but I thought I might
> be better off with a 2x15 instead of a 1x15 in order to be a bit
> gentler on the speaker.
>
> So here's my question:
>
> If I were to build a new cab with ports at the base the same size and
> depth as the original and made the box twice the height, but half the
> depth of the original (possibly with with added volume to account for
> the space occupied by the 2nd speaker), would I have a cab that was
> tuned the same but allowed enough baffleboard to install two speakers
> (and as a fringe benifit, would be shallow enough to get through my car
> door)?
>

One thing you need to consider with the JBL D-130 (and the K-130 as well) is that this speaker is an
"extended range" speaker, not a "true" bass speaker for Bass guitar. Yes, you can use it for Bass,
obviously, but the characteristics of the speaker are different than with the D/K-140 bass speakers.

The rule of thumb, without all the math, used to be 3 cubic feet for a 15 inch speaker, if memory
serves. With a port, you can drop that to around 2 cubic feet or so, but the port has to be tuned.
Not impossible, but time consuming. As you may know, a port allows you to use less internal volume.
But that only goes so far; you can make the cabinet too small, internally, and screw everything up.

You also might wish to consider the less stressful route and think about buying a used Sunn or Eden
type 2-15 cabinet and save yourself the hassle, and you'll get a well built plywood (not mdf)
cabinet, maybe even with casters.

--fletch