423's as low bass speakers?

Hi Guys,
Happened into some old Altec 1204's that have slightly tired cabs but are
all there. Of course the 808 symbiotics were blown!
My question is, these are equipped with 423 bass speakers, and
I was wondering if these could be put into some sort of small bass reflex
cab to augment normal PA type work? Not metal or extreme volume
rock. I have a set of Ev SX 200 cabs for upper bass and hi's but they
could use some low bass help. Again, this is mostly for easy listening
background music etc. Or should I just try to sell them off and get
a dedicated subwoofer.
I am looking for a more hi fi sound, not ear bleed concert level playback.
Any suggestions for cab size and design would be appreciated also.
thanks again,
scott in nc

The 423 is basically an OEM 421

I'm thinking OG is saying no they aren't good for low bass. My 421's have trouble doing 50 Hz.

The 421 isn't a bad speaker, but it's mid bass not a sub.

I was just trying to provide a starting point for a forum search, I think we've discussed 421's a number of times. Way more than I could repeat in one post.

Quote:

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Originally Posted by Cal Weldon

I'm thinking OG is saying no they aren't good for low bass. My 421's have trouble doing 50 Hz.

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It just needs a large TQWT to load it down to Fs.

GM

Hi guys,
thanks for your responses.In listening my ears were telling me they weren't cut
out for hi-fi low bass [and I mean that in a sound reinforcement setting].
They just look like nice speakers and I wanted to see if anyone had any luck
with them in a smaller tuned box. GM, could you please translate TQWT?
That one escaped me!
Sounds like I should send them off to auction. My bass guitars are already
covered with an SWR cab.
Last question, would they do alright in old Yamaha 4115 cabs? My church
has a couple that have questionable drivers in them. Maybe I should donate them.
Any thoughts, and thanks again for your response. You all may have save me
a fair amount of "waste of time" trial and error!
regards,
scott in nc

You're welcome!

TQWT = tapered quarter wave tube that is big at the closed end where the driver is and tapers down to the terminus (mouth/vent opening), i.e. the inverse of a horn, though due to its mass loading it doesn't need to be nearly as long/large as a horn, so of course it doesn't have as much acoustic gain.

Anyway, for even a modest PA 'sub' app it probably won't be enough, but 421-8H loaded folded TQWTs pounded pretty good 'spinning vinyl' in a long gone neighbor's ~16 x 36 ft basement room, though DSOTM and a few others sustained 'low' notes tasked them to the max, requiring adding some serious isolation measures for the TT to keep the room modes from modulating the stylus. Don't know about the Yammie, but as a general rule, MI drivers are designed with an eye towards interchangeability with other brands, so will probably work OK in them.

GM

Wold not the tube have many of the phase issues of the rear loaded horn? Seems so anywhoo. The bass from a 4 ft tube would be 4 ms behind?

Of course in this case, separate driver so correctable with many newer active xovers.

No, being the inverse of a horn, it's delay is limited to its 3rd harmonic dip which is acoustically 1 WL away from its tuning (Fp), so in the case of a 25 Hz tuning this puts the notch around 100 Hz or a ~ -0.8 ms and once damped would have as little as near zero delay, putting them ~ on a par with an infinite baffle (IB) except in a whole lot less bulk.

GM