Altec 806a, 880b Utah 12" Seeburg DWS-2 mod questions

[streetwise]

I just bought a pair of Seeburg DWS-2 speakers and would like to rebuild or replace the old crossovers. My likes and dislikes currently the speakers have a very nice revealing mid range more impressive mid range than any speaker ive heard so far. When i use eq through my pc I pump up everything below 155hz because I don't here much bass unless my fisher 400 is about at 12o'clock on the volume dial. Also bump everything up at 10k plus from what ive read the horn drops off at that point. So what im seeing is the bass is shy unless eq'ed the horn in the midrange is over powering when I raise the volume to 12'oclock anything below the midrange is pretty well balanced. And the HF is very dropped off partially because of the design of the fisher 400 cuts off in the HF. Any ideas to get better performance out of these from the crossover or other modifications? Just a recap, redesign, modification... im all ears thank you

[gdmoore28]

Good description of the sound of those Seeburg speakers - and exactly the sound one would expect from that configuration. The answer to your question currently resides in the "fresh" part of my brain simply because I'm doing a build using the Altec 416Z woofers, 511B horns, and 802D drivers, and I've saved some articles that relate to your question. There are two directions you can go to smooth the frequency response:

- Active processing. Not as expensive or as complicated as it used to be. For example, you can pick up the Behringer DEQ2496 processor for $299 and its reference mic, the ECM8000, for $59. Forgive me if you already know how this works, but with this combination processor/microphone you can run a real-time analysis (RTA) of your speakers' frequency response (graphically displayed in "real time" on the head unit's front panel display). Once you tell the DEQ2496 what kind of frequency curve you want to hear from your speakers, the unit will automatically equalize the speakers as close to that curve as is possible.

If you go this route, simply use the stock crossover, but be sure to replace the capacitors, as they are too old to be dependable now. Be aware, too, that you will need to patch the DEQ2496 between your pre-amp and power amp. If you are using a receiver for power, be sure you have either a "pre-out/power in" connection, or at least a tape loop. If you use separates, there will be no problem inserting between the pre-amp and the power amp.

- Passive crossover with CD compensation. Too much to go into here, but here are the places to start:

http://www.audioheritage.org/vbulletin/showthread.php?14690-Look-at-my-new-babies-Altec-846Bs-w-EV-Tweeters!&highlight=babies

http://wajonaudio.webs.com/Voice%20of%20the%20theatre.pdf

Hope this is of some help to you. Keep us updated on your progress.

GeeDeeEmm

[streetwise]

Thanks for the reply I read the article from the 90s im guessing very interesting stuff there. I just opened up the speakers to do some tightening up of all the old bolts and check for any air leaks. I verified the drivers are 806A s. I took out the bug screens in both and can certainly hear an extension in the highs. cymbals are much more upfront now. also by putting in some winterizing compression tape around the back were the chipboard rear panel mounts has helped the bass direct itself forward much better along with the tightening of the drivers. The main issue with the bass is the size of the cabinets as far as I can tell the woofers just cant reach the sensitivity of the horns. also the crossovers are super simple and probably don't even come close to the quality of an original altec crossover. there are two inductors that I have no idea of the values, 2 caps 25mf 25vac, 7mf 25vnp and one 15U resistor. Most likely upgrading things to a Zilch Z19 crossover will be my next step.

My long term plan with these will be to find a reasonably priced pair of 515Bs and build a aesthetically appealing 825 or 828 cabinet to have a pair of A7s. The DWS-2 look nice even though the outsides are formica. from the A7 Il keep an eye out for 1505 horns to upgrade toward an A5 style speaker but thats long term plans. There will be alot of small upgrades in between.