LaScala with Altec woofer

[bluesboy]

Soundwise,what would be the advantages or disadvantages of a Altec 416 8-A woofer in a LaScala bass bin vs. the stock K-33? I know that the bass bin has to be modified to accept the larger frame of the Altec woofer.

[Duke Spinner]

i wouldn't view that as a good match

[Guest " "]

The below link has some data for the 416. Does'nt indicate the spl sensitivity.

http://alteclansingunofficial.nlenet.net/Thiele-Small.html

If your using an AA network, one problem you will have is the shift in xover frequency of the woofer due to the inpediance change. An impediance change from 4 to 8 ohms, will shift the xover point of the woofer form 400hz to 800hz.

If your using an AL or AL-3 network, in stead of a crossover frequency shift, you would get a significant dip from 400hz to 800hz as a result of the higher order cap used between the woofer inductor and the woofer.

[bluesboy]

Thanks for the input. The reason I'm asking is I built a pair of LaScalas for Tarheel a year ago with 416s and we've always been satisfied with the bass responce. Tarheel was thinking about upgrading from the K-400 horn and was told he was using the wrong woofers. I could switch them out with K-33s.

[colterphoto1]

yup, dese guys is right- that'd be the thang to do

[Tarheel]

These are my lascalas were talking about so I have a couple of questions. Has anyone heard this combination before (416 8A) with the other components being stock lascala parts? What is the audible effect or what am I missing by not using the K-33s? Please speak in laymans terms since I probably won't know what you are talking about if you don't.

I welcome all imput prior to doing invasive surgery on these 1 year old speakers. Al are you out there?

Chuck

[colterphoto1]

as mentioned before the K33 is a 4 ohm woofer and the Altec 8 ohms. Right away you might expect 3 db or so difference in output with the Altec being on the short side. Then that also affects the way any crossover network intended to see the load of the K33 would react, so the crossover point would shift.

Overall, probably noticably less bass than a stock LS. That is without hearing the setup, just by the numbers.

M

[bluesboy]

as mentioned before the K33 is a 4 ohm woofer and the Altec 8 ohms. Right away you might expect 3 db or so difference in output with the Altec being on the short side. Then that also affects the way any crossover network intended to see the load of the K33 would react, so the crossover point would shift.

Overall, probably noticably less bass than a stock LS. That is without hearing the setup, just by the numbers.

M

What kills me is that Chuck and I have had discussions in the past about people on this forum posting that LaScalas are somewhat lacking in bass compaired to say a Cornwall. After listening to these speakers for the past year the last thing I would have expected would be that they were lacking in the bass department. If anything I felt that the K-400 midrange and stock crossover networks could stand some upgrades. Go figure. I wish one you guys lived closer by so I could get another opinion.

[seti]

as mentioned before the K33 is a 4 ohm woofer and the Altec 8 ohms. Right away you might expect 3 db or so difference in output with the Altec being on the short side. Then that also affects the way any crossover network intended to see the load of the K33 would react, so the crossover point would shift.

Overall, probably noticably less bass than a stock LS. That is without hearing the setup, just by the numbers.

M

What kills me is that Chuck and I have had discussions in the past about people on this forum posting that LaScalas are somewhat lacking in bass compaired to say a Cornwall. After listening to these speakers for the past year the last thing I would have expected would be that they were lacking in the bass department. If anything I felt that the K-400 midrange and stock crossover networks could stand some upgrades. Go figure. I wish one you guys lived closer by so I could get another opinion.

People say the same thing about the Belle's. I just love the folded bass horn sound. They might not go as low as the cornwall or khorn but they sound great. You should hear the new La Scalas because they sound incredible. I wouldn't have guessed 1inch mdf would have made that big of a difference but it did. I still want KHorns though : ) always have.

[D-MAN]

That would be a waste of a fine horn driver. The LS has too small of a back chamber for that particular driver, and will raise its FS.

So my advice is, go ahead as long as it is a turn-key operation.

If you have to hack, definitely NOT!

[bluesboy]

That would be a waste of a fine horn driver. The LS has too small of a back chamber for that particular driver, and will raise its FS.

So my advice is, go ahead as long as it is a turn-key operation.

If you have to hack, definitely NOT!

D-Man

The 416s are already in the LaScalas. Theyv'e been that way since I built them a year ago. The question remains; will we get signifcantly better sound quality switching from the 416s to K-33s?

[Tarheel]

Hacking is the last thing I want but you guys all seem to agree that I have the wrong woofer. Here I was thinking that my midrange sounded a bit harsh and looking into ALK universals and/or trachorns. I guess my tweeter and cabinets are okay! It sure gets expensive paying for mistakes.

If I decide to live with the Altec how will that effect the Alk x-overs?

Thanks to all who responded. I value your opinions.

Chuck

[colterphoto1]

if you are saying that you think your speakers sound too mid-y, ie too much midrange in relation to the bass output, that might very well be cured by the change to the K33. Despite all the mods away from the K400/K55 mid section, it's still a very solid, very smooth, well voiced performer imho.

so if the BALANCE of lows to mids is off, I'd say the woofer change-out would be in order. If there is something inherent in the QUALITY of the mids you don't care for, then by all means, experiment with mid horns and drivers. But for pete's sake, do it ONE at a time, to ONE speaker at a time, so you can A/B the changes.

I'm not fluent enough in xover-speak to help you with that one.

[Tarheel]

Bluesboy has a set of k-33s....Maybe we can try one and do a comparison as you suggest. The harshness that I am referring to is not a matter of balance but more like I have heard it described before....a ringing. Maybe sound deadner on the horn would help if I have room to get in that section. I talked with ALK yesterday and he suggested I may want to try the trachorn before I change x-overs. I think I would have to enlarge the opening. There are so many modifications now it is overwhelming, Better tweeters, trachorns, crossovers, 1 inch mdf. All in the quest for better sound.

Thanks for your caution and I will proceed slowly.

[Guest " "]

"If I decide to live with the Altec how will that effect the Alk x-overs?"

If you think you are going to use an 8 ohm driver with one of al's xovers you should discuss with him if a componet value adjustment can be made for you. I would be easier to do with a gentle slope xover like the universal upgrade and might get complicated on the extreme slope xover.

Alternatively, you can use a large autoformer (about 50 bucks each) to change the impediance from 8 to 4 ohms, but lowering impediance via an autoformer usally decreases the SPL sensitivity by the insertion loss of the autoformer being considered. A 150 watt autoformer usally has an insertion loss of .6 db

[cjgeraci]

Tarheel:

If I read some of your comments correctly (and some of Bluesboy's comments), it appears as though your thoughts of switching to K-33s may be motivated by a desire (or curiosity) to have the right woofers in there as opposed to any curing any dissatisfaction with your current bass response. Having owned Belles (with Trachorns, ALK Universals) and also Altec Valencias (with 806As - abeit in a non-horn application), I agree with Al and would pluck down the money to solve the midhorn once and for all - by going with Trachorns before I went the crossover route. Don't get me wrong, Al's ALK Universal is a great crossover, but the Trachorn gives you much more bang for the buck in the upgrade dept. Plus, with the superior squawker, you can get by with running a much less sophisticated crossover (i.e. OEM). Yes, the Altec is a bit of a mismatch for your bass bin, but if it currently works well enough I would not cut on 'em (I am also a fan of the 806As anyway). After Trachorns, if you are so inclined, slap a pair of Bob's tweeters in them (or keep the K77s)....... If you decide that your upper end is too high at that point (or bottom end is too down spl-wise), you could cross that bridge with K33 replacement or ALK's universals.

Just a thought.....

Carl.

[Tarheel]

Tarheel:

If I read some of your comments correctly (and some of Bluesboy's comments), it appears as though your thoughts of switching to K-33s may be motivated by a desire (or curiosity) to have the right woofers in there as opposed to any curing any dissatisfaction with your current bass response. Having owned Belles (with Trachorns, ALK Universals) and also Altec Valencias (with 806As - abeit in a non-horn application), I agree with Al and would pluck down the money to solve the midhorn once and for all - by going with Trachorns before I went the crossover route. Don't get me wrong, Al's ALK Universal is a great crossover, but the Trachorn gives you much more bang for the buck in the upgrade dept. Plus, with the superior squawker, you can get by with running a much less sophisticated crossover (i.e. OEM). Yes, the Altec is a bit of a mismatch for your bass bin, but if it currently works well enough I would not cut on 'em (I am also a fan of the 806As anyway). After Trachorns, if you are so inclined, slap a pair of Bob's tweeters in them (or keep the K77s)....... If you decide that your upper end is too high at that point (or bottom end is too down spl-wise), you could cross that bridge with K33 replacement or ALK's universals.

Just a thought.....

Carl.

Thanks Carl,,,,that sounds like good advice. Bluesboy at this point wants to pull the Altecs out just out of curiosity. He doesn't think the difference in woofers/bass will be significant. My speakers are wedged in pretty tight in the corners and I really don't know if I want to wrestle them out and remove the bottom hatch, remove the solder to the leads, change out the woofers, reassemble, put them back in place just to find little difference. I may opt for the trachorns or wait to build another set with 1inch mdf, trachorns, k-33s, better tweeters.

Chuck

[Duke Spinner]

. He doesn't think the difference in woofers/bass will be significant.

Chuck

I'd have to think, just moving the crossover point back to 400 hz ...

is gonna be real significant