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La scala mid driver


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16 hours ago, mark1101 said:

 

Yes, many prefer the stock horns.

 

My setup with the Fastracs and ALKs not only reduce the mid horn but also reduces the tweeter.  You forgot that part.   The result is a lascala with a nice balanced top end but that actually sounds like it makes some bass.  :smile:

  On a set of LSI's I rebuilt recently decided that while the K-55-V soldered lug helped the big change was the tweeter and making the side walls on the horn bin 1" Baltic. Stuck one of my larger MAHL tweeters on a rebuilt motorboard and it was still to shrill. However when an L-Pad was added to the tweeter it changed the whole ball game. Seriously thinking of adding an L-Pad to every La Scala rebuild from now on. Between the heavier side walls and the rest of it you are right about bass. It seems to dig much deeper than stock La Scalas and I have not measured anything but assume it is because all the resonance is gone and the shrillness dialed down.

  Have an LS BR coming in next week and will try just recapping and replacing the tweeter and adding an L-Pad and see how it does. I am thinking a big difference. Quickly coming to think the tweeter on an LS causes more trouble than the mid horn does. That and side wall resonance.

 

  Do you have a picture of the Fastrac horn you can send me? I am seriously thinking of making something for the mid range too. Probably a modified Tractix or a convex elliptical similar to the  tweeters I make. 

Designer Brown Sound.jpg

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Long time lurker, first-time poster. Anyway, people have mentioned the A-55G from Crites. I used it as a drop in for my Klf 20s and it does sound a lot better. The distortion is incredibly low so the music always sounds quieter than what it actually is. It also images really well. Since my Klfs are on the skinnier side it made it even better that the driver makes it sound like I'm listening to a wider speaker. It also is a little tamer. By saying that I mean that it is likely that it is a few dB less than your current midrange in terms of sensitivity. Whether that is a good thing is up to you.
Pretty much the same results I got with my 30's. Throw Dave's tweeters in there and then you'll be even more impressed.

Sent from my SM-G950U using Tapatalk

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7 hours ago, Dave A said:

 Do you have a picture of the Fastrac horn you can send me? I am seriously thinking of making something for the mid range too.

 

Dave, most people building the wood tractrix horns have used the spreadsheet from Erik Forker. He mentions this, but understand that his sheet has the curves as the top/bottom, not the left/right. For our midrange horns you would rotate 90 degrees.

 

http://wp.volvotreter.de/dl-section/tools/

 

Bruce

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9 hours ago, Dave A said:

  On a set of LSI's I rebuilt recently decided that while the K-55-V soldered lug helped the big change was the tweeter and making the side walls on the horn bin 1" Baltic. Stuck one of my larger MAHL tweeters on a rebuilt motorboard and it was still to shrill. However when an L-Pad was added to the tweeter it changed the whole ball game. Seriously thinking of adding an L-Pad to every La Scala rebuild from now on. Between the heavier side walls and the rest of it you are right about bass. It seems to dig much deeper than stock La Scalas and I have not measured anything but assume it is because all the resonance is gone and the shrillness dialed down.

  Have an LS BR coming in next week and will try just recapping and replacing the tweeter and adding an L-Pad and see how it does. I am thinking a big difference. Quickly coming to think the tweeter on an LS causes more trouble than the mid horn does. That and side wall resonance.

 

  Do you have a picture of the Fastrac horn you can send me? I am seriously thinking of making something for the mid range too. Probably a modified Tractix or a convex elliptical similar to the  tweeters I make. 

Designer Brown Sound.jpg

L-pad?

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3 hours ago, Cinema_head said:

L-pad?

It reduces the wattage going to the tweeter. These new drivers are more efficient and they can handle far more watts so sometimes you have to rein them in. It does not change the tone but it does match the output to the other drivers so they are balanced. For example you want to hear your cymbals but not have them intrusively loud just like it would be live. The only times I have found this necessary has been with Fortes and now I am thinking La Scalas which have a reputation for being a bit shrill at times. I will have a better opinion on the La Scalas after I work on a couple more variations and see how they respond.

 

https://www.parts-express.com/parts-express-speaker-l-pad-attenuator-50w-mono-1-shaft-8-ohm--260-255

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6 hours ago, SWL said:

Pretty much the same results I got with my 30's. Throw Dave's tweeters in there and then you'll be even more impressed.

Sent from my SM-G950U using Tapatalk
 

Honestly, I'm gonna regret asking this; but what are daves tweeters? I have never read about those. I have crites titanium tweeters so would it be a worthwhile upgrade?

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4 hours ago, Cinema_head said:

L-pad?

I'm probably gonna butcher this, but this is what I think it is; it keeps the impedance constant. When I say that it can either raise or lower the ohm rating that the amp sees. This will allow you to raise or lower the power that the driver receives. For instance: if the driver is rated at 8 ohms but the Lpad is set to 4 ohms than the amp is going to see 4 ohms and send 4 ohms worth of power. This is typically almost double the rated power of 8 ohms. This would raise the driver by 3 dB compared to the other drivers. If you want to lower the volume you would set the Lpad to 16 ohms. This would split the power sent to the driver in half, essentially lowering the volume by 3 dB. 

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5 hours ago, MoreCowbell said:

I'm probably gonna butcher this, but this is what I think it is; it keeps the impedance constant. When I say that it can either raise or lower the ohm rating that the amp sees. This will allow you to raise or lower the power that the driver receives. For instance: if the driver is rated at 8 ohms but the Lpad is set to 4 ohms than the amp is going to see 4 ohms and send 4 ohms worth of power. This is typically almost double the rated power of 8 ohms. This would raise the driver by 3 dB compared to the other drivers. If you want to lower the volume you would set the Lpad to 16 ohms. This would split the power sent to the driver in half, essentially lowering the volume by 3 dB. 

 Ohms is just resistance though right?

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55 minutes ago, Cinema_head said:

 Ohms is just resistance though right?

 

Ohms can be DC resistance, or it can be impedance, which is AC resistance.  Speakers operate on AC, as they move back and forth to vibrate the air around them and produce sound.  Impedance has to be measured while the speaker’s driver is operating, as it varies with the frequency of the sound being produced.  If it has any deep dips that go below 4 ohms, it can cause trouble for some power amps.

 

DC type resistance can be measured with a multimeter or ohmmeter when the driver is inactive, but it will not give an accurate picture of what happens when the driver is working.

 

Simce impedance does vary, how can a speaker be rated at a particular impedance?  Well, it’s sort of an average.  The engineering department will discuss it, and it may go like, “The impedance has a high of 11 ohms and a low of 4, so let’s call it an 8 ohm speaker.”  You may have noticed that it’s sometimes referred to as the nominal impedance, which suggests that it’s not an absolute value.  That’s correct.  It’s an agreed-upon value that’s close enough in most cases.

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I just saw this post and when I re-veneered my Scalas I put some screws or brad nails I cant remember now in the side wall top and bottom and then veneer over that. Before I did that I could move side walls with my fingers in and out now you cant even move them with a knee on one side and 2 hands on other side. So I dont think you need the inside bracing at all. I wish I had made a video of it maybe someone with stock LaScalas could show how much theirs moves then I could post one of me trying to move mine. I showed my son the day I did it he was impressed. Before I could just grab front edges with fingers and make the side walls move. 

Now that I thought about it I think I used my air powered brad nailer and put like 5 nails in top and bottom. I did it right after my transplant so not to sure what I used. Doesn't really matter either one will do the job probably. IMAG0326.thumb.jpg.378b4f01182745aa65692cb92cab1556.jpg

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2 hours ago, ricktate said:

I just saw this post and when I re-veneered my Scalas I put some screws or brad nails I cant remember now in the side wall top and bottom and then veneer over that. Before I did that I could move side walls with my fingers in and out now you cant even move them with a knee on one side and 2 hands on other side. So I dont think you need the inside bracing at all. I wish I had made a video of it maybe someone with stock LaScalas could show how much theirs moves then I could post one of me trying to move mine. I showed my son the day I did it he was impressed. Before I could just grab front edges with fingers and make the side walls move. 

Now that I thought about it I think I used my air powered brad nailer and put like 5 nails in top and bottom. I did it right after my transplant so not to sure what I used. Doesn't really matter either one will do the job probably. IMAG0326.thumb.jpg.378b4f01182745aa65692cb92cab1556.jpg

Mine seem pretty sturdy. I Havnt put any real force (would hate to break them lose). Not sure how hard I would need to go to reach the same pressure?

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  The L-Pad allows adjust of the output. Just for the driver it is attached to.

  The factory Klipsch crossovers used them to flatten the frequency response. Not all the drivers have the same efficiency.

  I do not seem them used in the latest factory crossovers. They use wire wound resistors instead. More stable, cheaper, and less time adjusting.

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5 hours ago, Cinema_head said:

Mine seem pretty sturdy. I Havnt put any real force (would hate to break them lose). Not sure how hard I would need to go to reach the same pressure?

Did not take much before to make them move I could see it move with very little pressure. You wont break them apart. I think veneer on the outside did a lot to stiffen them up. It was also Iron on veneer I used contact cement type on my K-Horns and wanted to try the iron on type. It was just as good maybe even a little easier.

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5 hours ago, Cinema_head said:

So the l-pad keeps the ohms from bouncing around? And keeps a steady resistance? As long as the ohms don’t dip or  Peak  to much shouldn’t it not matter for performance if the amp has no issues in those dips and Peaks?

OK guys when you have questions the internet is your friend and you do not have to wonder and wait for an answer. Type in "what does a speaker L-Pad do" and you will find more info than you know what to do with. For instance.......

 

http://www.bcae1.com/lpad.htm

 

 

" An L-pad is a passive device which lets you control the output level of speakers without changing the impedance seen by the amplifier. A constant impedance is not really necessary for the amplifier but if you are using passive crossovers, a constant impedance is necessary to prevent the crossover frequency from changing. The following image shows what typical L-pad looks like. This L-pad is relatively large (~3" in diameter) because it's rated at 100 watts. L-pads rated for higher power have to be larger than ones rated for lower power because they have to dissipate more heat. This one has an unusually long shaft. This would generally be installed directly into the wall of the speaker enclosure. If you were using a terminal cup, you could use this (using nuts to allow only a fraction of the shaft to protrude through the terminal cup but it would be better to use one with a proper/short shaft. "

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