Replacing speakers in Lat-1's

I realize your post is old but I have 4 new old stock 21w 16555 speakers available for sale.    I purchased for a project that I never completed.   

Have a pair of Krell LAT 1 speakers and have looked everywhere for replacement 8” woofers  Scan Speak Type 21W/16555-2 16 ohm speakers Called Krell and scan speak none available. I’ve looked everywhere and can’t find any.  Any suggestions on something that would work without having to modify the speakers. Thanks, Russell 

the answer is- Yes you can improove.and a lot. but-
1)I would strongly recomend not to change xover unless you want to fine tune speakers a litle. you can change tweeter to 70000 series ring radiator you will get better dynamic ,more imediacy insound(just measure/calculate krell xover voltage divider or serial resistor to ensure the same eficienty with THE SAME voltage divider values)

bass drivers also can be changed to better ones (22W) bass will be fuller and more punchy not hard sounding .

what you can not change its midrange.yoiu can but its likely 99% that it will sound worse. even the same drivers with 1mm shorter coil will have diferent response and will kill krells enginiers sound conseption.

as for my self I am using aluminium enclosures also and they deserves very best drivers, better thant theese in krell Lat1 IMHO

There sounding better. OOOps there brand new. Need to be broken in along with the new tweeters.

Since you have a Krell system I doubt you can improve your speakers other than changing them for LAT1000 ...
However DIY people with some knowledge of loudspeaker design and the help of of a measurement system can modify these speakers to sweet other amplification systems (eg. tube amplifiers) and their taste.
Can you imagine a tri-amplified LAT1 without passive crossover using an active crossover?

What is your system by the way????

Nothing fancy, but I like it. I've got a pair of Spendor SP1/2Es driven by an Image 65i tube amp. Source is a Squeezebox through a Lavry DA-10 DAC.

Spendor makes their own mid/bass units in house and use a fairly high crossover point to the tweeter. There would be no practical substitute for the mid-woofer and they are already using Scanspeak for the tweeters. Use any other drivers in that speaker and you've completely defeated the purpose of buying a Spendor. You're in the same boat with any high quality design.

There are a few manufacturers that allow upgrades in consumer audio - although it is not al that common in speakers. Merlin speakers comes to mind. ATC also, if you bought an ATC 100 in the early 90's, it would have an older design woofer and an older type tweeter - it would also have a first generation amplifier pack. ATC sells kits to upgrade front baffle to fit a newer tweeter, while the woofer is a simple replacement (with the old one sent back for refurb) and the amp pack is also a replacement pack that just pops in. They also sell recone kits because the drivers are simply too expensive to toss in the garbage if they get blown up from abuse. The reason they can do this is that ATC make almost all the parts in house (just outsource the cabinet work) and they haven't substantially changed the major aspects of the design so improvements can be retrofitted in much the same way you still see Boeing 737 aircraft flying around after all these years (after all acoustic and aeronautical physics doesn't change all that fast so the designs progress but do not change that often.). The only way this works is if you have a design that continues to sell after many years. It also means your target market are customers who tend to keep gear longer and expect it to be reliable and easy to maintain.

What is your system by the way????

Ok I just learned something. Nothing is wrong with them. Just thought I could upgrade the speakers. I guess I was wrong.

Just thought I would ask since the Lat-1's have one of the best crossovers money can buy in them. Thought if i get same impedance etc. I could get a better speaker to put in the Lat-1's.

There is a heck of a lot more to matching specifications than driver impedance! If you take just the impedance, you'll find this varies with frequency. First, there is the DC electrical resistance. Then you have the AC impedance which will vary with frequency. The curve for 8 ohm driver "A" may be completely different than the plot for 8 ohm driver "B".

If these don't match exactly, your "best crossover money can buy" might as well be a generic unit from Parts Express.

From there you have "free air resonance", the "Q" (both electrical and mechanical), dispersion patterns, excursion potentials, equivalent air compliance and on and on.

I guess my question for you would be: what's wrong with the current drivers?

For my system, the LAST thing I'd want would be drivers that were not specifically selected for my speakers.

Just thought I would ask since the Lat-1's have one of the best crossovers money can buy in them. Thought if i get same impedance etc. I could get a better speaker to put in the Lat-1's.

Surely speakers that cost a whopping jar dropping $37k should be awesome already, no?
Then again Krell use cheapo cones (apparently).

Not unless you know how to rework a crossover network. A designer spends countless hours modeling and testing those exact drivers and crossover parts in that exact cabinet until the desired results are obtained. The sum of ALL parts including the cabinets work together and they all have specific values associated to them. If one decides they like a different brand woofer, mid or tweeter, that alternate driver has a totally different set of T/S parameters and will react differently in the Lat's crossover and cabinet configuration. Most if not all of the time in a negative manner. Crossovers are built very specific to the intended drivers and their placement in the cabinet.

Generally if the original speaker is a well designed model for its price point, it is not a good idea to just replace drivers. The cabinet should have been designed to match the characteristics of the woofer for low frequency extension, compliance, efficiency and so on. Similary the crossover needs to match the characteristics of both the woofer and tweeter (and midrange if one).

Putting another driver in place ignores all of these factors. Even if it is "higher quality" driver, the chance that it will match the needed characteristics is simply a shot in the dark.

If you want to learn about speaker design, determine the original design specs and then pick a replacement driver based on that info, your odds of good results will improve. But the relationship between components in a speaker is complex and it is easy to overlook things. You may think you've covered all the bases and still find your change is not an improvement.

The key is to treat the speaker as an integrated whole where the parts match each other.