Replacing hifi speaker drivers - advice wanted

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   Hi all,
I have got hold of a set of floorstanding 3 way speakers for very cheap. They are called TTC System 3, K-1410. Made in Japan. They sound pretty rubbish, very fuzzy sound and lacking any real power. I have always fantasised about building my own system from scratch, but with limited time, money and most importantly technological understanding, it occurred to me that a good starting point could be to adapt this set of speakers, replacing some components but keeping the boxes.

The dimensions of the boxes are approx 50x25x25 cm. Having got inside  I see the drivers currently in there is a 6.5", a 4.5" and a tweeter whose cut-out size seems to be around 2.25" squared, though as i can't get the front cover off, i can't immediately see the cone diameter. The bass and mids both say 20W max power, and all say 8 ohms. Then there is a crossover.

My amp is a Technics SU-V300 which provides 27 watts per channel into 8Ω.

My questions to get started are:
1. What is the reason likely reason that they currently sound so bad, in technical terms? I.e. is it the low power capacity and therefore at anything other than very low volume they distort? Or is there likely to be something else that is wrong with them?
2. Would you recommend replacing all three drivers or would, for example, getting something that can handle more power in just the bass make enough difference?
3. How much difference does the crossover make in all this? Can you notice a big difference between a low quality crossover (which i assume the current one is) and something high end? Should i look to replace that as well?
4. I think i am right in saying that you measure the larger drivers in their diameter (that's what the sizes i refer to above are anyway). For tweeters, from my brief searches so far I can't seem to find anything that comes close to a 2" tweeter for hifi - they seem to be more in the 1" area. Could anyone explain the basics of tweeter sizes?
5. In an ideal world i would like to get these sounding decent enough with my Technics amp, operating at a volume sufficient to fill a small-ish room full of people with loud music and solid bass for under £100. Is that realistic and if so can anyone recommend which new drivers to go for and in particular what sort of power?

Massive thanks for reading this far and in advance for any advice I get!

Edited by rasjahsk - 05 February 2017 at 8:36pm

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rasjahsk Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 07 February 2016 Location: E1 Status: Offline Points: 24	Post Options Post Reply Quote rasjahsk Report Post Thanks(0) Quote Reply Topic: Replacing hifi speaker drivers - advice wanted Posted: 05 February 2017 at 8:36pm
	Hi all, I have got hold of a set of floorstanding 3 way speakers for very cheap. They are called TTC System 3, K-1410. Made in Japan. They sound pretty rubbish, very fuzzy sound and lacking any real power. I have always fantasised about building my own system from scratch, but with limited time, money and most importantly technological understanding, it occurred to me that a good starting point could be to adapt this set of speakers, replacing some components but keeping the boxes. The dimensions of the boxes are approx 50x25x25 cm. Having got inside I see the drivers currently in there is a 6.5", a 4.5" and a tweeter whose cut-out size seems to be around 2.25" squared, though as i can't get the front cover off, i can't immediately see the cone diameter. The bass and mids both say 20W max power, and all say 8 ohms. Then there is a crossover. My amp is a Technics SU-V300 which provides 27 watts per channel into 8Ω. My questions to get started are: 1. What is the reason likely reason that they currently sound so bad, in technical terms? I.e. is it the low power capacity and therefore at anything other than very low volume they distort? Or is there likely to be something else that is wrong with them? 2. Would you recommend replacing all three drivers or would, for example, getting something that can handle more power in just the bass make enough difference? 3. How much difference does the crossover make in all this? Can you notice a big difference between a low quality crossover (which i assume the current one is) and something high end? Should i look to replace that as well? 4. I think i am right in saying that you measure the larger drivers in their diameter (that's what the sizes i refer to above are anyway). For tweeters, from my brief searches so far I can't seem to find anything that comes close to a 2" tweeter for hifi - they seem to be more in the 1" area. Could anyone explain the basics of tweeter sizes? 5. In an ideal world i would like to get these sounding decent enough with my Technics amp, operating at a volume sufficient to fill a small-ish room full of people with loud music and solid bass for under £100. Is that realistic and if so can anyone recommend which new drivers to go for and in particular what sort of power? Massive thanks for reading this far and in advance for any advice I get! Edited by rasjahsk - 05 February 2017 at 8:36pm

Elliot Thompson Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 02 April 2004 Location: United States Status: Offline Points: 5174	Post Options Post Reply Quote Elliot Thompson Report Post Thanks(0) Quote Reply Posted: 05 February 2017 at 11:24pm
	Hi. If the loudspeakers offer a listing of 20 watts in an 8 ohm load and, you are feeding the loudspeakers 27 watts per channel in an 8 ohm load from your receiver, you may find yourself driving your receiver to its limits hence, having your speakers sound like utter rubbish. I have a pair of bookshelf speakers in which, I use as computer speakers. Each cabinet comprise of an 8 inch woofer accompanied by a 2.5 inch tweeter. Despite the rating on the back of the enclosures stating 20 watts @ 8 ohms, I am feeding each loudspeaker 150 watts per channel @ 8 ohms. Try using a larger wattage receiver or amplifier and see if that improves the sound before you commence to butchering the cabinets. Best Regards, Edited by Elliot Thompson - 05 February 2017 at 11:25pm
	Elliot Thompson

rasjahsk Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 07 February 2016 Location: E1 Status: Offline Points: 24	Post Options Post Reply Quote rasjahsk Report Post Thanks(0) Quote Reply Posted: 06 February 2017 at 7:09pm
	Thanks for getting back to me Elliot. I am confused as to why you think a more powerful amp would help. I have another set of floorstanding speakers that take 180W RMS each. And those combine with my Technics amp to produce a reasonable sound at a reasonable volume. Doesn't that suggest that the drivers in these speakers i am talking about replacing are just too wimpy? Thanks again, Sam

Elliot Thompson Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 02 April 2004 Location: United States Status: Offline Points: 5174	Post Options Post Reply Quote Elliot Thompson Report Post Thanks(0) Quote Reply Posted: 06 February 2017 at 9:05pm
	Home audio speakers are generally inefficient. So you are going to need more power since you require more volume. Your speakers are rated 20 watts maximum under an 8 ohm load. Your amplifier is rated 27 watts per channel under an 8 ohm load. So the amplifier is operating a smidgen below its limit to deliver 20 watts. A stronger amplifier (100 watts per channel in an 8 ohm load) can reach the loudspeaker’s maximum rating with enough headroom on its behalf to prevent any distortion during the process. Best Regards,
	Elliot Thompson

rasjahsk Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 07 February 2016 Location: E1 Status: Offline Points: 24	Post Options Post Reply Quote rasjahsk Report Post Thanks(0) Quote Reply Posted: 06 February 2017 at 9:26pm
	Ok I see, thanks. Just to follow up on that (and excuse my ignorance), why do my other speakers, with their higher power rating (and the same 8ohm impedance) produce a much louder sound with the same amp?

edboom Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 13 May 2011 Location: manchester Status: Offline Points: 48	Post Options Post Reply Quote edboom Report Post Thanks(0) Quote Reply Posted: 06 February 2017 at 9:53pm
	Probably because there's a difference in sensitivity, or efficiency, between your two sets of speakers. Sensitivity is quoted as db/watt of power. The higher the db(decibels), the louder your speakers are.

Elliot Thompson Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 02 April 2004 Location: United States Status: Offline Points: 5174	Post Options Post Reply Quote Elliot Thompson Report Post Thanks(0) Quote Reply Posted: 07 February 2017 at 11:46am
	It would not make logical sense trying to upgrade the speakers when you have so little power in terms of amplification to begin with. A loudspeaker system offering 20 watts is possibly close to 40 years of age. If you decide to buy a stronger amplifier in which, the speakers still sound horrendous, you still have the Technics loudspeaker system that will benefit on a higher power amplifier. If the Technics loudspeakers are indeed 180 watts RMS (Knowing Technics it is probably peak) a 100 watt per channel amplifier is going to offer far better results from a volume perspective than having the speakers residing on a 27 watt per channel amplifier. Not everything is salvageable especially when the items you are looking to modify were not popular to begin with. If the speakers shown below resemble your speakers accept them for what they are and, focus on getting a stronger amplifier for your Technics loudspeaker system so you can attain more volume. Best Regards, Edited by Elliot Thompson - 07 February 2017 at 11:47am
	Elliot Thompson

odc04r Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 12 July 2006 Location: Sarfampton Status: Offline Points: 5483	Post Options Post Reply Quote odc04r Report Post Thanks(0) Quote Reply Posted: 07 February 2017 at 4:50pm
	With all the hassle that swapping drivers and rejigging the box would entail, plus the design limitations of being constrained to that enclosure in terms of volume your best bet is to buy or build something completely new. What you have sounds old, and unless some component in it is of interest to the vintage HiFi crowd probably not worth messing about with. I don't think the budget of £100 for a small room with solid bass is realistic unfortunately. Do you want to achieve this with HiFi style speakers, or larger PA enclosures. Your best budget bet is a small 2.1 system, one sub and two top midrange speakers. Maybe you can find one second hand with integrated amplification for a few hundred £.

VECTORDJ Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 11 June 2006 Location: United States Status: Offline Points: 514	Post Options Post Reply Quote VECTORDJ Report Post Thanks(0) Quote Reply Posted: 10 February 2017 at 11:50pm
	partsexpress.com has lots of hifi parts, plans, and tips.

rasjahsk Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 07 February 2016 Location: E1 Status: Offline Points: 24	Post Options Post Reply Quote rasjahsk Report Post Thanks(0) Quote Reply Posted: 11 February 2017 at 2:19pm
	Thanks all for your advice and comments. To be clear I only thought spending less than £100 to get what i wanted was realistic if i was replacing the drivers in these old speakers, obviously not starting from scratch. I'll look out for an amp upgrade in the first place though, and go from there.