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Crossover mods and speaker efficiancy?

I was just wondering if anyone can tell me if it makes sense that with complete crossover mods(caps, coils, resistors, and internal cabling)that the speakers would draw more current from my amp? My speakers are Hales T5's with totally upgraded crossovers. I am using Dynamicaps for the tweeter section, Dynamicap,Audiocap and auricaps for the midsection and Solen/Axon for the bass area. My coils were replaced with Solo foill coils(16guage for tweeter, 14 guage for mid and 12 guage for bass). Finally as well the internal cabling was replaced with cardas chasis wire of three guages for the three drivers.
My question is that should these changes make my speakers less efficient or draw more current from my amp. I have a Pass X250 which has a meter on it which indicates how much current is being drawn and when the amp is going out of A mode. When the needle moves at all it's out of A mode and into AB mode. What I have noticed with the crossover mod is that the meter is reading that the speakers are taking very much more current than before the mods. The needle bounces to around the 2 or 3 O'clock point on loud passages where as before the mods the needle rarely passed 12 or 1 O'clock. The sound is way bigger sounding and I suppose the bigger sound is due to the larger current draw but I'm not sure. Would this type of crossover mod make my speakers less efficient in that my amp is obviously working much harder than before but the sound is much bigger than before. Any opinions would be greatly appreciated. I should note that I can listen to louder levels of volume of the music as the sound is clean and doesn't sound "loud" as the speakers now tend to have less distortion and I can play loud without being annoyed. The needle on the X250 meter now tends to bounce around alot where as before it just wiggled.
128x128mitchb
herman
2,259 posts
 
If the speakers are drawing more current (=using more power) to produce the same volume, then by definition they are less efficient. This could be because your mods changed the impedance of the crossover network and more current is bypassing the drivers. The impedance will change unless the new components are exactly the same value as the ones they replaced, and since caps and coils are notorious for having actual values that are quite a bit different from the stated value, this is highly likely. Plus or minus 20% is not unusual. If this is the case, you most certainly changed the crossover frequencies and the resulting increase or decrease in volume at certain frequencies around the crossover points may be what you perceive as being an improvement in the sound.

All crossovers waste a certain amount of power, and your new crossovers may waste more than the originals due to the change in impedance. This is not neccesarily bad if they sound better and the amp has enough oomph to provide the extra current.

The other explanation is as above, you are listening at louder levels without realizing it. This would explain why the sound is "bigger." It's louder so it sounds bigger.

Unless you took measurements before and after the mods you'll never know for sure which it is.
mitchb's avatar
mitchb OP
336 posts
 
Thanks for your responses. This morning at 6 am I decided to listen to music but had to keep the volume down as my wife and daughter were still sleeping and I realised that in fact I am listening at louder volumes than I used to when it doesn't disturb anyone in the house. There is a lot less distortion and the sound in general is bigger. I have been playing my revised Hales now for 90 hours 24/7 and I'm blown away on just how good the system sounds. It truly was like investing in a brand new pair of speakers without taking the loss on my Hales if I sold them. I never thought my system could sound the way it does regardless of tweeks and mods. I am happy and would reccommend this type of mod to anyone but would beware that it could be a gamble and not everyone is happy with crossover mod results. I got lucky!
jond's avatar
jond
5,849 posts
 
Mitch,
Who performed these mods and how much was it? It sounds like a very worthwhile investment and since my Alon's use outboard crossovers it would probably not be difficult to access them, but I'm completely non-handy so I would need someone to do it for me. Of course if you did it yourself I guess I'm out of luck.
mitchb's avatar
mitchb OP
336 posts
 
Jond, I did not do it myself. I have trouble installing light bulbs.I had a tech do it for me but I ended up waiting for 4 months till he finally did the work and that was only after I bought the parts privately and took them to the tech and said "here are the parts, I'll pay for the labour, please install them". 4 months later I have my speakers back. The moral of this story is find a tech who will do what you want when you want it done. If you buy the parts privately it can have it's advantages. I was fortunate to be introduced by phone to Jeff at Sonicraft, Andre at e-speakers and finally I bought the parts from Michael Percy who was extremely helpful and uncomplicated. I told him what I wanted and he had the parts. Everyone I mentioned above was extremely helpful and patient in helping me. I would reccommend any of the people I mentioned. FIND A TECH WHO HAS THE TIME TO HELP YOU. The advice of people on Audiogon was/is invaluable and I would ask questions on line. If it wasn't for the kind responses on Audiogon to my posts I would have exchanged Axon parts for Solen parts which is like "6 of 1 or half dozen of the other" Good luck!
My mods cost about $1200 but you surely can get alot done for less money. I went wild.
sean
6,231 posts
 
Trelja: Once again, right on the money. As usual, you summed my thoughts up quite well : )

Herman: Mitch stated that the amp is delivering more power, but also sounds much louder and "bigger". As such, it is hard to imagine heavier gauge inductors and lower loss components being "less efficient" or a greater "wattage waster". I do agree that crossover points may have shifted slightly. However, i sincerely doubt that Hales was using THAT sloppy of parts tolerance in their speakers. They would have had to be horribly out of spec to achieve the shift in values that would cause the changes in required drive levels that Mitch is talking about.

I have to agree with Trelja's assessment above. That is, the better that your system gets, the more likely you are to listen to it louder. The lack of grain, glare and distortion are no longer an irritant, so you end up compensating for those factors with increased volume. Not only do you end up "rocking out" more, you end up enjoying it more too.

One problem with this type of situation though. Now that you've increased power transfer into the speakers, reduced passive losses and are also listening louder, the drivers have a LOT more thermal stress to deal with. Be careful. Your either well onto the road of "sonic bliss" or "thermal melt-down". Hopefully, the drivers and crossover freq's / slopes were well chosen by Hales and you won't run into problems. Sean
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