10" jaycar sub

[DrewP]

Jaycar Sub Amps

Folks, yesterday I had the chance to compare a Jaycar plate amp to a 20 year old NAD 3240PE integrated amplifier. (40w)

Playing low freq test tones into a protype clone of a Bose bass cannon (5m long and with output to 20hz without eq!) the NAD sounded far superior. (this was the plate amp with the IR reciever and the remote controll for the freq/level panel (200w I think)).

Not wanting to destroy either the drive unit or my friends NAD, we were keeping the volume down to a window rattling level but the sound is definitely far superior with the NAD.

A friend of mine who builds amps as a living has done service on number of the subwoofer plate amps and was far from impressed with the quality of the amp, the psu, the filtering methods, the distortion levels and the frequency response. Yes, they work and yes, they are a turn key solution but he didn't find them that great.

For my money, getting a good second hand integrated amp (Rotel, Harmon Kardon, Denon) and feeding it from a simple low pass cct knocked up around an NE5534 and a couple of 9volt batts in a jiffy box would give you way better sound.

The cct is not complex and a google search for active low pass second order filter or similar should give you all the info you need.

My 2 cents

drew

[michael]

what type of box is the one on your sight michael is it better than a ported or sealed one.

Mine is a ported, though it has both front firing port and driver.

the sound is definitely far superior with the NAD.

This will happen with most high quality amps, the plate amps are designed for volume and independance, not low distortion and high detail. but they are easy to use and inexpensive for their output.

For my money, getting a good second hand integrated amp (Rotel, Harmon Kardon, Denon) and feeding it from a simple low pass cct knocked up around an NE5534 and a couple of 9volt batts in a jiffy box would give you way better sound.

True you would get much better sound and may be the same money but you would have far far less power to play with, most of those integrated amps you speak of in the price range of plate amps are 50-80wrms, whilst this is enough for most music it is not enough for HT sub duties where a high excursion 12" is used.
Power amps are the ideal solution but they cost too much for most people.

[paulspencer]

I'm surprised to hear Drew's comments on the Nad power amp being so superior to the plate amps. I have an old NAD power amp for my subwoofers. I find the NAD to have a very pleasing sound for the bass. I think the bass is one of the strong points of NAD amps (at least the ones I have heard). I find it hard to believe that the difference between it and the plate amps is anything but very subtle. I haven't compared myself, however, and so it is hard to comment.

I suspect distortion is less critical in sub amps. The distortion of subwoofer drivers is so much higher in the driver than the amp itself, that I suspect you can't tell the difference. Also keep in mind that plate amps are cost effective given the simplicity of their design - they have an integrated plate/heatsink and don't need a case.

One suggestion I would make is to avoid jumping to certain conclusions regarding what will be best for bass. Hifi power amps are likely not to perform at times as well as you might expect in this application. A number of people have commented to me that on comparison they found some PA amps to be superior in the bass region than Hifi power amps (including a NAD). However, this is overkill for the CSX driver.

Don't underestimate the amount of power for a sub - bass is much more dynamic.

If you use the CSX I think you will find a plate amp with 200 watts into 8 ohms is fine for your application.

regards,
Paul

[b<ben>n]

ok im going to use the 150W 4ohm jaycar plate amp i dont realy think i need all the full 200W and if i do i will sell it and buy a better one.

[michael]

my reason for going to the 200w amp is that if i ever wanted to upgrade the subwoofer to something bigger then i would have more power on tap for that.
i think you should email wescomponents and get their 150w plate amp as it is only $230!!!!

[b<ben>n]

im going to try and get the whole sale price on the jaycar amp. if that dosent work im going to go for the wes one. got to earn a little more money first

[michael]

mmmmmmmm, wholesale, it always makes things so much happier
well let me know if you need any help during construction or design as im on holidays so have some free time

[loonatron]

Hello fellow Australians!

Hey Drew P, how do you know the sound quality of the NAD is better, if you just used test tones?

just wondering, as I've never run test tones to compare quality before.

[DrewP]

Using test tones you can hear the second and third harmonic output of the plate amp. The higher frequency multiples of the original tone are quite audible. The output also sounds far more "unpleasant" for a given volume and less a clean tone with the impression that the driver is in distress.

To be sure, test tones are far from a real world signal, but if these sound worse, surely "real" sounds will suffer deterioration too.

I'm contemplating using a parallel/bridge quad chipamp as the power stage instead of a prebuilt amp but it'll take a fair while to breadboard and implement

as i said earlier, plate amps are a far simpler solution, look better, require no R&D etc and so on but I don't believe that they are the last word in quality.

Frankly, i was very suprised that there was a difference between the nad and the plate amp but i guess that's the wonder of comparison testing.

Drew

[paulspencer]

Drew,

What about doing actual music comparisons?

Ben,

The Wes Components plate amps seem to be cheaper for what they are. IIRC the Wes 200 watt plate amp is cheaper than the Jaycar 150 watt one. However, you should also check out ebay as they often have the Jarcar amps on auction for sigificantly less than retail, but they are new plate amps with a warranty. Just be sure to allow for the shipping (which is normally shown on the auctions).

regards,
paul