Sub-woofer / Amplifier Combination Query

[Kwongwing]

China girls Singapore got plenty alreadi right?

Heard that the prettiest come from Tianjing - may pop by on this trip or the next.

Missed an earlier company trip to Yunnan some years back Wife due to deliver so couldn't go

Anyway, I haven't been to that many places in China, just the following:

Zhongshan, Guangzhou, Panyu, Fuzhou, Shanghai, Nantong, Shunde, Zhuhai, Sancun, and some other small towns

Except for the big cities, the places I end up at are usually quite rural - due to the industry I am in lotsa bumpy roads machiam SAF exercise area

The company I am in is into shipbuilding (considered heavy industry), so need waterfront and usually a distance away from the city.

[Headshok]

haha..

 

okok.. cool cool..

 

i was in yunnan in june.. went there got community trip.. ended up being like a 2 week field camp in the village. haha. but it gave me the best view when i was takin a crap.. u can pay thousands to stay in the suite at westin or at ritz carlton, my view still the best.. haha.. facin the hill.. super beautiful..

 

aniway.. their roads really like machiam SAF exercise area lor.. took a few overnite buses.. can die man.. haha.. can really fly off the bed.. heheh..

[Hyun]

orh so this is the thread that ended up in the birth of the XXX in the boot of the Estima :)

 

let me tongpang the thread with a similar question on a VERY different vein :)

 

Question:

looking at the lower end ah ...hehehee... not 4 digit wattage lah, but at 175W RMS for my sub ah .... hehe eh u there, dun laff hor. got such thing as 175W sub one lah, i not kidding u! just answer the question dammit ...

 

for a 175W RMS sub ah .. if going for a budget amp (headshok took must of my money away liao), 2nd hand sounds preferable to keep to budget (got such thing as KEEP to BUDGET one meh?? we talking I.C.E. here right??)

 

The Actual Question(s):

----------------------

1) how bad is SQ on a sub when u get pariah amp but still can match 175W specs? sub SQ a bit harder to judge because it's all low frequency and often we use a poorer quality amp for sub and better one for fronts. but have u guys seriously observed before a poor quality amp running a sub -> and the sound turns out bad?

 

1a) After all, "damping" is one feature that is well-controlled in better quality amps. Good damping should produce a nice tight bass. So on the contrary, a poorer quality amp with unacceptable damping would end up giving a muffled boomy bass? all that is theory but has any1 observed this in practice?

 

1b) we should at least match the power rating so that we dun have a situation of cheap amp + UNDERPOWERING of the sub.

 

1c) regarding subsonic filter and the usual low-pass filter, i suppose cheaper amps may not have a good low-pass filter? but do u think this is significant in a sub where the sound is not so audible? Also, the amp may not have a subsonic filter. do you guys hear an effect when u turn on and turn off your subsonic filter? is it really necessary?

 

2) the question of Class D and Class A/B again. to summarise that discussion here, class D would provide a low-current cooler unit suitable for sub. and class A/B u'd expect it to run hotter. but SQ-wise seriously any1 heard the difference in sub frequencies?

 

3) the brand. does anyone have some well-known pretty-good cheapo amps to recommend? like i said i'm targetting at least 175W, preferably 2nd hand. also, in my case, needs to be 2-ohm stable, so that eliminates many cheapo models right ...

 

4) extending the argument one step further, if i'm looking for down to 1 ohm stable, cheapos amps are out of the question liao?

 

 

Heh. lots of questions. any takers?

[Sidestepper]

hello ,

i'll try to give my 2cents of input onto helping u answer your querys. Imo first of all, one shouldnt judge the subwoofer as any less significant to other drivers in the system, just cos it handles the lower end of the frequency spectrum. A good subass would definately contribute to the 'ommph' n overall presence of the SQ in the car. A in-adequate subwoofer will only drag the rest of the system down, hence i dun see any reason why an inferior amp should be choosen for the sub. Although it seems fair that u may wanna go the cheaper route to save some wattage money. However nowadays due to the high public demand for high power amps the slope for watt/person has become less steap which is a good thing for us end buyers, u can get 2000rms for 1/4 the money even compared to say 7-9 years ago. When coming to choose an amp for the sub, personally i would initially look at the power ratings n also the damping factor, the latter which is an important aspect on how an amp is goin to deliver power to your sub. Other than that, i would go for built quality, do some research on the net to see wat experiences people might have etc2. But i would rather choose a reputated brand over a lesser unknown say 'china-made' counterpart. Also, why would u need to choose to run at a higher current. Cheapers amps were introduced long ago to mock at the still-new iasca SPL rules be4 so to get the competitor under a wattage class. If u run lower impedence the current draw from the electrical system will double, the efficieny of the transitors will decrease, heat will increase, damping factor and headroom will reduce etc2. I rather choose sub configuratiosn to suit the amp rather than the other way round. Ultimatlely i reckon its still clean power, u dun need ridiculously expensive amp to make a system sound good, wat u need is a realiable n well design amp that makes the power it is rated at that will never shut down on you.

i hope i did help to answer a bit of your questions, forgive me if i sound brief as wth am i up at wee hours of the mornings. ahauahuaha. Good luck n have fun with system building.

Edited March 13, 2006 by Sidestepper

[Hyun]

thanks man!

 

about "high current", no i wasn't trying to get high current. i was saying if i choose class D it may mean higher efficiency (hence lower power draw / heat / current etc), whereas if i choose class A/B it may mean better SQ (which may not be felt in a sub) but lower efficiency etc ...

 

so the good thing about choosing A/B is next time i can run, say, my tweeters with them (e.g. 2 channel amp). bad thing is, usually class A/B wun have subsonic filter - mainly found in class D monoblocks meant for subs right?

 

which leads to: is subsonic filter important? can u feel the difference when u turn on, or off? which sounds nicer? on or off?

 

what would your opinion of an OK amp be, with regard to price range? looks like most decent models sell first hand for at least about $350. anything less would not fulfill some criterias - e.g. nobody heard of the brand, made in bangradett etc ...

 

a friend advised me, instead of getting a sub amp, get a proper front amp to driver my tweeters, and use my current setup for sub. this, i feel, would push the cost up. cos if u want nice sound, u cant stinge on a front amp, even if it's a 2 channel for running tweets. so i felt might be easier to obtain "just as good" sound by investing in sub amp rather than tweeter amp.

[Yuhsuan]

whereas if i choose class A/B it may mean better SQ (which may not be felt in a sub) but lower efficiency etc ...

 

 

Unless there is a problem with your tuning or unless the sub is so inefficient/power-hungry, if you replace a class D amp with a comparative AB amp, I believe you can hear the difference in SQ. I'm saying this because I heard a difference myself.

 

Lower efficiency? How loud do you want your sub to be? If a sub has a power handling of say 300W RMS, a decent class AB amp that puts out 250W RMS should be able to drive it without difficulty at normal listening levels. It's not like if you don't meet the power-handling of the sub with the exact same wattage, your SQ will suffer tremendously....

 

I'm NOT dissing the class D amps here, these amps do have their place in car audio (smaller size for same power, higher efficiency which means less current draw, less heat etc). It is just my own preference to use a class AB amp for a sub at moderate listening levels.

 

which leads to: is subsonic filter important? can u feel the difference when u turn on, or off? which sounds nicer? on or off?

 

subsonic filter is if you are installing your sub in a ported box. The cut-off frequency of the subsonic filter should match the tuning frequency of your port. If you are using your sub as a free-air sub (infinite baffle) then it should match the resonant frequency of the sub. If you are using your sub in a sealed box, the subsonic filter makes no impact on the sound at all.

Edited March 14, 2006 by Yuhsuan

[Hyun]

great reply yuhsuan, thanks!

 

> Unless there is a problem with your tuning or unless the sub is so inefficient/power-hungry, if you replace a class D amp with a comparative AB amp, I believe you can hear the difference in SQ. I'm saying this because I heard a difference myself.

 

i read from u that class AB amp gives superior SQ in your opinion. can u describe the difference?

 

> It is just my own preference to use a class AB amp for a sub at moderate listening levels.

 

your drift is that mono class D is easier to get one at a good price for high wattage per $, but if u get a powerful AB, u'd be paying a lot for the same equivalent power. so at "moderate listening levels", a 250W RMS class AB is more worthwhile an investment than a similarly-priced class D. but if going for 600W+ a class D makes more sense economically. did i get this right?

 

well for my application, i'm looking at 2 ohms stable with 175W minimum. something cheap, 2nd hand preferably, and decent sounding. for class AB i suppose that would mean a 2x50 @ 4ohm bridged to 1x100 @ 4ohm running at about 1x175 @ 2 ohm right. u have any brands in mind that offers such a description?

 

i suppose u think i should disregard pariah amps?

[Yuhsuan]

read from u that class AB amp gives superior SQ in your opinion. can u describe the difference?

 

When I was using my JBL BP1200.1 (on my old RF HX2), the bass was hard but not tuneful. When I changed to a class AB mono amp with about half the power, I could hear that the bass notes were rounder, the pitch from bass guitar notes could be heard clearly. Of course, I had to turn the gain up more than my JBL and it did not hit quite as hard when I was playing drum&bass.

 

well for my application, i'm looking at 2 ohms stable with 175W minimum. something cheap, 2nd hand preferably, and decent sounding. for class AB i suppose that would mean a 2x50 @ 4ohm bridged to 1x100 @ 4ohm running at about 1x175 @ 2 ohm right. u have any brands in mind that offers such a description?

 

The class AB mono amp that I used was this:

http://www.crossfirecaraudio.com/prodInfo.asp?IDProduct=87

200W into 4 ohm, 400W into 2 ohm, power rated at 12.5V!! (NOT 14.4)

Not sure how much this sells here in SG, I bought it in the states for about USD200 new.

[Sidestepper]

hello ,

i guess yushuan answered all there is to your questions. kekeek. However ultimately theres no rule to say why an a/b should sound better than a class D though. The classes r just an indication of how the circuitry is based. Compared to class a, a/b amps, class D r still in their trial stage of progession, although imo i still admendently feel that class D is the future of amps, right now the cost of designing a good quality Class D is still pretty prohibitive. Due to this pretty 'new' technolgy, i guess buildhouses that have plans for a proven Class D circuitry would charge a premium to build their products. Like for example, the zapco 9.0D is a very good class D example. IVE heard n know peopel who have used aps with over 1000rms more than the 9.0 that says that 9.0 gives more punch n more 'bite'. But yea......like yushuan said....look out in the us market..there r a lot of great value for money amps out there. Old pgs ms, mps, Z n Tis r good, so is soundstream refs n rubicon. crossfire r good too.even the korean made ones r decent. Or if u want something newer......i recoomand arc audios........its got that dynamic american amp sound.....perfect for powering subs n brings out the detial in the speakers too. For the price they r goin for now, its a steal.

 

http://cgi.ebay.com/RUBICON-1002-SOUNDSTRE...1QQcmdZViewItem

 

http://cgi.ebay.com/O-S-Soundstream-10-0-P...1QQcmdZViewItem

 

thats class10.0 is bascially the same amp just that its 'hi-current' cos its 1/2 ohm stable. But both r very good man man..keep a look out on the net for good buys.

Edited March 14, 2006 by Sidestepper

[Hyun]

thanks guys for your detailed replies!

 

i think i again lapsed into the misunderstanding of Class A/B -vs- D, confusing it with stereo -vs- monoblock amps. i keep thinking that when we speak of "D" we speak of monoblock, and when we talk about A/B we talk about stereo bridged to run sub.

 

as mentioned, here are AB monos. i suppose these are MEANT for subs. that brings me to the next question: should i get a mono AB or a stereo AB and what would be the difference in SQ?

 

certainly stereo AB can be used next time to power fronts if i dun use it for sub. mono AB wun have such an option. so are there features in mono AB that makes subs sound better? or stereo AB still wins? are mono ABs generally cheaper than stereo ABs for the same output?

 

before i invest, i think one day i should just switch my system to active without sub to do an A-B test and compare whether i find active worthwhile. if not worthwhile this question of buying amp won't exist liao ... but i'm certainly looking forward to it - the theory of active is very tempting!

[Muths66]

Hi i like to ask u if currently i using rockford P1 and phoniex amp 200x2.Is it worth it to change to rockford P3 and rockford T1000td monoblock?

[Yuhsuan]

Is it worth it to change to rockford P3 and rockford T1000td monoblock?

 

To ask if it is worth it, you need to ask what is it about the sound that you not happy about. Which PG amp is the 200X2? Xenon or Octane-R? Is your P1 sub installed in a correct sized box? If you do not know what is the root cause of your dissatisfaction, just wholesale change of equipment MAY not be the correct solution, not to mention the money spent....

[Muths66]

The amp is tantrumn model old model.

I looking for tight and deep bass

The volume is ok check with sin kit already.

[Imdone]

hi am looking at a few amps and have been recommended JL 300/4 to power my front components, does anyone have experience with this amp? Any feedback would be great/helpful!

Thanks

[Mafia]

Hello hello

 

 

long time no see cool dude wassup just to let u guys know the hustler audio subs are designed by adire audio and infact they are the brahmas combined with tumult magnets now these are my kind of sq subwoofers wow wow check the amp too damn really high class.

Edited July 23, 2006 by Mafia

[Headshok]

wah.. hustler subs design by adire ah? brama and tumult combi ah.. sui man!!!!

 

but aniway, there are sure to be pple who will be sayin " huh? adire audio got famous meh? prob lousier than kicker or JL"

 

 

aniway mafia, where u disappear ? back in sg?

 

the hustler amp look like can use to beat up pple.. hahaha

[Mafia]

yo dude

 

hows the tutorial with george wu???rgards to him i was in singpore for 2 days went for ice meet up,met slonez and guys,but had to run bck and finish some stuff and working on new projects.

 

hope to meet you soon

 

tc bro