The bang for buck Saga

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greenhorn

greenhorn

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suddenly felt like building a sub today. No idea why . maybe its the lack of propah bass in moviemachine. Maybe the two 5 inch woofers just arent enough.

went to thakaraparambu- the mecca in trivandrum for electronic spares. Went to the dainty Dealer. the guy had a boxed 10 inch sub which was part of an HTiB system, but was willing to sell loose for 2.6k but it was a bandpass enclosure , so couldn't see anything within it. Anyway , asked for an audition. The guy hooked it up to a PA amp, and it was absolutely bland ( my front 8 inchers can do better bass:P)

anyway, onto the next shop, which is run by a sardarji, which has some relatively higher end ( read harrot ) which just looks better. No idea if it sounds any better . he talks in jargon, and to the most clueless mallus who go in there , coupled with the impressive looking speakers on display, clinch the deal. Of course , they still offer better VFM compared to the branded HtiB / very generic sub / sat HTiB boxen out there, me is still not satisfied.

besides the guy's prices are astronomical

I move on. There is this small shop which sells bolton speakers. No, not as in michael bolton :P . Bolton is to most DIY folks the best there is that is made in india ( actually its Peerless, but that's out of reach for most local folks , and bolton are quite nice. ) the guy unfortunately didnt have a piece at hand . However , he did have the rest of the stuff- an amp board, an active crossover ( with NE5532's )and a PSU board. Nearly bought it when i discoverered that a 27-0-27 V 5A transformer was available only made to order. Anyway, the sub driver will be in stock only on monday. Hopefully I'll have the sub, the boards , and some pics to post then ! :D
 
Good luck man.. :thumb:

me got (as in received :P) custom built hp-amp tonite.. enjoying it now.. the sounds are so much clearer now :hap2:

</OT>
 
Had bought 2 x 8" Peerless woofers way back for 1k each and man they are too good for that price..............
 
Some made in india peerless drivers are actually very good bang for the buck. Greeny you'd be better off replacing those 5532 chips with a proper OPA2134. Will sound gazillion times better.
 
its for a sub, so i wonder if the difference is that big. Anyway the guys who made it seem to have anticipated this , and put the op amps in DIP sockets :D

I've been asking this for a LONG time now on TE, but where to get peerless drivers from? I'm in TVM, and does anyone ship it ?

I know they only sell in pairs, in which case I'd be happy to buy 2 12 inchers...
 
i wish i could , but dont have that much spare time, and carpenters are notoriously unavailable and exorbitant. The shop offered to make a cubic box out of quarter inch MDF for 1.2k. I'm happy with that. Might have to ask them to use a smaller port though. The ones they tend to use are huge, and I'd prefer tighter bass ( thats Why I'm getting a 10" , not a 12)
 
Try sealed. You'll have all sorts of problems with improper (read: with no driver measurements) port sizing. Sealed will give up a little more apparent bass for a much more predictable response, and you can always use equalisation to correct the response. Ported response is a little shelved but drops off quickly along with the power handling, so it works better with smaller drivers (10" and below) and in smaller rooms.

Equalisation is not taboo in low-frequency part of the spectrum - in fact you already will have a phase error due to different location of the sub from the main speakers. You just need to ensure you have sufficient power available, 3x the driver capacity is a good start. And with sub amps available in class-D format, it doesn't have to be killingly expensive.

I think a 12" in a sealed box is the way to go. You can tune the bass response using stuffing, a more tightly stuffed box will have more apparent volume, lowering the Q and response.

The 8" Peerless are quite good as midbass drivers, as subs the excursion is too low. If you really want to experiment you might want to try a large car sub. There was a discussion we were having earlier about some JBL subs, I dont know what finally came of it.

Abt the box: 1/4 inch is going to become the second loudspeaker. The panel will vibrate a lot if it's not reinforced, and in a sealed box, may actually explode. Minimum for the application would be 3/4", and 1" would be better. At worst, you should ask them to sandwich three 1/4 inch layers together with glue and then cut. This box will be incredibly rigid and strong. Remember to chamfer (google it) the driver hole for good airflow around the driver.

Have fun!
 
sangram said:
Abt the box: 1/4 inch is going to become the second loudspeaker. The panel will vibrate a lot if it's not reinforced, and in a sealed box, may actually explode. Minimum for the application would be 3/4", and 1" would be better. At worst, you should ask them to sandwich three 1/4 inch layers together with glue and then cut. This box will be incredibly rigid and strong. Remember to chamfer (google it) the driver hole for good airflow around the driver.

Have fun!
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whoops . my bad. i meant 3/4 inch :ashamed:

My dad's old panasonic hi fi boxen were sealed 1/2 inch or so, and towards the end of their lives, the boxes themselves began to add their own trademark bass boost :P

so you think a 12" in a sealed box will get faster bass than a 10" in a ported enclosure ? I guess its a risk free strategy, so many ways to go wrong with a ported box done improperly.

I'm not sure about their reinforcing though. Dont think I'll have a lot to say about the construction. The Amp is a normal class AB amp with discrete FET's amd an LPF at the output. heck, i think it costs ~ 500 bucks for the amp PCB with components.

since the main speakers are driven off a 12W RMS minicompo . think the amp power will be sufficient. they asked me to get a 27-0-27 transformer to power it . They said 4A should do fine, But I'm getting a 5A just in case :)
 
Not really sure what you mean by 'faster'. Yes, sealed boxes reduce group delay to manageable levels. The bass isn't quite pant-flapping/gut wrenching as a ported though, so it's largely a question of taste. Sealed does reach deeper than ported in a very general sense, though sometimes sealed boxes need to be very large (which would be true of most drivers in India including the Peerless drivers) and you may need to add a Linkwitz transform to get the Q within manageable levels. The bass may be very boomy/one-noteish otherwise.

For casual listening without driver measurements, either would do, on second thought.
 
While the bass is good for rock/jazz, trance sounds horrible. Would like a sub to play ATB/ Above and beyond properly, with accurate , and precise beats . something like a 6 incher can give at low volumes, only louder , not the wallowing and slow bass most people are happy with
 
rishia said:
^ IMO sealed subs would be smaller than vented/ported ones..
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thats odd. I thought the whole point of porting was to get deeper bass within a smaller enclosure.
 
Well, if you do the calculations.. I did for a Dayton 12" .. the vented sub would need a volume of about 71 lt.. while for the same driver it would be about 42 lt for a sealed box.
 
Not deeper, but 'more'.

Sealed boxes roll off gradually after their resonant frequency (f3), whereas ported boxes stay flat till a certain frequency (which is lower than an equivalent size sealed box), and then drop off sharply.

Ported box give the impression of more bass because of the better/flatter response characteristics till their f3 but due to the sharp rolloff the response and power handling drop like a rock below this. Also the port response is usually delayed (this is called group delay and is common to all ported boxes), which may cause decay effects depending on the room and sub placement relative to listener. Some group delay may sound desirable.

Ultimately a sealed box provides more power handling and better excursion control of the driver. The lowest frequencies to be emitted from a sealed box may also be slightly lower, however it's largely a question of taste.

If your looking to play trance bass you'll need something that goes really low. I've tested tracks to go till 18Hz, and your sub + room should be able to go flat to about 24 to be able to give you satisfaction. Not easily achievable without lots of power.

Like I said, if this is a bang-for-the-buck project, don't think too much about it, just build and check. Just remember the smaller the port the sharper the peak (and the more boomy the response). Without driver measurements anyway there's no point of much discussion on the subject - it's like buying a processor without knowing the FSB or the operating frequency and voltage, and slapping it onto an unknown motherboard. It may work, may work very well, or may not work at all. You'll get some sound, but of what quality it will be no one can tell.
 
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