Building Myself a Speaker cabinet.

[wishbone]

Like I said, you need to look at the speaker and amp as a package. The ideal use of 8 ohm speakers in car audio is probably to parallel a pair onto a bridged 4 ohm amp, or quad them on a 2 ohm capable bridged amp.


There's distortion and distortion. Some audiophiles state that if you can see a speaker moving it's already distorting. Do a search on power compression. Some industry people say a speaker starts compressing at 1/4 of its rated power.

I've got infinity comps in my daily driver . They're crossed at 90Hz and still distort at average volumes.

Rob.

[nero279]

Like I said, you need to look at the speaker and amp as a package. The ideal use of 8 ohm speakers in car audio is probably to parrallel a pair onto a bridged 4 ohm amp, or quad them on a 2 ohm capable bridged amp.

So actually what i was getting at in the first place on this thread was right in that if they are 8ohm speakers they want to be parralelled, just my reasoning was wrong.

There's distortion and distortion. Some audiophiles state that if you can see a speaker moving it's already distorting. Do a search on power compression. Some industry people say a speaker starts compressing at 1/4 of its rated power.

A speaker gotta move to make sound, if 'audiophiles' are listening to speakers that aint moving they either hearing things, or listening to silence. I agree that a small mid-high range speaker won't be moving much but it's still visible movement. A big subwoofer will be visibly moving well before it distorts.

I've got infinity comps in my daily driver . They're crossed at 90Hz and still distort at average volumes.

Mine was run using the headunits on board HPF at 125 Hz, and started to audibly distort at about 56-57 of the 65 on the volume dial of the headunit.

[wishbone]

""So actually what i was getting at in the first place on this thread was right in that if they are 8ohm speakers they want to be parralelled, just my reasoning was wrong.""


I think they'd sound pants either way tbh


What I was disagreeing with you was that you said was that running an 8 ohm speaker on the car amp would destroy the amp. Thats totally wrong. If anything the speaker could die but in reality it wouldn't.

Distortion in the bass region is less noticable than in the mid / highs. If you can see a midrange driver moving then it's definitely distorting. The idea for 'clean' bass is to use enough drivers that they're hardly moving on the loud passages. You need to have heard really clean speakers in order to notice the disortion on most 'normal' speakers. The home cinema guys are putting 8 x 15" drivers into their systems to get low distortion. Do a search on infinite baffles.

This seems to be going way off topic.

Rob.

[nero279]

No, what you said was that running an 8 ohm speaker on the car amp would destroy the amp. Thats totally wrong. If anything the speaker could die but in reality it wouldn't.

wasn't that the reasoning bit as to why it wanted to be parralleled?

You need to have heard really clean speakers in order to notice the disortion on most 'normal' speakers.

I'll not go there, but if that's implying i haven't heard 'clean' speakers it's way off the mark. There may be a difference between auible and actual distortion, but at the end of the day if the distortion is so minor that it can't be heard who's gonna know?

[wishbone]

""wasn't that the reasoning bit as to why it wanted to be parralleled?""

It may have been your reasoning bit as to why he should parallel, but it was incorrect reasoning.

You said running an 8 ohm speaker on a car amp would destroy the amp. I disagreed. The only reason to parallel it would be to use more of the amps available output.

You stated to parallel it for the wrong reasons. I never mentioned whether to parallel it or not. I said he should sell the drivers on ebay and buy a driver more suited to his application.

I stand by my suggestion.

Re. distortion. Its audible most of the time, then suddenly way audible.

Still off topic.

Rob

[nero279]

""wasn't that the reasoning bit as to why it wanted to be parralleled?""

It may have been your reasoning bit as to why he should parallel, but it was incorrect reasoning.

read post #32 first 2 sentences

You said running an 8 ohm speaker on a car amp would destroy the amp. I disagreed. The only reason to parallel it would be to use more of the amps available output.

You stated to parallel it for the wrong reasons. I never mentioned whether to parallel it or not. I said he should sell the drivers on ebay and buy a driver more suited to his application.

I stand by my suggestion.

Re. distortion. Its audible most of the time, then suddenly way audible.

Still off topic.

Rob

I'm gonna have to agree to disagree re: distortion, or this threads gonna run and run in circles

[wishbone]

A speaker gotta move to make sound, if 'audiophiles' are listening to speakers that aint moving they either hearing things, or listening to silence. I agree that a small mid-high range speaker won't be moving much but it's still visible movement. A big subwoofer will be visibly moving well before it distorts.

.

You've obviously never listened to horns or electrostatics then. You'd be lucky to see the driver / panel move at all. Even at full on home cinema levels.

Rob/still off topic.

[wishbone]

I'll agree to disagree. Car audio never mixes well with home audio and I love both, warts and all...

Rob.

btw my surfs green so hopefully when the heads done it will go anywhere too

[nero279]

You've obviously never listened to horns or electrostatics then. You'd be lucky to see the driver / panel move at all. Even at full on home cinema levels.

Rob/still off topic.

Going even further off topic if we're introducing totally different types of speaker, very rarely seen in car audio fields.

Home cinema levels being what in terms of SPL? Big amateur non-competition car audio builds being anything upto about 120dB, plenty too loud to sit in the car whilst it's cranked. I ran as loud as was comfortable to sit in the car, with a little bit to play with, probably why i seem to be deaf half the time.

[Apache]

the 15" bass speaker will kill that amp, because of the 8ohm impedance of the speaker and the amp only able to handle 2ohms bridged or 4ohms unbridged. Sorry to be the bearer of bad news.

A speaker of higher impedance than the amps capability is OK, lower is where the potential for damage comes in, and then only at higher powers. It's all about the amp's drive current capability.

In other words, 8 ohm speakers will be fine, but wont sound as loud as 4 ohm. All other things being equal.

BTW, musical instrument speakers, particularly bass guitar speakers are designed to work with musical instruments, so dont be surprised if the quality isn't what you expect. They are usually pretty efficient though, so will make the most of what power you have.

[MattF]

You've obviously never listened to horns or electrostatics then. You'd be lucky to see the driver / panel move at all. Even at full on home cinema levels.

Rob/still off topic.

You're working on a totally different premise, there. What you are referring to above are literally enhancements of piezo technology. Of course you won't see visible movement from those. Your assertion regarding normal speaker units is skewed, though. If a speaker cone unit is not moving, it is not producing sound, period. Even if that movement is not noticeable by the naked eye, it is moving.

[Apache]

Oh, and by the way, speaking as an ex-proper-hi-fi amp designer, all ICE is sh1te in comparison, and the specs are way out there with the tooth fairy!

[MattF]

Oh, and by the way, speaking as an ex-proper-hi-fi amp designer, all ICE is sh1te in comparison, and the specs are way out there with the tooth fairy!

Do they still use PMPO as the standard rating on I.C.E, then?

[Apache]

In comparison to what? Do they still use PMPO as the standard rating on I.C.E, then?

I would suggest they do. Can you really see them getting a kilowatt RMS out of a 10" square by 2" box? Last one I built was 19" rackmount 4U high, fan cooled. But then, that genuinley COULD fry my dummy load!

[wishbone]

Ok,

Apache seems to know his stuff...


Home cinema levels: If you run all speakers as small with all bass redirected to the subwoofer (like the thx standard all main speakers high passed at 80Hz) then the sub has to do 122dB cleanly to do reference levels. There are calibration discs available to set up your systen properly.


A horn has nothing to do with piezo technology, but piezos have been used to drive horns.. Horns go way back. I'm talking compression drivers and the big old altec voice of the theater type stuff. Have a listen to a pair of Martin Logan electrostats and then tell me they have anything to do with piezos. the idea is all the air in the horn is pushed by the little driver. Kind of if the 2" driver moves 0.5mm forwards, the entire air in the horn moves the same. Means the mouth size of the horn is moving 0.5mm. This is like a 2" driver becoming an 8" or whatever.

I said if you can see it moving btw. I know full well that they are moving even if they don't appear to be

Admittedly I have a pair of usd piezo horns for car use and they do sound like ar$e.

Why I'll be selling em on soon on ebay.

Rob.